vcl: interface for WinAPI FlashWindow() function

To improve LibreOffice UX it will be great to have possibility to
signal user on some event did happen, but without capuring focus
and bringing LO to foreground, like it is happenings sometimes. It
can be annoying.

For example, if dialog window is opening slowly and user did switch
to another application, this is used to inform user that there
are some updates in LO window: dialog finally alive.

There are somewhat confusing implementation of this feature: VCL dialog
window became visible and actual Windows window should use
::FlashWindow() are very different in hierarchies, so it is somewhat
challenging to find window to flash or even decide shoud we flash window
or not.

Change-Id: I6ca6706d2dda8902aea273ebe6e318ec9bf4beda
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/158472
Tested-by: Jenkins
Reviewed-by: Samuel Mehrbrodt <samuel.mehrbrodt@allotropia.de>

1 files changed, 8 insertions, 0 deletions

diff --git a/vcl/win/window/salframe.cxx b/vcl/win/window/salframe.cxx
index 81dcf341e60d..ab20e2411e42 100644
--- a/vcl/win/window/salframe.cxx
+++ b/vcl/win/window/salframe.cxx
@@ -2993,6 +2993,14 @@ void WinSalFrame::Beep()
     MessageBeep( 0 );
 }
 
+void WinSalFrame::FlashWindow() const
+{
+    if (GetForegroundWindow() != mhWnd)
+    {
+        ::FlashWindow(mhWnd, TRUE);
+    }
+}
+
 SalFrame::SalPointerState WinSalFrame::GetPointerState()
 {
     SalPointerState aState;