Initial touch-action main thread implementation

Source/core/page/EventHandler.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2012 Digia Plc. and/or its subsidiary(-ies)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 42 matching lines @@
 #include "core/fetch/ImageResource.h"
 #include "core/html/HTMLDialogElement.h"
 #include "core/html/HTMLFrameElementBase.h"
 #include "core/html/HTMLFrameSetElement.h"
 #include "core/html/HTMLInputElement.h"
 #include "core/loader/FrameLoader.h"
 #include "core/loader/FrameLoaderClient.h"
 #include "core/page/AutoscrollController.h"
 #include "core/page/BackForwardClient.h"
 #include "core/page/Chrome.h"
+#include "core/page/ChromeClient.h"
 #include "core/page/DragController.h"
 #include "core/page/DragState.h"
 #include "core/page/EditorClient.h"
 #include "core/page/FocusController.h"
 #include "core/frame/Frame.h"
 #include "core/page/FrameTree.h"
 #include "core/frame/FrameView.h"
 #include "core/inspector/InspectorController.h"
 #include "core/page/MouseEventWithHitTestResults.h"
 #include "core/page/Page.h"
 #include "core/page/Settings.h"
 #include "core/page/SpatialNavigation.h"
 #include "core/page/TouchAdjustment.h"
 #include "core/platform/Cursor.h"
 #include "core/platform/ScrollAnimator.h"
 #include "core/platform/Scrollbar.h"
 #include "core/platform/chromium/ChromiumDataObject.h"
 #include "core/platform/graphics/Image.h"
 #include "core/rendering/HitTestRequest.h"
 #include "core/rendering/HitTestResult.h"
 #include "core/rendering/RenderLayer.h"
 #include "core/rendering/RenderTextControlSingleLine.h"
 #include "core/rendering/RenderView.h"
 #include "core/rendering/RenderWidget.h"
 #include "core/rendering/style/CursorList.h"
+#include "core/rendering/style/RenderStyle.h"
 #include "core/svg/SVGDocument.h"
 #include "core/svg/SVGElementInstance.h"
 #include "core/svg/SVGUseElement.h"
 #include "platform/PlatformGestureEvent.h"
 #include "platform/PlatformKeyboardEvent.h"
 #include "platform/PlatformTouchEvent.h"
 #include "platform/PlatformWheelEvent.h"
 #include "platform/WindowsKeyboardCodes.h"
 #include "platform/geometry/FloatPoint.h"
 #include "wtf/Assertions.h"
@@ skipping 3524 matching lines @@
             Document& doc = node->document();
             // Record the originating touch document even if it does not have a touch listener.
             if (freshTouchEvents) {
                 m_originatingTouchPointDocument = &doc;
                 freshTouchEvents = false;
             }
             if (!doc.hasTouchEventHandlers())
                 continue;
             m_originatingTouchPointTargets.set(touchPointTargetKey, node);
             touchTarget = node;
+
+            // FIXME(rbyers): Should really be doing a second hit test that ignores inline elements - crbug.com/319479.
+            TouchAction effectiveTouchAction = computeEffectiveTouchAction(node);
+            if (effectiveTouchAction != TouchActionAuto) {
+                m_frame->page()->chrome().client().setTouchAction(point.id(), effectiveTouchAction);
+            }

[abarth-chromium, 2013/11/18 21:16:59]

No need for { }

[Rick Byers, 2013/11/19 21:24:21]

Done.

+
         } else if (pointState == PlatformTouchPoint::TouchReleased || pointState == PlatformTouchPoint::TouchCancelled) {
             // The target should be the original target for this touch, so get it from the hashmap. As it's a release or cancel
             // we also remove it from the map.
             touchTarget = m_originatingTouchPointTargets.take(touchPointTargetKey);
         } else
             // No hittest is performed on move or stationary, since the target is not allowed to change anyway.
             touchTarget = m_originatingTouchPointTargets.get(touchPointTargetKey);
 
         if (!touchTarget.get())
             continue;
@@ skipping 191 matching lines @@
 
     float magnifyDelta = exp(event.deltaY() * 0.002f);
     float newPageScaleFactor = pageScaleFactor * magnifyDelta;
 
     IntPoint anchorAfterCss(anchorBeforeDip);
     anchorAfterCss.scale(1.f / newPageScaleFactor, 1.f / newPageScaleFactor);
     page->inspectorController().requestPageScaleFactor(newPageScaleFactor, anchorBeforeCss - toIntSize(anchorAfterCss));
     return true;
 }
 
+TouchAction EventHandler::computeEffectiveTouchAction(Node* node)
+{
+    // Optimization to minimize risk of this new feature (behavior should be identical
+    // since there's no way to get non-default touch-action values).
+    if (!RuntimeEnabledFeatures::cssTouchActionEnabled())
+        return TouchActionAuto;
+
+    // Start by permitting all actions, then walk the block level elements from
+    // the target node up to the nearest scrollable ancestor and exclude any
+    // prohibited actions. For now this is trivial, but when we add more types
+    // of actions it'll get a little more complex.
+    TouchAction effectiveTouchAction = TouchActionAuto;
+
+    while (node) {
+        // The spec says only block and SVG elements get touch-action.
+        // FIXME(rbyers): Add correct support for SVG, crbug.com/247396.
+        if (node->isBlockFlowElement()) {
+            RenderObject* renderer = node->renderer();
+            if (renderer) {

[abarth-chromium, 2013/11/18 21:16:59]

You can combine this line with the previous one.

[Rick Byers, 2013/11/19 21:24:21]

Done.

+                TouchAction action = renderer->style()->touchAction();
+                if (action == TouchActionNone)
+                    effectiveTouchAction = action;
+            }
+        }
+
+        // If we've reached an ancestor that supports a touch action, search no further.
+        if (node->renderBox() && node->renderBox()->scrollsOverflow())
+            break;

[abarth-chromium, 2013/11/18 21:16:59]

I'm not sure if poking the render tree in this way is legit.  We'll need to get
help from some render tree experts.

[Rick Byers, 2013/11/19 21:24:21]

I think this is similar to what scrollNode (here in EventHandler.cpp) does for
mouse wheel and GestureScrollUpdate events - finding the appropriate renderBox
in the render tree and accessing it's state (in that case by calling
RenderBox::calling into it to scroll.  But yes, Elliott, I appreciate any input
you have here.


I think I need to add some iframe test cases though - I might not be handling
them properly (eg. iframes in multi-touch scenarios is already quite
complicated).

+
+        node = node->parentNode();
+    }
+    return effectiveTouchAction;
+}
+
 void EventHandler::setLastKnownMousePosition(const PlatformMouseEvent& event)
 {
     m_mousePositionIsUnknown = false;
     m_lastKnownMousePosition = event.position();
     m_lastKnownMouseGlobalPosition = event.globalPosition();
 }
 
 bool EventHandler::passMousePressEventToSubframe(MouseEventWithHitTestResults& mev, Frame* subframe)
 {
     // If we're clicking into a frame that is selected, the frame will appear
@@ skipping 65 matching lines @@
 unsigned EventHandler::accessKeyModifiers()
 {
 #if OS(MACOSX)
     return PlatformEvent::CtrlKey | PlatformEvent::AltKey;
 #else
     return PlatformEvent::AltKey;
 #endif
 }
 
 } // namespace WebCore