Bug 69787. Implement MouseEvent.offsetX/Y. r=mats,smaug

--HG-- extra : rebase_source : 0120fa29fb94c1c2f992b4e3bae63c5120b90f4b
2015-03-14 00:50:10 +13:00 · 2015-03-14 00:50:10 +13:00 · 843379803a
--- a/dom/events/Event.cpp
+++ b/dom/events/Event.cpp
@ -959,7 +959,6 @@ Event::GetClientCoords(nsPresContext* aPresContext,
  if (!shell) {
    return CSSIntPoint(0, 0);
  }
-
  nsIFrame* rootFrame = shell->GetRootFrame();
  if (!rootFrame) {
    return CSSIntPoint(0, 0);
@ -970,6 +969,44 @@ Event::GetClientCoords(nsPresContext* aPresContext,
  return CSSIntPoint::FromAppUnitsRounded(pt);
 }

+// static
+CSSIntPoint
+Event::GetOffsetCoords(nsPresContext* aPresContext,
+                       WidgetEvent* aEvent,
+                       LayoutDeviceIntPoint aPoint,
+                       CSSIntPoint aDefaultPoint)
+{
+  if (!aEvent->mFlags.mIsBeingDispatched) {
+    return GetPageCoords(aPresContext, aEvent, aPoint, aDefaultPoint);
+  }
+  nsCOMPtr<nsIContent> content = do_QueryInterface(aEvent->target);
+  if (!content) {
+    return CSSIntPoint(0, 0);
+  }
+  nsCOMPtr<nsIPresShell> shell = aPresContext->GetPresShell();
+  if (!shell) {
+    return CSSIntPoint(0, 0);
+  }
+  shell->FlushPendingNotifications(Flush_Layout);
+  nsIFrame* frame = content->GetPrimaryFrame();
+  if (!frame) {
+    return CSSIntPoint(0, 0);
+  }
+  nsIFrame* rootFrame = shell->GetRootFrame();
+  if (!rootFrame) {
+    return CSSIntPoint(0, 0);
+  }
+  CSSIntPoint clientCoords =
+    GetClientCoords(aPresContext, aEvent, aPoint, aDefaultPoint);
+  nsPoint pt = CSSPixel::ToAppUnits(clientCoords);
+  if (nsLayoutUtils::TransformPoint(rootFrame, frame, pt) ==
+      nsLayoutUtils::TRANSFORM_SUCCEEDED) {
+    pt -= frame->GetPaddingRectRelativeToSelf().TopLeft();
+    return CSSPixel::FromAppUnitsRounded(pt);
+  }
+  return CSSIntPoint(0, 0);
+}
+
 // To be called ONLY by Event::GetType (which has the additional
 // logic for handling user-defined events).
 // static
--- a/dom/events/Event.h
+++ b/dom/events/Event.h
@ -141,6 +141,10 @@ public:
  static LayoutDeviceIntPoint GetScreenCoords(nsPresContext* aPresContext,
                                              WidgetEvent* aEvent,
                                              LayoutDeviceIntPoint aPoint);
+  static CSSIntPoint GetOffsetCoords(nsPresContext* aPresContext,
+                                     WidgetEvent* aEvent,
+                                     LayoutDeviceIntPoint aPoint,
+                                     CSSIntPoint aDefaultPoint);

  static already_AddRefed<Event> Constructor(const GlobalObject& aGlobal,
                                             const nsAString& aType,
--- a/dom/events/MouseEvent.cpp
+++ b/dom/events/MouseEvent.cpp
@ -386,6 +386,20 @@ MouseEvent::ClientY()
                                mClientPoint).y;
 }

+int32_t
+MouseEvent::OffsetX()
+{
+  return Event::GetOffsetCoords(mPresContext, mEvent, mEvent->refPoint,
+                                mClientPoint).x;
+}
+
+int32_t
+MouseEvent::OffsetY()
+{
+  return Event::GetOffsetCoords(mPresContext, mEvent, mEvent->refPoint,
+                                mClientPoint).y;
+}
+
 bool
 MouseEvent::AltKey()
 {
--- a/dom/events/MouseEvent.h
+++ b/dom/events/MouseEvent.h
@ -45,6 +45,8 @@ public:
  int32_t ScreenY();
  int32_t ClientX();
  int32_t ClientY();
+  int32_t OffsetX();
+  int32_t OffsetY();
  bool CtrlKey();
  bool ShiftKey();
  bool AltKey();
--- a/dom/events/test/mochitest.ini
+++ b/dom/events/test/mochitest.ini
@ -182,3 +182,4 @@ skip-if = buildapp == 'b2g' || e10s
 [test_bug1096146.html]
 support-files =
  bug1096146_embedded.html
+[test_offsetxy.html]
--- a/dom/events/test/test_offsetxy.html
+++ b/dom/events/test/test_offsetxy.html
@ -0,0 +1,73 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for DOM MouseEvent offsetX/Y</title>
+  <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+<p id="display"></p>
+<div id="content" style="display: none">
+
+</div>
+<div id="d" style="position:absolute; top:100px; left:100px; width:100px; border:5px dotted black; height:100px"></div>
+<div id="d2" style="position:absolute; top:100px; left:100px; width:100px; border:5px dotted black; height:100px; transform:translateX(100px)"></div>
+<div id="d3" style="display:none; position:absolute; top:100px; left:100px; width:100px; border:5px dotted black; height:100px"></div>
+<div id="d4" style="transform:scale(0); position:absolute; top:100px; left:100px; width:100px; border:5px dotted black; height:100px"></div>
+
+<pre id="test">
+<script type="application/javascript">
+
+var offsetX = -1, offsetY = -1;
+var ev = new MouseEvent("click", {clientX:110, clientY:110});
+d.addEventListener("click", function (event) {
+  is(ev, event, "Event objects must match");
+  offsetX = event.offsetX;
+  offsetY = event.offsetY;
+});
+d.dispatchEvent(ev);
+is(offsetX, 5);
+is(offsetY, 5);
+is(ev.offsetX, ev.pageX);
+is(ev.offsetY, ev.pageY);
+
+var ev2 = new MouseEvent("click", {clientX:220, clientY:130});
+d2.addEventListener("click", function (event) {
+  is(ev2, event, "Event objects must match");
+  offsetX = event.offsetX;
+  offsetY = event.offsetY;
+});
+d2.dispatchEvent(ev2);
+is(offsetX, 15);
+is(offsetY, 25);
+is(ev2.offsetX, ev2.pageX);
+is(ev2.offsetY, ev2.pageY);
+
+var ev3 = new MouseEvent("click", {clientX:110, clientY:110});
+d3.addEventListener("click", function (event) {
+  is(ev3, event, "Event objects must match");
+  offsetX = event.offsetX;
+  offsetY = event.offsetY;
+});
+d3.dispatchEvent(ev3);
+is(offsetX, 0);
+is(offsetY, 0);
+is(ev3.offsetX, ev3.pageX);
+is(ev3.offsetY, ev3.pageY);
+
+var ev4 = new MouseEvent("click", {clientX:110, clientY:110});
+d4.addEventListener("click", function (event) {
+  is(ev4, event, "Event objects must match");
+  offsetX = event.offsetX;
+  offsetY = event.offsetY;
+});
+d4.dispatchEvent(ev4);
+is(offsetX, 0);
+is(offsetY, 0);
+is(ev4.offsetX, ev4.pageX);
+is(ev4.offsetY, ev4.pageY);
+
+</script>
+</pre>
+</body>
+</html>
--- a/dom/webidl/MouseEvent.webidl
+++ b/dom/webidl/MouseEvent.webidl
@ -15,6 +15,8 @@ interface MouseEvent : UIEvent {
  readonly attribute long           screenY;
  readonly attribute long           clientX;
  readonly attribute long           clientY;
+  readonly attribute long           offsetX;
+  readonly attribute long           offsetY;
  readonly attribute boolean        ctrlKey;
  readonly attribute boolean        shiftKey;
  readonly attribute boolean        altKey;
--- a/layout/base/nsLayoutUtils.cpp
+++ b/layout/base/nsLayoutUtils.cpp
@ -2403,8 +2403,8 @@ nsLayoutUtils::TransformPoint(nsIFrame* aFromFrame, nsIFrame* aToFrame,
    // coordinate space.
    return NONINVERTIBLE_TRANSFORM;
  }
-  aPoint.x = toDevPixels.x / devPixelsPerAppUnitToFrame;
-  aPoint.y = toDevPixels.y / devPixelsPerAppUnitToFrame;
+  aPoint.x = NSToCoordRound(toDevPixels.x / devPixelsPerAppUnitToFrame);
+  aPoint.y = NSToCoordRound(toDevPixels.y / devPixelsPerAppUnitToFrame);
  return TRANSFORM_SUCCEEDED;
 }

--- a/widget/tests/test_assign_event_data.html
+++ b/widget/tests/test_assign_event_data.html
@ -593,6 +593,9 @@ function doTest(aTest)
        is(gEvent[name], null, description + ": mismatch with fixed value (" + name + ")");
      } else if (aTest.todoMismatch.indexOf(name) >= 0) {
        todo_is(gEvent[name], gCopiedEvent[i].value, description + ": mismatch (" + name + ")");
+      } else if (name == "offsetX" || name == "offsetY") {
+        // do nothing; these are defined to return different values during event dispatch
+        // vs not during event dispatch
      } else {
        is(gEvent[name], gCopiedEvent[i].value, description + ": mismatch (" + name + ")");
      }