make opengl transitions under X flicker free on enter/leave

Change-Id: I109637dc6b3d23c0beca21f3cf0c7ba918ecb4f8
Reviewed-on: https://gerrit.libreoffice.org/38749
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>
(cherry picked from commit 277395b6266c57a7709c3c47986f135f6789c8e7)
Reviewed-on: https://gerrit.libreoffice.org/38753
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>
(cherry picked from commit b49779db18fa094f3b2f4166ee93c072d2f117a1)

5 files changed, 53 insertions, 2 deletions

diff --git a/vcl/inc/salobj.hxx b/vcl/inc/salobj.hxx
index b1005fb87846..08d8a39ed661 100644
--- a/vcl/inc/salobj.hxx
+++ b/vcl/inc/salobj.hxx
@@ -21,7 +21,7 @@
 #define INCLUDED_VCL_INC_SALOBJ_HXX
 
 #include <vcl/dllapi.h>
-
+#include <com/sun/star/uno/Sequence.hxx>
 #include "salwtype.hxx"
 
 struct SystemEnvData;
@@ -48,6 +48,8 @@ public:
 
     virtual void                    SetForwardKey( bool /* bEnable */ ) {}
 
+    virtual void                    SetLeaveEnterBackgrounds(const css::uno::Sequence<css::uno::Any>& /*rLeaveArgs*/, const css::uno::Sequence<css::uno::Any>& /*rEnterArgs*/) {}
+
     virtual const SystemEnvData*    GetSystemData() const = 0;
 
     void                            SetCallback( void* pInst, SALOBJECTPROC pProc )
diff --git a/vcl/inc/unx/salobj.h b/vcl/inc/unx/salobj.h
index ffc738aa6987..b3170cb6c0af 100644
--- a/vcl/inc/unx/salobj.h
+++ b/vcl/inc/unx/salobj.h
@@ -76,6 +76,8 @@ public:
     virtual void                    Show( bool bVisible ) override;
     virtual void                    GrabFocus() override;
 
+    virtual void                    SetLeaveEnterBackgrounds(const css::uno::Sequence<css::uno::Any>& rLeaveArgs, const css::uno::Sequence<css::uno::Any>& rEnterArgs) override;
+
     virtual const SystemEnvData*    GetSystemData() const override;
 };
 
diff --git a/vcl/source/window/syschild.cxx b/vcl/source/window/syschild.cxx
index d6595038991b..bdeebf118dfc 100644
--- a/vcl/source/window/syschild.cxx
+++ b/vcl/source/window/syschild.cxx
@@ -162,6 +162,12 @@ void SystemChildWindow::EnableEraseBackground( bool bEnable )
         mpWindowImpl->mpSysObj->EnableEraseBackground( bEnable );
 }
 
+void SystemChildWindow::SetLeaveEnterBackgrounds(const css::uno::Sequence<css::uno::Any>& rLeaveArgs, const css::uno::Sequence<css::uno::Any>& rEnterArgs)
+{
+    if (mpWindowImpl->mpSysObj)
+        mpWindowImpl->mpSysObj->SetLeaveEnterBackgrounds(rLeaveArgs, rEnterArgs);
+}
+
 void SystemChildWindow::SetForwardKey( bool bEnable )
 {
     if ( mpWindowImpl->mpSysObj )
diff --git a/vcl/unx/generic/window/salobj.cxx b/vcl/unx/generic/window/salobj.cxx
index 80c0726214c9..2f238b7f9d7e 100644
--- a/vcl/unx/generic/window/salobj.cxx
+++ b/vcl/unx/generic/window/salobj.cxx
@@ -249,6 +249,9 @@ X11SalObject::~X11SalObject()
     rObjects.remove( this );
 
     GetGenericData()->ErrorTrapPush();
+    const SystemEnvData* pEnv   = mpParent->GetSystemData();
+    ::Window aObjectParent      = (::Window)pEnv->aWindow;
+    XSetWindowBackgroundPixmap(static_cast<Display*>(maSystemChildData.pDisplay), aObjectParent, None);
     if ( maSecondary )
         XDestroyWindow( static_cast<Display*>(maSystemChildData.pDisplay), maSecondary );
     if ( maPrimary )
@@ -474,4 +477,40 @@ bool X11SalObject::Dispatch( XEvent* pEvent )
     return false;
 }
 
+void X11SalObject::SetLeaveEnterBackgrounds(const css::uno::Sequence<css::uno::Any>& rLeaveArgs, const css::uno::Sequence<css::uno::Any>& rEnterArgs)
+{
+    SalDisplay* pSalDisp        = vcl_sal::getSalDisplay(GetGenericData());
+    const SystemEnvData* pEnv   = mpParent->GetSystemData();
+    Display* pDisp              = pSalDisp->GetDisplay();
+    ::Window aObjectParent      = (::Window)pEnv->aWindow;
+
+    bool bFreePixmap = false;
+    Pixmap aPixmap = None;
+    if (rEnterArgs.getLength() == 3)
+    {
+        rEnterArgs[0] >>= bFreePixmap;
+        long pixmapHandle = None;
+        rEnterArgs[1] >>= pixmapHandle;
+        aPixmap = pixmapHandle;
+    }
+
+    XSetWindowBackgroundPixmap(pDisp, aObjectParent, aPixmap);
+    if (bFreePixmap)
+        XFreePixmap(pDisp, aPixmap);
+
+    bFreePixmap = false;
+    aPixmap = None;
+    if (rLeaveArgs.getLength() == 3)
+    {
+        rLeaveArgs[0] >>= bFreePixmap;
+        long pixmapHandle = None;
+        rLeaveArgs[1] >>= pixmapHandle;
+        aPixmap = pixmapHandle;
+    }
+
+    XSetWindowBackgroundPixmap(pDisp, maSecondary, aPixmap);
+    if (bFreePixmap)
+        XFreePixmap(pDisp, aPixmap);
+}
+
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/vcl/unx/gtk/gtksalframe.cxx b/vcl/unx/gtk/gtksalframe.cxx
index 1e28c041ea47..b10994d7d4d0 100644
--- a/vcl/unx/gtk/gtksalframe.cxx
+++ b/vcl/unx/gtk/gtksalframe.cxx
@@ -2882,7 +2882,9 @@ gboolean GtkSalFrame::signalExpose( GtkWidget*, GdkEventExpose* pEvent, gpointer
 {
     GtkSalFrame* pThis = static_cast<GtkSalFrame*>(frame);
 
-    struct SalPaintEvent aEvent( pEvent->area.x, pEvent->area.y, pEvent->area.width, pEvent->area.height, OpenGLHelper::isVCLOpenGLEnabled() );
+    const bool bImmediate = OpenGLHelper::isVCLOpenGLEnabled() || pThis->m_bFullscreen;
+
+    struct SalPaintEvent aEvent( pEvent->area.x, pEvent->area.y, pEvent->area.width, pEvent->area.height, bImmediate );
 
     pThis->CallCallback( SalEvent::Paint, &aEvent );