Windows/Linux: Cache cursors by mask/pixmap keys and shape.

Task-number: QTBUG-33383

Change-Id: I65a5a0870f50f42c26a4d297331224b3597a36e0
Reviewed-by: Andy Shaw <andy.shaw@digia.com>
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>

2 files changed, 56 insertions, 12 deletions

diff --git a/src/plugins/platforms/windows/qwindowscursor.cpp b/src/plugins/platforms/windows/qwindowscursor.cpp
index 5b2a3acbae..5e7944a4cf 100644
--- a/src/plugins/platforms/windows/qwindowscursor.cpp
+++ b/src/plugins/platforms/windows/qwindowscursor.cpp
@@ -45,7 +45,7 @@
 #include "qwindowswindow.h"
 #include "qwindowsscreen.h"
 
-#include <QtGui/QPixmap>
+#include <QtGui/QBitmap>
 #include <QtGui/QImage>
 #include <QtGui/QBitmap>
 #include <QtGui/QGuiApplication>
@@ -61,6 +61,30 @@ Q_GUI_EXPORT HBITMAP qt_pixmapToWinHBITMAP(const QPixmap &p, int hbitmapFormat =
 Q_GUI_EXPORT HBITMAP qt_createIconMask(const QBitmap &bitmap);
 
 /*!
+    \class QWindowsCursorCacheKey
+    \brief Cache key for storing values in a QHash with a QCursor as key.
+
+    \internal
+    \ingroup qt-lighthouse-win
+*/
+
+QWindowsCursorCacheKey::QWindowsCursorCacheKey(const QCursor &c)
+    : shape(c.shape()), bitmapCacheKey(0), maskCacheKey(0)
+{
+    if (shape == Qt::BitmapCursor) {
+        const qint64 pixmapCacheKey = c.pixmap().cacheKey();
+        if (pixmapCacheKey) {
+            bitmapCacheKey = pixmapCacheKey;
+        } else {
+            Q_ASSERT(c.bitmap());
+            Q_ASSERT(c.mask());
+            bitmapCacheKey = c.bitmap()->cacheKey();
+            maskCacheKey = c.mask()->cacheKey();
+        }
+    }
+}
+
+/*!
     \class QWindowsCursor
     \brief Platform cursor implementation
 
@@ -388,9 +412,10 @@ HCURSOR QWindowsCursor::createSystemCursor(const QCursor &c)
 
 QWindowsWindowCursor QWindowsCursor::standardWindowCursor(Qt::CursorShape shape)
 {
-    StandardCursorCache::iterator it = m_standardCursorCache.find(shape);
-    if (it == m_standardCursorCache.end())
-        it = m_standardCursorCache.insert(shape, QWindowsWindowCursor(QCursor(shape)));
+    const QWindowsCursorCacheKey key(shape);
+    CursorCache::iterator it = m_cursorCache.find(key);
+    if (it == m_cursorCache.end())
+        it = m_cursorCache.insert(key, QWindowsWindowCursor(QCursor(shape)));
     return it.value();
 }
 
@@ -400,10 +425,10 @@ QWindowsWindowCursor QWindowsCursor::standardWindowCursor(Qt::CursorShape shape)
 
 QWindowsWindowCursor QWindowsCursor::pixmapWindowCursor(const QCursor &c)
 {
-    const qint64 cacheKey = c.pixmap().cacheKey();
-    PixmapCursorCache::iterator it = m_pixmapCursorCache.find(cacheKey);
-    if (it == m_pixmapCursorCache.end())
-        it = m_pixmapCursorCache.insert(cacheKey, QWindowsWindowCursor(c));
+    const  QWindowsCursorCacheKey cacheKey(c);
+    CursorCache::iterator it = m_cursorCache.find(cacheKey);
+    if (it == m_cursorCache.end())
+        it = m_cursorCache.insert(cacheKey, QWindowsWindowCursor(c));
     return it.value();
 }
 
diff --git a/src/plugins/platforms/windows/qwindowscursor.h b/src/plugins/platforms/windows/qwindowscursor.h
index 1e818bc9b8..b366d9a06a 100644
--- a/src/plugins/platforms/windows/qwindowscursor.h
+++ b/src/plugins/platforms/windows/qwindowscursor.h
@@ -52,6 +52,27 @@ QT_BEGIN_NAMESPACE
 
 class QWindowsWindowCursorData;
 
+struct QWindowsCursorCacheKey
+{
+    explicit QWindowsCursorCacheKey(const QCursor &c);
+    explicit QWindowsCursorCacheKey(Qt::CursorShape s) : shape(s), bitmapCacheKey(0), maskCacheKey(0) {}
+    QWindowsCursorCacheKey() : shape(Qt::CustomCursor), bitmapCacheKey(0), maskCacheKey(0) {}
+
+    Qt::CursorShape shape;
+    qint64 bitmapCacheKey;
+    qint64 maskCacheKey;
+};
+
+inline bool operator==(const QWindowsCursorCacheKey &k1, const QWindowsCursorCacheKey &k2)
+{
+    return k1.shape == k2.shape && k1.bitmapCacheKey == k2.bitmapCacheKey && k1.maskCacheKey == k2.maskCacheKey;
+}
+
+inline uint qHash(const QWindowsCursorCacheKey &k, uint seed) Q_DECL_NOTHROW
+{
+    return (uint(k.shape) + uint(k.bitmapCacheKey) + uint(k.maskCacheKey)) ^ seed;
+}
+
 class QWindowsWindowCursor
 {
 public:
@@ -86,11 +107,9 @@ public:
     QWindowsWindowCursor pixmapWindowCursor(const QCursor &c);
 
 private:
-    typedef QHash<Qt::CursorShape, QWindowsWindowCursor> StandardCursorCache;
-    typedef QHash<qint64, QWindowsWindowCursor> PixmapCursorCache;
+    typedef QHash<QWindowsCursorCacheKey, QWindowsWindowCursor>  CursorCache;
 
-    StandardCursorCache m_standardCursorCache;
-    PixmapCursorCache m_pixmapCursorCache;
+    CursorCache m_cursorCache;
 };
 
 QT_END_NAMESPACE