Hide overlay play button if it can't be shown without clipping

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

 /*
  * Copyright (C) 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2011, 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.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 11 matching lines @@
  * 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/shadow/MediaControls.h"
 
 #include "bindings/core/v8/ExceptionState.h"
 #include "core/dom/ClientRect.h"
 #include "core/dom/Fullscreen.h"
+#include "core/dom/ResizeObserver.h"
+#include "core/dom/ResizeObserverCallback.h"
+#include "core/dom/ResizeObserverEntry.h"
 #include "core/dom/TaskRunnerHelper.h"
 #include "core/events/MouseEvent.h"
 #include "core/frame/Settings.h"
 #include "core/html/HTMLMediaElement.h"
 #include "core/html/HTMLVideoElement.h"
 #include "core/html/shadow/MediaControlsMediaEventListener.h"
 #include "core/html/shadow/MediaControlsOrientationLockDelegate.h"
 #include "core/html/shadow/MediaControlsWindowEventListener.h"
 #include "core/html/track/TextTrackContainer.h"
 #include "core/html/track/TextTrackList.h"
 #include "core/layout/LayoutObject.h"
 #include "core/layout/LayoutTheme.h"
 #include "platform/EventDispatchForbiddenScope.h"
 
 namespace blink {
 
+namespace {
+constexpr int kOverlayPlayButtonWidth = 48;
+constexpr int kOverlayPlayButtonHeight = 48;
+constexpr int kOverlayBottomMargin = 10;
+constexpr int kAndroidMediaPanelHeight = 48;
+
+constexpr int kMinWidthForOverlayPlayButton = kOverlayPlayButtonWidth;
+constexpr int kMinHeightForOverlayPlayButton = kOverlayPlayButtonHeight +
+                                               (2 * kAndroidMediaPanelHeight) +
+                                               (2 * kOverlayBottomMargin);
+}  // namespace
+
 // If you change this value, then also update the corresponding value in
 // LayoutTests/media/media-controls.js.
 static const double timeWithoutMouseMovementBeforeHidingMediaControls = 3;
 
 static bool shouldShowFullscreenButton(const HTMLMediaElement& mediaElement) {
   // Unconditionally allow the user to exit fullscreen if we are in it
   // now.  Especially on android, when we might not yet know if
   // fullscreen is supported, we sometimes guess incorrectly and show
   // the button earlier, and we don't want to remove it here if the
   // user chose to enter fullscreen.  crbug.com/500732 .
@@ skipping 41 matching lines @@
   }
 
  private:
   Member<MediaControls> m_controls;
   static int s_batchDepth;
 };
 
 // Count of number open batches for controls visibility.
 int MediaControls::BatchedControlUpdate::s_batchDepth = 0;
 
+class MediaControls::MediaControlsResizeObserverCallback
+    : public ResizeObserverCallback {
+ public:
+  explicit MediaControlsResizeObserverCallback(MediaControls* controls)
+      : m_controls(controls) {
+    DCHECK(controls);
+  }
+  ~MediaControlsResizeObserverCallback() override{};

[mlamouri (slow - plz ping), 2017/02/22 11:48:08]

nit: s/{};/ = default;/

[steimel, 2017/02/23 00:53:48]

Done.

+
+  void handleEvent(const HeapVector<Member<ResizeObserverEntry>>& entries,
+                   ResizeObserver* observer) override {
+    for (const auto& entry : entries) {

[mlamouri (slow - plz ping), 2017/02/22 11:48:08]

Is more than one entry expected? Should we DCHECK() for entries.size == 1?

[steimel, 2017/02/23 00:53:48]

Discussed offline. After looking at the spec, there will only be one entry per
observed element, and since we only observe one element, yes we should DCHECK

+      m_controls->notifyPanelSizeChanged((int)entry->contentRect()->width(),
+                                         (int)entry->contentRect()->height());
+    }
+  }
+
+  DEFINE_INLINE_TRACE() {
+    visitor->trace(m_controls);
+    ResizeObserverCallback::trace(visitor);
+  }
+
+ private:
+  Member<MediaControls> m_controls;
+};
+
 MediaControls::MediaControls(HTMLMediaElement& mediaElement)
     : HTMLDivElement(mediaElement.document()),
+      m_resizeObserver(ResizeObserver::create(
+          mediaElement.document(),
+          new MediaControlsResizeObserverCallback(this))),
       m_mediaElement(&mediaElement),
       m_overlayEnclosure(nullptr),
       m_overlayPlayButton(nullptr),
       m_overlayCastButton(nullptr),
       m_enclosure(nullptr),
       m_panel(nullptr),
       m_playButton(nullptr),
       m_timeline(nullptr),
       m_currentTimeDisplay(nullptr),
       m_durationDisplay(nullptr),
@@ skipping 10 matching lines @@
           this,
           WTF::bind(&MediaControls::hideAllMenus, wrapWeakPersistent(this)))),
       m_orientationLockDelegate(nullptr),
       m_hideMediaControlsTimer(TaskRunnerHelper::get(TaskType::UnspecedTimer,
                                                      &mediaElement.document()),
                                this,
                                &MediaControls::hideMediaControlsTimerFired),
       m_hideTimerBehaviorFlags(IgnoreNone),
       m_isMouseOverControls(false),
       m_isPausedForScrubbing(false),
-      m_panelWidthChangedTimer(TaskRunnerHelper::get(TaskType::UnspecedTimer,
-                                                     &mediaElement.document()),
-                               this,
-                               &MediaControls::panelWidthChangedTimerFired),
+      m_panelSizeChangedTimer(TaskRunnerHelper::get(TaskType::UnspecedTimer,
+                                                    &mediaElement.document()),
+                              this,
+                              &MediaControls::panelSizeChangedTimerFired),
       m_panelWidth(0),
-      m_keepShowingUntilTimerFires(false) {}
+      m_panelHeight(0),
+      m_keepShowingUntilTimerFires(false) {
+  m_resizeObserver->observe(m_mediaElement);

[mlamouri (slow - plz ping), 2017/02/22 11:48:08]

Would it make sense to initialise the current size in the case the resize
observer is set up after the first layout, thus would not notify us of the
current size?

[steimel, 2017/02/23 00:53:48]

Discussed offline, but re-adding some code in LayoutMedia to inform the
mediacontrols of layouts to handle initialization

+}
 
 MediaControls* MediaControls::create(HTMLMediaElement& mediaElement,
                                      ShadowRoot& shadowRoot) {
   MediaControls* controls = new MediaControls(mediaElement);
   controls->setShadowPseudoId(AtomicString("-webkit-media-controls"));
   controls->initializeControls();
   controls->reset();
 
   // Initialize the orientation lock when going fullscreen feature.
   if (RuntimeEnabledFeatures::videoFullscreenOrientationLockEnabled() &&
@@ skipping 617 matching lines @@
   stopHideMediaControlsTimer();
   startHideMediaControlsTimer();
 }
 
 void MediaControls::onExitedFullscreen() {
   m_fullscreenButton->setIsFullscreen(false);
   stopHideMediaControlsTimer();
   startHideMediaControlsTimer();
 }
 
-void MediaControls::notifyPanelWidthChanged(const LayoutUnit& newWidth) {
+void MediaControls::notifyPanelSizeChanged(int newWidth, int newHeight) {
   // Don't bother to do any work if this matches the most recent panel
-  // width, since we're called after layout.
+  // size, since we're called after layout.
   // Note that this code permits a bad frame on resize, since it is
   // run after the relayout / paint happens.  It would be great to improve
   // this, but it would be even greater to move this code entirely to
   // JS and fix it there.
-  m_panelWidth = newWidth.toInt();
+  m_panelWidth = newWidth;
+  m_panelHeight = newHeight;

[mlamouri (slow - plz ping), 2017/02/22 11:48:08]

Is it really still the panel width/height? Shouldn't that be the media element
instead?

[steimel, 2017/02/23 00:53:48]

Done.

 
   // Adjust for effective zoom.
   if (!m_panel->layoutObject() || !m_panel->layoutObject()->style())
     return;
+
   m_panelWidth =
       ceil(m_panelWidth / m_panel->layoutObject()->style()->effectiveZoom());
 
-  m_panelWidthChangedTimer.startOneShot(0, BLINK_FROM_HERE);
+  m_panelSizeChangedTimer.startOneShot(0, BLINK_FROM_HERE);
 }
 
-void MediaControls::panelWidthChangedTimerFired(TimerBase*) {
+void MediaControls::panelSizeChangedTimerFired(TimerBase*) {
   computeWhichControlsFit();
 }
 
 void MediaControls::computeWhichControlsFit() {
   // Hide all controls that don't fit, and show the ones that do.
   // This might be better suited for a layout, but since JS media controls
   // won't benefit from that anwyay, we just do it here like JS will.
 
   // Controls that we'll hide / show, in order of decreasing priority.
   MediaControlElement* elements[] = {
@@ skipping 90 matching lines @@
       if ((firstDisplacedElement == m_timeline.get()) ||
           (firstDisplacedElement == m_volumeSlider.get()))
         width += sliderMargin;
       if (usedWidth + width <= m_panelWidth)
         firstDisplacedElement->setDoesFit(true);
     }
   } else if (overflowElements.size() == 1) {
     m_overflowMenu->setIsWanted(false);
     overflowElements.front()->setDoesFit(true);
   }
+
+  // Decide if the overlay play button fits.
+  if (m_panelWidth && m_panelHeight && m_overlayPlayButton) {
+    bool doesFit = m_panelWidth >= kMinWidthForOverlayPlayButton &&
+                   m_panelHeight >= kMinHeightForOverlayPlayButton;
+    m_overlayPlayButton->setDoesFit(doesFit);
+  }
 }
 
 void MediaControls::invalidate(Element* element) {
   if (!element)
     return;
 
   if (LayoutObject* layoutObject = element->layoutObject())
     layoutObject
         ->setShouldDoFullPaintInvalidationIncludingNonCompositingDescendants();
 }
@@ skipping 23 matching lines @@
 void MediaControls::hideAllMenus() {
   m_windowEventListener->stop();
 
   if (m_overflowList->isWanted())
     m_overflowList->setIsWanted(false);
   if (m_textTrackList->isWanted())
     m_textTrackList->setVisible(false);
 }
 
 DEFINE_TRACE(MediaControls) {
+  visitor->trace(m_resizeObserver);
   visitor->trace(m_mediaElement);
   visitor->trace(m_panel);
   visitor->trace(m_overlayPlayButton);
   visitor->trace(m_overlayEnclosure);
   visitor->trace(m_playButton);
   visitor->trace(m_currentTimeDisplay);
   visitor->trace(m_timeline);
   visitor->trace(m_muteButton);
   visitor->trace(m_volumeSlider);
   visitor->trace(m_toggleClosedCaptionsButton);
   visitor->trace(m_fullscreenButton);
   visitor->trace(m_downloadButton);
   visitor->trace(m_durationDisplay);
   visitor->trace(m_enclosure);
   visitor->trace(m_textTrackList);
   visitor->trace(m_overflowMenu);
   visitor->trace(m_overflowList);
   visitor->trace(m_castButton);
   visitor->trace(m_overlayCastButton);
   visitor->trace(m_mediaEventListener);
   visitor->trace(m_windowEventListener);
   visitor->trace(m_orientationLockDelegate);
   HTMLDivElement::trace(visitor);
 }
 
 }  // namespace blink