Support Force click gesture. Can now map <ForceClick> gesture in MacVim

Can now map "<ForceClick>" similar to "<SwipeLeft/Right/Up/Down>"
gestures. Require a Mac that has a touchpad that supports Force Touch to
work.

Close #672

Author: ychin

runtime/doc/gui_mac.txt

@@ -633,6 +633,10 @@ Each gesture generates one of the following Vim pseudo keys:
 	Generated when swiping three fingers across the trackpad in a
 	vertical direction.  (Not supported by the Apple Magic Mouse.)
 
+						 *<ForceClick>*
+	Generated when doing a Force click by pressing hard on a trackpad.
+	(Only supported on trackpads that support Force Touch.)
+
 You can map these keys like with any other key using the |:map| family of
 commands.  For example, the following commands map left/right swipe to change
 to the previous/next tab in normal mode: >

runtime/doc/tags

@@ -3415,6 +3415,7 @@ $VIM_POSIX	vi_diff.txt	/*$VIM_POSIX*
 <F7>	term.txt	/*<F7>*
 <F8>	term.txt	/*<F8>*
 <F9>	term.txt	/*<F9>*
+<ForceClick>	gui_mac.txt	/*<ForceClick>*
 <Help>	helphelp.txt	/*<Help>*
 <Home>	motion.txt	/*<Home>*
 <Insert>	insert.txt	/*<Insert>*

src/MacVim/MMBackend.m

@@ -3004,6 +3004,7 @@ - (void)handleGesture:(NSData *)data
         case MMGestureSwipeRight:   string[5] = KE_SWIPERIGHT;	break;
         case MMGestureSwipeUp:	    string[5] = KE_SWIPEUP;	break;
         case MMGestureSwipeDown:    string[5] = KE_SWIPEDOWN;	break;
+        case MMGestureForceClick:   string[5] = KE_FORCECLICK;	break;
         default: return;
     }
 

src/MacVim/MMCoreTextView.m

@@ -556,6 +556,11 @@ - (void)swipeWithEvent:(NSEvent *)event
     [helper swipeWithEvent:event];
 }
 
+- (void)pressureChangeWithEvent:(NSEvent *)event
+{
+    [helper pressureChangeWithEvent:event];
+}
+
 - (NSMenu*)menuForEvent:(NSEvent *)event
 {
     // HACK! Return nil to disable default popup menus (Vim provides its own).

src/MacVim/MMTextView.m

@@ -795,6 +795,11 @@ - (void)swipeWithEvent:(NSEvent *)event
     [helper swipeWithEvent:event];
 }
 
+- (void)pressureChangeWithEvent:(NSEvent *)event
+{
+    [helper pressureChangeWithEvent:event];
+}
+
 - (NSMenu*)menuForEvent:(NSEvent *)event
 {
     // HACK! Return nil to disable NSTextView's popup menus (Vim provides its

src/MacVim/MMTextViewHelper.h

@@ -65,6 +65,7 @@
 - (void)mouseDragged:(NSEvent *)event;
 - (void)mouseMoved:(NSEvent *)event;
 - (void)swipeWithEvent:(NSEvent *)event;
+- (void)pressureChangeWithEvent:(NSEvent *)event;
 - (BOOL)performDragOperation:(id <NSDraggingInfo>)sender;
 - (NSDragOperation)draggingEntered:(id <NSDraggingInfo>)sender;
 - (NSDragOperation)draggingUpdated:(id <NSDraggingInfo>)sender;

src/MacVim/MMTextViewHelper.m

@@ -477,6 +477,20 @@ - (void)swipeWithEvent:(NSEvent *)event
     [self sendGestureEvent:type flags:[event modifierFlags]];
 }
 
+- (void)pressureChangeWithEvent:(NSEvent *)event
+{
+    static BOOL inForceClick = NO;
+    if (event.stage >= 2) {
+        if (!inForceClick) {
+            inForceClick = YES;
+            
+            [self sendGestureEvent:MMGestureForceClick flags:[event modifierFlags]];
+        }
+    } else {
+        inForceClick = NO;
+    }
+}
+
 - (BOOL)performDragOperation:(id <NSDraggingInfo>)sender
 {
     NSPasteboard *pboard = [sender draggingPasteboard];

src/MacVim/MacVim.h

@@ -296,6 +296,7 @@ enum {
     MMGestureSwipeRight,
     MMGestureSwipeUp,
     MMGestureSwipeDown,
+    MMGestureForceClick,
 };
 
 

src/edit.c

@@ -1264,6 +1264,7 @@ edit(
 	case K_SWIPERIGHT:
 	case K_SWIPEUP:
 	case K_SWIPEDOWN:
+	case K_FORCECLICK:
 	    break;
 # endif
 #endif
@@ -3896,7 +3897,7 @@ ins_compl_prep(int c)
 	    || c == K_MOUSELEFT || c == K_MOUSERIGHT
 # ifdef FEAT_GUI_MACVIM
 	    || c == K_SWIPELEFT || c == K_SWIPERIGHT || c == K_SWIPEUP
-	    || c == K_SWIPEDOWN
+	    || c == K_SWIPEDOWN || c == K_FORCECLICK
 # endif
 		    )
 	return retval;

src/evalfunc.c

@@ -4744,6 +4744,7 @@ f_getchar(typval_T *argvars, typval_T *rettv)
 		|| n == K_SWIPERIGHT
 		|| n == K_SWIPEUP
 		|| n == K_SWIPEDOWN
+		|| n == K_FORCECLICK
 # endif
 	   )
 	{