Extract more of the mouse logic from EventHandler

third_party/WebKit/Source/core/input/EventHandlingUtil.cpp

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/input/EventHandlingUtil.h"
 
 #include "core/frame/FrameView.h"
 #include "core/layout/api/LayoutViewItem.h"
 
 namespace blink {
@@ skipping 41 matching lines @@
     case DispatchEventResult::CanceledByDefaultEventHandler:
         return WebInputEventResult::HandledSystem;
     case DispatchEventResult::CanceledBeforeDispatch:
         return WebInputEventResult::HandledSuppressed;
     default:
         NOTREACHED();
         return WebInputEventResult::HandledSystem;
     }
 }
 
+PaintLayer* layerForNode(Node* node)
+{
+    if (!node)
+        return nullptr;
+
+    LayoutObject* layoutObject = node->layoutObject();
+    if (!layoutObject)
+        return nullptr;
+
+    PaintLayer* layer = layoutObject->enclosingLayer();
+    if (!layer)
+        return nullptr;
+
+    return layer;
+}
+
+ScrollableArea* associatedScrollableArea(const PaintLayer* layer)
+{
+    if (PaintLayerScrollableArea* scrollableArea = layer->getScrollableArea()) {
+        if (scrollableArea->scrollsOverflow())
+            return scrollableArea;
+    }
+
+    return nullptr;
+}
+
+ContainerNode* parentForClickEvent(const Node& node)
+{
+    // IE doesn't dispatch click events for mousedown/mouseup events across form
+    // controls.
+    if (node.isHTMLElement() && toHTMLElement(node).isInteractiveContent())
+        return nullptr;
+
+    return FlatTreeTraversal::parent(node);
+}
+
+LayoutPoint contentPointFromRootFrame(LocalFrame* frame, const IntPoint& pointInRootFrame)
+{
+    FrameView* view = frame->view();
+    // FIXME: Is it really OK to use the wrong coordinates here when view is 0?
+    // Historically the code would just crash; this is clearly no worse than that.
+    return view ? view->rootFrameToContents(pointInRootFrame) : pointInRootFrame;
+}
+
+MouseEventWithHitTestResults prepareMouseEvent(LocalFrame* frame,

[mustaq, 2016/09/21 17:28:14]

This has been a misnomer. Please rename to something meaningful:
performMouseEventHitTest?

Also rename Document::prepareMouseEvent. This looks too long:
performMouseEventHitTestAtGivenLocation. Any better idea? 

[Navid Zolghadr, 2016/09/22 12:24:29]

How about the same name? Document::performMouseEventHitTest?

[Navid Zolghadr, 2016/09/23 11:11:16]

Done.

+    const HitTestRequest& request, const PlatformMouseEvent& mev)
+{
+    DCHECK(frame);
+    DCHECK(frame->document());
+
+    return frame->document()->prepareMouseEvent(request, contentPointFromRootFrame(frame, mev.position()), mev);
+}
+
 } // namespace EventHandlingUtil
 } // namespace blink