[ASMapNode] Add custom pin annotation for static maps (#1890)

* Adds possibility to have custom annotation pins on static map. This resolves #1889.

* Removes wrong example for map annotations and adds some annotations to correct map example. #1889

* Static map node now uses specific property block to get annotation views.

* Changes self to strongSelf inside of the snapshotters completion block.

* MapNode: Adds statement in documentation.

* MapNode: Block for annotation view/image now returns UIImage and center offset is returned in inout param.

* MapNode and map example: Fixes from review.

* MapNode example: Gets image directly from custom annotation, without creating annotation view.

AsyncDisplayKit/ASMapNode.h

@@ -70,6 +70,12 @@ typedef NS_OPTIONS(NSUInteger, ASMapNodeShowAnnotationsOptions)
  */
 @property (nonatomic, assign) ASMapNodeShowAnnotationsOptions showAnnotationsOptions;
 
+/**
+ * @abstract The block which should return annotation image for static map based on provided annotation.
+ * @discussion This block is executed on an arbitrary serial queue. If this block is nil, standard pin is used.
+ */
+@property (nonatomic, copy, nullable) UIImage * _Nullable (^imageForStaticMapAnnotationBlock)(id<MKAnnotation> annotation, CGPoint *centerOffset);
+
 @end
 
 NS_ASSUME_NONNULL_END

AsyncDisplayKit/ASMapNode.mm

@@ -167,6 +167,14 @@
   self.options = options;
 }
 
+- (void)setMapDelegate:(id<MKMapViewDelegate>)mapDelegate {
+  _mapDelegate = mapDelegate;
+  
+  if (_mapView) {
+    _mapView.delegate = mapDelegate;
+  }
+}
+
 #pragma mark - Snapshotter
 
 - (void)takeSnapshot
@@ -209,15 +217,27 @@
                     UIGraphicsBeginImageContextWithOptions(image.size, YES, image.scale);
                     [image drawAtPoint:CGPointZero];
                     
-                    // Get a standard annotation view pin. Future implementations should use a custom annotation image property.
-                    MKAnnotationView *pin = [[MKPinAnnotationView alloc] initWithAnnotation:nil reuseIdentifier:@""];
-                    UIImage *pinImage = pin.image;
-                    CGSize pinSize = pin.bounds.size;
+                    UIImage *pinImage;
+                    CGPoint pinCenterOffset = CGPointZero;
+                    
+                    // Get a standard annotation view pin if there is no custom annotation block.
+                    if (!strongSelf.imageForStaticMapAnnotationBlock) {
+                      pinImage = [strongSelf.class defaultPinImageWithCenterOffset:&pinCenterOffset];
+                    }
                     
                     for (id<MKAnnotation> annotation in annotations) {
+                      if (strongSelf.imageForStaticMapAnnotationBlock) {
+                        // Get custom annotation image from custom annotation block.
+                        pinImage = strongSelf.imageForStaticMapAnnotationBlock(annotation, &pinCenterOffset);
+                        if (!pinImage) {
+                          // just for case block returned nil, which can happen
+                          pinImage = [strongSelf.class defaultPinImageWithCenterOffset:&pinCenterOffset];
+                        }
+                      }
+                      
                       CGPoint point = [snapshot pointForCoordinate:annotation.coordinate];
                       if (CGRectContainsPoint(finalImageRect, point)) {
-                        CGPoint pinCenterOffset = pin.centerOffset;
+                        CGSize pinSize = pinImage.size;
                         point.x -= pinSize.width / 2.0;
                         point.y -= pinSize.height / 2.0;
                         point.x += pinCenterOffset.x;
@@ -235,6 +255,17 @@
   }];
 }
 
++ (UIImage *)defaultPinImageWithCenterOffset:(CGPoint *)centerOffset
+{
+  static MKAnnotationView *pin;
+  static dispatch_once_t onceToken;
+  dispatch_once(&onceToken, ^{
+    pin = [[MKPinAnnotationView alloc] initWithAnnotation:nil reuseIdentifier:@""];
+  });
+  *centerOffset = pin.centerOffset;
+  return pin.image;
+}
+
 - (void)setUpSnapshotter
 {
   _snapshotter = [[MKMapSnapshotter alloc] initWithOptions:self.options];

examples/ASMapNode/Sample.xcodeproj/project.pbxproj

@@ -14,13 +14,14 @@
 		694993D81C8B334F00491CA5 /* ViewController.m in Sources */ = {isa = PBXBuildFile; fileRef = 694993D71C8B334F00491CA5 /* ViewController.m */; };
 		694993DD1C8B334F00491CA5 /* Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = 694993DC1C8B334F00491CA5 /* Assets.xcassets */; };
 		694993E01C8B334F00491CA5 /* LaunchScreen.storyboard in Resources */ = {isa = PBXBuildFile; fileRef = 694993DE1C8B334F00491CA5 /* LaunchScreen.storyboard */; };
+		905C815E1D362E9400EA2625 /* CustomMapAnnotation.m in Sources */ = {isa = PBXBuildFile; fileRef = 905C815D1D362E9400EA2625 /* CustomMapAnnotation.m */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXFileReference section */
 		15AD337503831C4D33FF8B3A /* Pods-Sample.debug.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-Sample.debug.xcconfig"; path = "Pods/Target Support Files/Pods-Sample/Pods-Sample.debug.xcconfig"; sourceTree = "<group>"; };
 		465082D55CCF1B0CB1AEBACC /* libPods-Sample.a */ = {isa = PBXFileReference; explicitFileType = archive.ar; includeInIndex = 0; path = "libPods-Sample.a"; sourceTree = BUILT_PRODUCTS_DIR; };
 		5E5E62821D13F39400D81E38 /* MapHandlerNode.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MapHandlerNode.h; sourceTree = "<group>"; };
-		5E5E62831D13F39400D81E38 /* MapHandlerNode.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MapHandlerNode.m; sourceTree = "<group>"; };
+		5E5E62831D13F39400D81E38 /* MapHandlerNode.m */ = {isa = PBXFileReference; fileEncoding = 4; indentWidth = 2; lastKnownFileType = sourcecode.c.objc; path = MapHandlerNode.m; sourceTree = "<group>"; tabWidth = 2; };
 		694993CD1C8B334F00491CA5 /* Sample.app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = Sample.app; sourceTree = BUILT_PRODUCTS_DIR; };
 		694993D11C8B334F00491CA5 /* main.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = main.m; sourceTree = "<group>"; };
 		694993D31C8B334F00491CA5 /* AppDelegate.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = AppDelegate.h; sourceTree = "<group>"; };
@@ -30,6 +31,8 @@
 		694993DC1C8B334F00491CA5 /* Assets.xcassets */ = {isa = PBXFileReference; lastKnownFileType = folder.assetcatalog; path = Assets.xcassets; sourceTree = "<group>"; };
 		694993DF1C8B334F00491CA5 /* Base */ = {isa = PBXFileReference; lastKnownFileType = file.storyboard; name = Base; path = Base.lproj/LaunchScreen.storyboard; sourceTree = "<group>"; };
 		694993E11C8B334F00491CA5 /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
+		905C815C1D362E9400EA2625 /* CustomMapAnnotation.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = CustomMapAnnotation.h; sourceTree = "<group>"; };
+		905C815D1D362E9400EA2625 /* CustomMapAnnotation.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = CustomMapAnnotation.m; sourceTree = "<group>"; };
 		97482F27BE2F7583EFE1BC2C /* Pods-Sample.release.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-Sample.release.xcconfig"; path = "Pods/Target Support Files/Pods-Sample/Pods-Sample.release.xcconfig"; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
@@ -89,6 +92,8 @@
 				694993D71C8B334F00491CA5 /* ViewController.m */,
 				5E5E62821D13F39400D81E38 /* MapHandlerNode.h */,
 				5E5E62831D13F39400D81E38 /* MapHandlerNode.m */,
+				905C815C1D362E9400EA2625 /* CustomMapAnnotation.h */,
+				905C815D1D362E9400EA2625 /* CustomMapAnnotation.m */,
 				694993DC1C8B334F00491CA5 /* Assets.xcassets */,
 				694993D01C8B334F00491CA5 /* Supporting Files */,
 			);
@@ -229,6 +234,7 @@
 				694993D81C8B334F00491CA5 /* ViewController.m in Sources */,
 				694993D51C8B334F00491CA5 /* AppDelegate.m in Sources */,
 				694993D21C8B334F00491CA5 /* main.m in Sources */,
+				905C815E1D362E9400EA2625 /* CustomMapAnnotation.m in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};

examples/ASMapNode/Sample/Assets.xcassets/Contents.json

@@ -0,0 +1,6 @@
+{
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  }
+}

examples/ASMapNode/Sample/Assets.xcassets/Hill.imageset/Contents.json

@@ -0,0 +1,23 @@
+{
+  "images" : [
+    {
+      "idiom" : "universal",
+      "filename" : "hill.png",
+      "scale" : "1x"
+    },
+    {
+      "idiom" : "universal",
+      "filename" : "hill@2x.png",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "universal",
+      "filename" : "hill@3x.png",
+      "scale" : "3x"
+    }
+  ],
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  }
+}

examples/ASMapNode/Sample/Assets.xcassets/Water.imageset/Contents.json

@@ -0,0 +1,23 @@
+{
+  "images" : [
+    {
+      "idiom" : "universal",
+      "filename" : "water.png",
+      "scale" : "1x"
+    },
+    {
+      "idiom" : "universal",
+      "filename" : "water@2x.png",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "universal",
+      "filename" : "water@3x.png",
+      "scale" : "3x"
+    }
+  ],
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  }
+}

examples/ASMapNode/Sample/CustomMapAnnotation.h

@@ -0,0 +1,28 @@
+//
+//  CustomMapAnnotation.h
+//  ASDKMapTest
+//
+//  Copyright (c) 2014-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under the BSD-style license found in the
+//  LICENSE file in the root directory of this source tree. An additional grant
+//  of patent rights can be found in the PATENTS file in the same directory.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+//  FACEBOOK BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+//  ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+//  CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+//
+
+#import <Foundation/Foundation.h>
+#import <MapKit/MapKit.h>
+
+@interface CustomMapAnnotation : NSObject<MKAnnotation>
+
+@property (assign, nonatomic) CLLocationCoordinate2D coordinate;
+@property (copy, nonatomic, nullable) UIImage *image;
+@property (copy, nonatomic, nullable) NSString *title;
+@property (copy, nonatomic, nullable) NSString *subtitle;
+
+@end

examples/ASMapNode/Sample/CustomMapAnnotation.m

@@ -0,0 +1,22 @@
+//
+//  CustomMapAnnotation.m
+//  ASDKMapTest
+//
+//  Copyright (c) 2014-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under the BSD-style license found in the
+//  LICENSE file in the root directory of this source tree. An additional grant
+//  of patent rights can be found in the PATENTS file in the same directory.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+//  FACEBOOK BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+//  ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+//  CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+//
+
+#import "CustomMapAnnotation.h"
+
+@implementation CustomMapAnnotation
+
+@end

examples/ASMapNode/Sample/MapHandlerNode.m

@@ -16,6 +16,7 @@
 //
 
 #import "MapHandlerNode.h"
+#import "CustomMapAnnotation.h"
 
 #import <AsyncDisplayKit/ASDisplayNode+Subclasses.h>
 
@@ -90,6 +91,22 @@
   [_liveMapToggleButton setTitle:[self liveMapStr] withFont:nil withColor:[UIColor blueColor] forState:ASControlStateNormal];
   [_liveMapToggleButton setTitle:[self liveMapStr] withFont:[UIFont systemFontOfSize:14] withColor:[UIColor blueColor] forState:ASControlStateHighlighted];
   [_liveMapToggleButton addTarget:self action:@selector(toggleLiveMap) forControlEvents:ASControlNodeEventTouchUpInside];
+  
+  // avoiding retain cycles
+  __weak MapHandlerNode *weakSelf = self;
+  
+  self.mapNode.imageForStaticMapAnnotationBlock = ^UIImage *(id<MKAnnotation> annotation, CGPoint *centerOffset){
+    MapHandlerNode *grabbedSelf = weakSelf;
+    if (grabbedSelf) {
+      if ([annotation isKindOfClass:[CustomMapAnnotation class]]) {
+        CustomMapAnnotation *customAnnotation = (CustomMapAnnotation *)annotation;
+        return customAnnotation.image;
+      }
+    }
+    return nil;
+  };
+  
+  [self addAnnotations];
 }
 
 #pragma mark - Layout
@@ -183,6 +200,30 @@
 
 #pragma mark - Helpers
 
+- (void)addAnnotations {
+  
+  MKPointAnnotation *brno = [MKPointAnnotation new];
+  brno.coordinate = CLLocationCoordinate2DMake(49.2002211, 16.6078411);
+  brno.title = @"Brno city";
+  
+  CustomMapAnnotation *atlantic = [CustomMapAnnotation new];
+  atlantic.coordinate = CLLocationCoordinate2DMake(38.6442228, -29.9956942);
+  atlantic.title = @"Atlantic ocean";
+  atlantic.image = [UIImage imageNamed:@"Water"];
+  
+  CustomMapAnnotation *kilimanjaro = [CustomMapAnnotation new];
+  kilimanjaro.coordinate = CLLocationCoordinate2DMake(-3.075833, 37.353333);
+  kilimanjaro.title = @"Kilimanjaro";
+  kilimanjaro.image = [UIImage imageNamed:@"Hill"];
+  
+  CustomMapAnnotation *mtblanc = [CustomMapAnnotation new];
+  mtblanc.coordinate = CLLocationCoordinate2DMake(45.8325, 6.864444);
+  mtblanc.title = @"Mont Blanc";
+  mtblanc.image = [UIImage imageNamed:@"Hill"];
+  
+  self.mapNode.annotations = @[brno, atlantic, kilimanjaro, mtblanc];
+}
+
 -(NSString *)liveMapStr
 {
   return _mapNode.liveMap ? @"Live Map is ON" : @"Live Map is OFF";
@@ -235,6 +276,21 @@
   return YES;
 }
 
+- (MKAnnotationView *)annotationViewForAnnotation:(id<MKAnnotation>)annotation
+{
+  MKAnnotationView *av;
+  if ([annotation isKindOfClass:[CustomMapAnnotation class]]) {
+    av = [[MKAnnotationView alloc] init];
+    av.centerOffset = CGPointMake(21, 21);
+    av.image = [(CustomMapAnnotation *)annotation image];
+  } else {
+    av = [[MKPinAnnotationView alloc] initWithAnnotation:nil reuseIdentifier:@""];
+  }
+  
+  av.opaque = NO;
+  return av;
+}
+
 #pragma mark - MKMapViewDelegate
 
 - (void)mapView:(MKMapView *)mapView regionDidChangeAnimated:(BOOL)animated {
@@ -244,4 +300,9 @@
   _deltaLonEditableNode.attributedText = [[NSAttributedString alloc] initWithString:[NSString stringWithFormat:@"%f", mapView.region.span.longitudeDelta]];
 }
 
+- (MKAnnotationView *)mapView:(MKMapView *)__unused mapView viewForAnnotation:(id<MKAnnotation>)annotation
+{
+  return [self annotationViewForAnnotation:annotation];
+}
+
 @end