Sanitize popup behavior.

Popups are pretty important for widget apps. Menus, combobox dropdows
and such are all popups. Currently they are completely borked when
activated via keyboard or touch. This is because of the bizarre set_popup
request in the protocol, and Weston's current implementation, that ignore
the fact that a popup can be opened as a result of a keyboard event too
or may not originate from an input event at all.

Pass the last input device and serial we have seen, regardless of the type,
by tracking it globally in the QWaylandDisplay.

With this patch menus and such will not freeze the application anymore
when activated with keyboard or touch without sending a mouse event
to the window first. The behavior is still broken in some ways, especially
with keyboard due to immediately getting a popup_done, but at least
applications remain usable.

Task-number: QTBUG-41142
Task-number: QTBUG-41147
Change-Id: I18de501004ae8a62ff8667e72225d08c2d3ba491
Reviewed-by: Laszlo Agocs <laszlo.agocs@theqtcompany.com>
Reviewed-by: Jørgen Lind <jorgen.lind@theqtcompany.com>

6 files changed, 37 insertions, 21 deletions

diff --git a/src/client/qwaylanddisplay.cpp b/src/client/qwaylanddisplay.cpp
index fda2c204e..9dedabda3 100644
--- a/src/client/qwaylanddisplay.cpp
+++ b/src/client/qwaylanddisplay.cpp
@@ -128,6 +128,9 @@ QWaylandDisplay::QWaylandDisplay(QWaylandIntegration *waylandIntegration)
     , mQtKeyExtension(0)
     , mTextInputManager(0)
     , mHardwareIntegration(0)
+    , mLastInputSerial(0)
+    , mLastInputDevice(0)
+    , mLastInputWindow(0)
 {
     qRegisterMetaType<uint32_t>("uint32_t");
 
@@ -359,4 +362,11 @@ bool QWaylandDisplay::supportsWindowDecoration() const
     return integrationSupport;
 }
 
+void QWaylandDisplay::setLastInputDevice(QWaylandInputDevice *device, uint32_t serial, QWaylandWindow *win)
+{
+    mLastInputDevice = device;
+    mLastInputSerial = serial;
+    mLastInputWindow = win;
+}
+
 QT_END_NAMESPACE
diff --git a/src/client/qwaylanddisplay_p.h b/src/client/qwaylanddisplay_p.h
index 8d1d26bba..d9619e6f1 100644
--- a/src/client/qwaylanddisplay_p.h
+++ b/src/client/qwaylanddisplay_p.h
@@ -159,6 +159,11 @@ public:
 
     bool supportsWindowDecoration() const;
 
+    uint32_t lastInputSerial() const { return mLastInputSerial; }
+    QWaylandInputDevice *lastInputDevice() const { return mLastInputDevice; }
+    QWaylandWindow *lastInputWindow() const { return mLastInputWindow; }
+    void setLastInputDevice(QWaylandInputDevice *device, uint32_t serial, QWaylandWindow *window);
+
 public slots:
     void blockingReadEvents();
     void flushRequests();
@@ -200,6 +205,9 @@ private:
     bool mScreensInitialized;
     QList<RegistryGlobal> mGlobals;
     int mCompositorVersion;
+    uint32_t mLastInputSerial;
+    QWaylandInputDevice *mLastInputDevice;
+    QWaylandWindow *mLastInputWindow;
 
     void registry_global(uint32_t id, const QString &interface, uint32_t version) Q_DECL_OVERRIDE;
     void registry_global_remove(uint32_t id) Q_DECL_OVERRIDE;
diff --git a/src/client/qwaylandinputdevice.cpp b/src/client/qwaylandinputdevice.cpp
index ad369bb32..14575146d 100644
--- a/src/client/qwaylandinputdevice.cpp
+++ b/src/client/qwaylandinputdevice.cpp
@@ -476,7 +476,6 @@ void QWaylandInputDevice::Pointer::pointer_motion(uint32_t time, wl_fixed_t surf
 void QWaylandInputDevice::Pointer::pointer_button(uint32_t serial, uint32_t time,
                                                   uint32_t button, uint32_t state)
 {
-    Q_UNUSED(serial);
     QWaylandWindow *window = mFocus;
     Qt::MouseButton qt_button;
 
@@ -509,6 +508,8 @@ void QWaylandInputDevice::Pointer::pointer_button(uint32_t serial, uint32_t time
 
     mParent->mTime = time;
     mParent->mSerial = serial;
+    if (state)
+        mParent->mQDisplay->setLastInputDevice(mParent, serial, window);
 
     QWaylandWindow *grab = QWaylandWindow::mouseGrab();
     if (grab && grab != mFocus) {
@@ -754,7 +755,6 @@ void QWaylandInputDevice::Keyboard::focusCallback(void *data, struct wl_callback
 
 void QWaylandInputDevice::Keyboard::keyboard_key(uint32_t serial, uint32_t time, uint32_t key, uint32_t state)
 {
-    Q_UNUSED(serial);
     QWaylandWindow *window = mFocus;
     uint32_t code = key + 8;
     bool isDown = state != 0;
@@ -769,6 +769,9 @@ void QWaylandInputDevice::Keyboard::keyboard_key(uint32_t serial, uint32_t time,
         return;
     }
 
+    if (isDown)
+        mParent->mQDisplay->setLastInputDevice(mParent, serial, window);
+
 #ifndef QT_NO_WAYLAND_XKB
     if (!mXkbMap)
         return;
@@ -875,6 +878,7 @@ void QWaylandInputDevice::Touch::touch_down(uint32_t serial,
     mParent->mTime = time;
     mParent->mSerial = serial;
     mFocus = QWaylandWindow::fromWlSurface(surface);
+    mParent->mQDisplay->setLastInputDevice(mParent, serial, mFocus);
     mParent->handleTouchPoint(id, wl_fixed_to_double(x), wl_fixed_to_double(y), Qt::TouchPointPressed);
 }
 
diff --git a/src/client/qwaylandwindow.cpp b/src/client/qwaylandwindow.cpp
index 13408b259..976ebba15 100644
--- a/src/client/qwaylandwindow.cpp
+++ b/src/client/qwaylandwindow.cpp
@@ -88,8 +88,6 @@ QWaylandWindow::QWaylandWindow(QWindow *window)
     , mResizeDirty(false)
     , mResizeAfterSwap(qEnvironmentVariableIsSet("QT_WAYLAND_RESIZE_AFTER_SWAP"))
     , mSentInitialResize(false)
-    , mMouseDevice(0)
-    , mMouseSerial(0)
     , mState(Qt::WindowNoState)
     , mBackingStore(Q_NULLPTR)
 {
@@ -229,18 +227,14 @@ void QWaylandWindow::setVisible(bool visible)
         if (window()->type() == Qt::Popup) {
             QWaylandWindow *parent = transientParent();
             if (!parent) {
-                // Try with the current focus window. It may be the wrong one but we need to have
-                // some parent to have popups act as popups.
-                parent = mDisplay->currentInputDevice()->pointerFocus();
+                // Try with the current focus window. It should be the right one and anyway
+                // better than having no parent at all.
+                parent = mDisplay->lastInputWindow();
             }
             if (parent) {
-                mMouseDevice = parent->mMouseDevice;
-                mMouseSerial = parent->mMouseSerial;
-
                 QWaylandWlShellSurface *wlshellSurface = dynamic_cast<QWaylandWlShellSurface*>(mShellSurface);
-                if (mMouseDevice && wlshellSurface) {
-                    wlshellSurface->setPopup(parent, mMouseDevice, mMouseSerial);
-                }
+                if (wlshellSurface)
+                    wlshellSurface->setPopup(parent, mDisplay->lastInputDevice(), mDisplay->lastInputSerial());
             }
         }
 
@@ -579,7 +573,7 @@ QWaylandWindow *QWaylandWindow::transientParent() const
     if (window()->transientParent()) {
         // Take the top level window here, since the transient parent may be a QWidgetWindow
         // or some other window without a shell surface, which is then not able to get mouse
-        // events, nor set mMouseSerial and mMouseDevice.
+        // events.
         return static_cast<QWaylandWindow *>(topLevelWindow(window()->transientParent())->handle());
     }
     return 0;
@@ -587,10 +581,6 @@ QWaylandWindow *QWaylandWindow::transientParent() const
 
 void QWaylandWindow::handleMouse(QWaylandInputDevice *inputDevice, ulong timestamp, const QPointF &local, const QPointF &global, Qt::MouseButtons b, Qt::KeyboardModifiers mods)
 {
-    if (b != Qt::NoButton) {
-        mMouseSerial = inputDevice->serial();
-        mMouseDevice = inputDevice;
-    }
 
     if (mWindowDecoration) {
         handleMouseEventWithDecoration(inputDevice, timestamp,local,global,b,mods);
diff --git a/src/client/qwaylandwindow_p.h b/src/client/qwaylandwindow_p.h
index 6c32bc3ef..9ad6fe2f8 100644
--- a/src/client/qwaylandwindow_p.h
+++ b/src/client/qwaylandwindow_p.h
@@ -220,8 +220,6 @@ protected:
     QPoint mOffset;
 
     QIcon mWindowIcon;
-    QWaylandInputDevice *mMouseDevice;
-    int mMouseSerial;
 
     Qt::WindowState mState;
 
diff --git a/src/client/qwaylandwlshellsurface.cpp b/src/client/qwaylandwlshellsurface.cpp
index 86115fa38..39505e1d8 100644
--- a/src/client/qwaylandwlshellsurface.cpp
+++ b/src/client/qwaylandwlshellsurface.cpp
@@ -187,8 +187,14 @@ void QWaylandWlShellSurface::updateTransientParent(QWindow *parent)
 void QWaylandWlShellSurface::setPopup(QWaylandWindow *parent, QWaylandInputDevice *device, int serial)
 {
     QWaylandWindow *parent_wayland_window = parent;
-    if (!parent_wayland_window)
+    if (!parent_wayland_window) {
+        qWarning("setPopup called without parent window");
+        return;
+    }
+    if (!device) {
+        qWarning("setPopup called without input device");
         return;
+    }
 
     // set_popup expects a position relative to the parent
     QPoint transientPos = m_window->geometry().topLeft(); // this is absolute