Added FL_ZOOM_GESTURE gesture for OS X.

Sadly, I have not commited any code in years, and despite the rumour that
I was hit by a train, or worse, move on to Qt, here I am, commmiting unwanted
code. Hopefully there are equivalents for this on other platforms?!


git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@10656 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

FL/Enumerations.H

@@ -300,7 +300,12 @@ enum Fl_Event {	// events
   FL_SCREEN_CONFIGURATION_CHANGED = 24,
   /** The fullscreen state of the window has changed
    */
-   FL_FULLSCREEN         = 25
+  FL_FULLSCREEN         = 25,
+  /** The user has made a zoom/pinch/magnification gesture. 
+      The Fl::event_dy() method can be used to find magnification amount,
+      Fl::event_x() and Fl::event_y() are set as well.
+     */
+  FL_ZOOM_GESTURE	= 26
 };
 
 /** \name When Conditions */

src/Fl_cocoa.mm

@@ -951,6 +951,30 @@ static void cocoaMouseWheelHandler(NSEvent *theEvent)
   //  return noErr;
 }
 
+/*
+ * Cocoa Magnify Gesture Handler
+ */
+static void cocoaMagnifyHandler(NSEvent *theEvent)
+{
+  fl_lock_function();
+  Fl_Window *window = (Fl_Window*)[(FLWindow*)[theEvent window] getFl_Window];
+  if ( !window->shown() ) {
+    fl_unlock_function();
+    return;
+  }
+  Fl::first_window(window);
+  Fl::e_dy = [theEvent magnification]*1000;
+  if ( Fl::e_dy) {
+    NSPoint pos = [theEvent locationInWindow];
+    pos.y = window->h() - pos.y;
+    NSUInteger mods = [theEvent modifierFlags];
+    mods_to_e_state( mods );
+    update_e_xy_and_e_xy_root([theEvent window]);
+    Fl::handle( FL_ZOOM_GESTURE, window );
+  }
+  fl_unlock_function();
+}
+
 /*
  * Cocoa Mouse Button Handler
  */
@@ -2152,6 +2176,7 @@ static FLTextInputContext* fltextinputcontext_instance = nil;
 - (void)rightMouseDragged:(NSEvent *)theEvent;
 - (void)otherMouseDragged:(NSEvent *)theEvent;
 - (void)scrollWheel:(NSEvent *)theEvent;
+- (void)magnifyWithEvent:(NSEvent *)theEvent;
 - (void)keyDown:(NSEvent *)theEvent;
 - (void)keyUp:(NSEvent *)theEvent;
 - (void)flagsChanged:(NSEvent *)theEvent;
@@ -2276,6 +2301,9 @@ static FLTextInputContext* fltextinputcontext_instance = nil;
 - (void)scrollWheel:(NSEvent *)theEvent {
   cocoaMouseWheelHandler(theEvent);
 }
+- (void)magnifyWithEvent:(NSEvent *)theEvent {
+  cocoaMagnifyHandler(theEvent);
+}
 - (void)keyDown:(NSEvent *)theEvent {
   //NSLog(@"keyDown:%@",[theEvent characters]);
   fl_lock_function();