diff options
| -rw-r--r-- | src/gui/painting/qbackingstore.cpp | 26 | ||||
| -rw-r--r-- | tests/auto/gui/kernel/qbackingstore/tst_qbackingstore.cpp | 39 |
2 files changed, 53 insertions, 12 deletions
diff --git a/src/gui/painting/qbackingstore.cpp b/src/gui/painting/qbackingstore.cpp index f76b9864fc..762938e764 100644 --- a/src/gui/painting/qbackingstore.cpp +++ b/src/gui/painting/qbackingstore.cpp @@ -298,32 +298,34 @@ bool QBackingStore::hasStaticContents() const void Q_GUI_EXPORT qt_scrollRectInImage(QImage &img, const QRect &rect, const QPoint &offset) { // make sure we don't detach - uchar *mem = const_cast<uchar*>(const_cast<const QImage &>(img).bits()); + uchar *mem = const_cast<uchar*>(img.constBits()); qsizetype lineskip = img.bytesPerLine(); int depth = img.depth() >> 3; const QRect imageRect(0, 0, img.width(), img.height()); - const QRect r = rect & imageRect & imageRect.translated(-offset); - const QPoint p = rect.topLeft() + offset; - - if (r.isEmpty()) + const QRect sourceRect = rect.intersected(imageRect).intersected(imageRect.translated(-offset)); + if (sourceRect.isEmpty()) return; + const QRect destRect = sourceRect.translated(offset); + Q_ASSERT_X(imageRect.contains(destRect), "qt_scrollRectInImage", + "The sourceRect should already account for clipping, both pre and post scroll"); + const uchar *src; uchar *dest; - if (r.top() < p.y()) { - src = mem + r.bottom() * lineskip + r.left() * depth; - dest = mem + (p.y() + r.height() - 1) * lineskip + p.x() * depth; + if (sourceRect.top() < destRect.top()) { + src = mem + sourceRect.bottom() * lineskip + sourceRect.left() * depth; + dest = mem + (destRect.top() + sourceRect.height() - 1) * lineskip + destRect.left() * depth; lineskip = -lineskip; } else { - src = mem + r.top() * lineskip + r.left() * depth; - dest = mem + p.y() * lineskip + p.x() * depth; + src = mem + sourceRect.top() * lineskip + sourceRect.left() * depth; + dest = mem + destRect.top() * lineskip + destRect.left() * depth; } - const int w = r.width(); - int h = r.height(); + const int w = sourceRect.width(); + int h = sourceRect.height(); const int bytes = w * depth; // overlapping segments? diff --git a/tests/auto/gui/kernel/qbackingstore/tst_qbackingstore.cpp b/tests/auto/gui/kernel/qbackingstore/tst_qbackingstore.cpp index 5349119b6d..14cb58315b 100644 --- a/tests/auto/gui/kernel/qbackingstore/tst_qbackingstore.cpp +++ b/tests/auto/gui/kernel/qbackingstore/tst_qbackingstore.cpp @@ -43,8 +43,47 @@ class tst_QBackingStore : public QObject private slots: void flush(); + + void scrollRectInImage_data(); + void scrollRectInImage(); }; +void tst_QBackingStore::scrollRectInImage_data() +{ + QTest::addColumn<QRect>("rect"); + QTest::addColumn<QPoint>("offset"); + + QTest::newRow("empty rect") << QRect() << QPoint(); + QTest::newRow("rect outside image") << QRect(-100, -100, 1000, 1000) << QPoint(10, 10); + QTest::newRow("scroll outside positive") << QRect(10, 10, 10, 10) << QPoint(1000, 1000); + QTest::newRow("scroll outside negative") << QRect(10, 10, 10, 10) << QPoint(-1000, -1000); + + QTest::newRow("sub-rect positive scroll") << QRect(100, 100, 50, 50) << QPoint(10, 10); + QTest::newRow("sub-rect negative scroll") << QRect(100, 100, 50, 50) << QPoint(-10, -10); + + QTest::newRow("positive vertical only") << QRect(100, 100, 50, 50) << QPoint(0, 10); + QTest::newRow("negative vertical only") << QRect(100, 100, 50, 50) << QPoint(0, -10); + QTest::newRow("positive horizontal only") << QRect(100, 100, 50, 50) << QPoint(10, 0); + QTest::newRow("negative horizontal only") << QRect(100, 100, 50, 50) << QPoint(-10, 0); + + QTest::newRow("whole rect positive") << QRect(0, 0, 250, 250) << QPoint(10, 10); + QTest::newRow("whole rect negative") << QRect(0, 0, 250, 250) << QPoint(-10, -10); +} + +QT_BEGIN_NAMESPACE +Q_GUI_EXPORT void qt_scrollRectInImage(QImage &, const QRect &, const QPoint &); +QT_END_NAMESPACE + +void tst_QBackingStore::scrollRectInImage() +{ + QImage test(250, 250, QImage::Format_ARGB32_Premultiplied); + + QFETCH(QRect, rect); + QFETCH(QPoint, offset); + + qt_scrollRectInImage(test, rect, offset); +} + class Window : public QWindow { public: |