Implemented jessesquires#810: An easier way to handle custom menu actions.

Author: sebastianludwig

JSQMessagesDemo/DemoMessagesViewController.m

@@ -36,6 +36,8 @@ - (void)viewDidLoad
 {
     [super viewDidLoad];
 
+    [JSQMessagesCollectionViewCell registerMenuAction:@selector(delete:)];
+    
     self.title = @"JSQMessages";
 
     /**
@@ -502,7 +504,25 @@ - (UICollectionViewCell *)collectionView:(JSQMessagesCollectionView *)collection
     return cell;
 }
 
+#pragma mark - UICollectionView Delegate
 
+- (BOOL)collectionView:(UICollectionView *)collectionView canPerformAction:(SEL)action forItemAtIndexPath:(NSIndexPath *)indexPath withSender:(id)sender
+{
+    if (action == @selector(delete:)) {
+        return YES;
+    }
+    
+    return [super collectionView:collectionView canPerformAction:action forItemAtIndexPath:indexPath withSender:sender];
+}
+
+- (void)collectionView:(UICollectionView *)collectionView performAction:(SEL)action forItemAtIndexPath:(NSIndexPath *)indexPath withSender:(id)sender
+{
+    if (action == @selector(delete:)) {
+        NSLog(@"delegate action %@", NSStringFromSelector(action));
+    } else {
+        [super collectionView:collectionView performAction:action forItemAtIndexPath:indexPath withSender:sender];
+    }
+}
 
 #pragma mark - JSQMessages collection view flow layout delegate
 

JSQMessagesViewController/Views/JSQMessagesCollectionView.m

@@ -165,4 +165,17 @@ - (void)messagesCollectionViewCellDidTapCell:(JSQMessagesCollectionViewCell *)ce
                     touchLocation:position];
 }
 
+- (void)messagesCollectionViewCell:(JSQMessagesCollectionViewCell *)cell didPerformAction:(SEL)action withSender:(id)sender
+{
+    NSIndexPath *indexPath = [self indexPathForCell:cell];
+    if (indexPath == nil) {
+        return;
+    }
+    
+    [self.delegate collectionView:self
+                    performAction:action
+               forItemAtIndexPath:indexPath
+                       withSender:sender];
+}
+
 @end

JSQMessagesViewController/Views/JSQMessagesCollectionViewCell.h

@@ -60,6 +60,19 @@
  */
 - (void)messagesCollectionViewCellDidTapCell:(JSQMessagesCollectionViewCell *)cell atPosition:(CGPoint)position;
 
+/**
+ * Tells the delegate that an actions has been selected from the menu of this cell.
+ *
+ * @param cell The cell that displayed the menu.
+ * @param action The action that has been performed.
+ * @param sender The object that initiated the action.
+ * 
+ * @discussion This method is automatically called for any registered actions.
+ *
+ * @see `JSQMessagesCollectionViewCell`
+ */
+- (void)messagesCollectionViewCell:(JSQMessagesCollectionViewCell *)cell didPerformAction:(SEL)action withSender:(id)sender;
+
 @end
 
 
@@ -180,4 +193,12 @@
  */
 + (NSString *)mediaCellReuseIdentifier;
 
+/**
+ * Registeres an action to be available in the cell's menu. 
+ *
+ * @discussion Non-Standard actions still need to be added to the `UIMenuController`
+ * manually.
+ */
++ (void)registerMenuAction:(SEL)action;
+
 @end

JSQMessagesViewController/Views/JSQMessagesCollectionViewCell.m

@@ -66,11 +66,21 @@ - (void)jsq_updateConstraint:(NSLayoutConstraint *)constraint withConstant:(CGFl
 @end
 
 
+static NSMutableArray *jsqMessagesCollectionViewCellActions = nil;
+
 
 @implementation JSQMessagesCollectionViewCell
 
 #pragma mark - Class methods
 
++ (void)initialize
+{
+    static dispatch_once_t onceToken;
+    dispatch_once(&onceToken, ^{
+        jsqMessagesCollectionViewCellActions = [[NSMutableArray alloc] init];
+    });
+}
+
 + (UINib *)nib
 {
     return [UINib nibWithNibName:NSStringFromClass([self class]) bundle:[NSBundle bundleForClass:[self class]]];
@@ -86,6 +96,11 @@ + (NSString *)mediaCellReuseIdentifier
     return [NSString stringWithFormat:@"%@_JSQMedia", NSStringFromClass([self class])];
 }
 
++ (void)registerMenuAction:(SEL)action
+{
+    [jsqMessagesCollectionViewCellActions addObject:NSStringFromSelector(action)];
+}
+
 #pragma mark - Initialization
 
 - (void)awakeFromNib
@@ -216,6 +231,37 @@ - (void)setBounds:(CGRect)bounds
     }
 }
 
+#pragma mark - Menu actions
+
+- (BOOL)respondsToSelector:(SEL)aSelector
+{
+    if ([jsqMessagesCollectionViewCellActions containsObject:NSStringFromSelector(aSelector)]) {
+        return YES;
+    } else {
+        return [super respondsToSelector:aSelector];
+    }
+}
+
+- (void)forwardInvocation:(NSInvocation *)anInvocation
+{
+    if ([jsqMessagesCollectionViewCellActions containsObject:NSStringFromSelector(anInvocation.selector)]) {
+        id sender;
+        [anInvocation getArgument:&sender atIndex:0];
+        [self.delegate messagesCollectionViewCell:self didPerformAction:anInvocation.selector withSender:sender];
+    } else {
+        [super forwardInvocation:anInvocation];
+    }
+}
+
+- (NSMethodSignature *)methodSignatureForSelector:(SEL)aSelector
+{
+    if ([jsqMessagesCollectionViewCellActions containsObject:NSStringFromSelector(aSelector)]) {
+        return [NSMethodSignature signatureWithObjCTypes: "v@:@"];
+    } else {
+        return [super methodSignatureForSelector:aSelector];
+    }
+}
+
 #pragma mark - Setters
 
 - (void)setBackgroundColor:(UIColor *)backgroundColor