move getPixel into CairoCommon and reuse from X11CairoSalGraphicsImpl

2nd attempt. This reverts commit 8d0b7bdb8c9ae8254e5b77b533a158734affc4f5.

Change-Id: I8901a1258e0b0d89170f4e056516c5211801456a
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/145109
Tested-by: Caolán McNamara <caolanm@redhat.com>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>

7 files changed, 48 insertions, 65 deletions

diff --git a/vcl/headless/CairoCommon.cxx b/vcl/headless/CairoCommon.cxx
index 5781eff048e8..39538a9f9f40 100644
--- a/vcl/headless/CairoCommon.cxx
+++ b/vcl/headless/CairoCommon.cxx
@@ -623,6 +623,39 @@ void CairoCommon::drawPixel(cairo_t* cr, basegfx::B2DRange* pExtents, const Colo
         *pExtents = getClippedFillDamage(cr);
 }
 
+Color CairoCommon::getPixel(cairo_surface_t* pSurface, tools::Long nX, tools::Long nY)
+{
+    cairo_surface_t* target
+        = cairo_surface_create_similar_image(pSurface, CAIRO_FORMAT_ARGB32, 1, 1);
+
+    cairo_t* cr = cairo_create(target);
+
+    cairo_rectangle(cr, 0, 0, 1, 1);
+    cairo_set_source_surface(cr, pSurface, -nX, -nY);
+    cairo_paint(cr);
+    cairo_destroy(cr);
+
+    cairo_surface_flush(target);
+#if !ENABLE_WASM_STRIP_PREMULTIPLY
+    vcl::bitmap::lookup_table const& unpremultiply_table = vcl::bitmap::get_unpremultiply_table();
+#endif
+    unsigned char* data = cairo_image_surface_get_data(target);
+    sal_uInt8 a = data[SVP_CAIRO_ALPHA];
+#if ENABLE_WASM_STRIP_PREMULTIPLY
+    sal_uInt8 b = vcl::bitmap::unpremultiply(a, data[SVP_CAIRO_BLUE]);
+    sal_uInt8 g = vcl::bitmap::unpremultiply(a, data[SVP_CAIRO_GREEN]);
+    sal_uInt8 r = vcl::bitmap::unpremultiply(a, data[SVP_CAIRO_RED]);
+#else
+    sal_uInt8 b = unpremultiply_table[a][data[SVP_CAIRO_BLUE]];
+    sal_uInt8 g = unpremultiply_table[a][data[SVP_CAIRO_GREEN]];
+    sal_uInt8 r = unpremultiply_table[a][data[SVP_CAIRO_RED]];
+#endif
+    Color aColor(ColorAlpha, a, r, g, b);
+    cairo_surface_destroy(target);
+
+    return aColor;
+}
+
 void CairoCommon::drawLine(cairo_t* cr, basegfx::B2DRange* pExtents, const Color& rLineColor,
                            bool bAntiAlias, tools::Long nX1, tools::Long nY1, tools::Long nX2,
                            tools::Long nY2)
diff --git a/vcl/headless/SvpGraphicsBackend.cxx b/vcl/headless/SvpGraphicsBackend.cxx
index 84d6aa1dcd09..efff52387575 100644
--- a/vcl/headless/SvpGraphicsBackend.cxx
+++ b/vcl/headless/SvpGraphicsBackend.cxx
@@ -566,35 +566,7 @@ void SvpGraphicsBackend::drawBitmapBuffer(const SalTwoRect& rTR, const BitmapBuf
 
 Color SvpGraphicsBackend::getPixel(tools::Long nX, tools::Long nY)
 {
-    cairo_surface_t* target
-        = cairo_surface_create_similar_image(m_rCairoCommon.m_pSurface, CAIRO_FORMAT_ARGB32, 1, 1);
-
-    cairo_t* cr = cairo_create(target);
-
-    cairo_rectangle(cr, 0, 0, 1, 1);
-    cairo_set_source_surface(cr, m_rCairoCommon.m_pSurface, -nX, -nY);
-    cairo_paint(cr);
-    cairo_destroy(cr);
-
-    cairo_surface_flush(target);
-#if !ENABLE_WASM_STRIP_PREMULTIPLY
-    vcl::bitmap::lookup_table const& unpremultiply_table = vcl::bitmap::get_unpremultiply_table();
-#endif
-    unsigned char* data = cairo_image_surface_get_data(target);
-    sal_uInt8 a = data[SVP_CAIRO_ALPHA];
-#if ENABLE_WASM_STRIP_PREMULTIPLY
-    sal_uInt8 b = vcl::bitmap::unpremultiply(a, data[SVP_CAIRO_BLUE]);
-    sal_uInt8 g = vcl::bitmap::unpremultiply(a, data[SVP_CAIRO_GREEN]);
-    sal_uInt8 r = vcl::bitmap::unpremultiply(a, data[SVP_CAIRO_RED]);
-#else
-    sal_uInt8 b = unpremultiply_table[a][data[SVP_CAIRO_BLUE]];
-    sal_uInt8 g = unpremultiply_table[a][data[SVP_CAIRO_GREEN]];
-    sal_uInt8 r = unpremultiply_table[a][data[SVP_CAIRO_RED]];
-#endif
-    Color aColor(ColorAlpha, a, r, g, b);
-    cairo_surface_destroy(target);
-
-    return aColor;
+    return CairoCommon::getPixel(m_rCairoCommon.m_pSurface, nX, nY);
 }
 
 void SvpGraphicsBackend::invert(tools::Long nX, tools::Long nY, tools::Long nWidth,
diff --git a/vcl/inc/headless/CairoCommon.hxx b/vcl/inc/headless/CairoCommon.hxx
index 743c962c9423..3e78b435dbc5 100644
--- a/vcl/inc/headless/CairoCommon.hxx
+++ b/vcl/inc/headless/CairoCommon.hxx
@@ -155,6 +155,8 @@ struct VCL_DLLPUBLIC CairoCommon
     static void drawPixel(cairo_t* cr, basegfx::B2DRange* pExtents, const Color& rLineColor,
                           tools::Long nX, tools::Long nY);
 
+    static Color getPixel(cairo_surface_t* pSurface, tools::Long nX, tools::Long nY);
+
     static void drawLine(cairo_t* cr, basegfx::B2DRange* pExtents, const Color& rLineColor,
                          bool bAntiAlias, tools::Long nX1, tools::Long nY1, tools::Long nX2,
                          tools::Long nY2);
diff --git a/vcl/unx/generic/gdi/X11CairoSalGraphicsImpl.cxx b/vcl/unx/generic/gdi/X11CairoSalGraphicsImpl.cxx
index c45990b35263..2c85f690698d 100644
--- a/vcl/unx/generic/gdi/X11CairoSalGraphicsImpl.cxx
+++ b/vcl/unx/generic/gdi/X11CairoSalGraphicsImpl.cxx
@@ -140,6 +140,17 @@ void X11CairoSalGraphicsImpl::drawPixel(tools::Long nX, tools::Long nY, Color nC
     X11Common::releaseCairoContext(cr);
 }
 
+Color X11CairoSalGraphicsImpl::getPixel(tools::Long nX, tools::Long nY)
+{
+    cairo_t* cr = mrX11Common.getCairoContext(mrParent.GetGeometryProvider());
+
+    Color aRet = CairoCommon::getPixel(cairo_get_target(cr), nX, nY);
+
+    X11Common::releaseCairoContext(cr);
+
+    return aRet;
+}
+
 void X11CairoSalGraphicsImpl::drawLine(tools::Long nX1, tools::Long nY1, tools::Long nX2,
                                        tools::Long nY2)
 {
diff --git a/vcl/unx/generic/gdi/X11CairoSalGraphicsImpl.hxx b/vcl/unx/generic/gdi/X11CairoSalGraphicsImpl.hxx
index 7462089ab29f..314e441aaac6 100644
--- a/vcl/unx/generic/gdi/X11CairoSalGraphicsImpl.hxx
+++ b/vcl/unx/generic/gdi/X11CairoSalGraphicsImpl.hxx
@@ -78,6 +78,7 @@ public:
 
     void drawPixel(tools::Long nX, tools::Long nY) override;
     void drawPixel(tools::Long nX, tools::Long nY, Color nColor) override;
+    Color getPixel(tools::Long nX, tools::Long nY) override;
 
     void drawLine(tools::Long nX1, tools::Long nY1, tools::Long nX2, tools::Long nY2) override;
 
diff --git a/vcl/unx/generic/gdi/gdiimpl.cxx b/vcl/unx/generic/gdi/gdiimpl.cxx
index 68d44afdb684..9f9f45afb4ad 100644
--- a/vcl/unx/generic/gdi/gdiimpl.cxx
+++ b/vcl/unx/generic/gdi/gdiimpl.cxx
@@ -1789,40 +1789,6 @@ bool X11SalGraphicsImpl::drawPolyLine(
     return bDrawnOk;
 }
 
-Color X11SalGraphicsImpl::getPixel( tools::Long nX, tools::Long nY )
-{
-    if( mrParent.bWindow_ && !mrParent.bVirDev_ )
-    {
-        XWindowAttributes aAttrib;
-
-        XGetWindowAttributes( mrParent.GetXDisplay(), mrParent.GetDrawable(), &aAttrib );
-        if( aAttrib.map_state != IsViewable )
-        {
-            SAL_WARN( "vcl", "X11SalGraphics::GetPixel drawable not viewable" );
-            return 0;
-        }
-    }
-
-    XImage *pXImage = XGetImage( mrParent.GetXDisplay(),
-                                     mrParent.GetDrawable(),
-                                 nX, nY,
-                                 1,  1,
-                                 AllPlanes,
-                                 ZPixmap );
-    if( !pXImage )
-    {
-        SAL_WARN( "vcl", "X11SalGraphics::GetPixel !XGetImage()" );
-        return 0;
-    }
-
-    XColor aXColor;
-
-    aXColor.pixel = XGetPixel( pXImage, 0, 0 );
-    XDestroyImage( pXImage );
-
-    return mrParent.GetColormap().GetColor( aXColor.pixel );
-}
-
 std::shared_ptr<SalBitmap> X11SalGraphicsImpl::getBitmap( tools::Long nX, tools::Long nY, tools::Long nDX, tools::Long nDY )
 {
     bool bFakeWindowBG = false;
diff --git a/vcl/unx/generic/gdi/gdiimpl.hxx b/vcl/unx/generic/gdi/gdiimpl.hxx
index bec45a01dd31..14220f2e0e78 100644
--- a/vcl/unx/generic/gdi/gdiimpl.hxx
+++ b/vcl/unx/generic/gdi/gdiimpl.hxx
@@ -215,8 +215,6 @@ public:
 
     virtual std::shared_ptr<SalBitmap> getBitmap( tools::Long nX, tools::Long nY, tools::Long nWidth, tools::Long nHeight ) override;
 
-    virtual Color getPixel( tools::Long nX, tools::Long nY ) override;
-
     // invert --> ClipRegion (only Windows or VirDevs)
     virtual void invert(
                 tools::Long nX, tools::Long nY,