Replace MultiPtHndlr.pointDistanceThreshold with PointerHandler.margin

It's not just useful for PinchHandler: TapHandler has a good use for it
too.  But unfortunately if the handler's parent Item has a custom mask,
we don't have a way to augment the mask with a margin; so if margin is
set, we assume the bounds are rectangular.

QQuickMultiPointHandler::eligiblePoints() now calls wantsEventPoint()
rather than bounds-checking the point directly: this adds flexibility,
potentially allowing an override in subclasses, if we need it later.

Task-number: QTBUG-68077
Change-Id: I65c95f00c532044a5862654e58c9c5f8c973df81
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>

1 files changed, 11 insertions, 0 deletions

diff --git a/src/quick/items/qquickitem.cpp b/src/quick/items/qquickitem.cpp
index 3b1402fe16..b09dbdad84 100644
--- a/src/quick/items/qquickitem.cpp
+++ b/src/quick/items/qquickitem.cpp
@@ -5140,6 +5140,17 @@ void QQuickItemPrivate::deliverShortcutOverrideEvent(QKeyEvent *event)
     }
 }
 
+bool QQuickItemPrivate::anyPointerHandlerWants(QQuickEventPoint *point) const
+{
+    if (!hasPointerHandlers())
+        return false;
+    for (QQuickPointerHandler *handler : extra->pointerHandlers) {
+        if (handler->wantsEventPoint(point))
+            return true;
+    }
+    return false;
+}
+
 /*!
     \internal
     Deliver the \a event to all PointerHandlers which are in the pre-determined