tdf#115057 Never use ImplPopupFloatWin for anything except ToolBox

ImplPopupFloatWin draws the window title and frame directly on the client
window, which is incompatible with .ui layouts, as they try to occupy the
whole available space. Instead just use a plain FloatingWindow whenever
possible, and change the border window code to mimic the behavior of
ImplPopupFloatWin, wrt removing part of the frame of toolbar popups w/o a
title.

Change-Id: If72ea89e31f913470faad7fcb8083f9b9787c9a8
Reviewed-on: https://gerrit.libreoffice.org/48094Reviewed-by: Maxim Monastirsky <momonasmon@gmail.com>
Tested-by: Maxim Monastirsky <momonasmon@gmail.com>

vcl/source/window/brdwin.cxx

@@ -1418,7 +1418,7 @@ void ImplStdBorderWindowView::DrawWindow(vcl::RenderContext& rRenderContext, con
     vcl::Region oldClipRgn(rRenderContext.GetClipRegion());
 
     // for popups, don't draw part of the frame
-    if (pData->mnTitleType == BorderWindowTitleType::Popup)
+    if (pData->mnTitleType >= BorderWindowTitleType::Popup)
     {
         FloatingWindow* pWin = dynamic_cast<FloatingWindow*>(pData->mpBorderWindow->GetWindow(GetWindowType::Client));
         if (pWin)
@@ -1444,7 +1444,7 @@ void ImplStdBorderWindowView::DrawWindow(vcl::RenderContext& rRenderContext, con
     --aInRect.Bottom();
 
     // restore
-    if (pData->mnTitleType == BorderWindowTitleType::Popup)
+    if (pData->mnTitleType >= BorderWindowTitleType::Popup)
         rRenderContext.SetClipRegion(oldClipRgn);
 
     // Draw Border

vcl/source/window/dockmgr.cxx

@@ -933,7 +933,7 @@ void ImplDockingWindowWrapper::ImplPreparePopupMode( FloatWinPopupFlags nFlags )
         mpOldBorderWin = nullptr;  // no border window found
 
     bool bAllowTearOff = bool( nFlags & FloatWinPopupFlags::AllowTearOff );
-    bool bUseStdPopup = bAllowTearOff && GetWindow()->GetType() != WindowType::TOOLBOX;
+    bool bUseStdPopup = GetWindow()->GetType() != WindowType::TOOLBOX;
 
     // the new parent for popup mode
     VclPtr<FloatingWindow> pWin;

vcl/source/window/floatwin.cxx

@@ -427,7 +427,7 @@ Point FloatingWindow::ImplCalcPos( vcl::Window* pWindow,
     aPos = pW->AbsoluteScreenToOutputPixel( aPos );
 
     // store a cliprect that can be used to clip the common edge of the itemrect and the floating window
-    if( pFloatingWindow )
+    if( pFloatingWindow && pFloatingWindow->mpImplData->mpBox )
     {
         pFloatingWindow->mpImplData->maItemEdgeClipRect =
             tools::Rectangle( e1, e2 );