Fix virtual joysticks triggering pinch-to-zoom on map

Restrict the map's PinchHandler grabPermissions so it cannot steal
touch grabs from MultiPointTouchArea items (the joystick thumb pads).
Previously, when both thumbs were on the virtual joysticks simultaneously,
the PinchHandler's default CanTakeOverFromItems permission allowed it to
interpret the two touch points as a pinch gesture and zoom the map instead
of letting the joysticks operate independently.

Fixes #13450

Author: DonLakeFlyer

src/FlightMap/FlightMap.qml

@@ -116,24 +116,6 @@ Map {
     signal mapRightClicked(var position)
     signal mapPressAndHold(var position)
 
-    PinchHandler {
-        id:     pinchHandler
-        target: null
-
-        property var pinchStartCentroid
-
-        onActiveChanged: {
-            if (active) {
-                pinchStartCentroid = _map.toCoordinate(pinchHandler.centroid.position, false)
-            }
-        }
-        onScaleChanged: (delta) => {
-            let newZoomLevel = Math.max(_map.zoomLevel + Math.log2(delta), 0)
-            _map.zoomLevel = newZoomLevel
-            _map.alignCoordinateToPoint(pinchStartCentroid, pinchHandler.centroid.position)
-        }
-    }
-
     WheelHandler {
         // workaround for QTBUG-87646 / QTBUG-112394 / QTBUG-112432:
         // Magic Mouse pretends to be a trackpad but doesn't work with PinchHandler
@@ -151,57 +133,109 @@ Map {
     }
 
     // We specifically do not use a DragHandler for panning. It just causes too many problems if you overlay anything else like a Flickable above it.
-    // Causes all sorts of crazy problems where dragging/scrolling  no longerr works on items above in the hierarchy.
+    // Causes all sorts of crazy problems where dragging/scrolling no longer works on items above in the hierarchy.
     // Since we are using a MouseArea we also can't use TapHandler for clicks. So we handle that here as well.
+    // Pinch-to-zoom is also handled here rather than via PinchHandler to prevent the handler from stealing
+    // touch grabs from items above (e.g. virtual joystick pads). See GitHub issue #13450.
     MultiPointTouchArea {
         id: multiTouchArea
         anchors.fill: parent
-        maximumTouchPoints: 1
+        maximumTouchPoints: 2
         mouseEnabled: true
 
+        touchPoints: [
+            TouchPoint { id: tp1 },
+            TouchPoint { id: tp2 }
+        ]
+
         property bool dragActive: false
+        property bool pinchActive: false
+        property bool wasMultiTouch: false
         property real lastMouseX
         property real lastMouseY
         property bool isPressed: false
         property bool pressAndHold: false
+        property real pinchStartDist
+        property real pinchStartZoom
+        property var pinchStartCentroid
+
+        function pinchDistance() {
+            let dx = tp2.x - tp1.x
+            let dy = tp2.y - tp1.y
+            return Math.sqrt(dx * dx + dy * dy)
+        }
 
         onPressed: (touchPoints) => {
-            lastMouseX = touchPoints[0].x
-            lastMouseY = touchPoints[0].y
-            isPressed = true
-            pressAndHold = false
-            pressAndHoldTimer.start()
+            if (!pinchActive && !dragActive) {
+                lastMouseX = tp1.x
+                lastMouseY = tp1.y
+                isPressed = true
+                pressAndHold = false
+                pressAndHoldTimer.start()
+            }
         }
 
         onGestureStarted: (gesture) => {
-            dragActive = true
             gesture.grab()
-            mapPanStart()
+            if (!pinchActive && !dragActive) {
+                dragActive = true
+                mapPanStart()
+            }
         }
 
         onUpdated: (touchPoints) => {
-            if (dragActive) {
-                let deltaX = touchPoints[0].x - lastMouseX
-                let deltaY = touchPoints[0].y - lastMouseY
+            if (tp1.pressed && tp2.pressed) {
+                if (!pinchActive) {
+                    // Transition to pinch
+                    pinchActive = true
+                    wasMultiTouch = true
+                    dragActive = false
+                    pinchStartDist = pinchDistance()
+                    pinchStartZoom = _map.zoomLevel
+                    let cx = (tp1.x + tp2.x) / 2
+                    let cy = (tp1.y + tp2.y) / 2
+                    pinchStartCentroid = _map.toCoordinate(Qt.point(cx, cy), false)
+                    pressAndHoldTimer.stop()
+                }
+                let currentDist = pinchDistance()
+                if (pinchStartDist > 0) {
+                    let scale = currentDist / pinchStartDist
+                    _map.zoomLevel = pinchStartZoom + Math.log2(scale)
+                    let cx = (tp1.x + tp2.x) / 2
+                    let cy = (tp1.y + tp2.y) / 2
+                    _map.alignCoordinateToPoint(pinchStartCentroid, Qt.point(cx, cy))
+                }
+            } else if (dragActive && !pinchActive) {
+                let deltaX = tp1.x - lastMouseX
+                let deltaY = tp1.y - lastMouseY
                 if (Math.abs(deltaX) >= 1.0 || Math.abs(deltaY) >= 1.0) {
-                    _map.pan(lastMouseX - touchPoints[0].x, lastMouseY - touchPoints[0].y)
-                    lastMouseX = touchPoints[0].x
-                    lastMouseY = touchPoints[0].y
+                    _map.pan(lastMouseX - tp1.x, lastMouseY - tp1.y)
+                    lastMouseX = tp1.x
+                    lastMouseY = tp1.y
                 }
             }
         }
 
         onReleased: (touchPoints) => {
-            isPressed = false
-            pressAndHoldTimer.stop()
-            if (dragActive) {
-                _map.pan(lastMouseX - touchPoints[0].x, lastMouseY - touchPoints[0].y)
-                dragActive = false
-                mapPanStop()
-            } else if (!pressAndHold) {
-                mapClicked(Qt.point(touchPoints[0].x, touchPoints[0].y))
+            if (!tp1.pressed && !tp2.pressed) {
+                // All fingers up
+                isPressed = false
+                pressAndHoldTimer.stop()
+                if (pinchActive) {
+                    pinchActive = false
+                } else if (dragActive) {
+                    _map.pan(lastMouseX - touchPoints[0].x, lastMouseY - touchPoints[0].y)
+                    dragActive = false
+                    mapPanStop()
+                } else if (!pressAndHold && !wasMultiTouch) {
+                    mapClicked(Qt.point(touchPoints[0].x, touchPoints[0].y))
+                }
+                pressAndHold = false
+                wasMultiTouch = false
+            } else if (pinchActive) {
+                // One finger lifted during pinch - end pinch but don't start panning
+                pinchActive = false
             }
-            pressAndHold = false
         }
 
         Timer {