Support grabWindow() in linuxfb

Task-number: QTBUG-44465
Change-Id: Id4b0fcbcce3e005c1f147fa227ef987daac20fd5
Reviewed-by: Andy Nichols <andy.nichols@theqtcompany.com>

src/platformsupport/fbconvenience/qfbbackingstore.cpp

@@ -46,7 +46,7 @@ QFbBackingStore::QFbBackingStore(QWindow *window)
     if (window->handle())
         (static_cast<QFbWindow *>(window->handle()))->setBackingStore(this);
     else
-        (static_cast<QFbScreen *>(window->screen()->handle()))->addBackingStore(this);
+        (static_cast<QFbScreen *>(window->screen()->handle()))->addPendingBackingStore(this);
 }
 
 QFbBackingStore::~QFbBackingStore()

src/platformsupport/fbconvenience/qfbscreen.cpp

@@ -74,15 +74,15 @@ bool QFbScreen::event(QEvent *event)
 void QFbScreen::addWindow(QFbWindow *window)
 {
     mWindowStack.prepend(window);
-    if (!mBackingStores.isEmpty()) {
+    if (!mPendingBackingStores.isEmpty()) {
         //check if we have a backing store for this window
-        for (int i = 0; i < mBackingStores.size(); ++i) {
-            QFbBackingStore *bs = mBackingStores.at(i);
+        for (int i = 0; i < mPendingBackingStores.size(); ++i) {
+            QFbBackingStore *bs = mPendingBackingStores.at(i);
             // this gets called during QWindow::create() at a point where the
             // invariant (window->handle()->window() == window) is broken
             if (bs->window() == window->window()) {
                 window->setBackingStore(bs);
-                mBackingStores.removeAt(i);
+                mPendingBackingStores.removeAt(i);
                 break;
             }
         }
@@ -295,5 +295,14 @@ QRegion QFbScreen::doRedraw()
     return touchedRegion;
 }
 
+QFbWindow *QFbScreen::windowForId(WId wid) const
+{
+    for (int i = 0; i < mWindowStack.count(); ++i)
+        if (mWindowStack[i]->winId() == wid)
+            return mWindowStack[i];
+
+    return 0;
+}
+
 QT_END_NAMESPACE
 

src/platformsupport/fbconvenience/qfbscreen_p.h

@@ -80,7 +80,7 @@ public:
     virtual void lower(QFbWindow *window);
     virtual void topWindowChanged(QWindow *) {}
 
-    void addBackingStore(QFbBackingStore *bs) {mBackingStores << bs;}
+    void addPendingBackingStore(QFbBackingStore *bs) { mPendingBackingStores << bs; }
 
     void scheduleUpdate();
 
@@ -89,13 +89,14 @@ public slots:
     void setPhysicalSize(const QSize &size);
     void setGeometry(const QRect &rect);
 
-protected slots:
+protected:
     virtual QRegion doRedraw();
 
-protected:
     void initializeCompositor();
     bool event(QEvent *event);
 
+    QFbWindow *windowForId(WId wid) const;
+
     QList<QFbWindow *> mWindowStack;
     QRegion mRepaintRegion;
     bool mUpdatePending;
@@ -113,7 +114,7 @@ private:
 
     QPainter *mCompositePainter;
     QVector<QPair<QRect, int> > mCachedRects;
-    QList <QFbBackingStore*> mBackingStores;
+    QList<QFbBackingStore*> mPendingBackingStores;
 
     friend class QFbWindow;
     bool mIsUpToDate;

src/plugins/platforms/linuxfb/qlinuxfbscreen.cpp

@@ -33,6 +33,7 @@
 
 #include "qlinuxfbscreen.h"
 #include <QtPlatformSupport/private/qfbcursor_p.h>
+#include <QtPlatformSupport/private/qfbwindow_p.h>
 #include <QtCore/QRegularExpression>
 #include <QtGui/QPainter>
 
@@ -421,5 +422,32 @@ QRegion QLinuxFbScreen::doRedraw()
     return touched;
 }
 
+// grabWindow() grabs "from the screen" not from the backingstores.
+// In linuxfb's case it will also include the mouse cursor.
+QPixmap QLinuxFbScreen::grabWindow(WId wid, int x, int y, int width, int height) const
+{
+    if (!wid) {
+        if (width < 0)
+            width = mFbScreenImage.width() - x;
+        if (height < 0)
+            height = mFbScreenImage.height() - y;
+        return QPixmap::fromImage(mFbScreenImage).copy(x, y, width, height);
+    }
+
+    QFbWindow *window = windowForId(wid);
+    if (window) {
+        const QRect geom = window->geometry();
+        if (width < 0)
+            width = geom.width() - x;
+        if (height < 0)
+            height = geom.height() - y;
+        QRect rect(geom.topLeft() + QPoint(x, y), QSize(width, height));
+        rect &= window->geometry();
+        return QPixmap::fromImage(mFbScreenImage).copy(rect);
+    }
+
+    return QPixmap();
+}
+
 QT_END_NAMESPACE
 

src/plugins/platforms/linuxfb/qlinuxfbscreen.h

@@ -50,7 +50,8 @@ public:
 
     bool initialize();
 
-public slots:
+    QPixmap grabWindow(WId wid, int x, int y, int width, int height) const Q_DECL_OVERRIDE;
+
     QRegion doRedraw() Q_DECL_OVERRIDE;
 
 private: