Multitouch trackpad 2 fingers gestures implementation

- 2 fingers scroll (MOUSEPAN / GHOST_kTrackpadEventScroll event) pans/scrolls the view
- 2 fingers pinch (MOUSEZOOM / GHOST_kTrackpadEventMagnify event) zooms the view
And in 3D view:
- alt + 2 fingers scroll rotates the view
- 2 fingers rotation (MOUSEROTATE / GHOST_kTrackpadEventRotate) orbits the view.

The implementation uses a new GHOST event type: GHOST_kEventTrackpad, that is then dispatched as Blender MOUSEPAN, MOUSEZOOM
or MOUSEROTATE events.

This is currently fully implemented for OSX (GHOST Cocoa fires the new events), with auto-detection of the source peripheral, so that a regular mouse still sends MOUSEWHEEL events.

2 files changed, 35 insertions, 19 deletions

diff --git a/source/blender/editors/space_text/space_text.c b/source/blender/editors/space_text/space_text.c
index 292249bb0e8..c7601ef692e 100644
--- a/source/blender/editors/space_text/space_text.c
+++ b/source/blender/editors/space_text/space_text.c
@@ -313,6 +313,7 @@ static void text_keymap(struct wmKeyConfig *keyconf)
 	WM_keymap_add_item(keymap, "TEXT_OT_overwrite_toggle", INSERTKEY, KM_PRESS, 0, 0);
 
 	WM_keymap_add_item(keymap, "TEXT_OT_scroll", MIDDLEMOUSE, KM_PRESS, 0, 0);
+	WM_keymap_add_item(keymap, "TEXT_OT_scroll", MOUSEPAN, 0, 0, 0);
 	WM_keymap_add_item(keymap, "TEXT_OT_scroll_bar", LEFTMOUSE, KM_PRESS, 0, 0);
 	WM_keymap_add_item(keymap, "TEXT_OT_cursor_set", LEFTMOUSE, KM_PRESS, 0, 0);
 	RNA_boolean_set(WM_keymap_add_item(keymap, "TEXT_OT_cursor_set", LEFTMOUSE, KM_PRESS, KM_SHIFT, 0)->ptr, "select", 1);
diff --git a/source/blender/editors/space_text/text_ops.c b/source/blender/editors/space_text/text_ops.c
index 0504db51a72..e5a1e772523 100644
--- a/source/blender/editors/space_text/text_ops.c
+++ b/source/blender/editors/space_text/text_ops.c
@@ -1720,25 +1720,6 @@ static int scroll_exec(bContext *C, wmOperator *op)
 	return OPERATOR_FINISHED;
 }
 
-static int scroll_invoke(bContext *C, wmOperator *op, wmEvent *event)
-{
-	SpaceText *st= CTX_wm_space_text(C);
-	TextScroll *tsc;
-
-	if(RNA_property_is_set(op->ptr, "lines"))
-		return scroll_exec(C, op);
-	
-	tsc= MEM_callocN(sizeof(TextScroll), "TextScroll");
-	tsc->first= 1;
-	op->customdata= tsc;
-	
-	st->flags|= ST_SCROLL_SELECT;
-
-	WM_event_add_modal_handler(C, op);
-
-	return OPERATOR_RUNNING_MODAL;
-}
-
 static void scroll_apply(bContext *C, wmOperator *op, wmEvent *event)
 {
 	SpaceText *st= CTX_wm_space_text(C);
@@ -1816,6 +1797,40 @@ static int scroll_cancel(bContext *C, wmOperator *op)
 	return OPERATOR_CANCELLED;
 }
 
+static int scroll_invoke(bContext *C, wmOperator *op, wmEvent *event)
+{
+	SpaceText *st= CTX_wm_space_text(C);
+	TextScroll *tsc;
+	
+	if(RNA_property_is_set(op->ptr, "lines"))
+		return scroll_exec(C, op);
+	
+	tsc= MEM_callocN(sizeof(TextScroll), "TextScroll");
+	tsc->first= 1;
+	op->customdata= tsc;
+	
+	st->flags|= ST_SCROLL_SELECT;
+	
+	if (event->type == MOUSEPAN) {
+		text_update_character_width(st);
+		
+		tsc->hold[0] = event->prevx;
+		tsc->hold[1] = event->prevy;
+		/* Sensitivity of scroll set to 4pix per line/char */
+		event->mval[0] = event->prevx + (event->x - event->prevx)*st->cwidth/4;
+		event->mval[1] = event->prevy + (event->y - event->prevy)*st->lheight/4;
+		tsc->first = 0;
+		tsc->scrollbar = 0;
+		scroll_apply(C, op, event);
+		scroll_exit(C, op);
+		return OPERATOR_FINISHED;
+	}	
+	
+	WM_event_add_modal_handler(C, op);
+	
+	return OPERATOR_RUNNING_MODAL;
+}
+
 void TEXT_OT_scroll(wmOperatorType *ot)
 {
 	/* identifiers */