Unify IDirectFBSurface->Lock() calls

Certain compilers warns on this kind of code:

uchar *mem = ...;
(void**)(&mem)

dereferencing type punned pointer etc.

Since we had this for every call to Lock I put it all into a convenience
function. Also fix some issues where we memcpy'ed more bytes than
necessary (when stride != w * depth() / 8) and fix issue with
QDirectFBScreen::solidFill with pixelFormat == RGB32

Reviewed-by: Donald <qt-info@nokia.com>

4 files changed, 58 insertions, 46 deletions

diff --git a/src/plugins/gfxdrivers/directfb/qdirectfbpaintdevice.cpp b/src/plugins/gfxdrivers/directfb/qdirectfbpaintdevice.cpp
index 2a2ef5c..924090c 100644
--- a/src/plugins/gfxdrivers/directfb/qdirectfbpaintdevice.cpp
+++ b/src/plugins/gfxdrivers/directfb/qdirectfbpaintdevice.cpp
@@ -56,23 +56,16 @@ IDirectFBSurface *QDirectFBPaintDevice::directFBSurface() const
 }
 
 
-// Locks the dfb surface and creates a QImage (lockedImage) from the pointer
-void QDirectFBPaintDevice::lockDirectFB() {
-
+void QDirectFBPaintDevice::lockDirectFB()
+{
     if (lockedImage)
         return; // Already locked
 
-    void *mem;
-    int w, h;
-    DFBResult result = dfbSurface->Lock(dfbSurface, DSLF_WRITE, &mem, &bpl);
-    if (result != DFB_OK || !mem) {
-        DirectFBError("QDirectFBPixmapData::buffer()", result);
-        return;
+    if (uchar *mem = QDirectFBScreen::lockSurface(dfbSurface, DSLF_WRITE, &bpl)) {
+        const QSize s = size();
+        lockedImage = new QImage(mem, s.width(), s.height(), bpl,
+                                 QDirectFBScreen::getImageFormat(dfbSurface));
     }
-
-    dfbSurface->GetSize(dfbSurface, &w, &h);
-    lockedImage = new QImage(static_cast<uchar*>(mem), w, h, bpl,
-                             QDirectFBScreen::getImageFormat(dfbSurface));
 }
 
 
diff --git a/src/plugins/gfxdrivers/directfb/qdirectfbpixmap.cpp b/src/plugins/gfxdrivers/directfb/qdirectfbpixmap.cpp
index 0a1696a..a6017b8 100644
--- a/src/plugins/gfxdrivers/directfb/qdirectfbpixmap.cpp
+++ b/src/plugins/gfxdrivers/directfb/qdirectfbpixmap.cpp
@@ -267,16 +267,17 @@ void QDirectFBPixmapData::fill(const QColor &color)
     if (forceRaster) {
         // in DSPF_RGB32 all dfb drawing causes the Alpha byte to be
         // set to 0. This causes issues for the raster engine.
-        char *mem;
-        int bpl;
-        const int h = QPixmapData::height();
-        dfbSurface->Lock(dfbSurface, DSLF_WRITE, (void**)&mem, &bpl);
-        const int c = color.rgba();
-        for (int i = 0; i < h; ++i) {
-            memset(mem, c, bpl);
-            mem += bpl;
+        uchar *mem = QDirectFBScreen::lockSurface(dfbSurface, DSLF_WRITE, &bpl);
+        if (mem) {
+            const int h = QPixmapData::height();
+            const int w = QPixmapData::width() * 4; // 4 bytes per 32 bit pixel
+            const int c = color.rgba();
+            for (int i = 0; i < h; ++i) {
+                memset(mem, c, w);
+                mem += bpl;
+            }
+            dfbSurface->Unlock(dfbSurface);
         }
-        dfbSurface->Unlock(dfbSurface);
     } else {
         dfbSurface->Clear(dfbSurface, color.red(), color.green(), color.blue(),
                           color.alpha());
diff --git a/src/plugins/gfxdrivers/directfb/qdirectfbscreen.cpp b/src/plugins/gfxdrivers/directfb/qdirectfbscreen.cpp
index 65c027d..490eeb0 100644
--- a/src/plugins/gfxdrivers/directfb/qdirectfbscreen.cpp
+++ b/src/plugins/gfxdrivers/directfb/qdirectfbscreen.cpp
@@ -159,15 +159,17 @@ IDirectFBSurface* QDirectFBScreen::createDFBSurface(const QImage &img, SurfaceCr
     IDirectFBSurface *surface = createDFBSurface(&desc, options);
 #ifdef QT_NO_DIRECTFB_PREALLOCATED
     if (surface) {
-        char *mem;
         int bpl;
-        surface->Lock(surface, DSLF_WRITE, (void**)&mem, &bpl);
-        const int h = img.height();
-        for (int i = 0; i < h; ++i) {
-            memcpy(mem, img.scanLine(i), bpl);
-            mem += bpl;
+        uchar *mem = QDirectFBScreen::lockSurface(surface, DSLF_WRITE, &bpl);
+        if (mem) {
+            const int h = img.height();
+            const int w = img.width() * img.depth() / 8;
+            for (int i = 0; i < h; ++i) {
+                memcpy(mem, img.scanLine(i), w);
+                mem += bpl;
+            }
+            surface->Unlock(surface);
         }
-        surface->Unlock(surface);
     }
 #endif
 #ifndef QT_NO_DIRECTFB_PALETTE
@@ -317,15 +319,17 @@ IDirectFBSurface *QDirectFBScreen::copyToDFBSurface(const QImage &img,
     imgSurface->Release(imgSurface);
 #else // QT_NO_DIRECTFB_PREALLOCATED
     Q_ASSERT(image.format() == pixmapFormat);
-    char *mem;
     int bpl;
-    dfbSurface->Lock(dfbSurface, DSLF_WRITE, (void**)&mem, &bpl);
-    const int w = image.width() * image.depth() / 8;
-    for (int i = 0; i < image.height(); ++i) {
-        memcpy(mem, image.scanLine(i), w);
-        mem += bpl;
+    uchar *mem = QDirectFBScreen::lockSurface(dfbSurface, DSLF_WRITE, &bpl);
+    if (mem) {
+        const int h = image.height();
+        const int w = image.width() * image.depth() / 8;
+        for (int i=0; i<h; ++i) {
+            memcpy(mem, image.scanLine(i), w);
+            mem += bpl;
+        }
+        dfbSurface->Unlock(dfbSurface);
     }
-    dfbSurface->Unlock(dfbSurface);
 #endif
     return dfbSurface;
 }
@@ -1188,23 +1192,23 @@ void QDirectFBScreen::blit(IDirectFBSurface *src, const QPoint &topLeft,
                                  points.data(), n);
 }
 
+// This function is only ever called by QScreen::drawBackground which
+// is only ever called by QScreen::compose which is never called with
+// DirectFB so it's really a noop.
 void QDirectFBScreen::solidFill(const QColor &color, const QRegion &region)
 {
     if (region.isEmpty())
         return;
 
     if (QDirectFBScreen::getImageFormat(d_ptr->dfbSurface) == QImage::Format_RGB32) {
-        uchar *mem;
-        int bpl;
-        d_ptr->dfbSurface->Lock(d_ptr->dfbSurface, DSLF_WRITE, (void**)&mem, &bpl);
-        QImage img(mem, w, h, bpl, QImage::Format_RGB32);
-        QPainter p(&img);
-        p.setBrush(color);
-        p.setPen(Qt::NoPen);
-        const QVector<QRect> rects = region.rects();
-        p.drawRects(rects.constData(), rects.size());
-        p.end();
+        data = QDirectFBScreen::lockSurface(d_ptr->dfbSurface, DSLF_WRITE, &lstep);
+        if (!data)
+            return;
+
+        QScreen::solidFill(color, region);
         d_ptr->dfbSurface->Unlock(d_ptr->dfbSurface);
+        data = 0;
+        lstep = 0;
     } else {
         d_ptr->dfbSurface->SetColor(d_ptr->dfbSurface,
                                     color.red(), color.green(), color.blue(),
@@ -1241,3 +1245,15 @@ bool QDirectFBScreen::initSurfaceDescriptionPixelFormat(DFBSurfaceDescription *d
     }
     return true;
 }
+
+uchar *QDirectFBScreen::lockSurface(IDirectFBSurface *surface, DFBSurfaceLockFlags flags, int *bpl)
+{
+    void *mem;
+    const DFBResult result = surface->Lock(surface, flags, static_cast<void**>(&mem), bpl);
+    if (result != DFB_OK) {
+        DirectFBError("QDirectFBPixmapData::lockSurface()", result);
+    }
+
+    return reinterpret_cast<uchar*>(mem);
+}
+
diff --git a/src/plugins/gfxdrivers/directfb/qdirectfbscreen.h b/src/plugins/gfxdrivers/directfb/qdirectfbscreen.h
index f394ac1..8dd38dc 100644
--- a/src/plugins/gfxdrivers/directfb/qdirectfbscreen.h
+++ b/src/plugins/gfxdrivers/directfb/qdirectfbscreen.h
@@ -127,6 +127,8 @@ public:
                                      const QImage &image);
 #endif
 
+    static uchar *lockSurface(IDirectFBSurface *surface, DFBSurfaceLockFlags flags, int *bpl = 0);
+
 private:
     void compose(const QRegion &r);
     void blit(IDirectFBSurface *src, const QPoint &topLeft,