Support text track selection in video controls

Source/core/html/shadow/MediaControls.cpp

Index: Source/core/html/shadow/MediaControls.cpp
diff --git a/Source/core/html/shadow/MediaControls.cpp b/Source/core/html/shadow/MediaControls.cpp
index b0560f11dddbc156a7e77c71ccca1c75b39140a6..1223d8663d5221610eef6c624e941c2ce9dad0de 100644
--- a/Source/core/html/shadow/MediaControls.cpp
+++ b/Source/core/html/shadow/MediaControls.cpp
@@ -59,6 +59,8 @@ MediaControls::MediaControls(HTMLMediaElement& mediaElement)
     , m_muteButton(nullptr)
     , m_volumeSlider(nullptr)
     , m_toggleClosedCaptionsButton(nullptr)
+    , m_closedCaptionsTrackListContainer(nullptr)
+    , m_closedCaptionsTrackList(nullptr)
     , m_fullScreenButton(nullptr)
     , m_castButton(nullptr)
     , m_overlayCastButton(nullptr)
@@ -95,6 +97,8 @@ PassRefPtrWillBeRawPtr<MediaControls> MediaControls::create(HTMLMediaElement& me
 //     +-MediaControlMuteButtonElement                 (-webkit-media-controls-mute-button)
 //     +-MediaControlVolumeSliderElement               (-webkit-media-controls-volume-slider)
 //     +-MediaControlToggleClosedCaptionsButtonElement (-webkit-media-controls-toggle-closed-captions-button)
+//     +-MediaControlClosedCaptionsTrackListContainerElement (-webkit-media-controls-closed-captions-track-list-container)
+//     +-MediaControlClosedCaptionsTrackListElement    (-webkit-media-controls-closed-captions-track-list)
 //     +-MediaControlCastButtonElement                 (-internal-media-controls-cast-button)
 //     \-MediaControlFullscreenButtonElement           (-webkit-media-controls-fullscreen-button)
 void MediaControls::initializeControls()
@@ -148,6 +152,15 @@ void MediaControls::initializeControls()
     m_toggleClosedCaptionsButton = toggleClosedCaptionsButton.get();
     panel->appendChild(toggleClosedCaptionsButton.release());
 
+    RefPtrWillBeRawPtr<MediaControlClosedCaptionsTrackListContainerElement> closedCaptionsTrackListContainer =
+        MediaControlClosedCaptionsTrackListContainerElement::create(*this);
+    m_closedCaptionsTrackListContainer = closedCaptionsTrackListContainer.get();
+    RefPtrWillBeRawPtr<MediaControlClosedCaptionsTrackListElement> closedCaptionsTrackList =
+        MediaControlClosedCaptionsTrackListElement::create(*this);
+    m_closedCaptionsTrackList = closedCaptionsTrackList.get();
+    m_closedCaptionsTrackListContainer->appendChild(closedCaptionsTrackList.release());
+    panel->appendChild(closedCaptionsTrackListContainer.release());
+
     RefPtrWillBeRawPtr<MediaControlCastButtonElement> castButton = MediaControlCastButtonElement::create(*this, false);
     m_castButton = castButton.get();
     panel->appendChild(castButton.release());
@@ -354,6 +367,25 @@ void MediaControls::refreshClosedCaptionsButtonVisibility()
         m_toggleClosedCaptionsButton->hide();
 }
 
+void MediaControls::toggleClosedCaptionsTrackList()
+{
+    if (!mediaElement().hasClosedCaptions() || !m_closedCaptionsTrackListContainer)

[fs, 2015/04/14 12:34:57]

m_closedCaptionsTrackListContainer is always created/set when creating the
controls, so this check seems redundant.

Also, what if the tracks are removed when the menu is open - what handles that.

[srivats, 2015/04/16 23:37:20]

Removed
If the tracks are removed while the menu is open, the user can still click on
the items in the track list but they don't do anything functionally(shows
checkmark). Once the menu is dismissed, you can't bring it back up again unless
new tracks are added cause there is no CC button anymore and no tracks to show.

+        return;
+
+    bool isTrackListVisible = m_closedCaptionsTrackListContainer->isVisible();
+    // Media controls panel has overflow set to hidden. To display track list,

[fs, 2015/04/14 12:34:57]

Maybe this is an indication that the menu should not be within the panel then?

[srivats, 2015/04/16 23:37:20]

Seems logical to be a part of media controls because the CC button brings this
menu up. Do you have an alternate approach for this?

[fs, 2015/04/17 11:54:46]

Well, first, a menu that's part of the page has a few issue in that it may end
up being clipped by the viewport... (compare for instance with <select>)

Ignoring that though, it should be possible to stack the text track menu on top
of the panel, since its layout is independent (AFAICS). Therë́'s already lots of
other "overlays" present in the control shadow tree.

[srivats, 2015/04/21 01:48:55]

Moved it out of media controls panel and added it to the enclosure instead.

+    // overflow has to be set to visible.
+    m_panel->setInlineStyleProperty(CSSPropertyOverflow, CSSValueVisible, isTrackListVisible);
+    if (isTrackListVisible) {
+        m_closedCaptionsTrackListContainer->hide();
+        m_closedCaptionsTrackList->hide();
+    } else {
+        m_closedCaptionsTrackListContainer->show();
+        m_closedCaptionsTrackList->refreshTextTrackListMenu();
+        m_closedCaptionsTrackList->show();
+    }
+}
+
 static Element* elementFromCenter(Element& element)
 {
     RefPtrWillBeRawPtr<ClientRect> clientRect = element.getBoundingClientRect();