Prevent Media Controls from hiding when the user is interacting via the keyboard

This CL prevents the controls from hiding by resetting the hide timer on events in two places:

1) Listening for focusin and input events on the MediaControls via defaultEventHandler, which get fired as the user tabs through the controls and as the user changes the timeline/volume sliders respectively.

2) Listening for keypress events on the media panel via adding an event listener to the panel element in MediaControlsMediaEventListener, which gets fired when the user mutes/unmutes, turns CC on/off, etc.

BUG=701440

Review-Url: https://codereview.chromium.org/2757323002
Cr-Commit-Position: refs/heads/master@{#462990}

third_party/WebKit/Source/core/html/media/MediaControls.h

@@ -93,6 +93,7 @@ class CORE_EXPORT MediaControls : public GarbageCollectedMixin {
   virtual void onLoadedMetadata() = 0;
   virtual void onEnteredFullscreen() = 0;
   virtual void onExitedFullscreen() = 0;
+  virtual void onPanelKeypress() = 0;
   virtual void beginScrubbing() = 0;
   virtual void endScrubbing() = 0;
   virtual void updateCurrentTimeDisplay() = 0;

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

@@ -7,6 +7,7 @@
 #include "core/events/Event.h"
 #include "core/html/HTMLMediaElement.h"
 #include "core/html/media/MediaControls.h"
+#include "core/html/shadow/MediaControlElements.h"
 #include "core/html/track/TextTrackList.h"
 
 namespace blink {
@@ -43,6 +44,12 @@ void MediaControlsMediaEventListener::attach() {
   textTracks->addEventListener(EventTypeNames::addtrack, this, false);
   textTracks->addEventListener(EventTypeNames::change, this, false);
   textTracks->addEventListener(EventTypeNames::removetrack, this, false);
+
+  // Keypress events.
+  if (m_mediaControls->panelElement()) {
+    m_mediaControls->panelElement()->addEventListener(EventTypeNames::keypress,
+                                                      this, false);
+  }
 }
 
 void MediaControlsMediaEventListener::detach() {
@@ -55,6 +62,11 @@ void MediaControlsMediaEventListener::detach() {
   textTracks->removeEventListener(EventTypeNames::addtrack, this, false);
   textTracks->removeEventListener(EventTypeNames::change, this, false);
   textTracks->removeEventListener(EventTypeNames::removetrack, this, false);
+
+  if (m_mediaControls->panelElement()) {
+    m_mediaControls->panelElement()->removeEventListener(
+        EventTypeNames::keypress, this, false);
+  }
 }
 
 bool MediaControlsMediaEventListener::operator==(
@@ -127,6 +139,13 @@ void MediaControlsMediaEventListener::handleEvent(
     return;
   }
 
+  // Keypress events.
+  if (event->type() == EventTypeNames::keypress) {
+    if (event->currentTarget() == m_mediaControls->panelElement())
+      m_mediaControls->onPanelKeypress();
+    return;
+  }
+
   NOTREACHED();
 }
 

third_party/WebKit/Source/modules/media_controls/MediaControlsImpl.cpp

@@ -765,6 +765,13 @@ void MediaControlsImpl::defaultEventHandler(Event* event) {
       startHideMediaControlsTimer();
     return;
   }
+
+  // If the user is interacting with the controls via the keyboard, don't hide
+  // the controls. This will fire when the user tabs between controls (focusin)
+  // or when they seek either the timeline or volume sliders (input).
+  if (event->type() == EventTypeNames::focusin ||
+      event->type() == EventTypeNames::input)
+    resetHideMediaControlsTimer();
 }
 
 void MediaControlsImpl::hideMediaControlsTimerFired(TimerBase*) {
@@ -912,6 +919,13 @@ void MediaControlsImpl::onExitedFullscreen() {
   startHideMediaControlsTimer();
 }
 
+void MediaControlsImpl::onPanelKeypress() {
+  // If the user is interacting with the controls via the keyboard, don't hide
+  // the controls. This is called when the user mutes/unmutes, turns CC on/off,
+  // etc.
+  resetHideMediaControlsTimer();
+}
+
 void MediaControlsImpl::notifyElementSizeChanged(ClientRect* newSize) {
   // 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

third_party/WebKit/Source/modules/media_controls/MediaControlsImpl.h

@@ -126,6 +126,7 @@ class MODULES_EXPORT MediaControlsImpl final : public HTMLDivElement,
   void onLoadedMetadata() override;
   void onEnteredFullscreen() override;
   void onExitedFullscreen() override;
+  void onPanelKeypress() override;
   Document& ownerDocument() { return document(); }
 
   DECLARE_VIRTUAL_TRACE();

third_party/WebKit/Source/modules/media_controls/MediaControlsImplTest.cpp

@@ -24,6 +24,7 @@
 #include "platform/heap/Handle.h"
 #include "platform/testing/EmptyWebMediaPlayer.h"
 #include "platform/testing/HistogramTester.h"
+#include "platform/testing/TestingPlatformSupport.h"
 #include "platform/testing/UnitTestHelpers.h"
 #include "public/platform/WebMouseEvent.h"
 #include "public/platform/WebScreenInfo.h"
@@ -160,7 +161,9 @@ enum DownloadActionMetrics {
 
 class MediaControlsImplTest : public ::testing::Test {
  protected:
-  virtual void SetUp() {
+  virtual void SetUp() { initializePage(); }
+
+  void initializePage() {
     Page::PageClients clients;
     fillWithEmptyClients(clients);
     clients.chromeClient = new MockChromeClient();
@@ -176,7 +179,7 @@ class MediaControlsImplTest : public ::testing::Test {
     m_pageHolder->frame().settings()->setScriptEnabled(true);
   }
 
-  void simulateRouteAvailabe() {
+  void simulateRouteAvailable() {
     m_mediaControls->mediaElement().remoteRouteAvailabilityChanged(
         WebRemotePlaybackAvailability::DeviceAvailable);
   }
@@ -321,7 +324,7 @@ TEST_F(MediaControlsImplTest, CastButtonRequiresRoute) {
 
   ASSERT_FALSE(isElementVisible(*castButton));
 
-  simulateRouteAvailabe();
+  simulateRouteAvailable();
   ASSERT_TRUE(isElementVisible(*castButton));
 }
 
@@ -335,7 +338,7 @@ TEST_F(MediaControlsImplTest, CastButtonDisableRemotePlaybackAttr) {
   ASSERT_NE(nullptr, castButton);
 
   ASSERT_FALSE(isElementVisible(*castButton));
-  simulateRouteAvailabe();
+  simulateRouteAvailable();
   ASSERT_TRUE(isElementVisible(*castButton));
 
   mediaControls().mediaElement().setBooleanAttribute(
@@ -352,7 +355,7 @@ TEST_F(MediaControlsImplTest, CastOverlayDefault) {
       mediaControls(), "-internal-media-controls-overlay-cast-button");
   ASSERT_NE(nullptr, castOverlayButton);
 
-  simulateRouteAvailabe();
+  simulateRouteAvailable();
   ASSERT_TRUE(isElementVisible(*castOverlayButton));
 }
 
@@ -362,7 +365,7 @@ TEST_F(MediaControlsImplTest, CastOverlayDisableRemotePlaybackAttr) {
   ASSERT_NE(nullptr, castOverlayButton);
 
   ASSERT_FALSE(isElementVisible(*castOverlayButton));
-  simulateRouteAvailabe();
+  simulateRouteAvailable();
   ASSERT_TRUE(isElementVisible(*castOverlayButton));
 
   mediaControls().mediaElement().setBooleanAttribute(
@@ -380,7 +383,7 @@ TEST_F(MediaControlsImplTest, CastOverlayMediaControlsDisabled) {
   ASSERT_NE(nullptr, castOverlayButton);
 
   EXPECT_FALSE(isElementVisible(*castOverlayButton));
-  simulateRouteAvailabe();
+  simulateRouteAvailable();
   EXPECT_TRUE(isElementVisible(*castOverlayButton));
 
   document().settings()->setMediaControlsEnabled(false);
@@ -793,4 +796,46 @@ TEST_F(MediaControlsImplTest, MAYBE_TimelineMetricsDragBackAndForth) {
                                        9 /* (-4m, -2m] */, 1);
 }
 
+TEST_F(MediaControlsImplTest, ControlsRemainVisibleDuringKeyboardInteraction) {
+  ScopedTestingPlatformSupport<TestingPlatformSupportWithMockScheduler>
+      m_platform;
+
+  // DocumentParserTiming has DCHECKS to make sure time > 0.0.
+  m_platform->advanceClockSeconds(1);
+
+  // Need to reinitialize page since we changed the platform.
+  initializePage();
+  ensureSizing();
+
+  Element* panel = mediaControls().panelElement();
+
+  mediaControls().mediaElement().setBooleanAttribute(HTMLNames::controlsAttr,
+                                                     true);
+  mediaControls().mediaElement().setSrc("http://example.com");
+  mediaControls().mediaElement().play();
+
+  // Controls start out visible.
+  EXPECT_TRUE(isElementVisible(*panel));
+
+  // Tabbing between controls prevents controls from hiding.
+  m_platform->runForPeriodSeconds(2);
+  mediaControls().dispatchEvent(Event::create("focusin"));
+  m_platform->runForPeriodSeconds(2);
+  EXPECT_TRUE(isElementVisible(*panel));
+
+  // Seeking on the timeline or volume bar prevents controls from hiding.
+  mediaControls().dispatchEvent(Event::create("input"));
+  m_platform->runForPeriodSeconds(2);
+  EXPECT_TRUE(isElementVisible(*panel));
+
+  // Pressing a key prevents controls from hiding.
+  mediaControls().panelElement()->dispatchEvent(Event::create("keypress"));
+  m_platform->runForPeriodSeconds(2);
+  EXPECT_TRUE(isElementVisible(*panel));
+
+  // Once user interaction stops, controls can hide.
+  m_platform->runForPeriodSeconds(2);
+  EXPECT_FALSE(isElementVisible(*panel));
+}
+
 }  // namespace blink