Identity the mouse pointer type from low-level events for Mac

content/browser/renderer_host/input/web_input_event_builders_mac.mm

Index: content/browser/renderer_host/input/web_input_event_builders_mac.mm
diff --git a/content/browser/renderer_host/input/web_input_event_builders_mac.mm b/content/browser/renderer_host/input/web_input_event_builders_mac.mm
index 2e8ea376b856638125284351bfa9cf527ce25316..dcf2ef4a8d1f3de7e275777bf475d535bd338739 100644
--- a/content/browser/renderer_host/input/web_input_event_builders_mac.mm
+++ b/content/browser/renderer_host/input/web_input_event_builders_mac.mm
@@ -663,12 +663,16 @@ blink::WebKeyboardEvent WebKeyboardEventBuilder::Build(NSEvent* event) {
 
 // WebMouseEvent --------------------------------------------------------------
 
-blink::WebMouseEvent WebMouseEventBuilder::Build(NSEvent* event, NSView* view) {
+blink::WebMouseEvent WebMouseEventBuilder::Build(
+    NSEvent* event,
+    NSView* view,
+    blink::WebPointerProperties::PointerType pointerType) {

[mustaq, 2016/06/02 15:39:12]

Please rename the |pointerType| param to |pointerTypeForEnterLeave| to make it
clear that this is used in a special case. Then move the comment on Line 736 to
above this function.

[lanwei, 2016/06/03 14:13:15]

Done.

   blink::WebMouseEvent result;
 
   result.clickCount = 0;
 
-  switch ([event type]) {
+  NSEventType type = [event type];
+  switch (type) {
     case NSMouseExited:
       result.type = blink::WebInputEvent::MouseLeave;
       result.button = blink::WebMouseEvent::ButtonNone;
@@ -729,6 +733,27 @@ blink::WebMouseEvent WebMouseEventBuilder::Build(NSEvent* event, NSView* view) {
 
   result.timeStampSeconds = [event timestamp];
 
+  // Currently, NSMouseExited and NSMouseEntered do not have the 'subtype' and
+  // 'deviceID' properties.
+  // This is a simple solution which works only for a single input device.
+  if (type == NSMouseExited || type == NSMouseEntered) {
+    // Set the pointerType based on if there is a stylus in the proximity of
+    // the tablet
+    result.pointerType = pointerType;
+    return result;
+  }
+
+  // For the mouse events and the touchpad events, the pointer type is mouse.
+  // For all tablet events, the pointer type will be just pen.
+  NSEventSubtype subtype = [event subtype];
+  if (subtype == NSTabletPointEventSubtype ||
+      subtype == NSTabletProximityEventSubtype) {
+    result.pointerType = blink::WebPointerProperties::PointerType::Pen;
+  } else {
+    result.pointerType = blink::WebPointerProperties::PointerType::Mouse;
+  }
+  result.id = [event deviceID];
+  result.force = [event pressure];
   return result;
 }