From 18b10527cc14a42a19b5d088845bfd2e96326bbb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Arve=20S=C3=A6ther?= <jan-arve.saether@qt.io>
Date: Thu, 3 Sep 2020 10:51:01 +0200
Subject: [PATCH 03/19] Fix TapHandler so that it actually registers a tap

This bug caused all quick examples that used the
shared\LauncherList.qml to be broken.

In QtGui, QSinglePointEvent will construct itself with a point id of 0
if there is a valid point, and with a point id of -1 if the point is
invalid (the default constructor does the latter).
However, QQuickSinglePointHandler::wantsPointerEvent() did not agree
with that, because it assumed that a point id of 0 meant
uninitialized/invalid point.
The fix is to change QQuickSinglePointHandler::wantsPointerEvent() and
QQuickHandlerPoint so that it assumes that the id -1 is now an invalid
point, (instead of 0)

Change-Id: I8c9683dfe06ebb77c5342a26f08174b67e7cbd90
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>
(cherry picked from commit 8d3a91016506fd0afedb0be535f7c34a4ca762f6)
---
 src/quick/handlers/qquickhandlerpoint.cpp       | 4 ++--
 src/quick/handlers/qquicksinglepointhandler.cpp | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/quick/handlers/qquickhandlerpoint.cpp b/src/quick/handlers/qquickhandlerpoint.cpp
index 72efdfd0f4..6aef3545dd 100644
--- a/src/quick/handlers/qquickhandlerpoint.cpp
+++ b/src/quick/handlers/qquickhandlerpoint.cpp
@@ -82,7 +82,7 @@ void QQuickHandlerPoint::localize(QQuickItem *item)
 
 void QQuickHandlerPoint::reset()
 {
-    m_id = 0;
+    m_id = -1;
     m_uniqueId = QPointingDeviceUniqueId();
     m_position = QPointF();
     m_scenePosition = QPointF();
@@ -165,7 +165,7 @@ void QQuickHandlerPoint::reset(const QVector<QQuickHandlerPoint> &points)
         pressureSum += point.pressure();
         ellipseDiameterSum += point.ellipseDiameters();
     }
-    m_id = 0;
+    m_id = -1;
     m_uniqueId = QPointingDeviceUniqueId();
     // all points are required to be from the same event, so pressed buttons and modifiers should be the same
     m_pressedButtons = points.first().pressedButtons();
diff --git a/src/quick/handlers/qquicksinglepointhandler.cpp b/src/quick/handlers/qquicksinglepointhandler.cpp
index b51f53b74f..89081b4e84 100644
--- a/src/quick/handlers/qquicksinglepointhandler.cpp
+++ b/src/quick/handlers/qquicksinglepointhandler.cpp
@@ -75,7 +75,7 @@ bool QQuickSinglePointHandler::wantsPointerEvent(QQuickPointerEvent *event)
     if (!QQuickPointerDeviceHandler::wantsPointerEvent(event))
         return false;
 
-    if (d->pointInfo.id()) {
+    if (d->pointInfo.id() != -1) {
         // We already know which one we want, so check whether it's there.
         // It's expected to be an update or a release.
         // If we no longer want it, cancel the grab.
@@ -125,7 +125,7 @@ bool QQuickSinglePointHandler::wantsPointerEvent(QQuickPointerEvent *event)
             chosen->setAccepted();
         }
     }
-    return d->pointInfo.id();
+    return d->pointInfo.id() != -1;
 }
 
 void QQuickSinglePointHandler::handlePointerEventImpl(QQuickPointerEvent *event)
-- 
2.40.0