Support text track selection in video controls

Source/core/html/shadow/MediaControlElements.cpp

Index: Source/core/html/shadow/MediaControlElements.cpp
diff --git a/Source/core/html/shadow/MediaControlElements.cpp b/Source/core/html/shadow/MediaControlElements.cpp
index f64e0c885a218012531856eae13dab7a3929a1cc..c4dedc52a038fb8c101e1e95b48207a880849f89 100644
--- a/Source/core/html/shadow/MediaControlElements.cpp
+++ b/Source/core/html/shadow/MediaControlElements.cpp
@@ -33,18 +33,25 @@
 #include "bindings/core/v8/ExceptionStatePlaceholder.h"
 #include "core/InputTypeNames.h"
 #include "core/dom/DOMTokenList.h"
+#include "core/dom/Document.h"
+#include "core/dom/Element.h"
+#include "core/dom/Text.h"
 #include "core/dom/shadow/ShadowRoot.h"
 #include "core/events/MouseEvent.h"
 #include "core/frame/LocalFrame.h"
+#include "core/html/HTMLLabelElement.h"
 #include "core/html/HTMLVideoElement.h"
 #include "core/html/MediaController.h"
 #include "core/html/TimeRanges.h"
 #include "core/html/shadow/MediaControls.h"
+#include "core/html/track/TextTrackList.h"
 #include "core/layout/LayoutSlider.h"
 #include "core/layout/LayoutTheme.h"
 #include "core/layout/LayoutVideo.h"
 #include "core/page/EventHandler.h"
+#include "platform/EventDispatchForbiddenScope.h"
 #include "platform/RuntimeEnabledFeatures.h"
+#include "platform/text/PlatformLocale.h"
 
 namespace blink {
 
@@ -53,6 +60,12 @@ using namespace HTMLNames;
 // This is the duration from mediaControls.css
 static const double fadeOutDuration = 0.3;
 
+// track index attribute specifies trackIndex for text track list elements
+static const char trackIndexAttr[] = "data-webkit-track-index";
+
+// when specified as trackIndex, disable text tracks
+static const int trackIndexOffValue = -1;
+
 static bool isUserInteractionEvent(Event* event)
 {
     const AtomicString& type = event->type();
@@ -341,14 +354,12 @@ void MediaControlToggleClosedCaptionsButtonElement::updateDisplayType()
 {
     bool captionsVisible = mediaElement().closedCaptionsVisible();
     setDisplayType(captionsVisible ? MediaHideClosedCaptionsButton : MediaShowClosedCaptionsButton);
-    setChecked(captionsVisible);
 }
 
 void MediaControlToggleClosedCaptionsButtonElement::defaultEventHandler(Event* event)
 {
     if (event->type() == EventTypeNames::click) {
-        mediaElement().setClosedCaptionsVisible(!mediaElement().closedCaptionsVisible());
-        setChecked(mediaElement().closedCaptionsVisible());
+        mediaControls().toggleTextTrackList();
         updateDisplayType();
         event->setDefaultHandled();
     }
@@ -358,6 +369,145 @@ void MediaControlToggleClosedCaptionsButtonElement::defaultEventHandler(Event* e
 
 // ----------------------------
 
+MediaControlTextTrackListElement::MediaControlTextTrackListElement(MediaControls& mediaControls)
+    : MediaControlDivElement(mediaControls, MediaTextTrackList)
+{
+}
+
+PassRefPtrWillBeRawPtr<MediaControlTextTrackListElement> MediaControlTextTrackListElement::create(MediaControls& mediaControls)
+{
+    RefPtrWillBeRawPtr<MediaControlTextTrackListElement> element =
+        adoptRefWillBeNoop(new MediaControlTextTrackListElement(mediaControls));
+    element->setShadowPseudoId(AtomicString("-webkit-media-controls-text-track-list",

[fs, 2015/04/21 12:13:34]

s/webkit/internal/ for all new pseudo elements IIRC.

[srivats, 2015/04/21 21:11:18]

Done.

+        AtomicString::ConstructFromLiteral));
+    element->hide();
+    return element.release();
+}
+
+void MediaControlTextTrackListElement::defaultEventHandler(Event* event)
+{
+    if (event->type() == EventTypeNames::change) {
+        // Identify which input element was selected and set track to showing
+        Node* target = event->target()->toNode();
+        if (!target || !target->isElementNode())
+            return;
+
+        bool validIndex;
+        int trackIndex = toElement(target)->getAttribute(trackIndexAttr).toInt(&validIndex);
+        if (!validIndex)

[fs, 2015/04/21 12:13:34]

This seems "unexpected", so maybe it should suffice to assert it.

[srivats, 2015/04/21 21:11:18]

Done.

+            return;
+        if (trackIndex != trackIndexOffValue) {
+            showTextTrackAtIndex(trackIndex);
+            mediaElement().setClosedCaptionsVisible(true);
+        } else {
+            mediaElement().setClosedCaptionsVisible(false);
+        }
+
+        mediaControls().toggleTextTrackList();
+        event->setDefaultHandled();
+    }
+    HTMLDivElement::defaultEventHandler(event);
+}
+
+void MediaControlTextTrackListElement::showTextTrackAtIndex(unsigned index)
+{
+    TextTrackList* trackList = mediaElement().textTracks();
+    for (unsigned i = 0; i < trackList->length(); ++i) {
+        TextTrack* track = trackList->item(i);
+        if (track->mode() == TextTrack::showingKeyword())

[fs, 2015/04/21 12:13:34]

Should check isRenderable() here too I think. Might make sense to just merge the
"disabling" and the "enabling".

if (!track->isRenderable())
    continue;
if (i == indexToEnable) {
    ...
} else if (track->mode() == showingKeyword()) {
    ...
}

or somesuch.

[srivats, 2015/04/21 21:11:18]

Done.

+            track->setMode(TextTrack::disabledKeyword());
+    }
+
+    if (index < trackList->length()) {
+        TextTrack* track = trackList->item(index);
+        if (!track->isRenderable())
+            return;
+        track->setMode(TextTrack::showingKeyword());
+        mediaElement().disableAutomaticTextTrackSelection();
+    }
+}
+
+String MediaControlTextTrackListElement::getTextTrackLabel(TextTrack* track)
+{
+    if (!track)
+        return mediaElement().locale().queryString(WebLocalizedString::TextTracksOff);
+
+    String trackLabel = track->label();
+
+    if (trackLabel.isEmpty())
+        trackLabel = track->language();
+
+    if (trackLabel.isEmpty())
+        trackLabel = String(mediaElement().locale().queryString(WebLocalizedString::TextTracksNoLabel));
+
+    // When the track kind is captions, add a captions marker to distinguish between captions and subtitles.
+    if (track->kind() == track->captionsKeyword())
+        trackLabel.append(mediaElement().locale().queryString(WebLocalizedString::TextTracksCaptionsMarker));
+    return trackLabel;
+}
+
+RefPtrWillBeRawPtr<Element> MediaControlTextTrackListElement::createTextTrackListItem(TextTrack* track)
+{
+    Document& document = this->document();
+    int trackIndex = track ? track->trackIndex() : trackIndexOffValue;
+    RefPtrWillBeRawPtr<HTMLLabelElement> trackItem = HTMLLabelElement::create(document, 0);
+    trackItem->setShadowPseudoId(AtomicString("-webkit-media-controls-text-track-list-item",
+        AtomicString::ConstructFromLiteral));
+    RefPtrWillBeRawPtr<HTMLInputElement> trackItemInput = HTMLInputElement::create(document, 0, false);
+    trackItemInput->setShadowPseudoId(AtomicString("-webkit-media-controls-text-track-list-item-input",
+        AtomicString::ConstructFromLiteral));
+    trackItemInput->setType(InputTypeNames::radio);
+    trackItemInput->setAttribute(nameAttr, AtomicString("tracks", AtomicString::ConstructFromLiteral));
+    trackItemInput->setAttribute(trackIndexAttr, AtomicString::number(trackIndex), ASSERT_NO_EXCEPTION);
+    if (!mediaElement().closedCaptionsVisible()) {
+        if (!track)
+            trackItemInput->setChecked(true);
+    } else {
+        if (track && track->mode() == TextTrack::showingKeyword())
+            trackItemInput->setChecked(true);
+    }
+    trackItem->appendChild(trackItemInput);
+    trackItem->appendChild(document.createTextNode(getTextTrackLabel(track)));

[fs, 2015/04/21 12:13:34]

document.createTextNode(...) -> Text::create(document, ...)

[srivats, 2015/04/21 21:11:18]

Done.

+    return trackItem;
+}
+
+void MediaControlTextTrackListElement::refreshTextTrackListMenu()
+{
+    DEFINE_STATIC_LOCAL(const AtomicString, tracksSectionId, ("tracks-header", AtomicString::ConstructFromLiteral));
+    if (!mediaElement().hasClosedCaptions() || !mediaElement().textTracksAreReady())
+        return;
+
+    removeChildren();
+
+    // Construct a menu for subtitles and captions
+    EventDispatchForbiddenScope::AllowUserAgentEvents allowEvents;
+    Document& document = this->document();
+    RefPtrWillBeRawPtr<HTMLElement> tracksHeader = HTMLElement::create(h3Tag, document);

[fs, 2015/04/21 12:13:34]

HTMLElement -> HTMLHeadingElement

[srivats, 2015/04/21 21:11:18]

Done.

+    tracksHeader->setShadowPseudoId(AtomicString("-webkit-media-controls-text-track-list-header",
+        AtomicString::ConstructFromLiteral));
+    RefPtrWillBeRawPtr<HTMLDivElement> tracksSection = HTMLDivElement::create(document);
+
+    tracksHeader->appendChild(document.createTextNode(mediaElement().locale().queryString(WebLocalizedString::TextTracksSubtitlesCC)));
+    tracksHeader->setAttribute(idAttr, tracksSectionId);
+    tracksSection->setAttribute(roleAttr, radiogroupAttr.localName());
+    tracksSection->setAttribute(aria_labeledbyAttr, tracksSectionId);
+
+    tracksSection->appendChild(createTextTrackListItem(nullptr));
+
+    TextTrackList* trackList = mediaElement().textTracks();
+    for (unsigned i = 0; i < trackList->length(); i++) {
+        TextTrack* track = trackList->item(i);
+        if (!track->isRenderable())
+            continue;
+        RefPtrWillBeRawPtr<Element> trackItem = createTextTrackListItem(track);
+        tracksSection->appendChild(trackItem);
+    }
+    appendChild(tracksHeader);
+    appendChild(tracksSection);
+}
+
+// ----------------------------
+
 MediaControlTimelineElement::MediaControlTimelineElement(MediaControls& mediaControls)
     : MediaControlInputElement(mediaControls, MediaSlider)
 {