Enabling autoplay and fullscreen for downloaded media

third_party/WebKit/Source/core/html/MediaDocument.cpp

 /*
  * Copyright (C) 2008 Apple 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.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "core/html/MediaDocument.h"
 
 #include "bindings/core/v8/ExceptionState.h"
 #include "core/HTMLNames.h"
+#include "core/dom/DocumentUserGestureToken.h"
 #include "core/dom/ElementTraversal.h"
+#include "core/dom/GetRootNodeOptions.h"
 #include "core/dom/RawDataDocumentParser.h"
 #include "core/dom/shadow/ShadowRoot.h"
 #include "core/events/Event.h"
 #include "core/events/EventListener.h"
 #include "core/events/KeyboardEvent.h"
 #include "core/frame/LocalFrame.h"
+#include "core/frame/Settings.h"
 #include "core/frame/UseCounter.h"
 #include "core/html/HTMLAnchorElement.h"
 #include "core/html/HTMLBodyElement.h"
 #include "core/html/HTMLContentElement.h"
 #include "core/html/HTMLDivElement.h"
 #include "core/html/HTMLHeadElement.h"
 #include "core/html/HTMLHtmlElement.h"
 #include "core/html/HTMLMetaElement.h"
 #include "core/html/HTMLSourceElement.h"
 #include "core/html/HTMLStyleElement.h"
 #include "core/html/HTMLVideoElement.h"
 #include "core/loader/DocumentLoader.h"
 #include "core/loader/FrameLoader.h"
 #include "core/loader/FrameLoaderClient.h"
 #include "platform/Histogram.h"
 #include "platform/KeyboardCodes.h"
+#include "platform/UserGestureIndicator.h"
 #include "platform/text/PlatformLocale.h"
 
 namespace blink {
 
 using namespace HTMLNames;
 
 // Enums used for UMA histogram.
 enum MediaDocumentDownloadButtonValue {
   MediaDocumentDownloadButtonShown,
   MediaDocumentDownloadButtonClicked,
@@ skipping 43 matching lines @@
   void handleEvent(ExecutionContext* context, Event* event) override {
     if (!m_clicked) {
       recordDownloadMetric(MediaDocumentDownloadButtonClicked);
       m_clicked = true;
     }
   }
 
   bool m_clicked;
 };
 
+class MediaLoadedEventListener final : public EventListener {
+ public:

[mlamouri (slow - plz ping), 2017/02/21 11:33:03]

`WTF_MAKE_NONCOPYABLE(MediaLoadedEventListener);` ?

[shaktisahu, 2017/02/21 16:51:57]

Done.

+  static MediaLoadedEventListener* create() {
+    return new MediaLoadedEventListener();
+  }

[mlamouri (slow - plz ping), 2017/02/21 11:33:03]

What's the benefit of using create over the ctor?

[shaktisahu, 2017/02/21 16:51:57]

hmm.. I wanted to keep it consistent with the other subclasses of EventListener
(see above).

+
+  bool operator==(const EventListener& other) const override {
+    return this == &other;
+  }
+
+ private:
+  MediaLoadedEventListener() : EventListener(CPPEventListenerType) {}

[mlamouri (slow - plz ping), 2017/02/21 11:33:03]

`= default;` instead of `{}`

[shaktisahu, 2017/02/21 16:51:57]

I think default works with only empty initialization list.

+
+  void handleEvent(ExecutionContext* context, Event* event) override {
+    HTMLVideoElement* media = Traversal<HTMLVideoElement>::firstWithin(
+        *event->target()->toNode()->getRootNode(GetRootNodeOptions()));

[mlamouri (slow - plz ping), 2017/02/21 11:33:03]

Why are you using Traversal<> here? Shouldn't `event->target()` be the video
element?

[shaktisahu, 2017/02/21 16:51:57]

Done.

+    UserGestureIndicator gesture(
+        DocumentUserGestureToken::create(&media->document()));
+    media->webkitEnterFullscreen();
+    media->play();

[mlamouri (slow - plz ping), 2017/02/21 11:33:03]

Maybe it would be better to start playback when we have transitionned to
fullscreen but that might be good enough :)

[shaktisahu, 2017/02/21 16:51:57]

I plan to revisit this depending on how the experience looks. Also I wanted to
see if I could get rid of the control panel that shows at the start, but may be
that's for later. For the released build, it looks smooth though, but there is
room for improvement.

+  }
+};
+
 void MediaDocumentParser::createDocumentStructure() {
   DCHECK(document());
   HTMLHtmlElement* rootElement = HTMLHtmlElement::create(*document());
   document()->appendChild(rootElement);
   rootElement->insertedByParser();
 
   if (isDetached())
     return;  // runScriptsAtDocumentElementAvailable can detach the frame.
 
   HTMLHeadElement* head = HTMLHeadElement::create(*document());
@@ skipping 30 matching lines @@
   div->setAttribute(styleAttr,
                     "display: flex;"
                     "flex-direction: column;"
                     "justify-content: center;"
                     "align-items: center;"
                     "min-height: min-content;"
                     "height: 100%;");
   HTMLContentElement* content = HTMLContentElement::create(*document());
   div->appendChild(content);
 
+  if (document()->settings() &&
+      document()->settings()->getEmbeddedMediaExperienceEnabled()) {
+    EventListener* listener = MediaLoadedEventListener::create();
+    media->addEventListener(EventTypeNames::loadedmetadata, listener, false);

[mlamouri (slow - plz ping), 2017/02/21 11:33:03]

Would it make sense to do:
```
AddEventListenerOptions options;
options.setOnce(true);
AddEventListenerOptionsOrBoolean optionsOrBoolean;
options.setAddEventListenerOptions(options);
media->addEventListener(EventTypeNames::loadedMetadata, optionsOrBoolean);
```

It might be cleaner because the listener would be free'd up after being fired.
It would be nicer if we had an internal method that takes
AddEventListenerOptions but that's maybe for later :)

[shaktisahu, 2017/02/21 16:51:57]

Done.

+  }
+
   if (RuntimeEnabledFeatures::mediaDocumentDownloadButtonEnabled()) {
     HTMLAnchorElement* anchor = HTMLAnchorElement::create(*document());
     anchor->setAttribute(downloadAttr, "");
     anchor->setURL(document()->url());
     anchor->setTextContent(
         document()
             ->getCachedLocale(document()->contentLanguage())
             .queryString(WebLocalizedString::DownloadButtonLabel)
             .upper());
     // Using CSS style according to Android material design.
@@ skipping 77 matching lines @@
     if (keyboardEvent->key() == " " ||
         keyboardEvent->keyCode() == VKEY_MEDIA_PLAY_PAUSE) {
       // space or media key (play/pause)
       video->togglePlayState();
       event->setDefaultHandled();
     }
   }
 }
 
 }  // namespace blink