Client: Avoid unnecessarily redrawing decorations

Note: QWaylandAbstractDecoration::update() doesn't actually update anything, it
just sets a dirty flag, and this is done explicitly in the other cases when the
decorations need to be redrawn as well (title and icon changes).

Fixes: QTBUG-75377
Change-Id: I2e8bd3abd3664c741e69a3e83ebf409872ddf31a
Reviewed-by: Paul Olav Tvete <paul.tvete@qt.io>
This commit is contained in:
Johan Klokkhammer Helsing 2019-04-25 08:58:49 +02:00 committed by Aapo Keskimolo
parent e3a9660499
commit 3a3f3eb924

View File

@ -288,12 +288,15 @@ void QWaylandShmBackingStore::resize(const QSize &size)
buffer = getBuffer(sizeWithMargins);
}
qsizetype oldSize = mBackBuffer ? mBackBuffer->image()->sizeInBytes() : 0;
qsizetype oldSizeInBytes = mBackBuffer ? mBackBuffer->image()->sizeInBytes() : 0;
qsizetype newSizeInBytes = buffer->image()->sizeInBytes();
// mBackBuffer may have been deleted here but if so it means its size was different so we wouldn't copy it anyway
if (mBackBuffer != buffer && oldSize == buffer->image()->sizeInBytes()) {
memcpy(buffer->image()->bits(), mBackBuffer->image()->constBits(), buffer->image()->sizeInBytes());
}
if (mBackBuffer != buffer && oldSizeInBytes == newSizeInBytes)
memcpy(buffer->image()->bits(), mBackBuffer->image()->constBits(), newSizeInBytes);
mBackBuffer = buffer;
// ensure the new buffer is at the beginning of the list so next time getBuffer() will pick
// it if possible
if (mBuffers.first() != buffer) {
@ -301,7 +304,7 @@ void QWaylandShmBackingStore::resize(const QSize &size)
mBuffers.prepend(buffer);
}
if (windowDecoration() && window()->isVisible())
if (windowDecoration() && window()->isVisible() && oldSizeInBytes != newSizeInBytes)
windowDecoration()->update();
}