/* |
Copyright (C) 2014 Apple Inc. All Rights Reserved. |
See LICENSE.txt for this sample’s licensing information |
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*/ |
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#import "GetLocationViewController.h" |
#import "LocationDetailViewController.h" |
#import "SetupViewController.h" |
#import "CLLocation+Strings.h" |
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@interface GetLocationViewController () <SetupViewControllerDelegate, CLLocationManagerDelegate> |
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@property (nonatomic, weak) IBOutlet UIButton *startButton; |
@property (nonatomic, weak) IBOutlet UILabel *descriptionLabel; |
@property (nonatomic, weak) IBOutlet UITableView *tableView; |
@property (nonatomic, strong) SetupViewController* setupViewController; |
@property (nonatomic, copy) NSString *stateString; |
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@property (nonatomic, strong) CLLocationManager *locationManager; |
@property (nonatomic, strong) NSDateFormatter *dateFormatter; |
@property (nonatomic, strong) NSMutableArray *locationMeasurements; |
@property (nonatomic, strong) CLLocation *bestEffortAtLocation; |
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@end |
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#pragma mark - |
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@implementation GetLocationViewController |
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- (void)viewDidLoad { |
[super viewDidLoad]; |
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_locationMeasurements = [NSMutableArray array]; |
} |
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- (NSDateFormatter *)dateFormatter { |
if (_dateFormatter == nil) { |
_dateFormatter = [[NSDateFormatter alloc] init]; |
[_dateFormatter setDateStyle:NSDateFormatterMediumStyle]; |
[_dateFormatter setTimeStyle:NSDateFormatterLongStyle]; |
} |
return _dateFormatter; |
} |
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- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender { |
UINavigationController *nv = segue.destinationViewController; |
_setupViewController = nv.viewControllers[0]; |
self.setupViewController.delegate = self; |
} |
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#pragma mark - Actions |
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// The reset method allows the user to repeatedly test the location functionality. |
// In addition to discarding all of the location measurements from the previous "run", |
// it animates a transition in the user interface between the table which displays location |
// data and the start button and description label presented at launch. |
// |
- (void)reset { |
_bestEffortAtLocation = nil; |
[self.locationMeasurements removeAllObjects]; |
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// fade in the rest of the UI and fade out the table view |
[UIView animateWithDuration:0.6f animations:^(void) { |
self.startButton.alpha = 1.0; |
self.descriptionLabel.alpha = 1.0; |
self.tableView.alpha = 0.0; |
[self.navigationItem setLeftBarButtonItem:nil animated:YES]; |
} completion:^(BOOL finished) { |
if (finished) { |
//.. |
} |
}]; |
} |
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#pragma mark - Location Manager Interactions |
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// This method is invoked when the user hits "Done" in the setup view controller. |
// The options chosen by the user are passed in as a dictionary. The keys for this dictionary |
// are declared in SetupViewController.h. |
// |
- (void)setupViewController:(SetupViewController *)controller didFinishSetupWithInfo:(NSDictionary *)setupInfo { |
self.startButton.alpha = 0.0; |
self.descriptionLabel.alpha = 0.0; |
self.tableView.alpha = 1.0; |
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// Create the core location manager object |
_locationManager = [[CLLocationManager alloc] init]; |
self.locationManager.delegate = self; |
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// This is the most important property to set for the manager. It ultimately determines how the manager will |
// attempt to acquire location and thus, the amount of power that will be consumed. |
self.locationManager.desiredAccuracy = [setupInfo[kSetupInfoKeyAccuracy] doubleValue]; |
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// Once configured, the location manager must be "started" |
// |
// for iOS 8, specific user level permission is required, |
// "when-in-use" authorization grants access to the user's location |
// |
// important: be sure to include NSLocationWhenInUseUsageDescription along with its |
// explanation string in your Info.plist or startUpdatingLocation will not work. |
// |
if ([self.locationManager respondsToSelector:@selector(requestWhenInUseAuthorization)]) { |
[self.locationManager requestWhenInUseAuthorization]; |
} |
[self.locationManager startUpdatingLocation]; |
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[self performSelector:@selector(stopUpdatingLocationWithMessage:) |
withObject:@"Timed Out" |
afterDelay:[setupInfo[kSetupInfoKeyTimeout] doubleValue]]; |
self.stateString = NSLocalizedString(@"Updating", @"Updating"); |
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[self.tableView reloadData]; |
} |
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// We want to get and store a location measurement that meets the desired accuracy. |
// For this example, we are going to use horizontal accuracy as the deciding factor. |
// In other cases, you may wish to use vertical accuracy, or both together. |
// |
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation { |
// store all of the measurements, just so we can see what kind of data we might receive |
[self.locationMeasurements addObject:newLocation]; |
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// test the age of the location measurement to determine if the measurement is cached |
// in most cases you will not want to rely on cached measurements |
// |
NSTimeInterval locationAge = -[newLocation.timestamp timeIntervalSinceNow]; |
if (locationAge > 5.0) { |
return; |
} |
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// test that the horizontal accuracy does not indicate an invalid measurement |
if (newLocation.horizontalAccuracy < 0) { |
return; |
} |
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// test the measurement to see if it is more accurate than the previous measurement |
if (self.bestEffortAtLocation == nil || self.bestEffortAtLocation.horizontalAccuracy > newLocation.horizontalAccuracy) { |
// store the location as the "best effort" |
_bestEffortAtLocation = newLocation; |
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// test the measurement to see if it meets the desired accuracy |
// |
// IMPORTANT!!! kCLLocationAccuracyBest should not be used for comparison with location coordinate or altitidue |
// accuracy because it is a negative value. Instead, compare against some predetermined "real" measure of |
// acceptable accuracy, or depend on the timeout to stop updating. This sample depends on the timeout. |
// |
if (newLocation.horizontalAccuracy <= self.locationManager.desiredAccuracy) { |
// we have a measurement that meets our requirements, so we can stop updating the location |
// |
// IMPORTANT!!! Minimize power usage by stopping the location manager as soon as possible. |
// |
[self stopUpdatingLocationWithMessage:NSLocalizedString(@"Acquired Location", @"Acquired Location")]; |
// we can also cancel our previous performSelector:withObject:afterDelay: - it's no longer necessary |
[NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(stopUpdatingLocationWithMessage:) object:nil]; |
} |
} |
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// update the display with the new location data |
[self.tableView reloadData]; |
} |
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- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error { |
// The location "unknown" error simply means the manager is currently unable to get the location. |
// We can ignore this error for the scenario of getting a single location fix, because we already have a |
// timeout that will stop the location manager to save power. |
// |
if ([error code] != kCLErrorLocationUnknown) { |
[self stopUpdatingLocationWithMessage:NSLocalizedString(@"Error", @"Error")]; |
} |
} |
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- (void)stopUpdatingLocationWithMessage:(NSString *)state { |
self.stateString = state; |
[self.tableView reloadData]; |
[self.locationManager stopUpdatingLocation]; |
self.locationManager.delegate = nil; |
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UIBarButtonItem *resetItem = [[UIBarButtonItem alloc] initWithTitle:NSLocalizedString(@"Reset", @"Reset") |
style:UIBarButtonItemStylePlain |
target:self |
action:@selector(reset)]; |
[self.navigationItem setLeftBarButtonItem:resetItem animated:YES]; |
} |
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#pragma mark - UITableViewDataSource |
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// The table view has three sections. The first has 1 row which displays status information. |
// The second has 1 row which displays the most accurate valid location measurement received. |
// The third has a row for each valid location object received |
// (including the one displayed in the second section) from the location manager. |
// |
- (NSInteger)numberOfSectionsInTableView:(UITableView *)table { |
return (self.bestEffortAtLocation != nil) ? 3 : 1; |
} |
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- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section { |
NSString *headerTitle = nil; |
switch (section) { |
case 0: { |
headerTitle = NSLocalizedString(@"Status", @"Status"); |
break; |
} |
case 1: { |
headerTitle = NSLocalizedString(@"Best Measurement", @"Best Measurement"); |
break; |
} |
default: { |
headerTitle = NSLocalizedString(@"All Measurements", @"All Measurements"); |
break; |
} |
} |
return headerTitle; |
} |
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- (NSInteger)tableView:(UITableView *)table numberOfRowsInSection:(NSInteger)section { |
NSInteger numRows = 0; |
switch (section) { |
case 0: { |
numRows = 1; |
break; |
} |
case 1: { |
numRows = 1; |
break; |
} |
default: { |
numRows = self.locationMeasurements.count; |
break; |
} |
} |
return numRows; |
} |
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- (UITableViewCell *)tableView:(UITableView *)table cellForRowAtIndexPath:(NSIndexPath *)indexPath { |
UITableViewCell *cell = nil; |
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switch (indexPath.section) { |
case 0: { |
// The cell for the status row uses the cell style "UITableViewCellStyleValue1", which has a label on the left side of the cell with left-aligned and black text; on the right side is a label that has smaller blue text and is right-aligned. An activity indicator has been added to the cell and is animated while the location manager is updating. The cell's text label displays the current state of the manager. |
static NSString * const kStatusCellID = @"StatusCellID"; |
static NSInteger const kStatusCellActivityIndicatorTag = 2; |
UIActivityIndicatorView *activityIndicator = nil; |
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cell = [table dequeueReusableCellWithIdentifier:kStatusCellID]; |
if (cell == nil) { |
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:kStatusCellID]; |
cell.selectionStyle = UITableViewCellSelectionStyleNone; |
activityIndicator = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray]; |
CGRect frame = activityIndicator.frame; |
frame.origin = CGPointMake(290.0, 12.0); |
activityIndicator.frame = frame; |
activityIndicator.autoresizingMask = UIViewAutoresizingFlexibleLeftMargin; |
activityIndicator.tag = kStatusCellActivityIndicatorTag; |
[cell.contentView addSubview:activityIndicator]; |
} else { |
activityIndicator = (UIActivityIndicatorView *)[cell.contentView viewWithTag:kStatusCellActivityIndicatorTag]; |
} |
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cell.textLabel.text = self.stateString; |
if ([self.stateString isEqualToString:NSLocalizedString(@"Updating", @"Updating")]) { |
if (activityIndicator.isAnimating == NO) { |
[activityIndicator startAnimating]; |
} |
} else { |
if (activityIndicator.isAnimating) { |
[activityIndicator stopAnimating]; |
} |
} |
break; |
} |
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case 1: { |
// The cells for the location rows use the cell style "UITableViewCellStyleSubtitle", which has a left-aligned label across the top and a left-aligned label below it in smaller gray text. The text label shows the coordinates for the location and the detail text label shows its timestamp. |
static NSString * const kBestMeasurementCellID = @"BestMeasurementCellID"; |
cell = [table dequeueReusableCellWithIdentifier:kBestMeasurementCellID]; |
if (cell == nil) { |
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:kBestMeasurementCellID]; |
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator; |
} |
cell.textLabel.text = self.bestEffortAtLocation.localizedCoordinateString; |
cell.detailTextLabel.text = [self.dateFormatter stringFromDate:self.bestEffortAtLocation.timestamp]; |
break; |
} |
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default: { |
// The cells for the location rows use the cell style "UITableViewCellStyleSubtitle", which has a left-aligned label across the top and a left-aligned label below it in smaller gray text. The text label shows the coordinates for the location and the detail text label shows its timestamp. |
static NSString * const kOtherMeasurementsCellID = @"OtherMeasurementsCellID"; |
cell = [table dequeueReusableCellWithIdentifier:kOtherMeasurementsCellID]; |
if (cell == nil) { |
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:kOtherMeasurementsCellID]; |
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator; |
} |
CLLocation *location = self.locationMeasurements[indexPath.row]; |
cell.textLabel.text = location.localizedCoordinateString; |
cell.detailTextLabel.text = [self.dateFormatter stringFromDate:location.timestamp]; |
break; |
} |
} |
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return cell; |
} |
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#pragma mark - UITableViewDelegate |
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// Delegate method invoked before the user selects a row. |
// In this sample, we use it to prevent selection in the first section of the table view. |
// |
- (NSIndexPath *)tableView:(UITableView *)tableView willSelectRowAtIndexPath:(NSIndexPath *)indexPath { |
return (indexPath.section == 0) ? nil : indexPath; |
} |
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// Delegate method invoked after the user selects a row. Selecting a row containing a location object |
// will navigate to a new view controller displaying details about that location. |
// |
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { |
[self.tableView deselectRowAtIndexPath:indexPath animated:YES]; |
CLLocation *location = self.locationMeasurements[indexPath.row]; |
LocationDetailViewController *detailVC = [[LocationDetailViewController alloc] initWithStyle:UITableViewStyleGrouped]; |
detailVC.location = location; |
[self.navigationController pushViewController:detailVC animated:YES]; |
} |
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@end |
