QDice Example: Add a timer-guard for rolling dices

There is a problem in QQ3DPhysics. onBodyContact may still refer to
already deleted object - which causes the application to crash.
It happens when Accelerometer spam a lot with scene.spawnDice(...)
calls.

To avoid this crash, the timer-guard for rolling dices was added.

Pick-to: 6.6
Fixes: QTBUG-120364
Change-Id: I3ca3811662fb2400d61cb256c8b34885a6fe028a
Reviewed-by: Jonas Karlsson <jonas.karlsson@qt.io>
(cherry picked from commit ffc1984fd325deae4925cc638d9f32e03a517ad8)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

1 files changed, 15 insertions, 1 deletions

diff --git a/examples/demos/dice/DiceSpawner.qml b/examples/demos/dice/DiceSpawner.qml
index 4e8a991a9..9ccbb0b86 100644
--- a/examples/demos/dice/DiceSpawner.qml
+++ b/examples/demos/dice/DiceSpawner.qml
@@ -10,6 +10,7 @@ Node {
     id: shapeSpawner
     property var dices: []
     property var dieComponent: Qt.createComponent("PhysicalDie.qml")
+    property bool justSpawned: false
 
     function randomInRange(min, max) {
         return Math.random() * (max - min) + min
@@ -38,7 +39,8 @@ Node {
         source: "sounds/rolling.wav"
     }
     function spawnDice(numberOfDice, physicsMaterial, rollForce, diceWidth) {
-        if (allAtRest()) {
+        if (!justSpawned && allAtRest()) {
+            justSpawned = true;
             reset()
             rollSound.play()
 
@@ -49,6 +51,18 @@ Node {
                                                   index * 2.1, 0)
                 createDie(initialPosition, physicsMaterial, rollForce, diceWidth)
             }
+            spawnTimer.start()
+        }
+    }
+
+    Timer {
+        id: spawnTimer
+        interval: 500
+        running: false
+        repeat: false
+        onRunningChanged: {
+            if (!running)
+                shapeSpawner.justSpawned = false
         }
     }