From acb67561a3753306a2262f7221baca2d727fd4cb Mon Sep 17 00:00:00 2001
From: Friedemann Kleint <Friedemann.Kleint@qt.io>
Date: Thu, 17 Mar 2016 13:33:50 +0100
Subject: Add imageToHBITMAP(), imageFromHBITMAP()

Add new functions for image conversions wrapping their QtGui
equivalents.

[ChangeLog][QtWin] Added functions imageToHBITMAP()
and imageFromHBITMAP() for conversion between QImage and HBITMAP,
preserving the format where possible.

Task-number: QTBUG-51124
Change-Id: I212b2dff182dce3a9b08753b6435d01b75bb5434
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>
---
 src/winextras/qwinfunctions.cpp    | 31 +++++++++++++++++++++++++++++++
 src/winextras/qwinfunctions.h      |  2 ++
 tests/auto/qpixmap/tst_qpixmap.cpp | 18 ++++++++++++++++++
 3 files changed, 51 insertions(+)

diff --git a/src/winextras/qwinfunctions.cpp b/src/winextras/qwinfunctions.cpp
index 7b102a8..7089966 100644
--- a/src/winextras/qwinfunctions.cpp
+++ b/src/winextras/qwinfunctions.cpp
@@ -69,6 +69,8 @@ Q_GUI_EXPORT HBITMAP qt_createIconMask(const QBitmap &bitmap);
 Q_GUI_EXPORT HBITMAP qt_pixmapToWinHBITMAP(const QPixmap &p, int hbitmapFormat = 0);
 Q_GUI_EXPORT QPixmap qt_pixmapFromWinHBITMAP(HBITMAP bitmap, int hbitmapFormat = 0);
 Q_GUI_EXPORT HICON   qt_pixmapToWinHICON(const QPixmap &p);
+Q_GUI_EXPORT HBITMAP qt_imageToWinHBITMAP(const QImage &imageIn, int hbitmapFormat = 0);
+Q_GUI_EXPORT QImage qt_imageFromWinHBITMAP(HBITMAP bitmap, int hbitmapFormat = 0);
 Q_GUI_EXPORT QImage  qt_imageFromWinHBITMAP(HDC hdc, HBITMAP bitmap, int w, int h);
 Q_GUI_EXPORT QPixmap qt_pixmapFromWinHICON(HICON icon);
 
@@ -138,6 +140,22 @@ HICON QtWin::toHICON(const QPixmap &p)
     return qt_pixmapToWinHICON(p);
 }
 
+/*!
+    \since 5.12
+
+    Creates a \c HBITMAP equivalent of the QImage \a image,
+    based on the given \a format. Returns the \c HBITMAP handle.
+
+    It is the caller's responsibility to free the \c HBITMAP data
+    after use.
+
+    \sa imageFromHBITMAP()
+*/
+HBITMAP QtWin::imageToHBITMAP(const QImage &image, QtWin::HBitmapFormat format)
+{
+    return qt_imageToWinHBITMAP(image, format);
+}
+
 /*!
     \since 5.2
 
@@ -152,6 +170,19 @@ QImage QtWin::imageFromHBITMAP(HDC hdc, HBITMAP bitmap, int width, int height)
     return qt_imageFromWinHBITMAP(hdc, bitmap, width, height);
 }
 
+/*!
+    \since 5.12
+
+    Returns a QImage that is equivalent to the
+    given \a bitmap.  The conversion is based on the specified \a format.
+
+    \sa imageToHBITMAP()
+*/
+QImage QtWin::imageFromHBITMAP(HBITMAP bitmap, QtWin::HBitmapFormat format)
+{
+    return qt_imageFromWinHBITMAP(bitmap, format);
+}
+
 /*!
     \since 5.2
 
diff --git a/src/winextras/qwinfunctions.h b/src/winextras/qwinfunctions.h
index bc07401..fe461d1 100644
--- a/src/winextras/qwinfunctions.h
+++ b/src/winextras/qwinfunctions.h
@@ -81,7 +81,9 @@ namespace QtWin
     Q_WINEXTRAS_EXPORT HBITMAP toHBITMAP(const QPixmap &p, HBitmapFormat format = HBitmapNoAlpha);
     Q_WINEXTRAS_EXPORT QPixmap fromHBITMAP(HBITMAP bitmap, HBitmapFormat format = HBitmapNoAlpha);
     Q_WINEXTRAS_EXPORT HICON toHICON(const QPixmap &p);
+    Q_WINEXTRAS_EXPORT HBITMAP imageToHBITMAP(const QImage &image, QtWin::HBitmapFormat format = HBitmapNoAlpha);
     Q_WINEXTRAS_EXPORT QImage imageFromHBITMAP(HDC hdc, HBITMAP bitmap, int width, int height);
+    Q_WINEXTRAS_EXPORT QImage imageFromHBITMAP(HBITMAP bitmap, QtWin::HBitmapFormat format = HBitmapNoAlpha);
     Q_WINEXTRAS_EXPORT QPixmap fromHICON(HICON icon);
     Q_WINEXTRAS_EXPORT HRGN toHRGN(const QRegion &region);
     Q_WINEXTRAS_EXPORT QRegion fromHRGN(HRGN hrgn);
diff --git a/tests/auto/qpixmap/tst_qpixmap.cpp b/tests/auto/qpixmap/tst_qpixmap.cpp
index 8a63e25..8383194 100644
--- a/tests/auto/qpixmap/tst_qpixmap.cpp
+++ b/tests/auto/qpixmap/tst_qpixmap.cpp
@@ -29,6 +29,7 @@
 #include <QtTest/QtTest>
 #include <QtCore/qt_windows.h>
 #include <QtCore/QFileInfo>
+#include <QtGui/QPainter>
 #include <QtGui/QPixmap>
 #include <QtGui/QImage>
 #include <QtWinExtras/QtWin>
@@ -53,6 +54,8 @@ private slots:
     void fromHICON_data();
     void fromHICON();
 
+    void imageConversion();
+
 private:
     const QString m_dataDirectory;
 };
@@ -279,6 +282,21 @@ void tst_QPixmap::fromHICON()
     QVERIFY2(compareImages(imageFromHICON, imageFromFile, &errorMessage), errorMessage.constData());
 }
 
+void tst_QPixmap::imageConversion()
+{
+    // Extensive testing of all formats is done in QtGui; this merely tests
+    // the exports/linkage.
+    QImage image(73, 57, QImage::Format_ARGB32_Premultiplied);
+    image.fill(Qt::red);
+    QPainter painter(&image);
+    painter.drawLine(0, 0, image.width(), image.height());
+    const HBITMAP hBitMap = QtWin::imageToHBITMAP(image);
+    QVERIFY(hBitMap);
+    const QImage fromHBitMap = QtWin::imageFromHBITMAP(hBitMap, QtWin::HBitmapPremultipliedAlpha);
+    QCOMPARE(fromHBitMap, image);
+    DeleteObject(hBitMap);
+}
+
 QTEST_MAIN(tst_QPixmap)
 
 #include "tst_qpixmap.moc"
-- 
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