From 4eb74f5b7173cbf8de15628fd0233b43d25bdbf8 Mon Sep 17 00:00:00 2001
From: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date: Tue, 29 May 2018 12:05:16 +0200
Subject: [PATCH] working with nested gesture recognizers fixed

---
 src/controls/QskGestureRecognizer.cpp | 21 ++++++++++++++++++++-
 src/controls/QskGestureRecognizer.h   |  2 ++
 src/controls/QskScrollView.cpp        |  6 ++++--
 3 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/src/controls/QskGestureRecognizer.cpp b/src/controls/QskGestureRecognizer.cpp
index dd8b185e..010e7c7e 100644
--- a/src/controls/QskGestureRecognizer.cpp
+++ b/src/controls/QskGestureRecognizer.cpp
@@ -74,8 +74,10 @@ namespace
 
             if ( m_recognizer )
             {
-                m_recognizer->reject();
+                auto recognizer = m_recognizer;
                 m_recognizer = nullptr;
+
+                recognizer->reject();
             }
         }
 
@@ -105,6 +107,7 @@ public:
     PrivateData():
         watchedItem( nullptr ),
         timestamp( 0 ),
+        timestampProcessed( 0 ),
         timeout( -1 ),
         buttons( Qt::NoButton ),
         state( QskGestureRecognizer::Idle ),
@@ -116,6 +119,7 @@ public:
 
     PendingEvents pendingEvents;
     ulong timestamp;
+    ulong timestampProcessed;
 
     int timeout; // ms
 
@@ -170,6 +174,11 @@ ulong QskGestureRecognizer::timestamp() const
     return m_data->timestamp;
 }
 
+bool QskGestureRecognizer::hasProcessedBefore( const QMouseEvent* event ) const
+{
+    return event && ( event->timestamp() <= m_data->timestampProcessed );
+}
+
 bool QskGestureRecognizer::isReplaying() const
 {
     return m_data->isReplayingEvents;
@@ -383,6 +392,16 @@ void QskGestureRecognizer::reject()
 
     if ( !events.isEmpty() && events[0]->type() == QEvent::MouseButtonPress )
     {
+        /*
+            In a situation of several recognizers ( f.e a vertical
+            scroll view inside a horizontal swipe view ), we might receive
+            cloned events from another recognizer.
+            To avoid to process them twice we store the most recent timestamp
+            of the cloned events we have already processed, but reposted.
+         */
+
+        m_data->timestampProcessed = events.last()->timestamp();
+
         QCoreApplication::sendEvent( window, events[0] );
 
         /*
diff --git a/src/controls/QskGestureRecognizer.h b/src/controls/QskGestureRecognizer.h
index 52af7676..7dedffa2 100644
--- a/src/controls/QskGestureRecognizer.h
+++ b/src/controls/QskGestureRecognizer.h
@@ -37,6 +37,7 @@ public:
     void setTimeout( int );
     int timeout() const;
 
+    // timestamp, when the Idle state had been left
     ulong timestamp() const;
 
     bool processEvent( QQuickItem*, QEvent*, bool blockReplayedEvents = true );
@@ -48,6 +49,7 @@ public:
     State state() const;
 
     bool isReplaying() const;
+    bool hasProcessedBefore( const QMouseEvent* ) const;
 
 protected:
     virtual void pressEvent( const QMouseEvent* );
diff --git a/src/controls/QskScrollView.cpp b/src/controls/QskScrollView.cpp
index 567232fa..0d1a8bdf 100644
--- a/src/controls/QskScrollView.cpp
+++ b/src/controls/QskScrollView.cpp
@@ -604,9 +604,11 @@ bool QskScrollView::gestureFilter( QQuickItem* item, QEvent* event )
 
     if ( event->type() == QEvent::MouseButtonPress )
     {
-        if ( recognizer.isReplaying() )
+        if ( ( item != this ) && ( recognizer.timeout() < 0 ) )
         {
-            if ( ( item != this ) || ( recognizer.timeout() < 0 ) )
+            const auto mouseEvent = static_cast< QMouseEvent* >( event );
+
+            if ( recognizer.hasProcessedBefore( mouseEvent ) )
                 return false;
         }