Add a backgroundColor property

This also allows setting a transparent color to see through
the web view's body if its background color isn't specified.

The color is initially held by the top API view and is pulled
by the WebContentsAdapter in order to set it on the RenderView.
Since both blink and our local compositors (in the QOpenGLWidget
case) need to know about this color, RWHVQt takes care of pushing
it to both. The former through an IPC message and the latter
directly on the RWHVQtDelegate.

Task-number: QTBUG-41960
Change-Id: Ie13317b2d087f5612ad9c5fb0e05ca3e91aec9af
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@theqtcompany.com>
Reviewed-by: Andras Becsi <andras.becsi@theqtcompany.com>

5 files changed, 43 insertions, 0 deletions

diff --git a/src/webengine/api/qquickwebengineview.cpp b/src/webengine/api/qquickwebengineview.cpp
index eea584d4d..1f5e56bdb 100644
--- a/src/webengine/api/qquickwebengineview.cpp
+++ b/src/webengine/api/qquickwebengineview.cpp
@@ -108,6 +108,7 @@ QQuickWebEngineViewPrivate::QQuickWebEngineViewPrivate()
     , m_activeFocusOnPress(true)
     , devicePixelRatio(QGuiApplication::primaryScreen()->devicePixelRatio())
     , m_dpiScale(1.0)
+    , m_backgroundColor(Qt::white)
 {
     // The gold standard for mobile web content is 160 dpi, and the devicePixelRatio expected
     // is the (possibly quantized) ratio of device dpi to 160 dpi.
@@ -365,6 +366,11 @@ qreal QQuickWebEngineViewPrivate::dpiScale() const
     return m_dpiScale;
 }
 
+QColor QQuickWebEngineViewPrivate::backgroundColor() const
+{
+    return m_backgroundColor;
+}
+
 void QQuickWebEngineViewPrivate::loadStarted(const QUrl &provisionalUrl, bool isErrorPage)
 {
     Q_Q(QQuickWebEngineView);
@@ -928,6 +934,34 @@ qreal QQuickWebEngineView::zoomFactor() const
     return d->adapter->currentZoomFactor();
 }
 
+/*!
+    \qmlproperty bool WebEngineView::backgroundColor
+    \since QtWebEngine 1.3
+
+    Sets this property to change the color of the WebEngineView's background,
+    behing the document's body. You can set it to "transparent" or to a translucent
+    color to see through the document, or you can set this color to match your
+    web content in an hybrid app to prevent the white flashes that may appear
+    during loading.
+
+    The default value is white.
+*/
+QColor QQuickWebEngineView::backgroundColor() const
+{
+    Q_D(const QQuickWebEngineView);
+    return d->m_backgroundColor;
+}
+
+void QQuickWebEngineView::setBackgroundColor(const QColor &color)
+{
+    Q_D(QQuickWebEngineView);
+    if (color == d->m_backgroundColor)
+        return;
+    d->m_backgroundColor = color;
+    d->ensureContentsAdapter();
+    d->adapter->backgroundColorChanged();
+    emit backgroundColorChanged();
+}
 
 bool QQuickWebEngineView::isFullScreen() const
 {
diff --git a/src/webengine/api/qquickwebengineview_p.h b/src/webengine/api/qquickwebengineview_p.h
index 5db15e873..e26e4f360 100644
--- a/src/webengine/api/qquickwebengineview_p.h
+++ b/src/webengine/api/qquickwebengineview_p.h
@@ -92,6 +92,7 @@ class Q_WEBENGINE_PRIVATE_EXPORT QQuickWebEngineView : public QQuickItem {
     Q_PROPERTY(QQmlWebChannel *webChannel READ webChannel WRITE setWebChannel NOTIFY webChannelChanged REVISION 1)
     Q_PROPERTY(QQmlListProperty<QQuickWebEngineScript> userScripts READ userScripts FINAL)
     Q_PROPERTY(bool activeFocusOnPress READ activeFocusOnPress WRITE setActiveFocusOnPress NOTIFY activeFocusOnPressChanged REVISION 2)
+    Q_PROPERTY(QColor backgroundColor READ backgroundColor WRITE setBackgroundColor NOTIFY backgroundColorChanged REVISION 3)
 
 #ifdef ENABLE_QML_TESTSUPPORT_API
     Q_PROPERTY(QQuickWebEngineTestSupport *testSupport READ testSupport WRITE setTestSupport FINAL)
@@ -122,6 +123,8 @@ public:
     bool isFullScreen() const;
     qreal zoomFactor() const;
     void setZoomFactor(qreal arg);
+    QColor backgroundColor() const;
+    void setBackgroundColor(const QColor &color);
 
     QQuickWebEngineViewExperimental *experimental() const;
 
@@ -274,6 +277,7 @@ Q_SIGNALS:
     Q_REVISION(1) void profileChanged();
     Q_REVISION(1) void webChannelChanged();
     Q_REVISION(2) void activeFocusOnPressChanged(bool);
+    Q_REVISION(3) void backgroundColorChanged();
 
 protected:
     void geometryChanged(const QRectF &newGeometry, const QRectF &oldGeometry);
diff --git a/src/webengine/api/qquickwebengineview_p_p.h b/src/webengine/api/qquickwebengineview_p_p.h
index 7e411d349..4d95de84e 100644
--- a/src/webengine/api/qquickwebengineview_p_p.h
+++ b/src/webengine/api/qquickwebengineview_p_p.h
@@ -123,6 +123,7 @@ public:
     virtual void selectionChanged() Q_DECL_OVERRIDE { }
     virtual QRectF viewportRect() const Q_DECL_OVERRIDE;
     virtual qreal dpiScale() const Q_DECL_OVERRIDE;
+    virtual QColor backgroundColor() const Q_DECL_OVERRIDE;
     virtual void loadStarted(const QUrl &provisionalUrl, bool isErrorPage = false) Q_DECL_OVERRIDE;
     virtual void loadCommitted() Q_DECL_OVERRIDE;
     virtual void loadVisuallyCommitted() Q_DECL_OVERRIDE;
@@ -194,6 +195,7 @@ private:
     QScopedPointer<QtWebEngineCore::UIDelegatesManager> m_uIDelegatesManager;
     QList<QQuickWebEngineScript *> m_userScripts;
     qreal m_dpiScale;
+    QColor m_backgroundColor;
 };
 
 #ifndef QT_NO_ACCESSIBILITY
diff --git a/src/webengine/render_widget_host_view_qt_delegate_quick.h b/src/webengine/render_widget_host_view_qt_delegate_quick.h
index ddd0e4d9e..eb2860b27 100644
--- a/src/webengine/render_widget_host_view_qt_delegate_quick.h
+++ b/src/webengine/render_widget_host_view_qt_delegate_quick.h
@@ -70,6 +70,8 @@ public:
     virtual void move(const QPoint&) Q_DECL_OVERRIDE { }
     virtual void inputMethodStateChanged(bool editorVisible) Q_DECL_OVERRIDE;
     virtual void setTooltip(const QString&) Q_DECL_OVERRIDE { }
+    // The QtQuick view doesn't have a backbuffer of its own and doesn't need this
+    virtual void setClearColor(const QColor &) Q_DECL_OVERRIDE { }
 
 protected:
     virtual void focusInEvent(QFocusEvent *event) Q_DECL_OVERRIDE;
diff --git a/src/webengine/render_widget_host_view_qt_delegate_quickwindow.h b/src/webengine/render_widget_host_view_qt_delegate_quickwindow.h
index cda51a1ab..a4b08482f 100644
--- a/src/webengine/render_widget_host_view_qt_delegate_quickwindow.h
+++ b/src/webengine/render_widget_host_view_qt_delegate_quickwindow.h
@@ -73,6 +73,7 @@ public:
     virtual void move(const QPoint &screenPos) Q_DECL_OVERRIDE;
     virtual void inputMethodStateChanged(bool) Q_DECL_OVERRIDE {}
     virtual void setTooltip(const QString &tooltip) Q_DECL_OVERRIDE;
+    virtual void setClearColor(const QColor &) Q_DECL_OVERRIDE { }
 
 private:
     QScopedPointer<RenderWidgetHostViewQtDelegate> m_realDelegate;