Move UIEvent.pageX/pageY/layerX/layerY to MouseEvent

Source/core/events/MouseEvent.idl

Index: Source/core/events/MouseEvent.idl
diff --git a/Source/core/events/MouseEvent.idl b/Source/core/events/MouseEvent.idl
index 21c0a2fd5059112c134a1d412a885c598ed4e266..095181695091bbe3593fc38a776b035307af7ec8 100644
--- a/Source/core/events/MouseEvent.idl
+++ b/Source/core/events/MouseEvent.idl
@@ -25,6 +25,8 @@
 ] interface MouseEvent : UIEvent {
     readonly attribute long             screenX;
     readonly attribute long             screenY;
+    readonly attribute long             pageX;

[Rick Byers, 2015/06/23 19:33:00]

nit: Philip has been trying to align the interfaces with the specs.  Please move
these to a new section below with a comment referencing
http://www.w3.org/TR/cssom-view/#extensions-to-the-mouseevent-interface

[dtapuska, 2015/06/23 19:36:39]

I was trying to keep the idl matching the spec (for ordering).

I'd argue that this class needs to be re-organized to match that; I can put that
reference to the spec above screenX...

and move the x,y,offsetX,offsetY from the Non-standard section.

[Rick Byers, 2015/06/23 19:44:46]

The official home of this event definition is
https://w3c.github.io/uievents/#interface-MouseEvent (which is the top-level
comment for this file).

CSSOM View defines some changes / extensions (mostly, I assume, because CSSOM
View is where fractional positioning comes from).  Until the time that we switch
to 'double', we're really implemewnting the UIEvents version of this API.

So I'd suggest putting pageX/pageY, offsetX,offsetY and x,y in a new section
referencing the CSSOM View spec with a "TODO: Should be double instead of long
(http://crbug.com/456625)".

Or if you prefer you can ALL the co-ordinate members down into the new CSSOM
View section (ordered as in that spec).  But hopefully the UIEvents spec will
eventually be updated to incorporate the improvements and additions from CSSOM
View.

[philipj_slow, 2015/07/01 14:17:46]

I made a mistake when cleaning up this file, I missed that CSSOM View defines
some of what I documented as non-standard. I've rectified this in
https://codereview.chromium.org/1214923005/ which I hope will land soon. (Rick,
maybe you can LGTM and CQ if Jens isn't around?)

When that lands, this CL should be a matter of moving pageX/Y into that new
section, and layerX/Y into the non-standard section.

[dtapuska, 2015/07/02 17:32:35]

Done.

+    readonly attribute long             pageY;
     readonly attribute long             clientX;
     readonly attribute long             clientY;
     readonly attribute boolean          ctrlKey;
@@ -69,6 +71,8 @@
     [MeasureAs=MouseEventWhich] readonly attribute long which;
     [DeprecateAs=PrefixedMouseEventMovementX, ImplementedAs=movementX] readonly attribute long webkitMovementX;
     [DeprecateAs=PrefixedMouseEventMovementY, ImplementedAs=movementY] readonly attribute long webkitMovementY;
+    [MeasureAs=MouseEventLayerX] readonly attribute long layerX;

[philipj_slow, 2015/07/01 14:17:46]

I would suggest just using [Measure] and using the generated names. (It's
newish, so you don't see it everywhere.)

[dtapuska, 2015/07/02 17:32:35]

Done.

+    [MeasureAs=MouseEventLayerY] readonly attribute long layerY;
 
     // FIXME: dataTransfer belongs on the DragEvent interface. crbug.com/498504
     readonly attribute DataTransfer dataTransfer;