Compositor: Fix popup support properly

- Make popups work with overlays such as QQuickDrawer.
- No longer require that there is a background item that
  accepts mouse events.
- UI items on top of the compositor area that should block mouse
  clicks on popups, must set the property "qtwayland_blocking_overlay".

Change-Id: If81793750e016f53e3873e216e90ed86d324c067
Reviewed-by: Pier Luigi Fiorini <pierluigi.fiorini@gmail.com>
Reviewed-by: Johan Helsing <johan.helsing@qt.io>

2 files changed, 38 insertions, 1 deletions

diff --git a/src/compositor/extensions/qwaylandquickshellsurfaceitem.cpp b/src/compositor/extensions/qwaylandquickshellsurfaceitem.cpp
index d4b16e85f..5fe43e547 100644
--- a/src/compositor/extensions/qwaylandquickshellsurfaceitem.cpp
+++ b/src/compositor/extensions/qwaylandquickshellsurfaceitem.cpp
@@ -192,13 +192,19 @@ QWaylandQuickShellEventFilter::QWaylandQuickShellEventFilter(QObject *parent)
 bool QWaylandQuickShellEventFilter::eventFilter(QObject *receiver, QEvent *e)
 {
     if (e->type() == QEvent::MouseButtonPress || e->type() == QEvent::MouseButtonRelease) {
+        bool press = e->type() == QEvent::MouseButtonPress;
+        if (press && !waitForRelease) {
+            // The user clicked something: we need to close popups unless this press is caught later
+            if (!mousePressTimeout.isActive())
+                mousePressTimeout.start(0, this);
+        }
+
         QQuickItem *item = qobject_cast<QQuickItem*>(receiver);
         if (!item)
             return false;
 
         QMouseEvent *event = static_cast<QMouseEvent*>(e);
         QWaylandQuickShellSurfaceItem *shellSurfaceItem = qobject_cast<QWaylandQuickShellSurfaceItem*>(item);
-        bool press = event->type() == QEvent::MouseButtonPress;
         bool finalRelease = (event->type() == QEvent::MouseButtonRelease) && (event->buttons() == Qt::NoButton);
         bool popupClient = shellSurfaceItem && shellSurfaceItem->surface()->client() == client;
 
@@ -211,6 +217,21 @@ bool QWaylandQuickShellEventFilter::eventFilter(QObject *receiver, QEvent *e)
             return true;
         }
 
+        if (finalRelease && mousePressTimeout.isActive()) {
+            // the user somehow managed to press and release the mouse button in 0 milliseconds
+            qWarning("Badly written autotest detected");
+            mousePressTimeout.stop();
+            stopFilter();
+        }
+
+        if (press && !shellSurfaceItem && !QQmlProperty(item, QStringLiteral("qtwayland_blocking_overlay")).isValid()) {
+            // the user clicked on something that's not blocking mouse events
+            e->ignore(); //propagate the event to items below
+            return true; // don't give the event to the item
+        }
+
+        mousePressTimeout.stop(); // we've got this
+
         if (press && !popupClient) {
             // The user clicked outside the active popup's client. The popups should
             // be closed, but the event filter will stay to catch the release-
@@ -224,4 +245,15 @@ bool QWaylandQuickShellEventFilter::eventFilter(QObject *receiver, QEvent *e)
     return false;
 }
 
+void QWaylandQuickShellEventFilter::timerEvent(QTimerEvent *event)
+{
+    if (event->timerId() == mousePressTimeout.timerId()) {
+        mousePressTimeout.stop();
+        closePopups();
+        stopFilter();
+        // Don't wait for release: Since the press wasn't accepted,
+        // the release won't be delivered.
+    }
+}
+
 QT_END_NAMESPACE
diff --git a/src/compositor/extensions/qwaylandquickshellsurfaceitem_p.h b/src/compositor/extensions/qwaylandquickshellsurfaceitem_p.h
index c2f46917e..c39a1cd08 100644
--- a/src/compositor/extensions/qwaylandquickshellsurfaceitem_p.h
+++ b/src/compositor/extensions/qwaylandquickshellsurfaceitem_p.h
@@ -38,6 +38,7 @@
 #define QWAYLANDQUICKSHELLSURFACEITEM_P_H
 
 #include <QtWaylandCompositor/private/qwaylandquickitem_p.h>
+#include <QtCore/QBasicTimer>
 
 QT_BEGIN_NAMESPACE
 
@@ -86,6 +87,9 @@ public:
     static void startFilter(QWaylandClient *client, CallbackFunction closePopupCallback);
     static void cancelFilter();
 
+protected:
+    void timerEvent(QTimerEvent *event) Q_DECL_OVERRIDE;
+
 private:
     void stopFilter();
 
@@ -95,6 +99,7 @@ private:
     bool waitForRelease;
     QPointer<QWaylandClient> client;
     CallbackFunction closePopups;
+    QBasicTimer mousePressTimeout;
     static QWaylandQuickShellEventFilter *self;
 };