From b36a345d727eab37ee4ec4c2dc4674d5971c81d8 Mon Sep 17 00:00:00 2001

From: David Edmundson <davidedmundson@kde.org>

Date: Mon, 14 Sep 2020 17:08:39 +0100

Subject: [PATCH] Client: Send exposeEvent to parent on subsurface position

 changes

When a subsurface is moved, we need the parent window to commit to apply

that move. Ideally we want this in sync with any potential rendering on

the parent window.

Currently the code calls requestUpdate() which acts more like a frame

callback; it will only do something if the main QWindow considers itself

dirty.

We want to force a repaint, which is semantically more similar to an

ExposeEvent.

Fixes: QTBUG-86177

Pick-to: 5.15

Change-Id: I30bdfa357beee860ce2b00a256eaea6d040dd55c

Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>

---

 src/client/qwaylandwindow.cpp             |  7 ++++-

 tests/auto/client/surface/tst_surface.cpp | 33 +++++++++++++++++++----

 2 files changed, 34 insertions(+), 6 deletions(-)

diff --git a/src/client/qwaylandwindow.cpp b/src/client/qwaylandwindow.cpp

index 3e26384..3cf1326 100644

--- a/src/client/qwaylandwindow.cpp

+++ b/src/client/qwaylandwindow.cpp

@@ -339,7 +339,12 @@ void QWaylandWindow::setGeometry_helper(const QRect &rect)

     if (mSubSurfaceWindow) {

         QMargins m = QPlatformWindow::parent()->frameMargins();

         mSubSurfaceWindow->set_position(rect.x() + m.left(), rect.y() + m.top());

-        mSubSurfaceWindow->parent()->window()->requestUpdate();

+

+        QWaylandWindow *parentWindow = mSubSurfaceWindow->parent();

+        if (parentWindow && parentWindow->isExposed()) {

+            QRect parentExposeGeometry(QPoint(), parentWindow->geometry().size());

+            parentWindow->sendExposeEvent(parentExposeGeometry);

+        }

     }

 }

diff --git a/tests/auto/client/surface/tst_surface.cpp b/tests/auto/client/surface/tst_surface.cpp

index b8a65f1..95e4e60 100644

--- a/tests/auto/client/surface/tst_surface.cpp

+++ b/tests/auto/client/surface/tst_surface.cpp

@@ -167,17 +167,40 @@ void tst_surface::negotiateShmFormat()

 void tst_surface::createSubsurface()

 {

     QRasterWindow window;

-    window.resize(64, 64);

-    window.show();

-    QCOMPOSITOR_TRY_VERIFY(xdgToplevel());

-    exec([=] { xdgToplevel()->sendCompleteConfigure(); });

-    QCOMPOSITOR_TRY_VERIFY(xdgSurface()->m_committedConfigureSerial);

+    window.setObjectName("main");

+    window.resize(200, 200);

     QRasterWindow subWindow;

+    subWindow.setObjectName("subwindow");

     subWindow.setParent(&window);

     subWindow.resize(64, 64);

+

+    window.show();

     subWindow.show();

+

     QCOMPOSITOR_TRY_VERIFY(subSurface());

+    QCOMPOSITOR_TRY_VERIFY(xdgToplevel());

+    exec([=] { xdgToplevel()->sendCompleteConfigure(); });

+    QCOMPOSITOR_TRY_VERIFY(xdgSurface()->m_committedConfigureSerial);

+

+    const Surface *mainSurface = exec([=] {return surface(0);});

+    const Surface *childSurface = exec([=] {return surface(1);});

+    QSignalSpy  mainSurfaceCommitSpy(mainSurface, &Surface::commit);

+    QSignalSpy childSurfaceCommitSpy(childSurface, &Surface::commit);

+

+    // Move subsurface. The parent should redraw and commit

+    subWindow.setGeometry(100, 100, 64, 64);

+    // the toplevel should commit to indicate the subsurface moved

+    QCOMPOSITOR_TRY_COMPARE(mainSurfaceCommitSpy.count(), 1);

+    mainSurfaceCommitSpy.clear();

+    childSurfaceCommitSpy.clear();

+

+    // Move and resize the subSurface. The parent should redraw and commit

+    // The child should also redraw

+    subWindow.setGeometry(50, 50, 80, 80);

+    QCOMPOSITOR_TRY_COMPARE(mainSurfaceCommitSpy.count(), 1);

+    QCOMPOSITOR_TRY_COMPARE(childSurfaceCommitSpy.count(), 1);

+

 }

 // Used to cause a crash in libwayland (QTBUG-79674)