New media playback UI.

Source/core/html/shadow/MediaControlElementTypes.h

 /*
  * Copyright (C) 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * 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 60 matching lines @@
 inline HTMLMediaElement* toParentMediaElement(LayoutObject* layoutObject) { return toParentMediaElement(layoutObject->node()); }
 
 CORE_EXPORT MediaControlElementType mediaControlElementType(Node*);
 
 // ----------------------------
 
 class MediaControlElement : public WillBeGarbageCollectedMixin {
 public:
     void hide();
     void show();
+    bool isShown();
+
+    // These hold the state about whether this control should be shown if

[philipj_slow, 2015/07/08 15:06:38]

OK, I take it the problem is that there are now two different reasons that
something can be hidden:
1. Because it makes no sense, e.g. the CC button where there are no captions.
2. Because it won't fit.

Keeping show() and hide() exposed and having want() and dontWant() call those
internally seems like it might invite mistakes, by code calling show() or hide()
directly, and just confusion about how this works.

Could the new model be made explicit by having exposed ways of saying that the
element isn't needed for the two different reasons, and then handling the actual
display state internally based on those two bits?

Alternatively, if there's any way for the elements to not have any knowledge
about the reason they're being shown or hidden, that would also be cleaner, but
I don't know where one would keep track of the state to avoid showing the
element again when just one of the bits flips to the "can show" state.

[liberato (no reviews please), 2015/07/09 12:10:56]

originally, i tried to keep the state in MediaControls, since i prefer for the
elements not to know anything about this.  however, it was fairly cumbersome.

i made fits/doesnt fit properties of the element, and made hide/show private.

+    // space permits.  These will also show / hide as needed, though
+    // calling show/hide does not impact the want/dontWant state.
+    void want();
+    void dontWant();
+    bool isWanted();
+
+    // This returns the minimum width in pixels that we need to show
+    // this control.  Ideally, this would just be shorthand for the css

[philipj_slow, 2015/07/08 15:06:38]

s/css attributes/computed style/

[liberato (no reviews please), 2015/07/09 12:10:56]

Done.

+    // attributes, but this must also work when the control is hidden.
+    int minimumWidth();
 
     MediaControlElementType displayType() { return m_displayType; }
 
     DECLARE_VIRTUAL_TRACE();
 
 protected:
     MediaControlElement(MediaControls&, MediaControlElementType, HTMLElement*);
 
     MediaControls& mediaControls() const { return m_mediaControls; }
     HTMLMediaElement& mediaElement() const;
 
     void setDisplayType(MediaControlElementType);
 
 private:
     MediaControls& m_mediaControls;
     MediaControlElementType m_displayType;
     RawPtrWillBeMember<HTMLElement> m_element;
+    bool m_isShown;
+    bool m_isWanted;
 };
 
 // ----------------------------
 
 class MediaControlDivElement : public HTMLDivElement, public MediaControlElement {
     WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(MediaControlDivElement);
 public:
     DECLARE_VIRTUAL_TRACE();
 
 protected:
@@ skipping 29 matching lines @@
 protected:
     MediaControlTimeDisplayElement(MediaControls&, MediaControlElementType);
 
 private:
     double m_currentValue;
 };
 
 } // namespace blink
 
 #endif // MediaControlElementTypes_h