Allow annotation images to be updated

gyp/platform-ios.gypi

@@ -60,6 +60,7 @@
         '../platform/ios/MGLUserLocationAnnotationView.h',
         '../platform/ios/MGLUserLocationAnnotationView.m',
         '../include/mbgl/ios/MGLAnnotationImage.h',
+        '../platform/ios/MGLAnnotationImage_Private.h',
         '../platform/ios/MGLAnnotationImage.m',
         '../platform/ios/MGLCategoryLoader.h',
         '../platform/ios/MGLCategoryLoader.m',

include/mbgl/ios/MGLAnnotationImage.h

@@ -18,7 +18,7 @@ NS_ASSUME_NONNULL_BEGIN
 /** @name Getting and Setting Attributes */
 
 /** The image to be displayed for the annotation. */
-@property (nonatomic, readonly) UIImage *image;
+@property (nonatomic, strong) UIImage *image;
 
 /** The string that identifies that this annotation image is reusable. (read-only)
 *

platform/ios/MGLAnnotationImage.m

@@ -1,9 +1,9 @@
-#import "MGLAnnotationImage.h"
+#import "MGLAnnotationImage_Private.h"
 
 @interface MGLAnnotationImage ()
 
-@property (nonatomic) UIImage *image;
-@property (nonatomic) NSString *reuseIdentifier;
+@property (nonatomic, strong) NSString *reuseIdentifier;
+@property (nonatomic, weak) id<MGLAnnotationImageDelegate> delegate;
 
 @end
 
@@ -28,4 +28,9 @@ - (instancetype)initWithImage:(UIImage *)image reuseIdentifier:(NSString *)reuse
     return self;
 }
 
+- (void)setImage:(UIImage *)image {
+    _image = image;
+    [self.delegate annotationImageNeedsRedisplay:self];
+}
+
 @end

platform/ios/MGLAnnotationImage_Private.h

@@ -0,0 +1,18 @@
+#import "MGLAnnotationImage.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+@protocol MGLAnnotationImageDelegate <NSObject>
+
+@required
+- (void)annotationImageNeedsRedisplay:(MGLAnnotationImage *)annotationImage;
+
+@end
+
+@interface MGLAnnotationImage (Private)
+
+@property (nonatomic, weak) id<MGLAnnotationImageDelegate> delegate;
+
+@end
+
+NS_ASSUME_NONNULL_END

platform/ios/MGLMapView.mm

@@ -36,6 +36,7 @@
 #import "MGLUserLocationAnnotationView.h"
 #import "MGLUserLocation_Private.h"
 #import "MGLAccountManager_Private.h"
+#import "MGLAnnotationImage_Private.h"
 #import "MGLMapboxEvents.h"
 
 #import "SMCalloutView.h"
@@ -120,7 +121,8 @@ @interface MGLMapView () <UIGestureRecognizerDelegate,
                           CLLocationManagerDelegate,
                           UIActionSheetDelegate,
                           SMCalloutViewDelegate,
-                          MGLMultiPointDelegate>
+                          MGLMultiPointDelegate,
+                          MGLAnnotationImageDelegate>
 
 @property (nonatomic) EAGLContext *context;
 @property (nonatomic) GLKView *glView;
@@ -2144,6 +2146,7 @@ - (void)addAnnotations:(NS_ARRAY_OF(id <MGLAnnotation>) *)annotations
             {
                 self.annotationImagesByIdentifier[annotationImage.reuseIdentifier] = annotationImage;
                 [self installAnnotationImage:annotationImage];
+                annotationImage.delegate = self;
             }
 
             NSString *symbolName = [MGLAnnotationSpritePrefix stringByAppendingString:annotationImage.reuseIdentifier];
@@ -2687,6 +2690,17 @@ - (void)showAnnotations:(NS_ARRAY_OF(id <MGLAnnotation>) *)annotations animated:
                             animated:animated];
 }
 
+#pragma mark Annotation Image Delegate
+
+- (void)annotationImageNeedsRedisplay:(MGLAnnotationImage *)annotationImage
+{
+    // remove sprite
+    NSString *symbolName = [MGLAnnotationSpritePrefix stringByAppendingString:annotationImage.reuseIdentifier];
+    _mbglMap->removeAnnotationIcon(symbolName.UTF8String);
+    [self installAnnotationImage:annotationImage];
+    _mbglMap->update(mbgl::Update::Annotations);
+}
+
 #pragma mark - User Location -
 
 - (void)setShowsUserLocation:(BOOL)showsUserLocation

src/mbgl/annotation/annotation_manager.cpp

@@ -159,6 +159,11 @@ void AnnotationManager::addIcon(const std::string& name, std::shared_ptr<const S
     spriteStore.setSprite(name, sprite);
     spriteAtlas.updateDirty();
 }
+
+void AnnotationManager::removeIcon(const std::string& name) {
+    spriteStore.removeSprite(name);
+    spriteAtlas.updateDirty();
+}
 
 double AnnotationManager::getTopOffsetPixelsForIcon(const std::string& name) {
     auto sprite = spriteStore.getSprite(name);

src/mbgl/annotation/annotation_manager.hpp

@@ -34,6 +34,7 @@ class AnnotationManager : private util::noncopyable {
     LatLngBounds getBoundsForAnnotations(const AnnotationIDs&) const;
 
     void addIcon(const std::string& name, std::shared_ptr<const SpriteImage>);
+    void removeIcon(const std::string& name);
     double getTopOffsetPixelsForIcon(const std::string& name);
     SpriteAtlas& getSpriteAtlas() { return spriteAtlas; }
 

src/mbgl/map/map.cpp

@@ -380,7 +380,7 @@ void Map::addAnnotationIcon(const std::string& name, std::shared_ptr<const Sprit
 }
 
 void Map::removeAnnotationIcon(const std::string& name) {
-    addAnnotationIcon(name, nullptr);
+    removeAnnotationIcon(name);
 }
 
 double Map::getTopOffsetPixelsForAnnotationIcon(const std::string& symbol) {

src/mbgl/map/map_context.cpp

@@ -272,6 +272,11 @@ void MapContext::addAnnotationIcon(const std::string& name, std::shared_ptr<cons
     assert(util::ThreadContext::currentlyOn(util::ThreadType::Map));
     data.getAnnotationManager()->addIcon(name, sprite);
 }
+
+void MapContext::removeAnnotationIcon(const std::string& name) {
+    assert(util::ThreadContext::currentlyOn(util::ThreadType::Map));
+    data.getAnnotationManager()->removeIcon(name);
+}
 
 double MapContext::getTopOffsetPixelsForAnnotationIcon(const std::string& name) {
     assert(util::ThreadContext::currentlyOn(util::ThreadType::Map));
@@ -298,7 +303,7 @@ void MapContext::onLowMemory() {
     style->onLowMemory();
     asyncInvalidate.send();
 }
-
+    
 void MapContext::onTileDataChanged() {
     assert(util::ThreadContext::currentlyOn(util::ThreadType::Map));
     updateFlags |= Update::Repaint;

src/mbgl/map/map_context.hpp

@@ -52,6 +52,7 @@ class MapContext : public Style::Observer {
 
     // Annotations
     void addAnnotationIcon(const std::string&, std::shared_ptr<const SpriteImage>);
+    void removeAnnotationIcon(const std::string&);
     double getTopOffsetPixelsForAnnotationIcon(const std::string&);
     void updateAnnotations();
 

src/mbgl/sprite/sprite_atlas.cpp

@@ -187,8 +187,12 @@ void SpriteAtlas::updateDirty() {
             // The two names match;
             Holder& holder = imageIterator->second;
             holder.texture = spriteIterator->second;
-            copy(holder, imageIterator->first.second);
-
+            if (holder.texture != nullptr) {
+                copy(holder, imageIterator->first.second);
+            } else {
+                images.erase(imageIterator);
+            }
+
             ++imageIterator;
             // Don't advance the spriteIterator because there might be another sprite with the same
             // name, but a different wrap value.