Update device pixel ratio on screen change

This patch makes QWebPage listen to QWindow::screenChangedEvent
and update the device pixel ratio when it is received.

Task-number: QTBUG-36190
Change-Id: Ia28571ef241a3a2f970876f6e474b01c1ac001e1
Reviewed-by: Jocelyn Turcotte <jocelyn.turcotte@digia.com>

5 files changed, 40 insertions, 6 deletions

diff --git a/Source/WebKit/qt/WebCoreSupport/QWebPageAdapter.cpp b/Source/WebKit/qt/WebCoreSupport/QWebPageAdapter.cpp
index a12ef553b..129f888b9 100644
--- a/Source/WebKit/qt/WebCoreSupport/QWebPageAdapter.cpp
+++ b/Source/WebKit/qt/WebCoreSupport/QWebPageAdapter.cpp
@@ -1362,7 +1362,7 @@ QWebPageAdapter::ViewportAttributes QWebPageAdapter::viewportAttributesForSize(c
     return result;
 }
 
-void QWebPageAdapter::setDevicePixelRatio(int devicePixelRatio)
+void QWebPageAdapter::setDevicePixelRatio(float devicePixelRatio)
 {
     page->setDeviceScaleFactor(devicePixelRatio);
 }
diff --git a/Source/WebKit/qt/WebCoreSupport/QWebPageAdapter.h b/Source/WebKit/qt/WebCoreSupport/QWebPageAdapter.h
index 3b6fc3a5c..3629e906d 100644
--- a/Source/WebKit/qt/WebCoreSupport/QWebPageAdapter.h
+++ b/Source/WebKit/qt/WebCoreSupport/QWebPageAdapter.h
@@ -352,7 +352,7 @@ public:
     };
 
     ViewportAttributes viewportAttributesForSize(const QSize& availableSize, const QSize& deviceSize) const;
-    void setDevicePixelRatio(int devicePixelRatio);
+    void setDevicePixelRatio(float devicePixelRatio);
 
     QWebSettings *settings;
 
diff --git a/Source/WebKit/qt/WidgetApi/qwebpage.cpp b/Source/WebKit/qt/WidgetApi/qwebpage.cpp
index dac343bd2..cb9559e33 100644
--- a/Source/WebKit/qt/WidgetApi/qwebpage.cpp
+++ b/Source/WebKit/qt/WidgetApi/qwebpage.cpp
@@ -68,6 +68,7 @@
 #include <QNetworkProxy>
 #include <QNetworkRequest>
 #include <QPainter>
+#include <QScreen>
 #include <QSslSocket>
 #include <QStyle>
 #include <QSysInfo>
@@ -80,6 +81,7 @@
 #include <QTouchEvent>
 #include <QUndoStack>
 #include <QUrl>
+#include <QWindow>
 #if defined(Q_WS_X11)
 #include <QX11Info>
 #endif
@@ -195,6 +197,7 @@ QWebPagePrivate::QWebPagePrivate(QWebPage *qq)
     , linkPolicy(QWebPage::DontDelegateLinks)
     , m_viewportSize(QSize(0, 0))
     , useFixedLayout(false)
+    , window(0)
     , inspectorFrontend(0)
     , inspector(0)
     , inspectorIsInternalOnly(false)
@@ -1941,15 +1944,39 @@ void QWebPage::setViewportSize(const QSize &size) const
 {
     d->m_viewportSize = size;
 
+    d->updateWindow();
+
     QWebFrameAdapter* mainFrame = d->mainFrameAdapter();
     if (!mainFrame->hasView())
         return;
 
-    d->setDevicePixelRatio(d->view->devicePixelRatio());
-
     mainFrame->setViewportSize(size);
 }
 
+void QWebPagePrivate::updateWindow()
+{
+    QWindow* _window = 0;
+    if (view && view->window())
+        _window = view->window()->windowHandle();
+
+    if (window == _window)
+        return;
+
+    if (window)
+        QObject::disconnect(window, SIGNAL(screenChanged(QScreen*)), q, SLOT(_q_updateScreen(QScreen*)));
+    window = _window;
+    if (window) {
+        QObject::connect(window, SIGNAL(screenChanged(QScreen*)), q, SLOT(_q_updateScreen(QScreen*)));
+        _q_updateScreen(window->screen());
+    }
+}
+
+void QWebPagePrivate::_q_updateScreen(QScreen* screen)
+{
+    if (screen)
+        setDevicePixelRatio(screen->devicePixelRatio());
+}
+
 static int getintenv(const char* variable)
 {
     bool ok;
diff --git a/Source/WebKit/qt/WidgetApi/qwebpage.h b/Source/WebKit/qt/WidgetApi/qwebpage.h
index 2e3f6aa50..24fe1383e 100644
--- a/Source/WebKit/qt/WidgetApi/qwebpage.h
+++ b/Source/WebKit/qt/WidgetApi/qwebpage.h
@@ -35,6 +35,7 @@ class QMenu;
 class QNetworkRequest;
 class QNetworkReply;
 class QNetworkAccessManager;
+class QScreen;
 QT_END_NAMESPACE
 
 class QWebElement;
@@ -444,6 +445,7 @@ private:
     Q_PRIVATE_SLOT(d, void _q_webActionTriggered(bool checked))
 #endif
     Q_PRIVATE_SLOT(d, void _q_cleanupLeakMessages())
+    Q_PRIVATE_SLOT(d, void _q_updateScreen(QScreen*))
 
     QWebPagePrivate *d;
 
diff --git a/Source/WebKit/qt/WidgetApi/qwebpage_p.h b/Source/WebKit/qt/WidgetApi/qwebpage_p.h
index b35cf2e19..8ba6c4c40 100644
--- a/Source/WebKit/qt/WidgetApi/qwebpage_p.h
+++ b/Source/WebKit/qt/WidgetApi/qwebpage_p.h
@@ -48,9 +48,11 @@ class Frame;
 }
 
 QT_BEGIN_NAMESPACE
-class QUndoStack;
-class QMenu;
 class QBitArray;
+class QMenu;
+class QScreen;
+class QUndoStack;
+class QWindow;
 QT_END_NAMESPACE
 
 class QtPluginWidgetAdapter;
@@ -163,6 +165,8 @@ public:
 
     bool gestureEvent(QGestureEvent*);
 
+    void updateWindow();
+    void _q_updateScreen(QScreen*);
 
     void setInspector(QWebInspector*);
     QWebInspector* getOrCreateInspector();
@@ -195,6 +199,7 @@ public:
 
     QAction *actions[QWebPage::WebActionCount];
 
+    QWindow* window;
     QWidget* inspectorFrontend;
     QWebInspector* inspector;
     bool inspectorIsInternalOnly; // True if created through the Inspect context menu action