Bug? Draggable Items in GridView: MouseArea stops working after Drop
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Hi,
I have a
GridView
with draggable items, basically Qt's draganddrop example. I pasted the code below. As you see, I have aMouseArea
: myProblematicMouseArea, and I want it to perform an Action onPressAndHold, but only if the item is not being dragged. This works at the beginning, but as soon as an item is dropped, the mouseArea is not working correctly, and misses my clicks. Then after some clicks it starts working again. Am I missing something?Does it have something to do with the reparenting of icon?
/**************************************************************************** ** ** Copyright (C) 2018 The Qt Company Ltd. ** Contact: https://www.qt.io/licensing/ ** ** This file is part of the examples of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:BSD$ ** Commercial License Usage ** Licensees holding valid commercial Qt licenses may use this file in ** accordance with the commercial license agreement provided with the ** Software or, alternatively, in accordance with the terms contained in ** a written agreement between you and The Qt Company. For licensing terms ** and conditions see https://www.qt.io/terms-conditions. For further ** information use the contact form at https://www.qt.io/contact-us. ** ** BSD License Usage ** Alternatively, you may use this file under the terms of the BSD license ** as follows: ** ** "Redistribution and use in source and binary forms, with or without ** modification, are permitted provided that the following conditions are ** met: ** * Redistributions of source code must retain the above copyright ** notice, this list of conditions and the following disclaimer. ** * Redistributions in binary form must reproduce the above copyright ** notice, this list of conditions and the following disclaimer in ** the documentation and/or other materials provided with the ** distribution. ** * Neither the name of The Qt Company Ltd nor the names of its ** contributors may be used to endorse or promote products derived ** from this software without specific prior written permission. ** ** ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." ** ** $QT_END_LICENSE$ ** ****************************************************************************/ import QtQuick 2.12 import QtQml.Models 2.1 GridView { id: root width: 320; height: 480 cellWidth: 80; cellHeight: 80 displaced: Transition { NumberAnimation { properties: "x,y"; easing.type: Easing.OutQuad } } //! [0] model: DelegateModel { //! [0] id: visualModel model: ListModel { id: colorModel ListElement { color: "blue" } ListElement { color: "green" } ListElement { color: "red" } ListElement { color: "yellow" } ListElement { color: "orange" } ListElement { color: "purple" } ListElement { color: "cyan" } ListElement { color: "magenta" } ListElement { color: "chartreuse" } ListElement { color: "aquamarine" } ListElement { color: "indigo" } ListElement { color: "black" } ListElement { color: "lightsteelblue" } ListElement { color: "violet" } ListElement { color: "grey" } ListElement { color: "springgreen" } ListElement { color: "salmon" } ListElement { color: "blanchedalmond" } ListElement { color: "forestgreen" } ListElement { color: "pink" } ListElement { color: "navy" } ListElement { color: "goldenrod" } ListElement { color: "crimson" } ListElement { color: "teal" } } //! [1] delegate: DropArea { id: delegateRoot width: 80; height: 80 onEntered: visualModel.items.move(drag.source.visualIndex, icon.visualIndex) property int visualIndex: DelegateModel.itemsIndex Binding { target: icon; property: "visualIndex"; value: visualIndex } Rectangle { id: icon property int visualIndex: 0 width: 72; height: 72 anchors { horizontalCenter: parent.horizontalCenter; verticalCenter: parent.verticalCenter } radius: 3 color: model.color MouseArea { id: myProblematicMouseArea anchors.fill: parent onPressAndHold: { // only trigger if drag is not active) console.log("is drag active? ",icon.Drag.active) if(icon.Drag.active==false) console.log("press and hold triggered") } onClicked: { console.log("clicked") } } Text { anchors.centerIn: parent color: "white" text: parent.visualIndex } DragHandler { id: dragHandler } Drag.active: dragHandler.active Drag.source: icon //Drag.dragType: Drag.Automatic Drag.hotSpot.x: 36 Drag.hotSpot.y: 36 Drag.onDragStarted: { console.log("drag started") } states: [ State { when: icon.Drag.active ParentChange { target: icon parent: root } AnchorChanges { target: icon anchors.horizontalCenter: undefined anchors.verticalCenter: undefined } } ] } } //! [1] } }
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It would already be helpful, if someone can reproduce this behaviour. The MouseArea writes a message via console.log if a click was received. The problem is, that after a drag, the MouseArea onClicked Event is not triggered anymore, only after some clicks it starts responding again.
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Here's what I noticed: every square that was dragged stops reacting to single clicks, but if you do double-click on it, then it will react to it, and then will continue reacting to single clicks as well. And other squares react to clicks just fine (till you drag them).
If that's what you wanted to reproduce, then it is reproduced by me.
Doesn't look like designed behavior to me, I guess we need to report it. But for what component, is it
DropArea
who causes the trouble? -
Thank you very much. I reported it here
https://bugreports.qt.io/browse/QTBUG-73735