Windows QPA: Prefer const-versions of API where applicable.

Ensure no detaching occurs by using Container::constFirst()
and QImage::constScanLine().

Change-Id: Ie197d795d9329de8be76ed388ba2c71ccf201f5c
Reviewed-by: Joerg Bornemann <joerg.bornemann@theqtcompany.com>

6 files changed, 12 insertions, 12 deletions

diff --git a/src/plugins/platforms/windows/qwindowscursor.cpp b/src/plugins/platforms/windows/qwindowscursor.cpp
index b9e893c650..9f65f73a81 100644
--- a/src/plugins/platforms/windows/qwindowscursor.cpp
+++ b/src/plugins/platforms/windows/qwindowscursor.cpp
@@ -142,8 +142,8 @@ static HCURSOR createBitmapCursor(const QImage &bbits, const QImage &mbits,
     QScopedArrayPointer<uchar> xMask(new uchar[height * n]);
     int x = 0;
     for (int i = 0; i < height; ++i) {
-        const uchar *bits = bbits.scanLine(i);
-        const uchar *mask = mbits.scanLine(i);
+        const uchar *bits = bbits.constScanLine(i);
+        const uchar *mask = mbits.constScanLine(i);
         for (int j = 0; j < n; ++j) {
             uchar b = bits[j];
             uchar m = mask[j];
@@ -173,8 +173,8 @@ static HCURSOR createBitmapCursor(const QImage &bbits, const QImage &mbits,
             x += sysN;
         } else {
             int fillWidth = n > sysN ? sysN : n;
-            const uchar *bits = bbits.scanLine(i);
-            const uchar *mask = mbits.scanLine(i);
+            const uchar *bits = bbits.constScanLine(i);
+            const uchar *mask = mbits.constScanLine(i);
             for (int j = 0; j < fillWidth; ++j) {
                 uchar b = bits[j];
                 uchar m = mask[j];
diff --git a/src/plugins/platforms/windows/qwindowseglcontext.cpp b/src/plugins/platforms/windows/qwindowseglcontext.cpp
index 20517bc5a9..5983741711 100644
--- a/src/plugins/platforms/windows/qwindowseglcontext.cpp
+++ b/src/plugins/platforms/windows/qwindowseglcontext.cpp
@@ -990,7 +990,7 @@ EGLConfig QWindowsEGLContext::chooseConfig(const QSurfaceFormat &format)
         QVector<EGLConfig> configs(matching);
         QWindowsEGLStaticContext::libEGL.eglChooseConfig(display, configureAttributes.constData(), configs.data(), configs.size(), &matching);
         if (!cfg && matching > 0)
-            cfg = configs.first();
+            cfg = configs.constFirst();
 
         EGLint red = 0;
         EGLint green = 0;
diff --git a/src/plugins/platforms/windows/qwindowsfontengine.cpp b/src/plugins/platforms/windows/qwindowsfontengine.cpp
index 4f463dd77c..00f9ecea60 100644
--- a/src/plugins/platforms/windows/qwindowsfontengine.cpp
+++ b/src/plugins/platforms/windows/qwindowsfontengine.cpp
@@ -1174,11 +1174,11 @@ QImage QWindowsFontEngine::alphaMapForGlyph(glyph_t glyph, const QTransform &xfo
     for (int y=0; y<mask->height(); ++y) {
         uchar *dest = alphaMap.scanLine(y);
         if (mask->image().format() == QImage::Format_RGB16) {
-            const qint16 *src = (qint16 *) ((const QImage &) mask->image()).scanLine(y);
+            const qint16 *src = reinterpret_cast<const qint16 *>(mask->image().constScanLine(y));
             for (int x=0; x<mask->width(); ++x)
                 dest[x] = 255 - qGray(src[x]);
         } else {
-            const uint *src = (uint *) ((const QImage &) mask->image()).scanLine(y);
+            const uint *src = reinterpret_cast<const uint *>(mask->image().constScanLine(y));
             for (int x=0; x<mask->width(); ++x) {
                 if (QWindowsNativeImage::systemFormat() == QImage::Format_RGB16)
                     dest[x] = 255 - qGray(src[x]);
@@ -1223,7 +1223,7 @@ QImage QWindowsFontEngine::alphaRGBMapForGlyph(glyph_t glyph, QFixed, const QTra
     QImage rgbMask(mask->width(), mask->height(), QImage::Format_RGB32);
     for (int y=0; y<mask->height(); ++y) {
         uint *dest = (uint *) rgbMask.scanLine(y);
-        const uint *src = (uint *) source.scanLine(y);
+        const uint *src = reinterpret_cast<const uint *>(source.constScanLine(y));
         for (int x=0; x<mask->width(); ++x) {
             dest[x] = 0xffffffff - (0x00ffffff & src[x]);
         }
diff --git a/src/plugins/platforms/windows/qwindowsfontenginedirectwrite.cpp b/src/plugins/platforms/windows/qwindowsfontenginedirectwrite.cpp
index bb4f4b1abd..71491595a4 100644
--- a/src/plugins/platforms/windows/qwindowsfontenginedirectwrite.cpp
+++ b/src/plugins/platforms/windows/qwindowsfontenginedirectwrite.cpp
@@ -493,7 +493,7 @@ QImage QWindowsFontEngineDirectWrite::alphaMapForGlyph(glyph_t glyph, QFixed sub
     QImage alphaMap(im.width(), im.height(), QImage::Format_Alpha8);
 
     for (int y=0; y<im.height(); ++y) {
-        uint *src = (uint*) im.scanLine(y);
+        const uint *src = reinterpret_cast<const uint *>(im.constScanLine(y));
         uchar *dst = alphaMap.scanLine(y);
         for (int x=0; x<im.width(); ++x) {
             *dst = 255 - (m_fontEngineData->pow_gamma[qGray(0xffffffff - *src)] * 255. / 2047.);
diff --git a/src/plugins/platforms/windows/qwindowsmime.cpp b/src/plugins/platforms/windows/qwindowsmime.cpp
index eaaf2820ee..a8264b55c0 100644
--- a/src/plugins/platforms/windows/qwindowsmime.cpp
+++ b/src/plugins/platforms/windows/qwindowsmime.cpp
@@ -175,8 +175,8 @@ static bool qt_write_dibv5(QDataStream &s, QImage image)
     memset(buf, 0, bpl_bmp);
     for (int y=image.height()-1; y>=0; y--) {
         // write the image bits
-        QRgb *p = (QRgb *)image.scanLine(y);
-        QRgb *end = p + image.width();
+        const QRgb *p = reinterpret_cast<const QRgb *>(image.constScanLine(y));
+        const QRgb *end = p + image.width();
         b = buf;
         while (p < end) {
             int alpha = qAlpha(*p);
diff --git a/src/plugins/platforms/windows/qwindowswindow.cpp b/src/plugins/platforms/windows/qwindowswindow.cpp
index 82d67e36f5..2ff71d827b 100644
--- a/src/plugins/platforms/windows/qwindowswindow.cpp
+++ b/src/plugins/platforms/windows/qwindowswindow.cpp
@@ -183,7 +183,7 @@ static QPoint windowPlacementOffset(HWND hwnd, const QPoint &point)
         return QPoint(0, 0);
     const QWindowsScreenManager &screenManager = QWindowsContext::instance()->screenManager();
     const QWindowsScreen *screen = screenManager.screens().size() == 1
-        ? screenManager.screens().first() : screenManager.screenAtDp(point);
+        ? screenManager.screens().constFirst() : screenManager.screenAtDp(point);
     if (screen)
         return screen->availableGeometry().topLeft() - screen->geometry().topLeft();
 #else