Round tap-zoom gestures to nearest integer

include/mbgl/map/map.hpp

@@ -98,6 +98,7 @@ class Map : private util::noncopyable {
     void setScale(double scale, optional<ScreenCoordinate> = {}, const Duration& = Duration::zero());
     double getScale() const;
     void setZoom(double zoom, const Duration& = Duration::zero());
+    void setZoom(double zoom, optional<ScreenCoordinate>, const Duration& = Duration::zero());
     void setZoom(double zoom, optional<EdgeInsets>, const Duration& = Duration::zero());
     double getZoom() const;
     void setLatLngZoom(const LatLng&, double zoom, const Duration& = Duration::zero());

platform/ios/CHANGELOG.md

@@ -42,6 +42,7 @@ Mapbox welcomes participation and contributions from everyone. Please read [CONT
 * Added a `MGLDistanceFormatter` class for formatting geographic distances. ([#7888](https://github.com/mapbox/mapbox-gl-native/pull/7888))
 * Added a method to MGLMapViewDelegate, `-mapView:shouldChangeFromCamera:toCamera:`, that you can implement to restrict which parts the user can navigate to using gestures. ([#5584](https://github.com/mapbox/mapbox-gl-native/pull/5584))
 * Annotations are no longer deselected when the map is panned or zoomed, even if the annotation moves out of the visible bounds. ([#8022](https://github.com/mapbox/mapbox-gl-native/pull/8022))
+* Double-tap and two-finger tap gestures now zoom to the nearest integer zoom level. ([#8027](https://github.com/mapbox/mapbox-gl-native/pull/8027))
 
 ## 3.4.1 - January 25, 2017
 

platform/ios/app/MBXViewController.m

@@ -77,6 +77,7 @@ typedef NS_ENUM(NSInteger, MBXSettingsMiscellaneousRows) {
     MBXSettingsMiscellaneousShowReuseQueueStats = 0,
     MBXSettingsMiscellaneousWorldTour,
     MBXSettingsMiscellaneousCustomUserDot,
+    MBXSettingsMiscellaneousShowZoomLevel,
     MBXSettingsMiscellaneousPrintLogFile,
     MBXSettingsMiscellaneousDeleteLogFile,
 };
@@ -113,6 +114,7 @@ @interface MBXViewController () <UITableViewDelegate,
 @property (nonatomic) BOOL customUserLocationAnnnotationEnabled;
 @property (nonatomic) BOOL usingLocaleBasedCountryLabels;
 @property (nonatomic) BOOL reuseQueueStatsEnabled;
+@property (nonatomic) BOOL showZoomLevelEnabled;
 
 @end
 
@@ -153,6 +155,7 @@ - (void)viewDidLoad
     [self restoreState:nil];
 
     self.debugLoggingEnabled = [[NSUserDefaults standardUserDefaults] boolForKey:@"MGLMapboxMetricsDebugLoggingEnabled"];
+
     self.hudLabel.hidden = YES;
 
     if ([MGLAccountManager accessToken].length)
@@ -339,11 +342,11 @@ - (void)dismissSettings:(__unused id)sender
             ]];
             break;
         case MBXSettingsMiscellaneous:
-            [settingsTitles addObject:@"Show Reuse Queue Stats"];
-
             [settingsTitles addObjectsFromArray:@[
+                [NSString stringWithFormat:@"%@ Reuse Queue Stats", (_reuseQueueStatsEnabled ? @"Hide" :@"Show")],
                 @"Start World Tour",
                 [NSString stringWithFormat:@"%@ Custom User Dot", (_customUserLocationAnnnotationEnabled ? @"Disable" : @"Enable")],
+                [NSString stringWithFormat:@"%@ Zoom Level", (_showZoomLevelEnabled ? @"Hide" :@"Show")],
             ]];
 
             if (self.debugLoggingEnabled)
@@ -522,8 +525,16 @@ - (void)performActionForSettingAtIndexPath:(NSIndexPath *)indexPath
                     break;
                 case MBXSettingsMiscellaneousShowReuseQueueStats:
                 {
-                    self.reuseQueueStatsEnabled = YES;
-                    self.hudLabel.hidden = NO;
+                    self.reuseQueueStatsEnabled = !self.reuseQueueStatsEnabled;
+                    self.hudLabel.hidden = !self.reuseQueueStatsEnabled;
+                    self.showZoomLevelEnabled = NO;
+                    break;
+                }
+                case MBXSettingsMiscellaneousShowZoomLevel:
+                {
+                    self.showZoomLevelEnabled = !self.showZoomLevelEnabled;
+                    self.hudLabel.hidden = !self.showZoomLevelEnabled;
+                    self.reuseQueueStatsEnabled = NO;
                     break;
                 }
                 default:
@@ -1711,7 +1722,15 @@ - (void)mapViewRegionIsChanging:(MGLMapView *)mapView
         {
             queuedAnnotations += queue.count;
         }
-        self.hudLabel.text = [NSString stringWithFormat:@"Visible: %ld  Queued: %ld", (unsigned long)mapView.visibleAnnotations.count, (unsigned long)queuedAnnotations];
+        self.hudLabel.text = [NSString stringWithFormat:@" Visible: %ld  Queued: %ld", (unsigned long)mapView.visibleAnnotations.count, (unsigned long)queuedAnnotations];
+    } else if (self.showZoomLevelEnabled) {
+        self.hudLabel.text = [NSString stringWithFormat:@" Zoom: %.2f", self.mapView.zoomLevel];
+    }
+}
+
+- (void)mapView:(MGLMapView *)mapView regionDidChangeAnimated:(BOOL)animated {
+    if (self.showZoomLevelEnabled) {
+        self.hudLabel.text = [NSString stringWithFormat:@" Zoom: %.2f", self.mapView.zoomLevel];
     }
 }
 

platform/ios/src/MGLMapView.mm

@@ -1556,18 +1556,20 @@ - (void)handleDoubleTapGesture:(UITapGestureRecognizer *)doubleTap
     if (doubleTap.state == UIGestureRecognizerStateEnded)
     {
         MGLMapCamera *oldCamera = self.camera;
-
+
+        double newZoom = round(self.zoomLevel) + 1.0;
+
         CGPoint gesturePoint = [self anchorPointForGesture:doubleTap];
-        
-        MGLMapCamera *toCamera = [self cameraByZoomingToZoomLevel:self.zoomLevel + 1.0 aroundAnchorPoint:gesturePoint];
+
+        MGLMapCamera *toCamera = [self cameraByZoomingToZoomLevel:newZoom aroundAnchorPoint:gesturePoint];
 
         if (![self.delegate respondsToSelector:@selector(mapView:shouldChangeFromCamera:toCamera:)] ||
             [self.delegate mapView:self shouldChangeFromCamera:oldCamera toCamera:toCamera])
         {
             [self trackGestureEvent:MGLEventGestureDoubleTap forRecognizer:doubleTap];
 
             mbgl::ScreenCoordinate center(gesturePoint.x, gesturePoint.y);
-            _mbglMap->scaleBy(2, center, MGLDurationInSecondsFromTimeInterval(MGLAnimationDuration));
+            _mbglMap->setZoom(newZoom, center, MGLDurationInSecondsFromTimeInterval(MGLAnimationDuration));
 
             __weak MGLMapView *weakSelf = self;
 
@@ -1595,16 +1597,17 @@ - (void)handleTwoFingerTapGesture:(UITapGestureRecognizer *)twoFingerTap
     {
         MGLMapCamera *oldCamera = self.camera;
 
-        double zoom = self.zoomLevel;
+        double newZoom = round(self.zoomLevel) - 1.0;
+
         CGPoint gesturePoint = [self anchorPointForGesture:twoFingerTap];
-        
-        MGLMapCamera *toCamera = [self cameraByZoomingToZoomLevel:zoom - 1.0 aroundAnchorPoint:gesturePoint];
+
+        MGLMapCamera *toCamera = [self cameraByZoomingToZoomLevel:newZoom aroundAnchorPoint:gesturePoint];
 
         if (![self.delegate respondsToSelector:@selector(mapView:shouldChangeFromCamera:toCamera:)] ||
             [self.delegate mapView:self shouldChangeFromCamera:oldCamera toCamera:toCamera])
         {
             mbgl::ScreenCoordinate center(gesturePoint.x, gesturePoint.y);
-            _mbglMap->scaleBy(0.5, center, MGLDurationInSecondsFromTimeInterval(MGLAnimationDuration));
+            _mbglMap->setZoom(newZoom, center, MGLDurationInSecondsFromTimeInterval(MGLAnimationDuration));
 
             __weak MGLMapView *weakSelf = self;
 

platform/macos/CHANGELOG.md

@@ -39,6 +39,7 @@
 * Fixed flickering that occurred when panning past the antimeridian. ([#7574](https://github.com/mapbox/mapbox-gl-native/pull/7574))
 * Added a method to MGLMapViewDelegate, `-mapView:shouldChangeFromCamera:toCamera:`, that you can implement to restrict which parts the user can navigate to using gestures. ([#5584](https://github.com/mapbox/mapbox-gl-native/pull/5584))
 * Added a `MGLDistanceFormatter` class for formatting geographic distances. ([#7888](https://github.com/mapbox/mapbox-gl-native/pull/7888))
+* Zooming by double-tap, two-finger tap, zoom buttons, shortcut keys, or demo app menu items or shortcut keys now zooms to the nearest integer zoom level. ([#8027](https://github.com/mapbox/mapbox-gl-native/pull/8027))
 
 ## 0.3.1
 

platform/macos/app/MapDocument.m

@@ -217,11 +217,11 @@ - (IBAction)chooseCustomStyle:(id)sender {
 }
 
 - (IBAction)zoomIn:(id)sender {
-    [self.mapView setZoomLevel:self.mapView.zoomLevel + 1 animated:YES];
+    [self.mapView setZoomLevel:round(self.mapView.zoomLevel) + 1 animated:YES];
 }
 
 - (IBAction)zoomOut:(id)sender {
-    [self.mapView setZoomLevel:self.mapView.zoomLevel - 1 animated:YES];
+    [self.mapView setZoomLevel:round(self.mapView.zoomLevel) - 1 animated:YES];
 }
 
 - (IBAction)snapToNorth:(id)sender {

platform/macos/src/MGLMapView.mm

@@ -1042,7 +1042,22 @@ - (void)setZoomLevel:(double)zoomLevel animated:(BOOL)animated {
 }
 
 - (void)zoomBy:(double)zoomDelta animated:(BOOL)animated {
-    [self setZoomLevel:self.zoomLevel + zoomDelta animated:animated];
+    [self setZoomLevel:round(self.zoomLevel) + zoomDelta animated:animated];
+}
+
+- (void)zoomBy:(double)zoomDelta atPoint:(NSPoint)point animated:(BOOL)animated {
+    [self willChangeValueForKey:@"centerCoordinate"];
+    [self willChangeValueForKey:@"zoomLevel"];
+    double newZoom = round(self.zoomLevel) + zoomDelta;
+    MGLMapCamera *oldCamera = self.camera;
+    mbgl::ScreenCoordinate center(point.x, self.bounds.size.height - point.y);
+    _mbglMap->setZoom(newZoom, center, MGLDurationInSecondsFromTimeInterval(animated ? MGLAnimationDuration : 0));
+    if ([self.delegate respondsToSelector:@selector(mapView:shouldChangeFromCamera:toCamera:)]
+        && ![self.delegate mapView:self shouldChangeFromCamera:oldCamera toCamera:self.camera]) {
+        self.camera = oldCamera;
+    }
+    [self didChangeValueForKey:@"zoomLevel"];
+    [self didChangeValueForKey:@"centerCoordinate"];
 }
 
 - (void)scaleBy:(double)scaleFactor atPoint:(NSPoint)point animated:(BOOL)animated {
@@ -1500,7 +1515,7 @@ - (void)handleDoubleClickGesture:(NSClickGestureRecognizer *)gestureRecognizer {
     _mbglMap->cancelTransitions();
 
     NSPoint gesturePoint = [gestureRecognizer locationInView:self];
-    [self scaleBy:2 atPoint:gesturePoint animated:YES];
+    [self zoomBy:1 atPoint:gesturePoint animated:YES];
 }
 
 - (void)smartMagnifyWithEvent:(NSEvent *)event {
@@ -1512,7 +1527,7 @@ - (void)smartMagnifyWithEvent:(NSEvent *)event {
 
     // Tap with two fingers (“right-click”) to zoom out on mice but not trackpads.
     NSPoint gesturePoint = [self convertPoint:event.locationInWindow fromView:nil];
-    [self scaleBy:0.5 atPoint:gesturePoint animated:YES];
+    [self zoomBy:-1 atPoint:gesturePoint animated:YES];
 }
 
 /// Rotate fingers to rotate.

src/mbgl/map/map.cpp

@@ -537,7 +537,13 @@ double Map::getScale() const {
 
 void Map::setZoom(double zoom, const Duration& duration) {
     impl->cameraMutated = true;
-    setZoom(zoom, {}, duration);
+    setZoom(zoom, optional<EdgeInsets> {}, duration);
+}
+
+void Map::setZoom(double zoom, optional<ScreenCoordinate> anchor, const Duration& duration) {
+    impl->cameraMutated = true;
+    impl->transform.setZoom(zoom, anchor, duration);
+    impl->onUpdate(Update::RecalculateStyle);
 }
 
 void Map::setZoom(double zoom, optional<EdgeInsets> padding, const Duration& duration) {