cool#10782 vcl lok: avoid changing the current view during Yield

Commit 520cc546e2940bdfbc45eab1e569bb06bab17a9c (cool#10782 sfx2 lok:
fix bad view id on PDF export, 2024-12-20) provided a specific fix for
one case where spinning the main loop can result in callbacks being
emitted on the wrong view.

Hunting down all the SfxViewShell::Current() calls and auditing them if
they are problematic in practice is a large task, so it's desirable to
handle this problem in a more generic way.

Fix the problem by pushing/popping the current LOK view in
Application::Reschedule(), which is what e.g. the framework/ status bar
code uses during PDF export. This keeps the original problem fixed but
is more generic.

This requires storing function pointers in comphelper/, since normally
vcl/ code can't call SfxLokHelper, since sfx2/ already depends on vcl/.
The fix can be tested by reverting the original fix:
git show 520cc546e2940bdfbc45eab1e569bb06bab17a9c -- sfx2|git apply -R
and then running the testcase:
make -C sw -sr CppunitTest_sw_tiledrendering CPPUNIT_TEST_NAME=testPDFExportViewSwitch
which now passes even if the sfx2-level fix is not there. Keep that
specific fix, though: the less time we assume SfxViewShell::Current()
returns the correct view, the better.

Change-Id: Ic1811ff1e67f73fa5066af775d31589136b8502a
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/179993
Tested-by: Jenkins
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>

1 files changed, 16 insertions, 1 deletions

diff --git a/vcl/source/app/svapp.cxx b/vcl/source/app/svapp.cxx
index 06a21d733177..8de62eb4c5d1 100644
--- a/vcl/source/app/svapp.cxx
+++ b/vcl/source/app/svapp.cxx
@@ -401,7 +401,22 @@ bool Application::Reschedule( bool i_bAllEvents )
         SAL_WARN("vcl.schedule", "Application::Reschedule(" << i_bAllEvents << ")");
         return false;
     }
-    return ImplYield(false, i_bAllEvents);
+    int nOldView = -1;
+    if (comphelper::LibreOfficeKit::isActive())
+    {
+        nOldView = comphelper::LibreOfficeKit::getView();
+    }
+    bool bRet = ImplYield(false, i_bAllEvents);
+    if (comphelper::LibreOfficeKit::isActive())
+    {
+        int nNewView = comphelper::LibreOfficeKit::getView();
+        if (nOldView != -1 && nNewView != -1 && nOldView != nNewView)
+        {
+            // Yield changed the current view, restore the old value.
+            comphelper::LibreOfficeKit::setView(nOldView);
+        }
+    }
+    return bRet;
 }
 
 bool Application::IsUseSystemEventLoop()