commit c04169c586ef1d55b1d0ac469bb4fbd4f50bd08a
author Miklos Vajna <vmiklos@collabora.com> Tue May 21 17:45:05 2019 +0200
committer Miklos Vajna <vmiklos@collabora.com> Tue May 21 23:59:28 2019 +0200
tree 6899ace1ac064621ddad4496dae05bb042619554
parent 845ebb4dd45ad4f93a6344d010f383be339ad488

tdf#125415 vcl menu floating window: avoid flicker

This is similar to e8d5b8beb5958147235ff955ed38c47b51d860ff (tdf#113714
vcl menu bar window: avoid flicker, 2019-05-20), except that was for the
menu bar window, and this is for the floating window opening from that
one.

Change-Id: Ib24f4999ad3e8cbbecc058368e9d112e106e9178
Reviewed-on: https://gerrit.libreoffice.org/72688
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>
Tested-by: Jenkins

vcl/source/window/menufloatingwindow.cxx

diff --git a/vcl/source/window/menufloatingwindow.cxx b/vcl/source/window/menufloatingwindow.cxx
index 7986679..631d275 100644
--- a/vcl/source/window/menufloatingwindow.cxx
+++ b/vcl/source/window/menufloatingwindow.cxx
@@ -27,6 +27,7 @@
#include <svdata.hxx>
#include <vcl/decoview.hxx>
#include <vcl/settings.hxx>
#include <vcl/virdev.hxx>
#include <window.h>

MenuFloatingWindow::MenuFloatingWindow( Menu* pMen, vcl::Window* pParent, WinBits nStyle ) :
@@ -1206,32 +1207,41 @@ void MenuFloatingWindow::Paint(vcl::RenderContext& rRenderContext, const tools::
    if (!pMenu)
        return;

    rRenderContext.Push( PushFlags::CLIPREGION );
    rRenderContext.SetClipRegion(vcl::Region(rPaintRect));
    // Make sure that all actual rendering happens in one go to avoid flicker.
    ScopedVclPtrInstance<VirtualDevice> pBuffer;
    pBuffer->SetOutputSizePixel(GetOutputSizePixel(), false);
    pBuffer->DrawOutDev(Point(0, 0), GetOutputSizePixel(), Point(0, 0), GetOutputSizePixel(),
                        rRenderContext);

    pBuffer->Push(PushFlags::CLIPREGION);
    pBuffer->SetClipRegion(vcl::Region(rPaintRect));

    if (rRenderContext.IsNativeControlSupported(ControlType::MenuPopup, ControlPart::Entire))
    {
        rRenderContext.SetClipRegion();
        pBuffer->SetClipRegion();
        long nX = 0;
        Size aPxSize(GetOutputSizePixel());
        aPxSize.AdjustWidth( -nX );
        ImplControlValue aVal(pMenu->nTextPos - GUTTERBORDER);
        rRenderContext.DrawNativeControl(ControlType::MenuPopup, ControlPart::Entire,
                                         tools::Rectangle(Point(nX, 0), aPxSize),
                                         ControlState::ENABLED, aVal, OUString());
        InitMenuClipRegion(rRenderContext);
        pBuffer->DrawNativeControl(ControlType::MenuPopup, ControlPart::Entire,
                                   tools::Rectangle(Point(nX, 0), aPxSize), ControlState::ENABLED,
                                   aVal, OUString());
        InitMenuClipRegion(*pBuffer);
    }
    if (IsScrollMenu())
    {
        ImplDrawScroller(rRenderContext, true);
        ImplDrawScroller(rRenderContext, false);
        ImplDrawScroller(*pBuffer, true);
        ImplDrawScroller(*pBuffer, false);
    }
    rRenderContext.SetFillColor(rRenderContext.GetSettings().GetStyleSettings().GetMenuColor());
    pMenu->ImplPaint(rRenderContext, GetOutputSizePixel(), nScrollerHeight, ImplGetStartY());
    pBuffer->SetFillColor(rRenderContext.GetSettings().GetStyleSettings().GetMenuColor());
    pMenu->ImplPaint(*pBuffer, GetOutputSizePixel(), nScrollerHeight, ImplGetStartY());
    if (nHighlightedItem != ITEMPOS_INVALID)
        RenderHighlightItem(rRenderContext, nHighlightedItem);
        RenderHighlightItem(*pBuffer, nHighlightedItem);

    rRenderContext.Pop();
    pBuffer->Pop();

    rRenderContext.DrawOutDev(Point(0, 0), GetOutputSizePixel(), Point(0, 0), GetOutputSizePixel(),
                              *pBuffer);
}

void MenuFloatingWindow::ImplDrawScroller(vcl::RenderContext& rRenderContext, bool bUp)