Add setting to inhibit autoplay until user interaction

Pass through the PlaybackRequiresUserGesture Chromium setting which
Chrome enables by default on Android.

Task-number: QTBUG-60799
Change-Id: I105fc7d558f9b67417a0047ecb1efe7677817ea4
Reviewed-by: Florian Bruhin <qt-project.org@the-compiler.org>
Reviewed-by: Peter Varga <pvarga@inf.u-szeged.hu>
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>

7 files changed, 59 insertions, 2 deletions

diff --git a/src/core/web_engine_settings.cpp b/src/core/web_engine_settings.cpp
index 44ecaf2ef..a585e7bb3 100644
--- a/src/core/web_engine_settings.cpp
+++ b/src/core/web_engine_settings.cpp
@@ -48,6 +48,7 @@
 #include "content/browser/gpu/gpu_process_host.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/common/web_preferences.h"
+#include "media/base/media_switches.h"
 #include "ui/events/event_switches.h"
 
 #include <QFont>
@@ -152,6 +153,17 @@ bool WebEngineSettings::testAttribute(WebEngineSettings::Attribute attr) const
     return m_attributes.value(attr, parentSettings->testAttribute(attr));
 }
 
+bool WebEngineSettings::isAttributeExplicitlySet(Attribute attr) const
+{
+    if (m_attributes.contains(attr))
+        return true;
+
+    if (parentSettings)
+        return parentSettings->isAttributeExplicitlySet(attr);
+
+    return false;
+}
+
 void WebEngineSettings::resetAttribute(WebEngineSettings::Attribute attr)
 {
     m_attributes.remove(attr);
@@ -270,6 +282,10 @@ void WebEngineSettings::initDefaults()
         s_defaultAttributes.insert(AllowRunningInsecureContent, allowRunningInsecureContent);
         s_defaultAttributes.insert(AllowGeolocationOnInsecureOrigins, false);
         s_defaultAttributes.insert(AllowWindowActivationFromJavaScript, false);
+        bool playbackRequiresUserGesture = false;
+        if (commandLine->HasSwitch(switches::kAutoplayPolicy))
+            playbackRequiresUserGesture = (commandLine->GetSwitchValueASCII(switches::kAutoplayPolicy) != switches::autoplay::kNoUserGestureRequiredPolicy);
+        s_defaultAttributes.insert(PlaybackRequiresUserGesture, playbackRequiresUserGesture);
     }
 
     if (s_defaultFontFamilies.isEmpty()) {
@@ -353,6 +369,11 @@ void WebEngineSettings::applySettingsToWebPreferences(content::WebPreferences *p
     prefs->allow_running_insecure_content = testAttribute(AllowRunningInsecureContent);
     prefs->allow_geolocation_on_insecure_origins = testAttribute(AllowGeolocationOnInsecureOrigins);
     prefs->hide_scrollbars = !testAttribute(ShowScrollBars);
+    if (isAttributeExplicitlySet(PlaybackRequiresUserGesture)) {
+        prefs->autoplay_policy = testAttribute(PlaybackRequiresUserGesture)
+                               ? content::AutoplayPolicy::kUserGestureRequired
+                               : content::AutoplayPolicy::kNoUserGestureRequired;
+    }
 
     // Fonts settings.
     prefs->standard_font_family_map[content::kCommonScript] = toString16(fontFamily(StandardFont));
diff --git a/src/core/web_engine_settings.h b/src/core/web_engine_settings.h
index ea647a61f..5881303a2 100644
--- a/src/core/web_engine_settings.h
+++ b/src/core/web_engine_settings.h
@@ -85,7 +85,8 @@ public:
         AllowRunningInsecureContent,
         AllowGeolocationOnInsecureOrigins,
         AllowWindowActivationFromJavaScript,
-        ShowScrollBars
+        ShowScrollBars,
+        PlaybackRequiresUserGesture,
     };
 
     // Must match the values from the public API in qwebenginesettings.h.
@@ -125,6 +126,7 @@ public:
     void setAttribute(Attribute, bool on);
     bool testAttribute(Attribute) const;
     void resetAttribute(Attribute);
+    bool isAttributeExplicitlySet(Attribute) const;
 
     void setFontFamily(FontFamily, const QString &);
     QString fontFamily(FontFamily);
diff --git a/src/webengine/api/qquickwebenginesettings.cpp b/src/webengine/api/qquickwebenginesettings.cpp
index 71af00d30..b238833ad 100644
--- a/src/webengine/api/qquickwebenginesettings.cpp
+++ b/src/webengine/api/qquickwebenginesettings.cpp
@@ -398,6 +398,20 @@ bool QQuickWebEngineSettings::showScrollBars() const
 }
 
 /*!
+  \qmlproperty bool WebEngineSettings::playbackRequiresUserGesture
+  \since QtWebEngine 1.7
+  Inhibits playback of media content until the user interacts with
+  the page. Disabled by default.
+
+  \note The behavior is similar to Chrome on Android when enabled,
+  and similar to Chrome on desktops when disabled (default).
+*/
+bool QQuickWebEngineSettings::playbackRequiresUserGesture() const
+{
+    return d_ptr->testAttribute(WebEngineSettings::PlaybackRequiresUserGesture);
+}
+
+/*!
     \qmlproperty string WebEngineSettings::defaultTextEncoding
     \since QtWebEngine 1.2
 
@@ -631,6 +645,14 @@ void QQuickWebEngineSettings::setShowScrollBars(bool on)
         Q_EMIT showScrollBarsChanged();
 }
 
+void QQuickWebEngineSettings::setPlaybackRequiresUserGesture(bool on)
+{
+    bool wasOn = d_ptr->testAttribute(WebEngineSettings::PlaybackRequiresUserGesture);
+    d_ptr->setAttribute(WebEngineSettings::PlaybackRequiresUserGesture, on);
+    if (wasOn != on)
+        Q_EMIT playbackRequiresUserGestureChanged();
+}
+
 void QQuickWebEngineSettings::setUnknownUrlSchemePolicy(QQuickWebEngineSettings::UnknownUrlSchemePolicy policy)
 {
     WebEngineSettings::UnknownUrlSchemePolicy oldPolicy = d_ptr->unknownUrlSchemePolicy();
diff --git a/src/webengine/api/qquickwebenginesettings_p.h b/src/webengine/api/qquickwebenginesettings_p.h
index 6e0900c58..63c397d21 100644
--- a/src/webengine/api/qquickwebenginesettings_p.h
+++ b/src/webengine/api/qquickwebenginesettings_p.h
@@ -89,6 +89,7 @@ class Q_WEBENGINE_PRIVATE_EXPORT QQuickWebEngineSettings : public QObject {
     Q_PROPERTY(bool allowWindowActivationFromJavaScript READ allowWindowActivationFromJavaScript WRITE setAllowWindowActivationFromJavaScript NOTIFY allowWindowActivationFromJavaScriptChanged REVISION 5 FINAL)
     Q_PROPERTY(bool showScrollBars READ showScrollBars WRITE setShowScrollBars NOTIFY showScrollBarsChanged REVISION 5 FINAL)
     Q_PROPERTY(UnknownUrlSchemePolicy unknownUrlSchemePolicy READ unknownUrlSchemePolicy WRITE setUnknownUrlSchemePolicy NOTIFY unknownUrlSchemePolicyChanged REVISION 6 FINAL)
+    Q_PROPERTY(bool playbackRequiresUserGesture READ playbackRequiresUserGesture WRITE setPlaybackRequiresUserGesture NOTIFY playbackRequiresUserGestureChanged REVISION 6 FINAL)
 
 public:
     enum UnknownUrlSchemePolicy {
@@ -127,6 +128,7 @@ public:
     bool allowWindowActivationFromJavaScript() const;
     bool showScrollBars() const;
     UnknownUrlSchemePolicy unknownUrlSchemePolicy() const;
+    bool playbackRequiresUserGesture() const;
 
     void setAutoLoadImages(bool on);
     void setJavascriptEnabled(bool on);
@@ -154,6 +156,7 @@ public:
     void setAllowWindowActivationFromJavaScript(bool on);
     void setShowScrollBars(bool on);
     void setUnknownUrlSchemePolicy(UnknownUrlSchemePolicy policy);
+    void setPlaybackRequiresUserGesture(bool on);
 
 signals:
     void autoLoadImagesChanged();
@@ -182,6 +185,7 @@ signals:
     Q_REVISION(5) void allowWindowActivationFromJavaScriptChanged();
     Q_REVISION(5) void showScrollBarsChanged();
     Q_REVISION(6) void unknownUrlSchemePolicyChanged();
+    Q_REVISION(6) void playbackRequiresUserGestureChanged();
 
 private:
     explicit QQuickWebEngineSettings(QQuickWebEngineSettings *parentSettings = 0);
diff --git a/src/webenginewidgets/api/qwebenginesettings.cpp b/src/webenginewidgets/api/qwebenginesettings.cpp
index 2d7c68926..b51f502a5 100644
--- a/src/webenginewidgets/api/qwebenginesettings.cpp
+++ b/src/webenginewidgets/api/qwebenginesettings.cpp
@@ -101,6 +101,8 @@ static WebEngineSettings::Attribute toWebEngineAttribute(QWebEngineSettings::Web
         return WebEngineSettings::AllowWindowActivationFromJavaScript;
     case QWebEngineSettings::ShowScrollBars:
         return WebEngineSettings::ShowScrollBars;
+    case QWebEngineSettings::PlaybackRequiresUserGesture:
+        return WebEngineSettings::PlaybackRequiresUserGesture;
 
     default:
         return WebEngineSettings::UnsupportedInCoreSettings;
diff --git a/src/webenginewidgets/api/qwebenginesettings.h b/src/webenginewidgets/api/qwebenginesettings.h
index fc9372968..ab03e207a 100644
--- a/src/webenginewidgets/api/qwebenginesettings.h
+++ b/src/webenginewidgets/api/qwebenginesettings.h
@@ -91,7 +91,8 @@ public:
         AllowRunningInsecureContent,
         AllowGeolocationOnInsecureOrigins,
         AllowWindowActivationFromJavaScript,
-        ShowScrollBars
+        ShowScrollBars,
+        PlaybackRequiresUserGesture
     };
 
     enum FontSize {
diff --git a/src/webenginewidgets/doc/src/qwebenginesettings_lgpl.qdoc b/src/webenginewidgets/doc/src/qwebenginesettings_lgpl.qdoc
index fb5ed019e..2f33d2e7a 100644
--- a/src/webenginewidgets/doc/src/qwebenginesettings_lgpl.qdoc
+++ b/src/webenginewidgets/doc/src/qwebenginesettings_lgpl.qdoc
@@ -168,6 +168,11 @@
     \value  ShowScrollBars
             Shows scroll bars.
             Enabled by default. (Added in Qt 5.10)
+    \value  PlaybackRequiresUserGesture
+            Inhibits playback of media content until the user interacts with
+            the page. This is similar to how Chrome on Android behaves, while
+            the default behavior when it is disabled is similar to Chrome on desktops.
+            Disabled by default. (Added in Qt 5.11)
 */
 
 /*!