tdf#74702 vcl: extract GetMonochromeButtonColor()

Change-Id: I67e430ae1e0834f087a2066ed7bf660ec1309a28
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/94726
Tested-by: Jenkins
Reviewed-by: Tomaž Vajngerl <quikee@gmail.com>
diff --git a/include/vcl/outdev.hxx b/include/vcl/outdev.hxx
index 18c4754..86c18f0 100644
--- a/include/vcl/outdev.hxx
+++ b/include/vcl/outdev.hxx
@@ -537,6 +537,7 @@

public:
    virtual Size GetButtonBorderSize() { return Size(1, 1); };
    virtual Color GetMonochromeButtonColor() { return COL_WHITE; }

    /** @name Direct OutputDevice drawing functions
     */
diff --git a/include/vcl/print.hxx b/include/vcl/print.hxx
index 6e0fd0d..2e72240 100644
--- a/include/vcl/print.hxx
+++ b/include/vcl/print.hxx
@@ -241,6 +241,7 @@
                                    const Gradient& rGradient );
    virtual Bitmap              GetBitmap( const Point& rSrcPt, const Size& rSize ) const override;
    virtual Size                GetButtonBorderSize() override;
    virtual Color               GetMonochromeButtonColor() override { return COL_LIGHTGRAY; }

    bool                        IsScreenComp() const override { return false; }

diff --git a/vcl/source/window/decoview.cxx b/vcl/source/window/decoview.cxx
index 2d418a0..fab8f18 100644
--- a/vcl/source/window/decoview.cxx
+++ b/vcl/source/window/decoview.cxx
@@ -509,10 +509,7 @@
        }

        // Hack: in monochrome mode on printers we like to have grey buttons
        if ( pDev->GetOutDevType() == OUTDEV_PRINTER )
            pDev->SetFillColor( COL_LIGHTGRAY );
        else
            pDev->SetFillColor( COL_WHITE );
        pDev->SetFillColor(pDev->GetMonochromeButtonColor());
        pDev->DrawRect( aFillRect );
    }
    else