[ios] Fix for user location annotation jittering (and view annotations lagging) (#12895)

3 files changed, 33 insertions, 16 deletions

diff --git a/platform/darwin/src/MGLFoundation.h b/platform/darwin/src/MGLFoundation.h
index 3400c63979..be86bb92f9 100644
--- a/platform/darwin/src/MGLFoundation.h
+++ b/platform/darwin/src/MGLFoundation.h
@@ -3,3 +3,10 @@
 #import <Foundation/Foundation.h>
 
 #define MGL_EXPORT __attribute__((visibility ("default")))
+
+/* Using a compound statement (GNU Extension, supported by clang) */
+#define MGL_OBJC_DYNAMIC_CAST(object, type) \
+    ({ \
+        __typeof__( object ) temp##__LINE__ = (object); \
+        (type *)([temp##__LINE__ isKindOfClass:[type class]] ? temp##__LINE__ : nil); \
+    })
diff --git a/platform/ios/CHANGELOG.md b/platform/ios/CHANGELOG.md
index 194d17fda0..7c391c9f22 100644
--- a/platform/ios/CHANGELOG.md
+++ b/platform/ios/CHANGELOG.md
@@ -8,6 +8,7 @@ Mapbox welcomes participation and contributions from everyone. Please read [CONT
 
 * Added an `MGLSymbolStyleLayer.symbolZOrder` property for forcing point features in a symbol layer to be layered in the same order that they are specified in the layer’s associated source. ([#12783](https://github.com/mapbox/mapbox-gl-native/pull/12783))
 * Fixed a crash when a style layer `*-pattern` property evaluates to nil for a particular feature. ([#12896](https://github.com/mapbox/mapbox-gl-native/pull/12896))
+* Fixed an issue with view annotations (including the user location annotation) and the GL map lagging relative to each other. ([#12895](https://github.com/mapbox/mapbox-gl-native/pull/12895))
 
 ### Offline maps
 
diff --git a/platform/ios/src/MGLMapView.mm b/platform/ios/src/MGLMapView.mm
index 92d3724b03..d550a086cb 100644
--- a/platform/ios/src/MGLMapView.mm
+++ b/platform/ios/src/MGLMapView.mm
@@ -636,6 +636,9 @@ public:
     _glView.layer.opaque = _opaque;
     _glView.delegate = self;
 
+    CAEAGLLayer *eaglLayer = MGL_OBJC_DYNAMIC_CAST(_glView.layer, CAEAGLLayer);
+    eaglLayer.presentsWithTransaction = YES;
+    
     [_glView bindDrawable];
     [self insertSubview:_glView atIndex:0];
     _glView.contentMode = UIViewContentModeCenter;
@@ -985,8 +988,6 @@ public:
     if ( ! self.dormant || ! _rendererFrontend)
     {
         _rendererFrontend->render();
-
-        [self updateUserLocationAnnotationView];
     }
 }
 
@@ -1117,6 +1118,11 @@ public:
     {
         _needsDisplayRefresh = NO;
 
+        // Update UIKit elements, prior to rendering
+        [self updateUserLocationAnnotationView];
+        [self updateAnnotationViews];
+        [self updateCalloutView];
+        
         [self.glView display];
     }
 
@@ -5709,8 +5715,7 @@ public:
         _isChangingAnnotationLayers = NO;
         [self.style didChangeValueForKey:@"layers"];
     }
-    [self updateAnnotationViews];
-    [self updateCalloutView];
+
     if ([self.delegate respondsToSelector:@selector(mapViewDidFinishRenderingFrame:fullyRendered:)])
     {
         [self.delegate mapViewDidFinishRenderingFrame:self fullyRendered:fullyRendered];
@@ -5767,9 +5772,6 @@ public:
         return;
     }
 
-    [CATransaction begin];
-    [CATransaction setDisableActions:YES];
-
     // If the map is pitched consider the viewport to be exactly the same as the bounds.
     // Otherwise, add a small buffer.
     CGFloat largestWidth = MAX(_largestAnnotationViewSize.width, CGRectGetWidth(self.frame));
@@ -5864,8 +5866,6 @@ public:
             }
         }
     }
-
-    [CATransaction commit];
 }
 
 - (void)updateCalloutView
@@ -5951,12 +5951,8 @@ public:
     {
         // Smoothly move the user location annotation view and callout view to
         // the new location.
-        [UIView animateWithDuration:duration
-                              delay:0
-                            options:(UIViewAnimationOptionCurveLinear |
-                                     UIViewAnimationOptionAllowUserInteraction |
-                                     UIViewAnimationOptionBeginFromCurrentState)
-                         animations:^{
+        
+        dispatch_block_t animation = ^{
             if (self.selectedAnnotation == self.userLocation)
             {
                 UIView <MGLCalloutView> *calloutView = self.calloutViewForSelectedAnnotation;
@@ -5965,7 +5961,20 @@ public:
                                                  userPoint.y - annotationView.center.y);
             }
             annotationView.center = userPoint;
-        } completion:NULL];
+        };
+        
+        if (duration > 0) {
+            [UIView animateWithDuration:duration
+                                  delay:0
+                                options:(UIViewAnimationOptionCurveLinear |
+                                         UIViewAnimationOptionAllowUserInteraction |
+                                         UIViewAnimationOptionBeginFromCurrentState)
+                             animations:animation
+                             completion:NULL];
+        }
+        else {
+            animation();
+        }
         _userLocationAnimationCompletionDate = [NSDate dateWithTimeIntervalSinceNow:duration];
 
         annotationView.hidden = NO;