Deduplicate QWidgetPrivate::invalidateBuffer

Now that MSVC (presumably) supports templates, we can merge the QRect
and QRegion versions of the functions into one.

The function has been renamed to invalidateBackingStore to better
reflect what it's doing.

Change-Id: I0e94a0cabd286cf97f2ba718a42ee0425f59d3ec
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

3 files changed, 60 insertions, 92 deletions

diff --git a/src/widgets/kernel/qwidget.cpp b/src/widgets/kernel/qwidget.cpp
index b4ae994375..b91d637766 100644
--- a/src/widgets/kernel/qwidget.cpp
+++ b/src/widgets/kernel/qwidget.cpp
@@ -5317,7 +5317,7 @@ void QWidget::setGraphicsEffect(QGraphicsEffect *effect)
         return;
 
     if (d->graphicsEffect) {
-        d->invalidateBuffer(rect());
+        d->invalidateBackingStore(rect());
         delete d->graphicsEffect;
         d->graphicsEffect = 0;
     }
@@ -7340,11 +7340,11 @@ void QWidgetPrivate::setGeometry_sys(int x, int y, int w, int h, bool isMove)
                 if (renderToTexture) {
                     QRegion updateRegion(q->geometry());
                     updateRegion += QRect(oldPos, olds);
-                    q->parentWidget()->d_func()->invalidateBuffer(updateRegion);
+                    q->parentWidget()->d_func()->invalidateBackingStore(updateRegion);
                 } else if (isMove && !isResize) {
                     moveRect(QRect(oldPos, olds), x - oldPos.x(), y - oldPos.y());
                 } else {
-                    invalidateBuffer_resizeHelper(oldPos, olds);
+                    invalidateBackingStore_resizeHelper(oldPos, olds);
                 }
             }
         }
@@ -8106,7 +8106,7 @@ void QWidgetPrivate::show_sys()
     QWidgetWindow *window = windowHandle();
 
     if (q->testAttribute(Qt::WA_DontShowOnScreen)) {
-        invalidateBuffer(q->rect());
+        invalidateBackingStore(q->rect());
         q->setAttribute(Qt::WA_Mapped);
         // add our window the modal window list (native dialogs)
         if (window && q->isWindow()
@@ -8149,7 +8149,7 @@ void QWidgetPrivate::show_sys()
 #ifndef QT_NO_CURSOR
         qt_qpa_set_cursor(q, false); // Needed in case cursor was set before show
 #endif
-        invalidateBuffer(q->rect());
+        invalidateBackingStore(q->rect());
         window->setNativeWindowVisibility(true);
         // Was the window moved by the Window system or QPlatformWindow::initialGeometry() ?
         if (window->isTopLevel()) {
@@ -8263,12 +8263,12 @@ void QWidgetPrivate::hide_sys()
         QWidget *p = q->parentWidget();
         if (p &&p->isVisible()) {
             if (renderToTexture)
-                p->d_func()->invalidateBuffer(q->geometry());
+                p->d_func()->invalidateBackingStore(q->geometry());
             else
-                invalidateBuffer(q->rect());
+                invalidateBackingStore(q->rect());
         }
     } else {
-        invalidateBuffer(q->rect());
+        invalidateBackingStore(q->rect());
     }
 
     if (window)
@@ -11901,7 +11901,7 @@ void QWidget::raise()
 
         QRegion region(rect());
         d->subtractOpaqueSiblings(region);
-        d->invalidateBuffer(region);
+        d->invalidateBackingStore(region);
     }
     if (testAttribute(Qt::WA_WState_Created))
         d->raise_sys();
@@ -11921,7 +11921,7 @@ void QWidgetPrivate::raise_sys()
     } else if (renderToTexture) {
         if (QWidget *p = q->parentWidget()) {
             setDirtyOpaqueRegion();
-            p->d_func()->invalidateBuffer(effectiveRectFor(q->geometry()));
+            p->d_func()->invalidateBackingStore(effectiveRectFor(q->geometry()));
         }
     }
 }
@@ -11971,7 +11971,7 @@ void QWidgetPrivate::lower_sys()
         q->windowHandle()->lower();
     } else if (QWidget *p = q->parentWidget()) {
         setDirtyOpaqueRegion();
-        p->d_func()->invalidateBuffer(effectiveRectFor(q->geometry()));
+        p->d_func()->invalidateBackingStore(effectiveRectFor(q->geometry()));
     }
 }
 
@@ -12015,7 +12015,7 @@ void QWidgetPrivate::stackUnder_sys(QWidget*)
     Q_Q(QWidget);
     if (QWidget *p = q->parentWidget()) {
         setDirtyOpaqueRegion();
-        p->d_func()->invalidateBuffer(effectiveRectFor(q->geometry()));
+        p->d_func()->invalidateBackingStore(effectiveRectFor(q->geometry()));
     }
 }
 
@@ -12457,7 +12457,7 @@ void QWidget::destroy(bool destroyWindow, bool destroySubWindows)
 
     d->aboutToDestroy();
     if (!isWindow() && parentWidget())
-        parentWidget()->d_func()->invalidateBuffer(d->effectiveRectFor(geometry()));
+        parentWidget()->d_func()->invalidateBackingStore(d->effectiveRectFor(geometry()));
     d->deactivateWidgetCleanup();
 
     if ((windowType() == Qt::Popup) && qApp)
diff --git a/src/widgets/kernel/qwidget_p.h b/src/widgets/kernel/qwidget_p.h
index ab5dc6bfba..60612e9b52 100644
--- a/src/widgets/kernel/qwidget_p.h
+++ b/src/widgets/kernel/qwidget_p.h
@@ -452,10 +452,11 @@ public:
     void scrollChildren(int dx, int dy);
     void moveRect(const QRect &, int dx, int dy);
     void scrollRect(const QRect &, int dx, int dy);
-    void invalidateBuffer_resizeHelper(const QPoint &oldPos, const QSize &oldSize);
-    // ### Qt 4.6: Merge into a template function (after MSVC isn't supported anymore).
-    void invalidateBuffer(const QRegion &);
-    void invalidateBuffer(const QRect &);
+    void invalidateBackingStore_resizeHelper(const QPoint &oldPos, const QSize &oldSize);
+
+    template <class T>
+    void invalidateBackingStore(const T &);
+
     QRegion overlappedRegion(const QRect &rect, bool breakAfterFirst = false) const;
     void syncBackingStore();
     void syncBackingStore(const QRegion &region);
diff --git a/src/widgets/kernel/qwidgetbackingstore.cpp b/src/widgets/kernel/qwidgetbackingstore.cpp
index a32eb2a03b..f4d1dab84e 100644
--- a/src/widgets/kernel/qwidgetbackingstore.cpp
+++ b/src/widgets/kernel/qwidgetbackingstore.cpp
@@ -859,11 +859,11 @@ void QWidgetPrivate::moveRect(const QRect &rect, int dx, int dy)
         if (!extra || !extra->hasMask) {
             parentR -= newRect;
         } else {
-            // invalidateBuffer() excludes anything outside the mask
+            // invalidateBackingStore() excludes anything outside the mask
             parentR += newRect & clipR;
         }
-        pd->invalidateBuffer(parentR);
-        invalidateBuffer((newRect & clipR).translated(-data.crect.topLeft()));
+        pd->invalidateBackingStore(parentR);
+        invalidateBackingStore((newRect & clipR).translated(-data.crect.topLeft()));
     } else {
 
         QWidgetBackingStore *wbs = x->backingStoreTracker.data();
@@ -894,7 +894,7 @@ void QWidgetPrivate::moveRect(const QRect &rect, int dx, int dy)
         if (childUpdatesEnabled) {
             if (!overlappedExpose.isEmpty()) {
                 overlappedExpose.translate(-data.crect.topLeft());
-                invalidateBuffer(overlappedExpose);
+                invalidateBackingStore(overlappedExpose);
             }
             if (!childExpose.isEmpty()) {
                 childExpose.translate(-data.crect.topLeft());
@@ -944,9 +944,9 @@ void QWidgetPrivate::scrollRect(const QRect &rect, int dx, int dy)
         if (!overlappedRegion(scrollRect.translated(data.crect.topLeft()), true).isEmpty()) {
             QRegion region(scrollRect);
             subtractOpaqueSiblings(region);
-            invalidateBuffer(region);
+            invalidateBackingStore(region);
         }else {
-            invalidateBuffer(scrollRect);
+            invalidateBackingStore(scrollRect);
         }
     } else {
         const QPoint toplevelOffset = q->mapTo(tlw, QPoint());
@@ -987,7 +987,7 @@ void QWidgetPrivate::scrollRect(const QRect &rect, int dx, int dy)
             return;
 
         if (!overlappedExpose.isEmpty())
-            invalidateBuffer(overlappedExpose);
+            invalidateBackingStore(overlappedExpose);
         if (!childExpose.isEmpty()) {
             wbs->markDirty(childExpose, q);
             isScrolled = true;
@@ -1471,26 +1471,11 @@ void QWidgetBackingStore::flush(QWidget *widget)
     dirtyOnScreenWidgets->clear();
 }
 
-static inline bool discardInvalidateBufferRequest(QWidget *widget, QTLWExtra *tlwExtra)
-{
-    Q_ASSERT(widget);
-    if (QApplication::closingDown())
-        return true;
-
-    if (!tlwExtra || tlwExtra->inTopLevelResize || !tlwExtra->backingStore)
-        return true;
-
-    if (!widget->isVisible() || !widget->updatesEnabled())
-        return true;
-
-    return false;
-}
-
 /*!
-    Invalidates the buffer when the widget is resized.
+    Invalidates the backing store when the widget is resized.
     Static areas are never invalidated unless absolutely needed.
 */
-void QWidgetPrivate::invalidateBuffer_resizeHelper(const QPoint &oldPos, const QSize &oldSize)
+void QWidgetPrivate::invalidateBackingStore_resizeHelper(const QPoint &oldPos, const QSize &oldSize)
 {
     Q_Q(QWidget);
     Q_ASSERT(!q->isWindow());
@@ -1515,10 +1500,10 @@ void QWidgetPrivate::invalidateBuffer_resizeHelper(const QPoint &oldPos, const Q
         if (hasStaticChildren) {
             QRegion dirty(newWidgetRect);
             dirty -= staticChildren;
-            invalidateBuffer(dirty);
+            invalidateBackingStore(dirty);
         } else {
             // Entire widget needs repaint.
-            invalidateBuffer(newWidgetRect);
+            invalidateBackingStore(newWidgetRect);
         }
 
         if (!parentAreaExposed)
@@ -1530,14 +1515,14 @@ void QWidgetPrivate::invalidateBuffer_resizeHelper(const QPoint &oldPos, const Q
             parentExpose &= QRect(oldPos, oldSize);
             if (hasStaticChildren)
                 parentExpose -= data.crect; // Offset is unchanged, safe to do this.
-            q->parentWidget()->d_func()->invalidateBuffer(parentExpose);
+            q->parentWidget()->d_func()->invalidateBackingStore(parentExpose);
         } else {
             if (hasStaticChildren && !graphicsEffect) {
                 QRegion parentExpose(QRect(oldPos, oldSize));
                 parentExpose -= data.crect; // Offset is unchanged, safe to do this.
-                q->parentWidget()->d_func()->invalidateBuffer(parentExpose);
+                q->parentWidget()->d_func()->invalidateBackingStore(parentExpose);
             } else {
-                q->parentWidget()->d_func()->invalidateBuffer(effectiveRectFor(QRect(oldPos, oldSize)));
+                q->parentWidget()->d_func()->invalidateBackingStore(effectiveRectFor(QRect(oldPos, oldSize)));
             }
         }
         return;
@@ -1558,7 +1543,7 @@ void QWidgetPrivate::invalidateBuffer_resizeHelper(const QPoint &oldPos, const Q
     if (!sizeDecreased || !oldWidgetRect.contains(newWidgetRect)) {
         QRegion newVisible(newWidgetRect);
         newVisible -= oldWidgetRect;
-        invalidateBuffer(newVisible);
+        invalidateBackingStore(newVisible);
     }
 
     if (!parentAreaExposed)
@@ -1570,74 +1555,56 @@ void QWidgetPrivate::invalidateBuffer_resizeHelper(const QPoint &oldPos, const Q
         QRegion parentExpose(oldRect);
         parentExpose &= extra->mask.translated(oldPos);
         parentExpose -= (extra->mask.translated(data.crect.topLeft()) & data.crect);
-        q->parentWidget()->d_func()->invalidateBuffer(parentExpose);
+        q->parentWidget()->d_func()->invalidateBackingStore(parentExpose);
     } else {
         QRegion parentExpose(oldRect);
         parentExpose -= data.crect;
-        q->parentWidget()->d_func()->invalidateBuffer(parentExpose);
+        q->parentWidget()->d_func()->invalidateBackingStore(parentExpose);
     }
 }
 
 /*!
-    Invalidates the \a rgn (in widget's coordinates) of the backing store, i.e.
-    all widgets intersecting with the region will be repainted when the backing store
-    is synced.
-
-    ### Qt 4.6: Merge into a template function (after MSVC isn't supported anymore).
+    Invalidates the \a r (in widget's coordinates) of the backing store, i.e.
+    all widgets intersecting with the region will be repainted when the backing
+    store is synced.
 */
-void QWidgetPrivate::invalidateBuffer(const QRegion &rgn)
+template <class T>
+void QWidgetPrivate::invalidateBackingStore(const T &r)
 {
-    Q_Q(QWidget);
-
-    QTLWExtra *tlwExtra = q->window()->d_func()->maybeTopData();
-    if (discardInvalidateBufferRequest(q, tlwExtra) || rgn.isEmpty())
+    if (r.isEmpty())
         return;
 
-    QRegion wrgn(rgn);
-    wrgn &= clipRect();
-    if (!graphicsEffect && extra && extra->hasMask)
-        wrgn &= extra->mask;
-    if (wrgn.isEmpty())
+    if (QApplication::closingDown())
         return;
 
-    tlwExtra->backingStoreTracker->markDirty(wrgn, q,
-            QWidgetBackingStore::UpdateLater, QWidgetBackingStore::BufferInvalid);
-}
-
-/*!
-    This function is equivalent to calling invalidateBuffer(QRegion(rect), ...), but
-    is more efficient as it eliminates QRegion operations/allocations and can
-    use the rect more precisely for additional cut-offs.
-
-    ### Qt 4.6: Merge into a template function (after MSVC isn't supported anymore).
-*/
-void QWidgetPrivate::invalidateBuffer(const QRect &rect)
-{
     Q_Q(QWidget);
-
-    QTLWExtra *tlwExtra = q->window()->d_func()->maybeTopData();
-    if (discardInvalidateBufferRequest(q, tlwExtra) || rect.isEmpty())
+    if (!q->isVisible() || !q->updatesEnabled())
         return;
 
-    QRect wRect(rect);
-    wRect &= clipRect();
-    if (wRect.isEmpty())
+    QTLWExtra *tlwExtra = q->window()->d_func()->maybeTopData();
+    if (!tlwExtra || tlwExtra->inTopLevelResize || !tlwExtra->backingStore)
         return;
 
-    if (graphicsEffect || !extra || !extra->hasMask) {
-        tlwExtra->backingStoreTracker->markDirty(wRect, q,
-                QWidgetBackingStore::UpdateLater, QWidgetBackingStore::BufferInvalid);
+    T clipped(r);
+    clipped &= clipRect();
+    if (clipped.isEmpty())
         return;
-    }
 
-    QRegion wRgn(extra->mask);
-    wRgn &= wRect;
-    if (wRgn.isEmpty())
-        return;
+    if (!graphicsEffect && extra && extra->hasMask) {
+        QRegion masked(extra->mask);
+        masked &= clipped;
+        if (masked.isEmpty())
+            return;
 
-    tlwExtra->backingStoreTracker->markDirty(wRgn, q,
+        tlwExtra->backingStoreTracker->markDirty(masked, q,
+            QWidgetBackingStore::UpdateLater, QWidgetBackingStore::BufferInvalid);
+    } else {
+        tlwExtra->backingStoreTracker->markDirty(clipped, q,
             QWidgetBackingStore::UpdateLater, QWidgetBackingStore::BufferInvalid);
+    }
 }
+// Needed by tst_QWidget
+template Q_AUTOTEST_EXPORT void QWidgetPrivate::invalidateBackingStore<QRect>(const QRect &r);
 
 void QWidgetPrivate::repaint_sys(const QRegion &rgn)
 {