JavaTM 2 Platform
Std. Ed. v1.3.1

java.awt
Class Component

java.lang.Object
  |
  +--java.awt.Component
All Implemented Interfaces:
ImageObserver, MenuContainer, Serializable
Direct Known Subclasses:
Box.Filler, Button, Canvas, Checkbox, Choice, Container, Label, List, Scrollbar, TextComponent

public abstract class Component
extends Object
implements ImageObserver, MenuContainer, Serializable

A component is an object having a graphical representation that can be displayed on the screen and that can interact with the user. Examples of components are the buttons, checkboxes, and scrollbars of a typical graphical user interface.

The Component class is the abstract superclass of the nonmenu-related Abstract Window Toolkit components. Class Component can also be extended directly to create a lightweight component. A lightweight component is a component that is not associated with a native opaque window.

See Also:
Serialized Form

Inner Class Summary
protected  class Component.AccessibleAWTComponent
          Inner class of Component used to provide default support for accessibility.
 
Field Summary
static float BOTTOM_ALIGNMENT
          Ease-of-use constant for getAlignmentY.
static float CENTER_ALIGNMENT
          Ease-of-use constant for getAlignmentY and getAlignmentX.
static float LEFT_ALIGNMENT
          Ease-of-use constant for getAlignmentX.
static float RIGHT_ALIGNMENT
          Ease-of-use constant for getAlignmentX.
static float TOP_ALIGNMENT
          Ease-of-use constant for getAlignmentY().
 
Fields inherited from interface java.awt.image.ImageObserver
ABORT, ALLBITS, ERROR, FRAMEBITS, HEIGHT, PROPERTIES, SOMEBITS, WIDTH
 
Constructor Summary
protected Component()
          Constructs a new component.
 
Method Summary
 boolean action(Event evt, Object what)
          Deprecated. As of JDK version 1.1, should register this component as ActionListener on component which fires action events.
 void add(PopupMenu popup)
          Adds the specified popup menu to the component.
 void addComponentListener(ComponentListener l)
          Adds the specified component listener to receive component events from this component.
 void addFocusListener(FocusListener l)
          Adds the specified focus listener to receive focus events from this component when this component gains input focus.
 void addHierarchyBoundsListener(HierarchyBoundsListener l)
          Adds the specified hierarchy bounds listener to receive hierarchy bounds events from this component when the hierarchy to which this container belongs changes.
 void addHierarchyListener(HierarchyListener l)
          Adds the specified hierarchy listener to receive hierarchy changed events from this component when the hierarchy to which this container belongs changes.
 void addInputMethodListener(InputMethodListener l)
          Adds the specified input method listener to receive input method events from this component.
 void addKeyListener(KeyListener l)
          Adds the specified key listener to receive key events from this component.
 void addMouseListener(MouseListener l)
          Adds the specified mouse listener to receive mouse events from this component.
 void addMouseMotionListener(MouseMotionListener l)
          Adds the specified mouse motion listener to receive mouse motion events from this component.
 void addNotify()
          Makes this Component displayable by connecting it to a native screen resource.
 void addPropertyChangeListener(PropertyChangeListener listener)
          Add a PropertyChangeListener to the listener list.
 void addPropertyChangeListener(String propertyName, PropertyChangeListener listener)
          Add a PropertyChangeListener for a specific property.
 Rectangle bounds()
          Deprecated. As of JDK version 1.1, replaced by getBounds().
 int checkImage(Image image, ImageObserver observer)
          Returns the status of the construction of a screen representation of the specified image.
 int checkImage(Image image, int width, int height, ImageObserver observer)
          Returns the status of the construction of a screen representation of the specified image.
protected  AWTEvent coalesceEvents(AWTEvent existingEvent, AWTEvent newEvent)
          Potentially coalesce an event being posted with an existing event.
 boolean contains(int x, int y)
          Checks whether this component "contains" the specified point, where x and y are defined to be relative to the coordinate system of this component.
 boolean contains(Point p)
          Checks whether this component "contains" the specified point, where the point's x and y coordinates are defined to be relative to the coordinate system of this component.
 Image createImage(ImageProducer producer)
          Creates an image from the specified image producer.
 Image createImage(int width, int height)
          Creates an off-screen drawable image to be used for double buffering.
 void deliverEvent(Event e)
          Deprecated. As of JDK version 1.1, replaced by dispatchEvent(AWTEvent e).
 void disable()
          Deprecated. As of JDK version 1.1, replaced by setEnabled(boolean).
protected  void disableEvents(long eventsToDisable)
          Disables the events defined by the specified event mask parameter from being delivered to this component.
 void dispatchEvent(AWTEvent e)
          Dispatches an event to this component or one of its sub components.
 void doLayout()
          Prompts the layout manager to lay out this component.
 void enable()
          Deprecated. As of JDK version 1.1, replaced by setEnabled(boolean).
 void enable(boolean b)
          Deprecated. As of JDK version 1.1, replaced by setEnabled(boolean).
protected  void enableEvents(long eventsToEnable)
          Enables the events defined by the specified event mask parameter to be delivered to this component.
 void enableInputMethods(boolean enable)
          Enables or disables input method support for this component.
protected  void firePropertyChange(String propertyName, Object oldValue, Object newValue)
          Support for reporting bound property changes.
 AccessibleContext getAccessibleContext()
          Get the AccessibleContext associated with this Component
 float getAlignmentX()
          Returns the alignment along the x axis.
 float getAlignmentY()
          Returns the alignment along the y axis.
 Color getBackground()
          Gets the background color of this component.
 Rectangle getBounds()
          Gets the bounds of this component in the form of a Rectangle object.
 Rectangle getBounds(Rectangle rv)
          Store the bounds of this component into "return value" rv and return rv.
 ColorModel getColorModel()
          Gets the instance of ColorModel used to display the component on the output device.
 Component getComponentAt(int x, int y)
          Determines if this component or one of its immediate subcomponents contains the (xy) location, and if so, returns the containing component.
 Component getComponentAt(Point p)
          Returns the component or subcomponent that contains the specified point.
 ComponentOrientation getComponentOrientation()
          Retrieve the language-sensitive orientation that is to be used to order the elements or text within this component.
 Cursor getCursor()
          Gets the cursor set in the component.
 DropTarget getDropTarget()
          Get the DropTarget associated with this Component
 Font getFont()
          Gets the font of this component.
 FontMetrics getFontMetrics(Font font)
          Gets the font metrics for the specified font.
 Color getForeground()
          Gets the foreground color of this component.
 Graphics getGraphics()
          Creates a graphics context for this component.
 GraphicsConfiguration getGraphicsConfiguration()
          Get the GraphicsConfiguration associated with this Component.
 int getHeight()
          Return the current height of this component.
 InputContext getInputContext()
          Gets the input context used by this component for handling the communication with input methods when text is entered in this component.
 InputMethodRequests getInputMethodRequests()
          Gets the input method request handler which supports requests from input methods for this component.
 EventListener[] getListeners(Class listenerType)
          Return an array of all the listeners that were added to the Component with addXXXListener(), where XXX is the name of the listenerType argument.
 Locale getLocale()
          Gets the locale of this component.
 Point getLocation()
          Gets the location of this component in the form of a point specifying the component's top-left corner.
 Point getLocation(Point rv)
          Store the x,y origin of this component into "return value" rv and return rv.
 Point getLocationOnScreen()
          Gets the location of this component in the form of a point specifying the component's top-left corner in the screen's coordinate space.
 Dimension getMaximumSize()
          Gets the maximum size of this component.
 Dimension getMinimumSize()
          Gets the mininimum size of this component.
 String getName()
          Gets the name of the component.
 Container getParent()
          Gets the parent of this component.
 java.awt.peer.ComponentPeer getPeer()
          Deprecated. As of JDK version 1.1, programs should not directly manipulate peers. replaced by boolean isDisplayable().
 Dimension getPreferredSize()
          Gets the preferred size of this component.
 Dimension getSize()
          Returns the size of this component in the form of a Dimension object.
 Dimension getSize(Dimension rv)
          Store the width/height of this component into "return value" rv and return rv.
 Toolkit getToolkit()
          Gets the toolkit of this component.
 Object getTreeLock()
          Gets the locking object for AWT component-tree and layout Gets this component's locking object (the object that owns the thread sychronization monitor) for AWT component-tree and layout operations.
 int getWidth()
          Return the current width of this component.
 int getX()
          Return the current x coordinate of the components origin.
 int getY()
          Return the current y coordinate of the components origin.
 boolean gotFocus(Event evt, Object what)
          Deprecated. As of JDK version 1.1, replaced by processFocusEvent(FocusEvent).
 boolean handleEvent(Event evt)
          Deprecated. As of JDK version 1.1 replaced by processEvent(AWTEvent).
 boolean hasFocus()
          Returns true if this Component has the keyboard focus.
 void hide()
          Deprecated. As of JDK version 1.1, replaced by setVisible(boolean).
 boolean imageUpdate(Image img, int infoflags, int x, int y, int w, int h)
          Repaints the component when the image has changed.
 boolean inside(int x, int y)
          Deprecated. As of JDK version 1.1, replaced by contains(int, int).
 void invalidate()
          Invalidates this component.
 boolean isDisplayable()
          Determines whether this component is displayable.
 boolean isDoubleBuffered()
          Returns true if this component is painted to an offscreen image ("buffer") that's copied to the screen later.
 boolean isEnabled()
          Determines whether this component is enabled.
 boolean isFocusTraversable()
          Returns the value of a flag that indicates whether this component can be traversed using Tab or Shift-Tab keyboard focus traversal.
 boolean isLightweight()
          A lightweight component doesn't have a native toolkit peer.
 boolean isOpaque()
          Returns true if this component is completely opaque, returns false by default.
 boolean isShowing()
          Determines whether this component is showing on screen.
 boolean isValid()
          Determines whether this component is valid.
 boolean isVisible()
          Determines whether this component should be visible when its parent is visible.
 boolean keyDown(Event evt, int key)
          Deprecated. As of JDK version 1.1, replaced by processKeyEvent(KeyEvent).
 boolean keyUp(Event evt, int key)
          Deprecated. As of JDK version 1.1, replaced by processKeyEvent(KeyEvent).
 void layout()
          Deprecated. As of JDK version 1.1, replaced by doLayout().
 void list()
          Prints a listing of this component to the standard system output stream System.out.
 void list(PrintStream out)
          Prints a listing of this component to the specified output stream.
 void list(PrintStream out, int indent)
          Prints out a list, starting at the specified indention, to the specified print stream.
 void list(PrintWriter out)
          Prints a listing to the specified print writer.
 void list(PrintWriter out, int indent)
          Prints out a list, starting at the specified indention, to the specified print writer.
 Component locate(int x, int y)
          Deprecated. As of JDK version 1.1, replaced by getComponentAt(int, int).
 Point location()
          Deprecated. As of JDK version 1.1, replaced by getLocation().
 boolean lostFocus(Event evt, Object what)
          Deprecated. As of JDK version 1.1, replaced by processFocusEvent(FocusEvent).
 Dimension minimumSize()
          Deprecated. As of JDK version 1.1, replaced by getMinimumSize().
 boolean mouseDown(Event evt, int x, int y)
          Deprecated. As of JDK version 1.1, replaced by processMouseEvent(MouseEvent).
 boolean mouseDrag(Event evt, int x, int y)
          Deprecated. As of JDK version 1.1, replaced by processMouseMotionEvent(MouseEvent).
 boolean mouseEnter(Event evt, int x, int y)
          Deprecated. As of JDK version 1.1, replaced by processMouseEvent(MouseEvent).
 boolean mouseExit(Event evt, int x, int y)
          Deprecated. As of JDK version 1.1, replaced by processMouseEvent(MouseEvent).
 boolean mouseMove(Event evt, int x, int y)
          Deprecated. As of JDK version 1.1, replaced by processMouseMotionEvent(MouseEvent).
 boolean mouseUp(Event evt, int x, int y)
          Deprecated. As of JDK version 1.1, replaced by processMouseEvent(MouseEvent).
 void move(int x, int y)
          Deprecated. As of JDK version 1.1, replaced by setLocation(int, int).
 void nextFocus()
          Deprecated. As of JDK version 1.1, replaced by transferFocus().
 void paint(Graphics g)
          Paints this component.
 void paintAll(Graphics g)
          Paints this component and all of its subcomponents.
protected  String paramString()
          Returns a string representing the state of this component.
 boolean postEvent(Event e)
          Deprecated. As of JDK version 1.1, replaced by dispatchEvent(AWTEvent).
 Dimension preferredSize()
          Deprecated. As of JDK version 1.1, replaced by getPreferredSize().
 boolean prepareImage(Image image, ImageObserver observer)
          Prepares an image for rendering on this component.
 boolean prepareImage(Image image, int width, int height, ImageObserver observer)
          Prepares an image for rendering on this component at the specified width and height.
 void print(Graphics g)
          Prints this component.
 void printAll(Graphics g)
          Prints this component and all of its subcomponents.
protected  void processComponentEvent(ComponentEvent e)
          Processes component events occurring on this component by dispatching them to any registered ComponentListener objects.
protected  void processEvent(AWTEvent e)
          Processes events occurring on this component.
protected  void processFocusEvent(FocusEvent e)
          Processes focus events occurring on this component by dispatching them to any registered FocusListener objects.
protected  void processHierarchyBoundsEvent(HierarchyEvent e)
          Processes hierarchy bounds events occurring on this component by dispatching them to any registered HierarchyBoundsListener objects.
protected  void processHierarchyEvent(HierarchyEvent e)
          Processes hierarchy events occurring on this component by dispatching them to any registered HierarchyListener objects.
protected  void processInputMethodEvent(InputMethodEvent e)
          Processes input method events occurring on this component by dispatching them to any registered InputMethodListener objects.
protected  void processKeyEvent(KeyEvent e)
          Processes key events occurring on this component by dispatching them to any registered KeyListener objects.
protected  void processMouseEvent(MouseEvent e)
          Processes mouse events occurring on this component by dispatching them to any registered MouseListener objects.
protected  void processMouseMotionEvent(MouseEvent e)
          Processes mouse motion events occurring on this component by dispatching them to any registered MouseMotionListener objects.
 void remove(MenuComponent popup)
          Removes the specified popup menu from the component.
 void removeComponentListener(ComponentListener l)
          Removes the specified component listener so that it no longer receives component events from this component.
 void removeFocusListener(FocusListener l)
          Removes the specified focus listener so that it no longer receives focus events from this component.
 void removeHierarchyBoundsListener(HierarchyBoundsListener l)
          Removes the specified hierarchy bounds listener so that it no longer receives hierarchy bounds events from this component.
 void removeHierarchyListener(HierarchyListener l)
          Removes the specified hierarchy listener so that it no longer receives hierarchy changed events from this component.
 void removeInputMethodListener(InputMethodListener l)
          Removes the specified input method listener so that it no longer receives input method events from this component.
 void removeKeyListener(KeyListener l)
          Removes the specified key listener so that it no longer receives key events from this component.
 void removeMouseListener(MouseListener l)
          Removes the specified mouse listener so that it no longer receives mouse events from this component.
 void removeMouseMotionListener(MouseMotionListener l)
          Removes the specified mouse motion listener so that it no longer receives mouse motion events from this component.
 void removeNotify()
          Makes this Component undisplayable by destroying it native screen resource.
 void removePropertyChangeListener(PropertyChangeListener listener)
          Remove a PropertyChangeListener from the listener list.
 void removePropertyChangeListener(String propertyName, PropertyChangeListener listener)
          Remove a PropertyChangeListener for a specific property.
 void repaint()
          Repaints this component.
 void repaint(int x, int y, int width, int height)
          Repaints the specified rectangle of this component.
 void repaint(long tm)
          Repaints the component.
 void repaint(long tm, int x, int y, int width, int height)
          Repaints the specified rectangle of this component within tm milliseconds.
 void requestFocus()
          Requests that this component get the input focus.
 void reshape(int x, int y, int width, int height)
          Deprecated. As of JDK version 1.1, replaced by setBounds(int, int, int, int).
 void resize(Dimension d)
          Deprecated. As of JDK version 1.1, replaced by setSize(Dimension).
 void resize(int width, int height)
          Deprecated. As of JDK version 1.1, replaced by setSize(int, int).
 void setBackground(Color c)
          Sets the background color of this component.
 void setBounds(int x, int y, int width, int height)
          Moves and resizes this component.
 void setBounds(Rectangle r)
          Moves and resizes this component to conform to the new bounding rectangle r.
 void setComponentOrientation(ComponentOrientation o)
          Set the language-sensitive orientation that is to be used to order the elements or text within this component.
 void setCursor(Cursor cursor)
          Sets the cursor image to the specified cursor.
 void setDropTarget(DropTarget dt)
          Associate a DropTarget with this Component.
 void setEnabled(boolean b)
          Enables or disables this component, depending on the value of the parameter b.
 void setFont(Font f)
          Sets the font of this component.
 void setForeground(Color c)
          Sets the foreground color of this component.
 void setLocale(Locale l)
          Sets the locale of this component.
 void setLocation(int x, int y)
          Moves this component to a new location.
 void setLocation(Point p)
          Moves this component to a new location.
 void setName(String name)
          Sets the name of the component to the specified string.
 void setSize(Dimension d)
          Resizes this component so that it has width d.width and height d.height.
 void setSize(int width, int height)
          Resizes this component so that it has width width and height.
 void setVisible(boolean b)
          Shows or hides this component depending on the value of parameter b.
 void show()
          Deprecated. As of JDK version 1.1, replaced by setVisible(boolean).
 void show(boolean b)
          Deprecated. As of JDK version 1.1, replaced by setVisible(boolean).
 Dimension size()
          Deprecated. As of JDK version 1.1, replaced by getSize().
 String toString()
          Returns a string representation of this component and its values.
 void transferFocus()
          Transfers the focus to the next component.
 void update(Graphics g)
          Updates this component.
 void validate()
          Ensures that this component has a valid layout.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

TOP_ALIGNMENT

public static final float TOP_ALIGNMENT
Ease-of-use constant for getAlignmentY(). Specifies an alignment to the top of the component.
See Also:
getAlignmentY()

CENTER_ALIGNMENT

public static final float CENTER_ALIGNMENT
Ease-of-use constant for getAlignmentY and getAlignmentX. Specifies an alignment to the center of the component
See Also:
getAlignmentX(), getAlignmentY()

BOTTOM_ALIGNMENT

public static final float BOTTOM_ALIGNMENT
Ease-of-use constant for getAlignmentY. Specifies an alignment to the bottom of the component.
See Also:
getAlignmentY()

LEFT_ALIGNMENT

public static final float LEFT_ALIGNMENT
Ease-of-use constant for getAlignmentX. Specifies an alignment to the left side of the component.
See Also:
getAlignmentX()

RIGHT_ALIGNMENT

public static final float RIGHT_ALIGNMENT
Ease-of-use constant for getAlignmentX. Specifies an alignment to the right side of the component.
See Also:
getAlignmentX()
Constructor Detail

Component

protected Component()
Constructs a new component. Class Component can be extended directly to create a lightweight component that does not utilize an opaque native window. A lightweight component must be hosted by a native container somewhere higher up in the component tree (for example, by a Frame object).
Method Detail

getName

public String getName()
Gets the name of the component.
Returns:
This component's name.
Since:
JDK1.1
See Also:
setName(java.lang.String)

setName

public void setName(String name)
Sets the name of the component to the specified string.
Parameters:
name - The string that is to be this component's name.
Since:
JDK1.1
See Also:
getName()

getParent

public Container getParent()
Gets the parent of this component.
Returns:
The parent container of this component.
Since:
JDK1.0

getPeer

public java.awt.peer.ComponentPeer getPeer()
Deprecated. As of JDK version 1.1, programs should not directly manipulate peers. replaced by boolean isDisplayable().


setDropTarget

public void setDropTarget(DropTarget dt)
Associate a DropTarget with this Component. The Component will receive drops only if it is enabled.
Parameters:
dt - The DropTarget
See Also:
isEnabled()

getDropTarget

public DropTarget getDropTarget()
Get the DropTarget associated with this Component

getGraphicsConfiguration

public GraphicsConfiguration getGraphicsConfiguration()
Get the GraphicsConfiguration associated with this Component. If the Component has not been assigned a specific GraphicsConfiguration, the GraphicsConfiguration of the Component object's top-level container is returned. If the Component has been created, but not yet added to a Container, this method returns null.
Returns:
the GraphicsConfiguration used by this Component or null
Since:
1.3

getTreeLock

public final Object getTreeLock()
Gets the locking object for AWT component-tree and layout Gets this component's locking object (the object that owns the thread sychronization monitor) for AWT component-tree and layout operations.
Returns:
This component's locking object.

getToolkit

public Toolkit getToolkit()
Gets the toolkit of this component. Note that the frame that contains a component controls which toolkit is used by that component. Therefore if the component is moved from one frame to another, the toolkit it uses may change.
Returns:
The toolkit of this component.
Since:
JDK1.0

isValid

public boolean isValid()
Determines whether this component is valid. A component is valid when it is correctly sized and positioned within its parent container and all its children are also valid. Components are invalidated when they are first shown on the screen.
Returns:
true if the component is valid; false otherwise.
Since:
JDK1.0
See Also:
validate(), invalidate()

isDisplayable

public boolean isDisplayable()
Determines whether this component is displayable. A component is displayable when it is connected to a native screen resource.

A component is made displayable either when it is added to a displayable containment hierarchy or when its containment hierarchy is made displayable. A containment hierarchy is made displayable when its ancestor window is either packed or made visible.

A component is made undisplayable either when it is removed from a displayable containment hierarchy or when its containment hierarchy is made undisplayable. A containment hierarchy is made undisplayable when its ancestor window is disposed.

Returns:
true if the component is displayable; false otherwise.
Since:
1.2
See Also:
Container.add(java.awt.Component), Window.pack(), Window.show(), Container.remove(java.awt.Component), Window.dispose()

isVisible

public boolean isVisible()
Determines whether this component should be visible when its parent is visible. Components are initially visible, with the exception of top level components such as Frame objects.
Returns:
true if the component is visible; false otherwise.
Since:
JDK1.0
See Also:
setVisible(boolean)

isShowing

public boolean isShowing()
Determines whether this component is showing on screen. This means that the component must be visible, and it must be in a container that is visible and showing.
Returns:
true if the component is showing; false otherwise.
Since:
JDK1.0
See Also:
setVisible(boolean)

isEnabled

public boolean isEnabled()
Determines whether this component is enabled. An enabled component can respond to user input and generate events. Components are enabled initially by default. A component may be enabled or disabled by calling its setEnabled method.
Returns:
true if the component is enabled; false otherwise.
Since:
JDK1.0
See Also:
setEnabled(boolean)

setEnabled

public void setEnabled(boolean b)
Enables or disables this component, depending on the value of the parameter b. An enabled component can respond to user input and generate events. Components are enabled initially by default.
Parameters:
b - If true, this component is enabled; otherwise this component is disabled.
Since:
JDK1.1
See Also:
isEnabled()

enable

public void enable()
Deprecated. As of JDK version 1.1, replaced by setEnabled(boolean).


enable

public void enable(boolean b)
Deprecated. As of JDK version 1.1, replaced by setEnabled(boolean).


disable

public void disable()
Deprecated. As of JDK version 1.1, replaced by setEnabled(boolean).


isDoubleBuffered

public boolean isDoubleBuffered()
Returns true if this component is painted to an offscreen image ("buffer") that's copied to the screen later. Component subclasses that support double buffering should override this method to return true if double buffering is enabled.
Returns:
false by default

enableInputMethods

public void enableInputMethods(boolean enable)
Enables or disables input method support for this component. If input method support is enabled and the component also processes key events, incoming events are offered to the current input method and will only be processed by the component or dispatched to its listeners if the input method does not consume them. By default, input method support is enabled.
Parameters:
enable - true to enable, false to disable.
Since:
1.2
See Also:
processKeyEvent(java.awt.event.KeyEvent)

setVisible

public void setVisible(boolean b)
Shows or hides this component depending on the value of parameter b.
Parameters:
b - If true, shows this component; otherwise, hides this component.
Since:
JDK1.1
See Also:
isVisible()

show

public void show()
Deprecated. As of JDK version 1.1, replaced by setVisible(boolean).


show

public void show(boolean b)
Deprecated. As of JDK version 1.1, replaced by setVisible(boolean).


hide

public void hide()
Deprecated. As of JDK version 1.1, replaced by setVisible(boolean).


getForeground

public Color getForeground()
Gets the foreground color of this component.
Returns:
This component's foreground color. If this component does not have a foreground color, the foreground color of its parent is returned.
Since:
JDK1.0
See Also:
setForeground(java.awt.Color)

setForeground

public void setForeground(Color c)
Sets the foreground color of this component.
Parameters:
c - The color to become this component's foreground color. If this parameter is null then this component will inherit the foreground color of its parent.
Since:
JDK1.0
See Also:
getForeground()

getBackground

public Color getBackground()
Gets the background color of this component.
Returns:
This component's background color. If this component does not have a background color, the background color of its parent is returned.
Since:
JDK1.0
See Also:
setBackground(java.awt.Color)

setBackground

public void setBackground(Color c)
Sets the background color of this component.
Parameters:
c - The color to become this component's color. If this parameter is null then this component will inherit the background color of its parent. background color.
Since:
JDK1.0
See Also:
getBackground()

getFont

public Font getFont()
Gets the font of this component.
Specified by:
getFont in interface MenuContainer
Returns:
This component's font. If a font has not been set for this component, the font of its parent is returned.
Since:
JDK1.0
See Also:
setFont(java.awt.Font)

setFont

public void setFont(Font f)
Sets the font of this component.
Parameters:
f - The font to become this component's font. If this parameter is null then this component will inherit the font of its parent.
Since:
JDK1.0
See Also:
getFont()

getLocale

public Locale getLocale()
Gets the locale of this component.
Returns:
This component's locale. If this component does not have a locale, the locale of its parent is returned.
Throws:
IllegalComponentStateException - If the Component does not have its own locale and has not yet been added to a containment hierarchy such that the locale can be determined from the containing parent.
Since:
JDK1.1
See Also:
setLocale(java.util.Locale)

setLocale

public void setLocale(Locale l)
Sets the locale of this component.
Parameters:
l - The locale to become this component's locale.
Since:
JDK1.1
See Also:
getLocale()

getColorModel

public ColorModel getColorModel()
Gets the instance of ColorModel used to display the component on the output device.
Returns:
The color model used by this component.
Since:
JDK1.0
See Also:
ColorModel, ComponentPeer.getColorModel(), Toolkit.getColorModel()

getLocation

public Point getLocation()
Gets the location of this component in the form of a point specifying the component's top-left corner. The location will be relative to the parent's coordinate space.

Due to the asynchronous nature of native event handling, this method can return outdated values (for instance, after several calls of setLocation() in rapid succession). For this reason, the recommended method of obtaining a Component's position is within java.awt.event.ComponentListener.componentMoved(), which is called after the operating system has finished moving the Component.

Returns:
An instance of Point representing the top-left corner of the component's bounds in the coordinate space of the component's parent.
Since:
JDK1.1
See Also:
setLocation(int, int), getLocationOnScreen()

getLocationOnScreen

public Point getLocationOnScreen()
Gets the location of this component in the form of a point specifying the component's top-left corner in the screen's coordinate space.
Returns:
An instance of Point representing the top-left corner of the component's bounds in the coordinate space of the screen.
See Also:
setLocation(int, int), getLocation()

location

public Point location()
Deprecated. As of JDK version 1.1, replaced by getLocation().


setLocation

public void setLocation(int x,
                        int y)
Moves this component to a new location. The top-left corner of the new location is specified by the x and y parameters in the coordinate space of this component's parent.
Parameters:
x - The x-coordinate of the new location's top-left corner in the parent's coordinate space.
y - The y-coordinate of the new location's top-left corner in the parent's coordinate space.
Since:
JDK1.1
See Also:
getLocation(), setBounds(int, int, int, int)

move

public void move(int x,
                 int y)
Deprecated. As of JDK version 1.1, replaced by setLocation(int, int).


setLocation

public void setLocation(Point p)
Moves this component to a new location. The top-left corner of the new location is specified by point p. Point p is given in the parent's coordinate space.
Parameters:
p - The point defining the top-left corner of the new location, given in the coordinate space of this component's parent.
Since:
JDK1.1
See Also:
getLocation(), setBounds(int, int, int, int)

getSize

public Dimension getSize()
Returns the size of this component in the form of a Dimension object. The height field of the Dimension object contains this component's height, and the width field of the Dimension object contains this component's width.
Returns:
A Dimension object that indicates the size of this component.
Since:
JDK1.1
See Also:
setSize(int, int)

size

public Dimension size()
Deprecated. As of JDK version 1.1, replaced by getSize().


setSize

public void setSize(int width,
                    int height)
Resizes this component so that it has width width and height.
Parameters:
width - The new width of this component in pixels.
height - The new height of this component in pixels.
Since:
JDK1.1
See Also:
getSize(), setBounds(int, int, int, int)

resize

public void resize(int width,
                   int height)
Deprecated. As of JDK version 1.1, replaced by setSize(int, int).


setSize

public void setSize(Dimension d)
Resizes this component so that it has width d.width and height d.height.
Parameters:
d - The dimension specifying the new size of this component.
Since:
JDK1.1
See Also:
setSize(int, int), setBounds(int, int, int, int)

resize

public void resize(Dimension d)
Deprecated. As of JDK version 1.1, replaced by setSize(Dimension).


getBounds

public Rectangle getBounds()
Gets the bounds of this component in the form of a Rectangle object. The bounds specify this component's width, height, and location relative to its parent.
Returns:
A rectangle indicating this component's bounds.
See Also:
setBounds(int, int, int, int), getLocation(), getSize()

bounds

public Rectangle bounds()
Deprecated. As of JDK version 1.1, replaced by getBounds().


setBounds

public void setBounds(int x,
                      int y,
                      int width,
                      int height)
Moves and resizes this component. The new location of the top-left corner is specified by x and y, and the new size is specified by width and height.
Parameters:
x - The new x-coordinate of this component.
y - The new y-coordinate of this component.
width - The new width of this component.
height - The new height of this component.
See Also:
getBounds(), setLocation(int, int), setLocation(java.awt.Point), setSize(int, int), setSize(java.awt.Dimension)

reshape

public void reshape(int x,
                    int y,
                    int width,
                    int height)
Deprecated. As of JDK version 1.1, replaced by setBounds(int, int, int, int).


setBounds

public void setBounds(Rectangle r)
Moves and resizes this component to conform to the new bounding rectangle r. This component's new position is specified by r.x and r.y, and its new size is specified by r.width and r.height
Parameters:
r - The new bounding rectangle for this component.
Since:
JDK1.1
See Also:
getBounds(), setLocation(int, int), setLocation(java.awt.Point), setSize(int, int), setSize(java.awt.Dimension)

getX

public int getX()
Return the current x coordinate of the components origin. This method is preferable to writing component.getBounds().x, or component.getLocation().x because it doesn't cause any heap allocations.
Returns:
the current x coordinate of the components origin.
Since:
1.2

getY

public int getY()
Return the current y coordinate of the components origin. This method is preferable to writing component.getBounds().y, or component.getLocation().y because it doesn't cause any heap allocations.
Returns:
the current y coordinate of the components origin.
Since:
1.2

getWidth

public int getWidth()
Return the current width of this component. This method is preferable to writing component.getBounds().width, or component.getSize().width because it doesn't cause any heap allocations.
Returns:
the current width of this component.
Since:
1.2

getHeight

public int getHeight()
Return the current height of this component. This method is preferable to writing component.getBounds().height, or component.getSize().height because it doesn't cause any heap allocations.
Returns:
the current height of this component.
Since:
1.2

getBounds

public Rectangle getBounds(Rectangle rv)
Store the bounds of this component into "return value" rv and return rv. If rv is null a new Rectangle is allocated. This version of getBounds() is useful if the caller wants to avoid allocating a new Rectangle object on the heap.
Parameters:
rv - the return value, modified to the components bounds
Returns:
rv

getSize

public Dimension getSize(Dimension rv)
Store the width/height of this component into "return value" rv and return rv. If rv is null a new Dimension object is allocated. This version of getSize() is useful if the caller wants to avoid allocating a new Dimension object on the heap.
Parameters:
rv - the return value, modified to the components size
Returns:
rv

getLocation

public Point getLocation(Point rv)
Store the x,y origin of this component into "return value" rv and return rv. If rv is null a new Point is allocated. This version of getLocation() is useful if the caller wants to avoid allocating a new Point object on the heap.
Parameters:
rv - the return value, modified to the components location
Returns:
rv

isOpaque

public boolean isOpaque()
Returns true if this component is completely opaque, returns false by default.

An opaque component paints every pixel within its rectangular region. A non-opaque component paints only some of its pixels, allowing the pixels underneath it to "show through". A component that does not fully paint its pixels therefore provides a degree of transparency. Only lightweight components can be transparent.

Subclasses that guarantee to always completely paint their contents should override this method and return true. All of the "heavyweight" AWT components are opaque.

Returns:
true if this component is completely opaque.
Since:
1.2
See Also:
isLightweight()

isLightweight

public boolean isLightweight()
A lightweight component doesn't have a native toolkit peer. Subclasses of Component and Container, other than the ones defined in this package like Button or Scrollbar, are lightweight. All of the Swing components are lightweights. This method will always return false if this Component is not displayable because it is impossible to determine the weight of an undisplayable Component.
Returns:
true if this component has a lightweight peer; false if it has a native peer or no peer.
Since:
1.2
See Also:
isDisplayable()

getPreferredSize

public Dimension getPreferredSize()
Gets the preferred size of this component.
Returns:
A dimension object indicating this component's preferred size.
See Also:
getMinimumSize(), LayoutManager

preferredSize

public Dimension preferredSize()
Deprecated. As of JDK version 1.1, replaced by getPreferredSize().


getMinimumSize

public Dimension getMinimumSize()
Gets the mininimum size of this component.
Returns:
A dimension object indicating this component's minimum size.
See Also:
getPreferredSize(), java.awtLayoutManager

minimumSize

public Dimension minimumSize()
Deprecated. As of JDK version 1.1, replaced by getMinimumSize().


getMaximumSize

public Dimension getMaximumSize()
Gets the maximum size of this component.
Returns:
A dimension object indicating this component's maximum size.
See Also:
getMinimumSize(), getPreferredSize(), LayoutManager

getAlignmentX

public float getAlignmentX()
Returns the alignment along the x axis. This specifies how the component would like to be aligned relative to other components. The value should be a number between 0 and 1 where 0 represents alignment along the origin, 1 is aligned the furthest away from the origin, 0.5 is centered, etc.

getAlignmentY

public float getAlignmentY()
Returns the alignment along the y axis. This specifies how the component would like to be aligned relative to other components. The value should be a number between 0 and 1 where 0 represents alignment along the origin, 1 is aligned the furthest away from the origin, 0.5 is centered, etc.

doLayout

public void doLayout()
Prompts the layout manager to lay out this component. This is usually called when the component (more specifically, container) is validated.
See Also:
validate(), LayoutManager

layout

public void layout()
Deprecated. As of JDK version 1.1, replaced by doLayout().


validate

public void validate()
Ensures that this component has a valid layout. This method is primarily intended to operate on instances of Container.
Since:
JDK1.0
See Also:
invalidate(), doLayout(), LayoutManager, Container.validate()

invalidate

public void invalidate()
Invalidates this component. This component and all parents above it are marked as needing to be laid out. This method can be called often, so it needs to execute quickly.
Since:
JDK1.0
See Also:
validate(), doLayout(), LayoutManager

getGraphics

public Graphics getGraphics()
Creates a graphics context for this component. This method will return null if this component is currently not displayable.
Returns:
A graphics context for this component, or null if it has none.
Since:
JDK1.0
See Also:
paint(java.awt.Graphics)

getFontMetrics

public FontMetrics getFontMetrics(Font font)
Gets the font metrics for the specified font.
Parameters:
font - The font for which font metrics is to be obtained.
font - the font.
Returns:
The font metrics for font.
Since:
JDK1.0
See Also:
getFont(), getPeer(), ComponentPeer.getFontMetrics(java.awt.Font), Toolkit.getFontMetrics(java.awt.Font)

setCursor

public void setCursor(Cursor cursor)
Sets the cursor image to the specified cursor. This cursor image is displayed when the contains method for this component returns true for the current cursor location, and this Component is visible, displayable, and enabled. Setting the cursor of a Container causes that cursor to be displayed within all of the container's subcomponents, except for those that have a non-null cursor.
Parameters:
cursor - One of the constants defined by the Cursor class. If this parameter is null then this component will inherit the cursor of its parent.
Since:
JDK1.1
See Also:
isEnabled(), isShowing(), getCursor(), contains(int, int), Toolkit.createCustomCursor(java.awt.Image, java.awt.Point, java.lang.String), Cursor

getCursor

public Cursor getCursor()
Gets the cursor set in the component. If the component does not have a cursor set, the cursor of its parent is returned. If no Cursor is set in the entire hierarchy, Cursor.DEFAULT_CURSOR is returned.
Since:
JDK1.1
See Also:
setCursor(java.awt.Cursor)

paint

public void paint(Graphics g)
Paints this component. This method is called when the contents of the component should be painted in response to the component first being shown or damage needing repair. The clip rectangle in the Graphics parameter will be set to the area which needs to be painted. For performance reasons, Components with zero width or height aren't considered to need painting when they are first shown, and also aren't considered to need repair.
Parameters:
g - The graphics context to use for painting.
Since:
JDK1.0
See Also:
update(java.awt.Graphics)

update

public void update(Graphics g)
Updates this component.

The AWT calls the update method in response to a call to repaintupdate or paint. You can assume that the background is not cleared.

The updatemethod of Component does the following:

  • Clears this component by filling it with the background color.
  • Sets the color of the graphics context to be the foreground color of this component.
  • Calls this component's paint method to completely redraw this component.

The origin of the graphics context, its (00) coordinate point, is the top-left corner of this component. The clipping region of the graphics context is the bounding rectangle of this component.

Parameters:
g - the specified context to use for updating.
Since:
JDK1.0
See Also:
paint(java.awt.Graphics), repaint()

paintAll

public void paintAll(Graphics g)
Paints this component and all of its subcomponents.

The origin of the graphics context, its (00) coordinate point, is the top-left corner of this component. The clipping region of the graphics context is the bounding rectangle of this component.

Parameters:
g - the graphics context to use for painting.
Since:
JDK1.0
See Also:
paint(java.awt.Graphics)

repaint

public void repaint()
Repaints this component.

This method causes a call to this component's update method as soon as possible.

Since:
JDK1.0
See Also:
update(java.awt.Graphics)

repaint

public void repaint(long tm)
Repaints the component. This will result in a call to update within tm milliseconds.
Parameters:
tm - maximum time in milliseconds before update
Since:
JDK1.0
See Also:
paint(java.awt.Graphics), update(java.awt.Graphics)

repaint

public void repaint(int x,
                    int y,
                    int width,
                    int height)
Repaints the specified rectangle of this component.

This method causes a call to this component's update method as soon as possible.

Parameters:
x - the x coordinate.
y - the y coordinate.
width - the width.
height - the height.
Since:
JDK1.0
See Also:
update(java.awt.Graphics)

repaint

public void repaint(long tm,
                    int x,
                    int y,
                    int width,
                    int height)
Repaints the specified rectangle of this component within tm milliseconds.

This method causes a call to this component's update method.

Parameters:
tm - maximum time in milliseconds before update.
x - the x coordinate.
y - the y coordinate.
width - the width.
height - the height.
Since:
JDK1.0
See Also:
update(java.awt.Graphics)

print

public void print(Graphics g)
Prints this component. Applications should override this method for components that must do special processing before being printed or should be printed differently than they are painted.

The default implementation of this method calls the paint method.

The origin of the graphics context, its (00) coordinate point, is the top-left corner of this component. The clipping region of the graphics context is the bounding rectangle of this component.

Parameters:
g - the graphics context to use for printing.
Since:
JDK1.0
See Also:
paint(java.awt.Graphics)

printAll

public void printAll(Graphics g)
Prints this component and all of its subcomponents.

The origin of the graphics context, its (00) coordinate point, is the top-left corner of this component. The clipping region of the graphics context is the bounding rectangle of this component.

Parameters:
g - the graphics context to use for printing.
Since:
JDK1.0
See Also:
print(java.awt.Graphics)

imageUpdate

public boolean imageUpdate(Image img,
                           int infoflags,
                           int x,
                           int y,
                           int w,
                           int h)
Repaints the component when the image has changed. This imageUpdate method of an ImageObserver is called when more information about an image which had been previously requested using an asynchronous routine such as the drawImage method of Graphics becomes available. See the definition of imageUpdate for more information on this method and its arguments.

The imageUpdate method of Component incrementally draws an image on the component as more of the bits of the image are available.

If the system property awt.image.incrementalDraw is missing or has the value true, the image is incrementally drawn, If the system property has any other value, then the image is not drawn until it has been completely loaded.

Also, if incremental drawing is in effect, the value of the system property awt.image.redrawrate is interpreted as an integer to give the maximum redraw rate, in milliseconds. If the system property is missing or cannot be interpreted as an integer, the redraw rate is once every 100ms.

The interpretation of the x, y, width, and height arguments depends on the value of the infoflags argument.

Specified by:
imageUpdate in interface ImageObserver
Parameters:
img - the image being observed.
infoflags - see imageUpdate for more information.
x - the x coordinate.
y - the y coordinate.
w - the width.
h - the height.
Returns:
false if the infoflags indicate that the image is completely loaded; true otherwise.
Since:
JDK1.0
See Also:
ImageObserver, Graphics.drawImage(java.awt.Image, int, int, java.awt.Color, java.awt.image.ImageObserver), Graphics.drawImage(java.awt.Image, int, int, java.awt.image.ImageObserver), Graphics.drawImage(java.awt.Image, int, int, int, int, java.awt.Color, java.awt.image.ImageObserver), Graphics.drawImage(java.awt.Image, int, int, int, int, java.awt.image.ImageObserver), ImageObserver.imageUpdate(java.awt.Image, int, int, int, int, int)

createImage

public Image createImage(ImageProducer producer)
Creates an image from the specified image producer.
Parameters:
producer - the image producer
Returns:
the image produced.
Since:
JDK1.0

createImage

public Image createImage(int width,
                         int height)
Creates an off-screen drawable image to be used for double buffering.
Parameters:
width - the specified width.
height - the specified height.
Returns:
an off-screen drawable image, which can be used for double buffering.
Since:
JDK1.0

prepareImage

public boolean prepareImage(Image image,
                            ImageObserver observer)
Prepares an image for rendering on this component. The image data is downloaded asynchronously in another thread and the appropriate screen representation of the image is generated.
Parameters:
image - the Image for which to prepare a screen representation.
observer - the ImageObserver object to be notified as the image is being prepared.
Returns:
true if the image has already been fully prepared; false otherwise.
Since:
JDK1.0

prepareImage

public boolean prepareImage(Image image,
                            int width,
                            int height,
                            ImageObserver observer)
Prepares an image for rendering on this component at the specified width and height.

The image data is downloaded asynchronously in another thread, and an appropriately scaled screen representation of the image is generated.

Parameters:
image - the instance of Image for which to prepare a screen representation.
width - the width of the desired screen representation.
height - the height of the desired screen representation.
observer - the ImageObserver object to be notified as the image is being prepared.
Returns:
true if the image has already been fully prepared; false otherwise.
Since:
JDK1.0
See Also:
ImageObserver

checkImage

public int checkImage(Image image,
                      ImageObserver observer)
Returns the status of the construction of a screen representation of the specified image.

This method does not cause the image to begin loading. An application must use the prepareImage method to force the loading of an image.

Information on the flags returned by this method can be found with the discussion of the ImageObserver interface.

Parameters:
image - the Image object whose status is being checked.
observer - the ImageObserver object to be notified as the image is being prepared.
Returns:
the bitwise inclusive OR of ImageObserver flags indicating what information about the image is currently available.
Since:
JDK1.0
See Also:
prepareImage(java.awt.Image, int, int, java.awt.image.ImageObserver), Toolkit.checkImage(java.awt.Image, int, int, java.awt.image.ImageObserver), ImageObserver

checkImage

public int checkImage(Image image,
                      int width,
                      int height,
                      ImageObserver observer)
Returns the status of the construction of a screen representation of the specified image.

This method does not cause the image to begin loading. An application must use the prepareImage method to force the loading of an image.

The checkImage method of Component calls its peer's checkImage method to calculate the flags. If this component does not yet have a peer, the component's toolkit's checkImage method is called instead.

Information on the flags returned by this method can be found with the discussion of the ImageObserver interface.

Parameters:
image - the Image object whose status is being checked.
width - the width of the scaled version whose status is to be checked.
height - the height of the scaled version whose status is to be checked.
observer - the ImageObserver object to be notified as the image is being prepared.
Returns:
the bitwise inclusive OR of ImageObserver flags indicating what information about the image is currently available.
Since:
JDK1.0
See Also:
prepareImage(java.awt.Image, int, int, java.awt.image.ImageObserver), Toolkit.checkImage(java.awt.Image, int, int, java.awt.image.ImageObserver), ImageObserver

contains

public boolean contains(int x,
                        int y)
Checks whether this component "contains" the specified point, where x and y are defined to be relative to the coordinate system of this component.
Parameters:
x - the x coordinate of the point.
y - the y coordinate of the point.
Since:
JDK1.1
See Also:
getComponentAt(int, int)

inside

public boolean inside(int x,
                      int y)
Deprecated. As of JDK version 1.1, replaced by contains(int, int).


contains

public boolean contains(Point p)
Checks whether this component "contains" the specified point, where the point's x and y coordinates are defined to be relative to the coordinate system of this component.
Parameters:
p - the point.
Since:
JDK1.1
See Also:
getComponentAt(java.awt.Point)

getComponentAt

public Component getComponentAt(int x,
                                int y)
Determines if this component or one of its immediate subcomponents contains the (xy) location, and if so, returns the containing component. This method only looks one level deep. If the point (xy) is inside a subcomponent that itself has subcomponents, it does not go looking down the subcomponent tree.

The locate method of Component simply returns the component itself if the (xy) coordinate location is inside its bounding box, and null otherwise.

Parameters:
x - the x coordinate.
y - the y coordinate.
Returns:
the component or subcomponent that contains the (xy) location; null if the location is outside this component.
Since:
JDK1.0
See Also:
contains(int, int)

locate

public Component locate(int x,
                        int y)
Deprecated. As of JDK version 1.1, replaced by getComponentAt(int, int).


getComponentAt

public Component getComponentAt(Point p)
Returns the component or subcomponent that contains the specified point.
Parameters:
p - the point.
Since:
JDK1.1
See Also:
contains(int, int)

deliverEvent

public void deliverEvent(Event e)
Deprecated. As of JDK version 1.1, replaced by dispatchEvent(AWTEvent e).


dispatchEvent

public final void dispatchEvent(AWTEvent e)
Dispatches an event to this component or one of its sub components. Calls processEvent() before returning for 1.1-style events which have been enabled for the Component.
Parameters:
e - the event

postEvent

public boolean postEvent(Event e)
Deprecated. As of JDK version 1.1, replaced by dispatchEvent(AWTEvent).

Specified by:
postEvent in interface MenuContainer

addComponentListener

public void addComponentListener(ComponentListener l)
Adds the specified component listener to receive component events from this component. If l is null, no exception is thrown and no action is performed.
Parameters:
l - the component listener.
Since:
JDK1.1
See Also:
ComponentEvent, ComponentListener, removeComponentListener(java.awt.event.ComponentListener)

removeComponentListener

public void removeComponentListener(ComponentListener l)
Removes the specified component listener so that it no longer receives component events from this component. This method performs no function, nor does it throw an exception, if the listener specified by the argument was not previously added to this component. If l is null, no exception is thrown and no action is performed.
Parameters:
l - the component listener.
Since:
JDK1.1
See Also:
ComponentEvent, ComponentListener, addComponentListener(java.awt.event.ComponentListener)

addFocusListener

public void addFocusListener(FocusListener l)
Adds the specified focus listener to receive focus events from this component when this component gains input focus. If l is null, no exception is thrown and no action is performed.
Parameters:
l - the focus listener.
Since:
JDK1.1
See Also:
FocusEvent, FocusListener, removeFocusListener(java.awt.event.FocusListener)

removeFocusListener

public void removeFocusListener(FocusListener l)
Removes the specified focus listener so that it no longer receives focus events from this component. This method performs no function, nor does it throw an exception, if the listener specified by the argument was not previously added to this component. If l is null, no exception is thrown and no action is performed.
Parameters:
l - the focus listener.
Since:
JDK1.1
See Also:
FocusEvent, FocusListener, addFocusListener(java.awt.event.FocusListener)

addHierarchyListener

public void addHierarchyListener(HierarchyListener l)
Adds the specified hierarchy listener to receive hierarchy changed events from this component when the hierarchy to which this container belongs changes. If l is null, no exception is thrown and no action is performed.
Parameters:
l - the hierarchy listener.
Since:
1.3
See Also:
HierarchyEvent, HierarchyListener, removeHierarchyListener(java.awt.event.HierarchyListener)

removeHierarchyListener

public void removeHierarchyListener(HierarchyListener l)
Removes the specified hierarchy listener so that it no longer receives hierarchy changed events from this component. This method performs no function, nor does it throw an exception, if the listener specified by the argument was not previously added to this component. If l is null, no exception is thrown and no action is performed.
Parameters:
l - the hierarchy listener.
Since:
1.3
See Also:
HierarchyEvent, HierarchyListener, addHierarchyListener(java.awt.event.HierarchyListener)

addHierarchyBoundsListener

public void addHierarchyBoundsListener(HierarchyBoundsListener l)
Adds the specified hierarchy bounds listener to receive hierarchy bounds events from this component when the hierarchy to which this container belongs changes. If l is null, no exception is thrown and no action is performed.
Parameters:
l - the hierarchy bounds listener.
Since:
1.3
See Also:
HierarchyEvent, HierarchyBoundsListener, removeHierarchyBoundsListener(java.awt.event.HierarchyBoundsListener)

removeHierarchyBoundsListener

public void removeHierarchyBoundsListener(HierarchyBoundsListener l)
Removes the specified hierarchy bounds listener so that it no longer receives hierarchy bounds events from this component. This method performs no function, nor does it throw an exception, if the listener specified by the argument was not previously added to this component. If l is null, no exception is thrown and no action is performed.
Parameters:
l - the hierarchy bounds listener.
Since:
1.3
See Also:
HierarchyEvent, HierarchyBoundsListener, addHierarchyBoundsListener(java.awt.event.HierarchyBoundsListener)

addKeyListener

public void addKeyListener(KeyListener l)
Adds the specified key listener to receive key events from this component. If l is null, no exception is thrown and no action is performed.
Parameters:
l - the key listener.
Since:
JDK1.1
See Also:
KeyEvent, KeyListener, removeKeyListener(java.awt.event.KeyListener)

removeKeyListener

public void removeKeyListener(KeyListener l)
Removes the specified key listener so that it no longer receives key events from this component. This method performs no function, nor does it throw an exception, if the listener specified by the argument was not previously added to this component. If l is null, no exception is thrown and no action is performed.
Parameters:
l - the key listener.
Since:
JDK1.1
See Also:
KeyEvent, KeyListener, addKeyListener(java.awt.event.KeyListener)

addMouseListener

public void addMouseListener(MouseListener l)
Adds the specified mouse listener to receive mouse events from this component. If l is null, no exception is thrown and no action is performed.
Parameters:
l - the mouse listener.
Since:
JDK1.1
See Also:
MouseEvent, MouseListener, removeMouseListener(java.awt.event.MouseListener)

removeMouseListener

public void removeMouseListener(MouseListener l)
Removes the specified mouse listener so that it no longer receives mouse events from this component. This method performs no function, nor does it throw an exception, if the listener specified by the argument was not previously added to this component. If l is null, no exception is thrown and no action is performed.
Parameters:
l - the mouse listener.
Since:
JDK1.1
See Also:
MouseEvent, MouseListener, addMouseListener(java.awt.event.MouseListener)

addMouseMotionListener

public void addMouseMotionListener(MouseMotionListener l)
Adds the specified mouse motion listener to receive mouse motion events from this component. If l is null, no exception is thrown and no action is performed.
Parameters:
l - the mouse motion listener.
Since:
JDK1.1
See Also:
java.awt.event.MouseMotionEvent, MouseMotionListener, removeMouseMotionListener(java.awt.event.MouseMotionListener)

removeMouseMotionListener

public void removeMouseMotionListener(MouseMotionListener l)
Removes the specified mouse motion listener so that it no longer receives mouse motion events from this component. This method performs no function, nor does it throw an exception, if the listener specified by the argument was not previously added to this component. If l is null, no exception is thrown and no action is performed.
Parameters:
l - the mouse motion listener.
Since:
JDK1.1
See Also:
java.awt.event.MouseMotionEvent, MouseMotionListener, addMouseMotionListener(java.awt.event.MouseMotionListener)

addInputMethodListener

public void addInputMethodListener(InputMethodListener l)
Adds the specified input method listener to receive input method events from this component. A component will only receive input method events from input methods if it also overrides getInputMethodRequests to return an InputMethodRequests instance. If l is null, no exception is thrown and no action is performed.
Parameters:
l - the input method listener.
Since:
1.2
See Also:
InputMethodEvent, InputMethodListener, removeInputMethodListener(java.awt.event.InputMethodListener), getInputMethodRequests()

removeInputMethodListener

public void removeInputMethodListener(InputMethodListener l)
Removes the specified input method listener so that it no longer receives input method events from this component. This method performs no function, nor does it throw an exception, if the listener specified by the argument was not previously added to this component. If l is null, no exception is thrown and no action is performed.
Parameters:
l - the input method listener.
Since:
1.2
See Also:
InputMethodEvent, InputMethodListener, addInputMethodListener(java.awt.event.InputMethodListener)

getListeners

public EventListener[] getListeners(Class listenerType)
Return an array of all the listeners that were added to the Component with addXXXListener(), where XXX is the name of the listenerType argument. For example, to get all of the MouseListeners for the given Component c, one would write:
 MouseListener[] mls = (MouseListener[])(c.getListeners(MouseListener.class))
 
If no such listener list exists, then an empty array is returned.
Parameters:
listenerType - Type of listeners requested. This parameter must be a java.util.EventListener or subclass.
Throws:
ClassCastException - if the listenerType parameter is not a java.util.EventListener or subclass.
Since:
1.3

getInputMethodRequests

public InputMethodRequests getInputMethodRequests()
Gets the input method request handler which supports requests from input methods for this component. A component that supports on-the-spot text input must override this method to return an InputMethodRequests instance. At the same time, it also has to handle input method events.
Returns:
the input method request handler for this component, null by default.
Since:
1.2
See Also:
addInputMethodListener(java.awt.event.InputMethodListener)

getInputContext

public InputContext getInputContext()
Gets the input context used by this component for handling the communication with input methods when text is entered in this component. By default, the input context used for the parent component is returned. Components may override this to return a private input context.
Returns:
The input context used by this component. Null if no context can be determined.
Since:
1.2

enableEvents

protected final void enableEvents(long eventsToEnable)
Enables the events defined by the specified event mask parameter to be delivered to this component.

Event types are automatically enabled when a listener for that event type is added to the component.

This method only needs to be invoked by subclasses of Component which desire to have the specified event types delivered to processEvent regardless of whether or not a listener is registered.

Parameters:
eventsToEnable - the event mask defining the event types.
Since:
JDK1.1
See Also:
processEvent(java.awt.AWTEvent), disableEvents(long)

disableEvents

protected final void disableEvents(long eventsToDisable)
Disables the events defined by the specified event mask parameter from being delivered to this component.
Parameters:
eventsToDisable - the event mask defining the event types
Since:
JDK1.1
See Also:
enableEvents(long)

coalesceEvents

protected AWTEvent coalesceEvents(AWTEvent existingEvent,
                                  AWTEvent newEvent)
Potentially coalesce an event being posted with an existing event. This method is called by EventQueue.postEvent if an event with the same ID as the event to be posted is found in the queue (both events must have this component as their source). This method either returns a coalesced event which replaces the existing event (and the new event is then discarded), or null to indicate that no combining should be done (add the second event to the end of the queue). Either event parameter may be modified and returned, as the other one is discarded unless null is returned.

This implementation of coalesceEvents coalesces two event types: mouse move (and drag) events, and paint (and update) events. For mouse move events the last event is always returned, causing intermediate moves to be discarded. For paint events, the new event is coalesced into a complex RepaintArea in the peer. The new Event is always returned.

Parameters:
existingEvent - the event already on the EventQueue.
newEvent - the event being posted to the EventQueue.
Returns:
a coalesced event, or null indicating that no coalescing was done.

processEvent

protected void processEvent(AWTEvent e)
Processes events occurring on this component. By default this method calls the appropriate process<event type>Event method for the given class of event.
Parameters:
e - the event.
Since:
JDK1.1
See Also:
processComponentEvent(java.awt.event.ComponentEvent), processFocusEvent(java.awt.event.FocusEvent), processKeyEvent(java.awt.event.KeyEvent), processMouseEvent(java.awt.event.MouseEvent), processMouseMotionEvent(java.awt.event.MouseEvent), processInputMethodEvent(java.awt.event.InputMethodEvent), processHierarchyEvent(java.awt.event.HierarchyEvent)

processComponentEvent

protected void processComponentEvent(ComponentEvent e)
Processes component events occurring on this component by dispatching them to any registered ComponentListener objects.

This method is not called unless component events are enabled for this component. Component events are enabled when one of the following occurs:

Parameters:
e - the component event.
Since:
JDK1.1
See Also:
ComponentEvent, ComponentListener, addComponentListener(java.awt.event.ComponentListener), enableEvents(long)

processFocusEvent

protected void processFocusEvent(FocusEvent e)
Processes focus events occurring on this component by dispatching them to any registered FocusListener objects.

This method is not called unless focus events are enabled for this component. Focus events are enabled when one of the following occurs:

Parameters:
e - the focus event.
Since:
JDK1.1
See Also:
FocusEvent, FocusListener, addFocusListener(java.awt.event.FocusListener), enableEvents(long)

processKeyEvent

protected void processKeyEvent(KeyEvent e)
Processes key events occurring on this component by dispatching them to any registered KeyListener objects.

This method is not called unless key events are enabled for this component. Key events are enabled when one of the following occurs:

Parameters:
e - the key event.
Since:
JDK1.1
See Also:
KeyEvent, KeyListener, addKeyListener(java.awt.event.KeyListener), enableEvents(long)

processMouseEvent

protected void processMouseEvent(MouseEvent e)
Processes mouse events occurring on this component by dispatching them to any registered MouseListener objects.

This method is not called unless mouse events are enabled for this component. Mouse events are enabled when one of the following occurs:

Parameters:
e - the mouse event.
Since:
JDK1.1
See Also:
MouseEvent, MouseListener, addMouseListener(java.awt.event.MouseListener), enableEvents(long)

processMouseMotionEvent

protected void processMouseMotionEvent(MouseEvent e)
Processes mouse motion events occurring on this component by dispatching them to any registered MouseMotionListener objects.

This method is not called unless mouse motion events are enabled for this component. Mouse motion events are enabled when one of the following occurs:

Parameters:
e - the mouse motion event.
Since:
JDK1.1
See Also:
java.awt.event.MouseMotionEvent, MouseMotionListener, addMouseMotionListener(java.awt.event.MouseMotionListener), enableEvents(long)

processInputMethodEvent

protected void processInputMethodEvent(InputMethodEvent e)
Processes input method events occurring on this component by dispatching them to any registered InputMethodListener objects.

This method is not called unless input method events are enabled for this component. Input method events are enabled when one of the following occurs:

Parameters:
e - the input method event
Since:
1.2
See Also:
InputMethodEvent, InputMethodListener, addInputMethodListener(java.awt.event.InputMethodListener), enableEvents(long)

processHierarchyEvent

protected void processHierarchyEvent(HierarchyEvent e)
Processes hierarchy events occurring on this component by dispatching them to any registered HierarchyListener objects.

This method is not called unless hierarchy events are enabled for this component. Hierarchy events are enabled when one of the following occurs:

Parameters:
e - the hierarchy event
Since:
1.3
See Also:
HierarchyEvent, HierarchyListener, addHierarchyListener(java.awt.event.HierarchyListener), enableEvents(long)

processHierarchyBoundsEvent

protected void processHierarchyBoundsEvent(HierarchyEvent e)
Processes hierarchy bounds events occurring on this component by dispatching them to any registered HierarchyBoundsListener objects.

This method is not called unless hierarchy bounds events are enabled for this component. Hierarchy bounds events are enabled when one of the following occurs:

Parameters:
e - the hierarchy event
Since:
1.3
See Also:
HierarchyEvent, HierarchyBoundsListener, addHierarchyBoundsListener(java.awt.event.HierarchyBoundsListener), enableEvents(long)

handleEvent

public boolean handleEvent(Event evt)
Deprecated. As of JDK version 1.1 replaced by processEvent(AWTEvent).


mouseDown

public boolean mouseDown(Event evt,
                         int x,
                         int y)
Deprecated. As of JDK version 1.1, replaced by processMouseEvent(MouseEvent).


mouseDrag

public boolean mouseDrag(Event evt,
                         int x,
                         int y)
Deprecated. As of JDK version 1.1, replaced by processMouseMotionEvent(MouseEvent).


mouseUp

public boolean mouseUp(Event evt,
                       int x,
                       int y)
Deprecated. As of JDK version 1.1, replaced by processMouseEvent(MouseEvent).


mouseMove

public boolean mouseMove(Event evt,
                         int x,
                         int y)
Deprecated. As of JDK version 1.1, replaced by processMouseMotionEvent(MouseEvent).


mouseEnter

public boolean mouseEnter(Event evt,
                          int x,
                          int y)
Deprecated. As of JDK version 1.1, replaced by processMouseEvent(MouseEvent).


mouseExit

public boolean mouseExit(Event evt,
                         int x,
                         int y)
Deprecated. As of JDK version 1.1, replaced by processMouseEvent(MouseEvent).


keyDown

public boolean keyDown(Event evt,
                       int key)
Deprecated. As of JDK version 1.1, replaced by processKeyEvent(KeyEvent).


keyUp

public boolean keyUp(Event evt,
                     int key)
Deprecated. As of JDK version 1.1, replaced by processKeyEvent(KeyEvent).


action

public boolean action(Event evt,
                      Object what)
Deprecated. As of JDK version 1.1, should register this component as ActionListener on component which fires action events.


addNotify

public void addNotify()
Makes this Component displayable by connecting it to a native screen resource. This method is called internally by the toolkit and should not be called directly by programs.
Since:
JDK1.0
See Also:
isDisplayable(), removeNotify()

removeNotify

public void removeNotify()
Makes this Component undisplayable by destroying it native screen resource. This method is called by the toolkit internally and should not be called directly by programs.
Since:
JDK1.0
See Also:
isDisplayable(), addNotify()

gotFocus

public boolean gotFocus(Event evt,
                        Object what)
Deprecated. As of JDK version 1.1, replaced by processFocusEvent(FocusEvent).


lostFocus

public boolean lostFocus(Event evt,
                         Object what)
Deprecated. As of JDK version 1.1, replaced by processFocusEvent(FocusEvent).


isFocusTraversable

public boolean isFocusTraversable()
Returns the value of a flag that indicates whether this component can be traversed using Tab or Shift-Tab keyboard focus traversal. If this method returns "false", this component may still request the keyboard focus using requestFocus(), but it will not automatically be assigned focus during tab traversal.
Returns:
true if this component is focus-traverable; false otherwise.
Since:
JDK1.1

requestFocus

public void requestFocus()
Requests that this component get the input focus. The component must be visible on the screen for this request to be granted
Since:
JDK1.0
See Also:
FocusEvent, addFocusListener(java.awt.event.FocusListener), processFocusEvent(java.awt.event.FocusEvent), isFocusTraversable()

transferFocus

public void transferFocus()
Transfers the focus to the next component.
Since:
JDK1.1s
See Also:
requestFocus()

nextFocus

public void nextFocus()
Deprecated. As of JDK version 1.1, replaced by transferFocus().


hasFocus

public boolean hasFocus()
Returns true if this Component has the keyboard focus.
Returns:
true if this Component has the keyboard focus.
Since:
1.2

add

public void add(PopupMenu popup)
Adds the specified popup menu to the component.
Parameters:
popup - the popup menu to be added to the component.
Since:
JDK1.1
See Also:
remove(java.awt.MenuComponent)

remove

public void remove(MenuComponent popup)
Removes the specified popup menu from the component.
Specified by:
remove in interface MenuContainer
Parameters:
popup - the popup menu to be removed.
Since:
JDK1.1
See Also:
add(java.awt.PopupMenu)

paramString

protected String paramString()
Returns a string representing the state of this component. This method is intended to be used only for debugging purposes, and the content and format of the returned string may vary between implementations. The returned string may be empty but may not be null.
Returns:
a string representation of this component's state.
Since:
JDK1.0

toString

public String toString()
Returns a string representation of this component and its values.
Overrides:
toString in class Object
Returns:
a string representation of this component.
Since:
JDK1.0

list

public void list()
Prints a listing of this component to the standard system output stream System.out.
Since:
JDK1.0
See Also:
System.out

list

public void list(PrintStream out)
Prints a listing of this component to the specified output stream.
Parameters:
out - a print stream.
Since:
JDK1.0

list

public void list(PrintStream out,
                 int indent)
Prints out a list, starting at the specified indention, to the specified print stream.
Parameters:
out - a print stream.
indent - number of spaces to indent.
Since:
JDK1.0
See Also:
PrintStream.println(java.lang.Object)

list

public void list(PrintWriter out)
Prints a listing to the specified print writer.
Parameters:
out - The print writer to print to.
Since:
JDK1.1

list

public void list(PrintWriter out,
                 int indent)
Prints out a list, starting at the specified indention, to the specified print writer.
Parameters:
out - The print writer to print to.
indent - The number of spaces to indent.
Since:
JDK1.1
See Also:
PrintStream.println(java.lang.Object)

addPropertyChangeListener

public void addPropertyChangeListener(PropertyChangeListener listener)
Add a PropertyChangeListener to the listener list. The listener is registered for all properties.

A PropertyChangeEvent will get fired in response to an explicit setFont, setBackground, or SetForeground on the current component. Note that if the current component is inheriting its foreground, background, or font from its container, then no event will be fired in response to a change in the inherited property. If listener is null, no exception is thrown and no action is performed.

Parameters:
listener - The PropertyChangeListener to be added

removePropertyChangeListener

public void removePropertyChangeListener(PropertyChangeListener listener)
Remove a PropertyChangeListener from the listener list. This removes a PropertyChangeListener that was registered for all properties. If listener is null, no exception is thrown and no action is performed.
Parameters:
listener - The PropertyChangeListener to be removed

addPropertyChangeListener

public void addPropertyChangeListener(String propertyName,
                                      PropertyChangeListener listener)
Add a PropertyChangeListener for a specific property. The listener will be invoked only when a call on firePropertyChange names that specific property. If listener is null, no exception is thrown and no action is performed.
Parameters:
propertyName - The name of the property to listen on.
listener - The PropertyChangeListener to be added

removePropertyChangeListener

public void removePropertyChangeListener(String propertyName,
                                         PropertyChangeListener listener)
Remove a PropertyChangeListener for a specific property. If listener is null, no exception is thrown and no action is performed.
Parameters:
propertyName - The name of the property that was listened on.
listener - The PropertyChangeListener to be removed

firePropertyChange

protected void firePropertyChange(String propertyName,
                                  Object oldValue,
                                  Object newValue)
Support for reporting bound property changes. This method can be called when a bound property has changed and it will send the appropriate PropertyChangeEvent to any registered PropertyChangeListeners.

setComponentOrientation

public void setComponentOrientation(ComponentOrientation o)
Set the language-sensitive orientation that is to be used to order the elements or text within this component. Language-sensitive LayoutManager and Component subclasses will use this property to determine how to lay out and draw components.

At construction time, a component's orientation is set to ComponentOrientation.UNKNOWN, indicating that it has not been specified explicitly. The UNKNOWN orientation behaves the same as ComponentOrientation.LEFT_TO_RIGHT.

To set the orientation of a single component, use this method. To apply a ResourceBundle's orientation to an entire component hierarchy, use java.awt.Window.applyResourceBundle.

See Also:
ComponentOrientation, Window.applyResourceBundle(java.util.ResourceBundle)

getComponentOrientation

public ComponentOrientation getComponentOrientation()
Retrieve the language-sensitive orientation that is to be used to order the elements or text within this component. LayoutManager and Component subclasses that wish to respect orientation should call this method to get the component's orientation before performing layout or drawing.
See Also:
ComponentOrientation

getAccessibleContext

public AccessibleContext getAccessibleContext()
Get the AccessibleContext associated with this Component
Returns:
the AccessibleContext of this Component

JavaTM 2 Platform
Std. Ed. v1.3.1

Submit a bug or feature
For further API reference and developer documentation, see Java 2 SDK SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.

Java, Java 2D, and JDBC are trademarks or registered trademarks of Sun Microsystems, Inc. in the US and other countries.
Copyright 1993-2001 Sun Microsystems, Inc. 901 San Antonio Road
Palo Alto, California, 94303, U.S.A. All Rights Reserved.



Spec-Zone.ru - all specs in one place



free hit counter