lokdialog: Implement hi-dpi support for the routed dialogs.

Change-Id: I770c605a049b7ac9c26c2773414eef8b6fc093a2
Reviewed-on: https://gerrit.libreoffice.org/63032
Tested-by: Jenkins
Reviewed-by: Jan Holesovsky <kendy@collabora.com>

desktop/qa/desktop_lib/test_desktop_lib.cxx

@@ -2431,12 +2431,13 @@ void DesktopLOKTest::testABI()
     CPPUNIT_ASSERT_EQUAL(documentClassOffset(39), offsetof(struct _LibreOfficeKitDocumentClass, setViewLanguage));
     CPPUNIT_ASSERT_EQUAL(documentClassOffset(40), offsetof(struct _LibreOfficeKitDocumentClass, postWindowExtTextInputEvent));
     CPPUNIT_ASSERT_EQUAL(documentClassOffset(41), offsetof(struct _LibreOfficeKitDocumentClass, getPartInfo));
-    CPPUNIT_ASSERT_EQUAL(documentClassOffset(42), offsetof(struct _LibreOfficeKitDocumentClass, insertCertificate));
-    CPPUNIT_ASSERT_EQUAL(documentClassOffset(43), offsetof(struct _LibreOfficeKitDocumentClass, addCertificate));
-    CPPUNIT_ASSERT_EQUAL(documentClassOffset(44), offsetof(struct _LibreOfficeKitDocumentClass, getSignatureState));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(42), offsetof(struct _LibreOfficeKitDocumentClass, paintWindowDPI));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(43), offsetof(struct _LibreOfficeKitDocumentClass, insertCertificate));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(44), offsetof(struct _LibreOfficeKitDocumentClass, addCertificate));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(45), offsetof(struct _LibreOfficeKitDocumentClass, getSignatureState));
     // Extending is fine, update this, and add new assert for the offsetof the
     // new method
-    CPPUNIT_ASSERT_EQUAL(documentClassOffset(45), sizeof(struct _LibreOfficeKitDocumentClass));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(46), sizeof(struct _LibreOfficeKitDocumentClass));
 }
 
 CPPUNIT_TEST_SUITE_REGISTRATION(DesktopLOKTest);

desktop/source/lib/init.cxx

@@ -686,6 +686,11 @@ static void doc_paintWindow(LibreOfficeKitDocument* pThis, unsigned nLOKWindowId
                             const int nX, const int nY,
                             const int nWidth, const int nHeight);
 
+static void doc_paintWindowDPI(LibreOfficeKitDocument* pThis, unsigned nLOKWindowId, unsigned char* pBuffer,
+                               const int nX, const int nY,
+                               const int nWidth, const int nHeight,
+                               const double fDPIScale);
+
 static void doc_postWindow(LibreOfficeKitDocument* pThis, unsigned nLOKWindowId, int nAction);
 
 static char* doc_getPartInfo(LibreOfficeKitDocument* pThis, int nPart);
@@ -756,6 +761,7 @@ LibLODocument_Impl::LibLODocument_Impl(const uno::Reference <css::lang::XCompone
         m_pDocumentClass->getPartHash = doc_getPartHash;
 
         m_pDocumentClass->paintWindow = doc_paintWindow;
+        m_pDocumentClass->paintWindowDPI = doc_paintWindowDPI;
         m_pDocumentClass->postWindow = doc_postWindow;
 
         m_pDocumentClass->setViewLanguage = doc_setViewLanguage;
@@ -3587,10 +3593,19 @@ unsigned char* doc_renderFont(SAL_UNUSED_PARAMETER LibreOfficeKitDocument* /*pTh
     return nullptr;
 }
 
-static void doc_paintWindow(LibreOfficeKitDocument* /*pThis*/, unsigned nLOKWindowId,
+static void doc_paintWindow(LibreOfficeKitDocument* pThis, unsigned nLOKWindowId,
                             unsigned char* pBuffer,
                             const int nX, const int nY,
                             const int nWidth, const int nHeight)
+{
+    doc_paintWindowDPI(pThis, nLOKWindowId, pBuffer, nX, nY, nWidth, nHeight, 1.0);
+}
+
+static void doc_paintWindowDPI(LibreOfficeKitDocument* /*pThis*/, unsigned nLOKWindowId,
+                               unsigned char* pBuffer,
+                               const int nX, const int nY,
+                               const int nWidth, const int nHeight,
+                               const double fDPIScale)
 {
     SolarMutexGuard aGuard;
     if (gImpl)
@@ -3603,6 +3618,11 @@ static void doc_paintWindow(LibreOfficeKitDocument* /*pThis*/, unsigned nLOKWind
         return;
     }
 
+    // Setup cairo to draw with the changed DPI scale (and return back to 1.0
+    // when the painting finishes)
+    comphelper::ScopeGuard dpiScaleGuard([]() { comphelper::LibreOfficeKit::setDPIScale(1.0); });
+    comphelper::LibreOfficeKit::setDPIScale(fDPIScale);
+
 #if defined(IOS)
 
     CGContextRef cgc = CGBitmapContextCreate(pBuffer, nWidth, nHeight, 8, nWidth*4, CGColorSpaceCreateDeviceRGB(), kCGImageAlphaNoneSkipFirst | kCGImageByteOrder32Little);
@@ -3636,7 +3656,7 @@ static void doc_paintWindow(LibreOfficeKitDocument* /*pThis*/, unsigned nLOKWind
     pDevice->SetOutputSizePixelScaleOffsetAndBuffer(Size(nWidth, nHeight), Fraction(1.0), Point(), pBuffer);
 
     MapMode aMapMode(pDevice->GetMapMode());
-    aMapMode.SetOrigin(Point(-nX, -nY));
+    aMapMode.SetOrigin(Point(-(nX / fDPIScale), -(nY / fDPIScale)));
     pDevice->SetMapMode(aMapMode);
 
     comphelper::LibreOfficeKit::setDialogPainting(true);

include/LibreOfficeKit/LibreOfficeKit.h

@@ -309,6 +309,15 @@ struct _LibreOfficeKitDocumentClass
     /// @see lok::Document::getPartInfo().
     char* (*getPartInfo) (LibreOfficeKitDocument* pThis, int nPart);
 
+    /// Paints window with given id to the buffer with the give DPI scale
+    /// (every pixel is dpiscale-times larger).
+    /// @see lok::Document::paintWindow().
+    void (*paintWindowDPI) (LibreOfficeKitDocument* pThis, unsigned nWindowId,
+                            unsigned char* pBuffer,
+                            const int x, const int y,
+                            const int width, const int height,
+                            const double dpiscale);
+
 #ifdef IOS
     /// @see lok::Document::paintTileToCGContext().
     void (*paintTileToCGContext) (LibreOfficeKitDocument* pThis,

include/LibreOfficeKit/LibreOfficeKit.hxx

@@ -164,16 +164,23 @@ public:
      * @param y y-coordinate from where the dialog should start painting
      * @param width The width of the dialog image to be painted
      * @param height The height of the dialog image to be painted
+     * @param dpiscale The dpi scale value used by the client.  Please note
+     *                 that the x, y, width, height are supposed to be the
+     *                 values with dpiscale applied (ie. dialog covering
+     *                 100x100 "normal" pixels with dpiscale '2' will have
+     *                 200x200 width x height), so that it is easy to compute
+     *                 the buffer sizes etc.
      */
     void paintWindow(unsigned nWindowId,
                      unsigned char* pBuffer,
                      const int x,
                      const int y,
                      const int width,
-                     const int height)
+                     const int height,
+                     const double dpiscale = 1.0)
     {
-        return mpDoc->pClass->paintWindow(mpDoc, nWindowId, pBuffer,
-                                          x, y, width, height);
+        return mpDoc->pClass->paintWindowDPI(mpDoc, nWindowId, pBuffer,
+                                             x, y, width, height, dpiscale);
     }
 
     /**