desktop: disable callback handling while changing the view

When changing the view, some components are disabled
and re-enabled. This triggers a flood of invalidations
that then result in rendering requests. For each rendering
the view is set, which triggers more invalidations.

The Sidebar suffers from this, and it causes cpu pegging.
This fix prevents this issue by disabling all callbacks
during setView.

Change-Id: If6b93b2ab31f568a0761f15d945a43de1bc2d4d0
Reviewed-on: https://gerrit.libreoffice.org/84184
Reviewed-by: Ashod Nakashian <ashnakash@gmail.com>
Tested-by: Ashod Nakashian <ashnakash@gmail.com>
Reviewed-on: https://gerrit.libreoffice.org/84224
Tested-by: Jenkins
Reviewed-by: Michael Meeks <michael.meeks@collabora.com>

1 files changed, 9 insertions, 10 deletions

diff --git a/desktop/inc/lib/init.hxx b/desktop/inc/lib/init.hxx
index 3587ba003e37..5957f56ed344 100644
--- a/desktop/inc/lib/init.hxx
+++ b/desktop/inc/lib/init.hxx
@@ -79,15 +79,14 @@ namespace desktop {
         static void callback(const int type, const char* payload, void* data);
         void queue(const int type, const char* data);
 
-        /// When enabled events are queued but callback not invoked.
-        void setEventLatch(const bool bEventLatch)
-        {
-            m_bEventLatch = bEventLatch;
-        }
-
-        bool isEventLatchOn() const { return m_bEventLatch; }
-        void setPartTilePainting(const bool bPartPainting) { m_bPartTilePainting = bPartPainting; }
-        bool isPartTilePainting() const { return m_bPartTilePainting; }
+        /// Disables callbacks on this handler. Must match with identical count
+        /// of enableCallbacks. Used during painting and changing views.
+        void disableCallbacks() { ++m_nDisableCallbacks; }
+        /// Enables callbacks on this handler. Must match with identical count
+        /// of disableCallbacks. Used during painting and changing views.
+        void enableCallbacks() { --m_nDisableCallbacks; }
+        /// Returns true iff callbacks are disabled.
+        bool callbacksDisabled() const { return m_nDisableCallbacks != 0; }
 
         void addViewStates(int viewId);
         void removeViewStates(int viewId);
@@ -140,7 +139,7 @@ namespace desktop {
         LibreOfficeKitDocument* m_pDocument;
         LibreOfficeKitCallback m_pCallback;
         void *m_pData;
-        bool m_bPartTilePainting;
+        int m_nDisableCallbacks;
         bool m_bEventLatch;
         std::mutex m_mutex;
     };