Make native cursor handles accessible.

Add QWindowsNativeInterface::nativeResourceForCursor() and
implement for Windows (returning the HCURSOR) and XCB (returning
the xcb_cursor).

Task-number: QTBUG-49386
Change-Id: I963869f6e8741449822ecbe6489f9c42a786c7a6
Reviewed-by: Joerg Bornemann <joerg.bornemann@theqtcompany.com>

src/gui/kernel/qplatformnativeinterface.cpp

@@ -80,6 +80,15 @@ void * QPlatformNativeInterface::nativeResourceForBackingStore(const QByteArray
     return 0;
 }
 
+#ifndef QT_NO_CURSOR
+void *QPlatformNativeInterface::nativeResourceForCursor(const QByteArray &resource, const QCursor &cursor)
+{
+    Q_UNUSED(resource);
+    Q_UNUSED(cursor);
+    return Q_NULLPTR;
+}
+#endif // !QT_NO_CURSOR
+
 QPlatformNativeInterface::NativeResourceForIntegrationFunction QPlatformNativeInterface::nativeResourceFunctionForIntegration(const QByteArray &resource)
 {
     Q_UNUSED(resource);

src/gui/kernel/qplatformnativeinterface.h

@@ -65,6 +65,9 @@ public:
     virtual void *nativeResourceForScreen(const QByteArray &resource, QScreen *screen);
     virtual void *nativeResourceForWindow(const QByteArray &resource, QWindow *window);
     virtual void *nativeResourceForBackingStore(const QByteArray &resource, QBackingStore *backingStore);
+#ifndef QT_NO_CURSOR
+    virtual void *nativeResourceForCursor(const QByteArray &resource, const QCursor &cursor);
+#endif
 
     typedef void * (*NativeResourceForIntegrationFunction)();
     typedef void * (*NativeResourceForContextFunction)(QOpenGLContext *context);

src/plugins/platforms/windows/qwindowscursor.cpp

@@ -780,6 +780,21 @@ QPixmap QWindowsCursor::dragDefaultCursor(Qt::DropAction action) const
     return m_ignoreDragCursor;
 }
 
+HCURSOR QWindowsCursor::hCursor(const QCursor &c) const
+{
+    const Qt::CursorShape shape = c.shape();
+    if (shape == Qt::BitmapCursor) {
+        const auto pit = m_pixmapCursorCache.constFind(QWindowsPixmapCursorCacheKey(c));
+        if (pit != m_pixmapCursorCache.constEnd())
+            return pit.value()->handle();
+    } else {
+        const auto sit = m_standardCursorCache.constFind(shape);
+        if (sit != m_standardCursorCache.constEnd())
+            return sit.value()->handle();
+    }
+    return HCURSOR(0);
+}
+
 /*!
     \class QWindowsWindowCursor
     \brief Per-Window cursor. Contains a QCursor and manages its associated system

src/plugins/platforms/windows/qwindowscursor.h

@@ -115,6 +115,8 @@ public:
 
     QPixmap dragDefaultCursor(Qt::DropAction action) const;
 
+    HCURSOR hCursor(const QCursor &c) const;
+
 private:
     typedef QHash<Qt::CursorShape, CursorHandlePtr> StandardCursorCache;
     typedef QHash<QWindowsPixmapCursorCacheKey, CursorHandlePtr> PixmapCursorCache;

src/plugins/platforms/windows/qwindowsnativeinterface.cpp

@@ -34,6 +34,7 @@
 #include "qwindowsnativeinterface.h"
 #include "qwindowswindow.h"
 #include "qwindowscontext.h"
+#include "qwindowscursor.h"
 #include "qwindowsfontdatabase.h"
 #include "qwindowsopenglcontext.h"
 #include "qwindowsopengltester.h"
@@ -42,6 +43,8 @@
 
 #include <QtGui/QWindow>
 #include <QtGui/QOpenGLContext>
+#include <QtGui/QScreen>
+#include <qpa/qplatformscreen.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -102,6 +105,19 @@ void *QWindowsNativeInterface::nativeResourceForWindow(const QByteArray &resourc
     return 0;
 }
 
+#ifndef QT_NO_CURSOR
+void *QWindowsNativeInterface::nativeResourceForCursor(const QByteArray &resource, const QCursor &cursor)
+{
+    if (resource == QByteArrayLiteral("hcursor")) {
+        if (const QScreen *primaryScreen = QGuiApplication::primaryScreen()) {
+            if (const QPlatformCursor *pCursor= primaryScreen->handle()->cursor())
+                return static_cast<const QWindowsCursor *>(pCursor)->hCursor(cursor);
+        }
+    }
+    return Q_NULLPTR;
+}
+#endif // !QT_NO_CURSOR
+
 static const char customMarginPropertyC[] = "WindowsCustomMargins";
 
 QVariant QWindowsNativeInterface::windowProperty(QPlatformWindow *window, const QString &name) const

src/plugins/platforms/windows/qwindowsnativeinterface.h

@@ -66,7 +66,9 @@ public:
     void *nativeResourceForContext(const QByteArray &resource, QOpenGLContext *context) Q_DECL_OVERRIDE;
 #endif
     void *nativeResourceForWindow(const QByteArray &resource, QWindow *window) Q_DECL_OVERRIDE;
-
+#ifndef QT_NO_CURSOR
+    void *nativeResourceForCursor(const QByteArray &resource, const QCursor &cursor) Q_DECL_OVERRIDE;
+#endif
     Q_INVOKABLE void *createMessageWindow(const QString &classNameTemplate,
                                           const QString &windowName,
                                           void *eventProc) const;

src/plugins/platforms/xcb/qxcbcursor.h

@@ -77,6 +77,11 @@ public:
 
     static void queryPointer(QXcbConnection *c, QXcbVirtualDesktop **virtualDesktop, QPoint *pos, int *keybMask = 0);
 
+#ifndef QT_NO_CURSOR
+    xcb_cursor_t xcbCursor(const QCursor &c) const
+        { return m_cursorHash.value(QXcbCursorCacheKey(c), xcb_cursor_t(0)); }
+#endif
+
 private:
 #ifndef QT_NO_CURSOR
     typedef QHash<QXcbCursorCacheKey, xcb_cursor_t> CursorHash;

src/plugins/platforms/xcb/qxcbnativeinterface.cpp

@@ -33,6 +33,7 @@
 
 #include "qxcbnativeinterface.h"
 
+#include "qxcbcursor.h"
 #include "qxcbscreen.h"
 #include "qxcbwindow.h"
 #include "qxcbintegration.h"
@@ -288,6 +289,20 @@ void *QXcbNativeInterface::nativeResourceForBackingStore(const QByteArray &resou
     return result;
 }
 
+#ifndef QT_NO_CURSOR
+void *QXcbNativeInterface::nativeResourceForCursor(const QByteArray &resource, const QCursor &cursor)
+{
+    if (resource == QByteArrayLiteral("xcbcursor")) {
+        if (const QScreen *primaryScreen = QGuiApplication::primaryScreen()) {
+            if (const QPlatformCursor *pCursor= primaryScreen->handle()->cursor()) {
+                xcb_cursor_t xcbCursor = static_cast<const QXcbCursor *>(pCursor)->xcbCursor(cursor);
+                return reinterpret_cast<void *>(quintptr(xcbCursor));
+            }
+        }
+    }
+    return Q_NULLPTR;
+}
+#endif // !QT_NO_CURSOR
 
 QPlatformNativeInterface::NativeResourceForIntegrationFunction QXcbNativeInterface::nativeResourceFunctionForIntegration(const QByteArray &resource)
 {

src/plugins/platforms/xcb/qxcbnativeinterface.h

@@ -78,6 +78,9 @@ public:
     void *nativeResourceForScreen(const QByteArray &resource, QScreen *screen) Q_DECL_OVERRIDE;
     void *nativeResourceForWindow(const QByteArray &resourceString, QWindow *window) Q_DECL_OVERRIDE;
     void *nativeResourceForBackingStore(const QByteArray &resource, QBackingStore *backingStore) Q_DECL_OVERRIDE;
+#ifndef QT_NO_CURSOR
+    void *nativeResourceForCursor(const QByteArray &resource, const QCursor &cursor) Q_DECL_OVERRIDE;
+#endif
 
     NativeResourceForIntegrationFunction nativeResourceFunctionForIntegration(const QByteArray &resource) Q_DECL_OVERRIDE;
     NativeResourceForContextFunction nativeResourceFunctionForContext(const QByteArray &resource) Q_DECL_OVERRIDE;