tdf#74702: use OutputDevice::GetBackgroundColor()

Apply the Liskov substitution principle to OutputDevice::GetBackgroundColor().
This helps in SmTmpDevice::Impl_GetColor() because it no longer needs to know
about what type of OutputDevice it is calling to get the background color.

This forced a rename of basctl::ModulWindowLayout::GetBackgroundColor() to be
GetSyntaxBackgroundColor(), but this is a happy coincidence as it makes the
function intent clearer anyway.

Change-Id: I11298a63cb01c187f3a8a4a2c9e90eacda6c3e6b
Reviewed-on: https://gerrit.libreoffice.org/75521
Tested-by: Jenkins
Reviewed-by: Tomaž Vajngerl <quikee@gmail.com>

4 files changed, 34 insertions, 2 deletions

diff --git a/vcl/qa/cppunit/outdev.cxx b/vcl/qa/cppunit/outdev.cxx
index 45bae92ca58c..b91248078ab8 100644
--- a/vcl/qa/cppunit/outdev.cxx
+++ b/vcl/qa/cppunit/outdev.cxx
@@ -10,6 +10,8 @@
 #include <test/bootstrapfixture.hxx>
 
 #include <vcl/virdev.hxx>
+#include <vcl/print.hxx>
+#include <vcl/window.hxx>
 #include <vcl/bitmapaccess.hxx>
 
 #include <basegfx/matrix/b2dhommatrix.hxx>
@@ -21,18 +23,38 @@ public:
 
     void testVirtualDevice();
     void testUseAfterDispose();
+    void testPrinterBackgroundColor();
+    void testWindowBackgroundColor();
 
     CPPUNIT_TEST_SUITE(VclOutdevTest);
     CPPUNIT_TEST(testVirtualDevice);
     CPPUNIT_TEST(testUseAfterDispose);
+    CPPUNIT_TEST(testPrinterBackgroundColor);
+    CPPUNIT_TEST(testWindowBackgroundColor);
     CPPUNIT_TEST_SUITE_END();
 };
 
+void VclOutdevTest::testPrinterBackgroundColor()
+{
+    ScopedVclPtrInstance<Printer> pPrinter;
+    CPPUNIT_ASSERT_EQUAL(pPrinter->GetBackgroundColor(), COL_WHITE);
+}
+
+void VclOutdevTest::testWindowBackgroundColor()
+{
+    ScopedVclPtrInstance<vcl::Window> pWindow(nullptr, WB_APP | WB_STDWORK);
+    pWindow->SetBackground(Wallpaper(COL_WHITE));
+    CPPUNIT_ASSERT_EQUAL(pWindow->GetBackgroundColor(), COL_WHITE);
+}
+
 void VclOutdevTest::testVirtualDevice()
 {
     ScopedVclPtrInstance< VirtualDevice > pVDev;
     pVDev->SetOutputSizePixel(Size(32,32));
     pVDev->SetBackground(Wallpaper(COL_WHITE));
+
+    CPPUNIT_ASSERT_EQUAL(pVDev->GetBackgroundColor(), COL_WHITE);
+
     pVDev->Erase();
     pVDev->DrawPixel(Point(1,2),COL_BLUE);
     pVDev->DrawPixel(Point(31,30),COL_RED);
diff --git a/vcl/source/outdev/wallpaper.cxx b/vcl/source/outdev/wallpaper.cxx
index 71cd67017bcd..d2a5f1003940 100644
--- a/vcl/source/outdev/wallpaper.cxx
+++ b/vcl/source/outdev/wallpaper.cxx
@@ -27,6 +27,11 @@
 
 #include <wall2.hxx>
 
+Color OutputDevice::GetBackgroundColor() const
+{
+    return GetBackground().GetColor();
+}
+
 void OutputDevice::DrawWallpaper( const tools::Rectangle& rRect,
                                   const Wallpaper& rWallpaper )
 {
diff --git a/vcl/source/window/paint.cxx b/vcl/source/window/paint.cxx
index 34e76fa6c316..8bdbc5a3b79f 100644
--- a/vcl/source/window/paint.cxx
+++ b/vcl/source/window/paint.cxx
@@ -333,7 +333,7 @@ void RenderTools::DrawSelectionBackground(vcl::RenderContext& rRenderContext, vc
     bool bBright = ( rStyles.GetFaceColor() == COL_WHITE );
 
     int c1 = aSelectionBorderColor.GetLuminance();
-    int c2 = rWindow.GetDisplayBackground().GetColor().GetLuminance();
+    int c2 = rWindow.GetBackgroundColor().GetLuminance();
 
     if (!bDark && !bBright && std::abs(c2 - c1) < (pPaintColor ? 40 : 75))
     {
diff --git a/vcl/source/window/window.cxx b/vcl/source/window/window.cxx
index 88ea0087a1f8..96b066ee23a0 100644
--- a/vcl/source/window/window.cxx
+++ b/vcl/source/window/window.cxx
@@ -585,6 +585,11 @@ Window::~Window()
     return this;
 }
 
+Color Window::GetBackgroundColor() const
+{
+    return GetDisplayBackground().GetColor();
+}
+
 } /* namespace vcl */
 
 WindowImpl::WindowImpl( WindowType nType )
@@ -3320,7 +3325,7 @@ void Window::DrawSelectionBackground( const tools::Rectangle& rRect,
     bool bBright = ( rStyles.GetFaceColor() == COL_WHITE );
 
     int c1 = aSelectionBorderCol.GetLuminance();
-    int c2 = GetDisplayBackground().GetColor().GetLuminance();
+    int c2 = GetBackgroundColor().GetLuminance();
 
     if( !bDark && !bBright && abs( c2-c1 ) < 75 )
     {