Support text track selection in video controls

third_party/WebKit/Source/core/html/shadow/MediaControlElements.cpp

Index: third_party/WebKit/Source/core/html/shadow/MediaControlElements.cpp
diff --git a/third_party/WebKit/Source/core/html/shadow/MediaControlElements.cpp b/third_party/WebKit/Source/core/html/shadow/MediaControlElements.cpp
index f8227ceb08b9f23789a9f777e3d47f94318a4d40..aaf45f56b0ac57c79b33985b1307867202aa25c9 100644
--- a/third_party/WebKit/Source/core/html/shadow/MediaControlElements.cpp
+++ b/third_party/WebKit/Source/core/html/shadow/MediaControlElements.cpp
@@ -32,17 +32,27 @@
 #include "bindings/core/v8/ExceptionStatePlaceholder.h"
 #include "core/InputTypeNames.h"
 #include "core/dom/ClientRect.h"
+#include "core/dom/DOMTokenList.h"

[fs, 2016/02/23 13:16:43]

What needs this?

[srivats, 2016/02/24 05:20:17]

Removed the stale import

+#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/HTMLHeadingElement.h"
+#include "core/html/HTMLLabelElement.h"
+#include "core/html/HTMLSpanElement.h"
 #include "core/html/HTMLVideoElement.h"
 #include "core/html/TimeRanges.h"
 #include "core/html/shadow/MediaControls.h"
+#include "core/html/track/TextTrackList.h"
 #include "core/input/EventHandler.h"
 #include "core/layout/LayoutSlider.h"
 #include "core/layout/LayoutTheme.h"
 #include "core/layout/LayoutVideo.h"
+#include "platform/EventDispatchForbiddenScope.h"
 #include "platform/RuntimeEnabledFeatures.h"
+#include "platform/text/PlatformLocale.h"
 #include "public/platform/Platform.h"
 
 namespace blink {
@@ -54,6 +64,12 @@ namespace {
 // This is the duration from mediaControls.css
 const double fadeOutDuration = 0.3;
 
+// Save the track index in an attribute to avoid holding a pointer to the text track element.
+static const char trackIndexAttr[] = "data-track-index";
+
+// When specified as trackIndex, disable text tracks.
+static const int trackIndexOffValue = -1;
+
 bool isUserInteractionEvent(Event* event)
 {
     const AtomicString& type = event->type();
@@ -353,14 +369,12 @@ 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();
     }
@@ -370,6 +384,148 @@ 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("-internal-media-controls-text-track-list",
+        AtomicString::ConstructFromLiteral));
+    element->setIsWanted(false);
+    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);

[fs, 2016/02/23 13:16:44]

getIntegralAttribute

(loses the validity checking but that isn't much use anyway)

[srivats, 2016/02/24 05:20:17]

Done.

+        ASSERT(validIndex);
+        if (trackIndex != trackIndexOffValue) {

[fs, 2016/02/23 13:16:43]

Nit: { } not needed

[srivats, 2016/02/24 05:20:17]

Done.

+            showTextTrackAtIndex(trackIndex);
+        } else {
+            disableTextTracks();
+        }
+
+        mediaControls().toggleTextTrackList();
+        event->setDefaultHandled();
+    }
+    HTMLDivElement::defaultEventHandler(event);

[fs, 2016/02/23 13:16:44]

MediaControlDivElement (unless there's a reason to skip the ancestors between
here and HTMLDivElement - which there doesn't seem to be.)

[srivats, 2016/02/24 05:20:17]

Done.

+}
+
+void MediaControlTextTrackListElement::showTextTrackAtIndex(unsigned indexToEnable)
+{
+    disableTextTracks();

[fs, 2016/02/23 13:16:44]

Could we hoist this out into callers instead? (Else this would be
showTextTrackAtIndexAndDisableOtherTracks.)

[srivats, 2016/02/24 05:20:17]

Done.

+    TextTrackList* trackList = mediaElement().textTracks();
+    if (trackList && trackList->length() == 0)

[fs, 2016/02/23 13:16:44]

I guess you want: !trackList || trackList->length() == 0 instead, but I think
that the textTracks() accessor guarantees a non-null return value so
null-checking is likely not needed at all.

[srivats, 2016/02/24 05:20:17]

Done.

+        return;
+    if (indexToEnable >= trackList->length())
+        return;
+    TextTrack* track = trackList->anonymousIndexedGetter(indexToEnable);
+    if (track && track->isRenderable())

[fs, 2016/02/23 13:16:44]

Since we know indexToEnable is in range, the null-check should not be needed
(the list will not store null TextTrack*s)

[srivats, 2016/02/24 05:20:17]

Done.

+        track->setMode(TextTrack::showingKeyword());
+    mediaElement().disableAutomaticTextTrackSelection();

[fs, 2016/02/23 13:16:43]

It could make sense to do this in the caller too (to avoid unnecessary
side-effects.)

[srivats, 2016/02/24 05:20:17]

Done.

+}
+
+void MediaControlTextTrackListElement::disableTextTracks()

[fs, 2016/02/23 13:16:44]

disableShowingTextTracks?

[srivats, 2016/02/24 05:20:17]

Done.

+{
+    TextTrackList* trackList = mediaElement().textTracks();
+    for (unsigned i = 0; i < trackList->length(); ++i) {
+        TextTrack* track = trackList->anonymousIndexedGetter(i);
+        if (track->mode() != TextTrack::hiddenKeyword())
+            track->setMode(TextTrack::disabledKeyword());
+    }
+}
+
+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));
+
+    return trackLabel;
+}
+
+// TextTrack parameter when passed in as a nullptr, creates the "Off" list item in the track list.
+PassRefPtrWillBeRawPtr<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("-internal-media-controls-text-track-list-item",
+        AtomicString::ConstructFromLiteral));
+    RefPtrWillBeRawPtr<HTMLInputElement> trackItemInput = HTMLInputElement::create(document, 0, false);
+    trackItemInput->setShadowPseudoId(AtomicString("-internal-media-controls-text-track-list-item-input",
+        AtomicString::ConstructFromLiteral));
+    trackItemInput->setType(InputTypeNames::radio);
+    trackItemInput->setAttribute(trackIndexAttr, AtomicString::number(trackIndex), ASSERT_NO_EXCEPTION);

[fs, 2016/02/23 13:16:43]

setIntegralAttribute

[srivats, 2016/02/24 05:20:17]

Done.

+    if (!mediaElement().closedCaptionsVisible()) {
+        if (!track)
+            trackItemInput->setChecked(true);
+    } else {
+        // If there are multiple text tracks set to showing, they must all have
+        // checkmarks displayed.
+        if (track && track->mode() == TextTrack::showingKeyword())
+            trackItemInput->setChecked(true);
+    }
+    RefPtrWillBeRawPtr<HTMLSpanElement> trackKindMarker = HTMLSpanElement::create(document);
+    if (track && track->kind() == track->captionsKeyword()) {
+        trackKindMarker->setShadowPseudoId(AtomicString("-internal-media-controls-text-track-list-kind-captions",
+            AtomicString::ConstructFromLiteral));
+    } else if (track && track->kind() == track->subtitlesKeyword()) {
+        trackKindMarker->setShadowPseudoId(AtomicString("-internal-media-controls-text-track-list-kind-subtitles",
+            AtomicString::ConstructFromLiteral));
+    }
+    trackItem->appendChild(trackItemInput);
+    trackItem->appendChild(Text::create(document, getTextTrackLabel(track)));
+    trackItem->appendChild(trackKindMarker);
+    return trackItem;
+}
+
+void MediaControlTextTrackListElement::refreshTextTrackListMenu()
+{
+    if (!mediaElement().hasClosedCaptions() || !mediaElement().textTracksAreReady())
+        return;
+
+    removeChildren();

[fs, 2016/02/23 13:16:44]

removeChildren(OmitSubtreeModifiedEvent)

I'm guessing (we don't want/need events from this.)

[srivats, 2016/02/24 05:20:17]

Done.

+
+    // Construct a menu for subtitles and captions
+    EventDispatchForbiddenScope::AllowUserAgentEvents allowEvents;
+    Document& document = this->document();

[fs, 2016/02/23 13:16:43]

Could just use document() directly in the single place that needs it?

[srivats, 2016/02/24 05:20:17]

Done.

+    RefPtrWillBeRawPtr<HTMLDivElement> tracksSection = HTMLDivElement::create(document);
+    tracksSection->setAttribute(roleAttr, radiogroupAttr.localName());

[fs, 2016/02/23 13:16:43]

I'm on the fence on whether this is "too smart" or not =)

+    // Pass in a nullptr to createTextTrackListItem to create the "Off" track item.
+    tracksSection->appendChild(createTextTrackListItem(nullptr));
+
+    TextTrackList* trackList = mediaElement().textTracks();
+    for (unsigned i = 0; i < trackList->length(); i++) {
+        TextTrack* track = trackList->anonymousIndexedGetter(i);
+        if (!track->isRenderable())
+            continue;
+        RefPtrWillBeRawPtr<Element> trackItem = createTextTrackListItem(track);

[fs, 2016/02/23 13:16:43]

No need for this temporary.

[srivats, 2016/02/24 05:20:17]

Done.

+        tracksSection->appendChild(trackItem);
+    }
+    appendChild(tracksSection);
+}
+
+// ----------------------------
+
 MediaControlTimelineElement::MediaControlTimelineElement(MediaControls& mediaControls)
     : MediaControlInputElement(mediaControls, MediaSlider)
 {