Don't send mouse events if we have touch support

Unfortunately, using stopPropagation() and preventDefault() does
not stop the mouse events from being sent for a touch. So we have
to assume that they will be handled by Qt one way or the other and
only send mouse events if we can tell that we are not on a touch
screen or that the mouse event was not synthesized by WebGL.

This was tested on a Windows host with an iPad and Microsoft Edge
to verify it works in both cases correctly.

Change-Id: Ia2297062b2e1a4894f52954dd567bab5b7df8fa1
Reviewed-by: Jesus Fernandez <[email protected]>

Author: AndyShawQt

src/plugins/platforms/webgl/webqt.jsx

@@ -54,6 +54,8 @@ window.onload = function () {
     var currentZIndex = 1;
     var textDecoder;
     var initialLoadingCanvas;
+    var supportsTouch = 'ontouchstart' in window || navigator.msMaxTouchPoints;
+
     if (typeof TextDecoder !== 'undefined') {
         textDecoder = new TextDecoder("utf8");
     } else {
@@ -227,19 +229,25 @@ window.onload = function () {
 
         canvas.onmousedown = function (event) {
             /* jslint bitwise: true */
+            if (supportsTouch && event.mozInputSource == MOZ_SOURCE_TOUCH)
+                return;
             qtButtons |= mapButton(event.button);
             sendMouseEvent(qtButtons, event.layerX, event.layerY, event.clientX, event.clientY,
                            name);
         };
 
         canvas.onmousemove = function (event) {
+            if (supportsTouch && event.mozInputSource == MOZ_SOURCE_TOUCH)
+                return;
             if (MOUSETRACKING || event.buttons > 0)
                 sendMouseEvent(qtButtons, event.layerX, event.layerY, event.clientX, event.clientY,
                                name);
         };
 
         canvas.onmouseup = function (event) {
             /* jslint bitwise: true */
+            if (supportsTouch && event.mozInputSource == MOZ_SOURCE_TOUCH)
+                return;
             qtButtons &= ~mapButton(event.button);
             sendMouseEvent(qtButtons, event.layerX, event.layerY, event.clientX, event.clientY,
                            name);