New media playback UI.

Source/core/html/shadow/SliderThumbElement.cpp

Index: Source/core/html/shadow/SliderThumbElement.cpp
diff --git a/Source/core/html/shadow/SliderThumbElement.cpp b/Source/core/html/shadow/SliderThumbElement.cpp
index 39043fdfaee819c22262c81b6e86d99c67c3ac6c..d5071c2917bd75bc3acf827c3caf371f5e8038b1 100644
--- a/Source/core/html/shadow/SliderThumbElement.cpp
+++ b/Source/core/html/shadow/SliderThumbElement.cpp
@@ -62,6 +62,7 @@ inline static bool hasVerticalAppearance(HTMLInputElement* input)
 inline SliderThumbElement::SliderThumbElement(Document& document)
     : HTMLDivElement(document)
     , m_inDragMode(false)
+    , m_didDragAnywhere(false)
 {
 }
 
@@ -169,6 +170,10 @@ void SliderThumbElement::setPositionFromPoint(const LayoutPoint& point)
     input->setValueFromRenderer(valueString);
     if (layoutObject())
         layoutObject()->setNeedsLayoutAndFullPaintInvalidation(LayoutInvalidationReason::SliderValueChanged);
+
+    // We actually changed the value as part of a drag.
+    if (m_inDragMode)
+        m_didDragAnywhere = true;
 }
 
 void SliderThumbElement::startDragging()
@@ -176,6 +181,7 @@ void SliderThumbElement::startDragging()
     if (LocalFrame* frame = document().frame()) {
         frame->eventHandler().setCapturingMouseEventsNode(this);
         m_inDragMode = true;
+        m_didDragAnywhere = false;
     }
 }
 
@@ -217,10 +223,19 @@ void SliderThumbElement::defaultEventHandler(Event* event)
     // MediaControlTimelineElement::defaultEventHandler() wants to handle these
     // mouse events.
     if (eventType == EventTypeNames::mousedown && isLeftButton) {
+
+        m_mouseDownLocation = mouseEvent->absoluteLocation();
         startDragging();
         return;
     } else if (eventType == EventTypeNames::mouseup && isLeftButton) {
+        if (m_inDragMode && !m_didDragAnywhere && isMediaSlider()) {
+            // We got a down / up with no drag in between, and we're a media

[philipj_slow, 2015/07/21 12:02:21]

I don't think this is quite right. When you click anywhere outside the slider,
the position is updated on mousedown and then you can drag with the "thumb
element" centered under the mouse/touch point. This also seems to be the
behavior of YouTube.

I think the desired behavior can be implemented by removing the |targetNode !=
element()| bit from RangeInputType::handleMouseDownEvent and thus not have any
changes to this file.

If you would like to limit the change to the media controls, please add a TODO
and a bug to do it after a Blink roll or two, so that it can be separated out in
a bisect, but to leave the difference indefinitely seems strange.

[liberato (no reviews please), 2015/07/27 20:26:09]

i agree in principle, but i don't have enough experience to say whether the
broader change is okay.  since you do, and since you seem fairly confident that
it is okay, i'll do it now.

[philipj_slow, 2015/07/28 15:23:49]

It definitely is possible that the change will result in bug reports, and if
that happens let's hope we remember that this was part of the CL. Perhaps
mention it in the description. If you're more paranoid, you could also do it in
a separate CL before or after this.

[liberato (no reviews please), 2015/07/30 05:54:23]

i've reverted all of this, since we're now shipping android only.  desktop is
deferred.  android doesn't have the issue, since touch events in RangeInputType
don't care about the thumb.

i can put together a separate CL to change the slider behavior, which will also
make me feel better.  :)

+            // slider.  Jump to the touch down.
+            setPositionFromPoint(m_mouseDownLocation);
+        }
+
         stopDragging();
+
         return;
     } else if (eventType == EventTypeNames::mousemove) {
         if (m_inDragMode)
@@ -277,11 +292,11 @@ static const AtomicString& mediaSliderThumbShadowPartId()
     return mediaSliderThumb;
 }
 
-const AtomicString& SliderThumbElement::shadowPseudoId() const
+bool SliderThumbElement::isMediaSlider() const
 {
     HTMLInputElement* input = hostInput();
     if (!input || !input->layoutObject())
-        return sliderThumbShadowPartId();
+        return false;
 
     const ComputedStyle& sliderStyle = input->layoutObject()->styleRef();
     switch (sliderStyle.appearance()) {
@@ -291,12 +306,19 @@ const AtomicString& SliderThumbElement::shadowPseudoId() const
     case MediaVolumeSliderThumbPart:
     case MediaFullScreenVolumeSliderPart:
     case MediaFullScreenVolumeSliderThumbPart:
-        return mediaSliderThumbShadowPartId();
+        return true;
     default:
-        return sliderThumbShadowPartId();
+        return false;
     }
 }
 
+const AtomicString& SliderThumbElement::shadowPseudoId() const
+{
+    if (isMediaSlider())
+        return mediaSliderThumbShadowPartId();
+    return sliderThumbShadowPartId();
+}
+
 // --------------------------------
 
 inline SliderContainerElement::SliderContainerElement(Document& document)