From 14a03df4e97188a4401e6e0cf335b13e7591ed30 Mon Sep 17 00:00:00 2001 From: Vlad Zahorodnii Date: Wed, 30 Aug 2023 09:49:41 +0300 Subject: [PATCH 54/59] Client: Avoid locking resizing in QWaylandShmBackingStore QWaylandWindow::setCanResize(false) will block applying configure events. QWaylandWindow::setCanResize(true) will unblock configure events and potentially apply a scheduled configure event if there's one. QWaylandWindow::setCanResize(true) has to be called **after** committing the surface to ensure that the xdg window geometry matches the buffer. We don't want the xdg window geometry change when painting. Unfortunately, setCanResize(true) can be called before the surface is committed when using a RasterSurface, for example - QWaylandShmBackingStore::beginPaint(): calls setCanResize(false) - QWaylandShmBackingStore::endPaint(): calls setCanResize(true) - QWaylandWindow::setCanResize(true): applies pending configure event - QWaylandShmBackingStore::flush(): commits the surface, but the xdg window geometry is wrong now As is, beginPaint() and endPaint() are not entirely correct functions where configure events can be blocked. We need functions that wrap both painting and flushing, which are not feasible with the current backing store design. On the other hand, it's worth noting that blocking configure events in the backing store is not necessary because painting happens on the main thread unlike OpenGL or Vulkan code paths. Given the lack of synchronization points and the fact that rendering happens on the main thread, this change removes blocking configure events in QWaylandShmBackingStore. It fixes dolphin and various other applications that use QtWidgets jumping while being interactively resized. Change-Id: I156e4fd5e04a6bba7e8d48171510d5ab0ec89713 Reviewed-by: David Edmundson (cherry picked from commit 8828452bcf2ecf4e02a64380a1697d148c4366b0) --- src/client/qwaylandshmbackingstore.cpp | 3 --- 1 file changed, 3 deletions(-) diff --git a/src/client/qwaylandshmbackingstore.cpp b/src/client/qwaylandshmbackingstore.cpp index 90e37e95..145f933b 100644 --- a/src/client/qwaylandshmbackingstore.cpp +++ b/src/client/qwaylandshmbackingstore.cpp @@ -186,8 +186,6 @@ void QWaylandShmBackingStore::beginPaint(const QRegion ®ion) mPainting = true; ensureSize(); - waylandWindow()->setCanResize(false); - if (mBackBuffer->image()->hasAlphaChannel()) { QPainter p(paintDevice()); p.setCompositionMode(QPainter::CompositionMode_Source); @@ -202,7 +200,6 @@ void QWaylandShmBackingStore::endPaint() mPainting = false; if (mPendingFlush) flush(window(), mPendingRegion, QPoint()); - waylandWindow()->setCanResize(true); } void QWaylandShmBackingStore::ensureSize() -- 2.46.0