Uploaded image for project: 'Qt'
  1. Qt
  2. QTBUG-77638

Delayed initialization of dragging is not working properly

XMLWordPrintable

    • Icon: Bug Bug
    • Resolution: Unresolved
    • Icon: P3: Somewhat important P3: Somewhat important
    • None
    • 5.13.0
    • Quick: Mouse Touch and Tablet input
    • None
    • Dell XPS 15 9560, Windows 10
    • Windows

      Motivation: It may be necessary to activate DragHandler under a certain condition, or create dragging item dynamically and continue the gesture without the need to click again on the item containing DragHandler (This is partly related with https://bugreports.qt.io/browse/QTBUG-68075)

      With the example code:

      import QtQuick 2.13
import QtQuick.Controls 2.13

ApplicationWindow {
    id: root
    visible: true
    width: 640
    height: 480

    Rectangle {
        x: 130
        width: 200
        height: 200
        color: backgroundDragHandler.active ? "red" : "orange"
        opacity: 0.6

        DragHandler {
            id: backgroundDragHandler
        }
    }
    Rectangle {
        y: 60
        width: 200
        height: 200
        color: tapHandler.pressed ? "red" : "green"
        opacity: 0.8

        TapHandler {
            id: tapHandler
            onLongPressed: {
                console.debug("onLongPressed!")
                if (dynamicallyCreation.checked) {
                    dynamicallyDragItemComponent.createObject(root);
                }
                else {
                    fordegroundDragHandler.enabled = true;
                }
            }
        }
        Label {
            x: 160
            y: 95
            text: "1"
            font.bold: true
            font.pixelSize: 20
            color: "black"

            Rectangle {
                anchors { fill: parent; margins: -10 }
                color: "transparent"
                border.color: "black"
            }
        }
        Label {
            x: 90
            y: 20
            text: "2"
            font.bold: true
            font.pixelSize: 20
            color: "black"

            Rectangle {
                anchors { fill: parent; margins: -10 }
                color: "transparent"
                border.color: "black"
            }
        }
        Label {
            x: 160
            y: 20
            text: "3"
            font.bold: true
            font.pixelSize: 20
            color: "black"

            Rectangle {
                anchors { fill: parent; margins: -10 }
                color: "transparent"
                border.color: "black"
            }
        }
        Label {
            x: 90
            y: 95
            text: "4"
            font.bold: true
            font.pixelSize: 20
            color: "black"

            Rectangle {
                anchors { fill: parent; margins: -10 }
                color: "transparent"
                border.color: "black"
            }
        }
    }
    Rectangle {
        x: 50
        y: 130
        width: 200
        height: 200
        color: fordegroundDragHandler.active ? "red" : "blue"
        opacity: 0.6
        visible: !dynamicallyCreation.checked
        enabled: !dynamicallyCreation.checked

        DragHandler {
            id: fordegroundDragHandler
            enabled: false
        }
        Label {
            anchors.bottom: parent.bottom
            text: "Drag enabled: %1".arg(fordegroundDragHandler.enabled)
        }
    }
    Component {
        id: dynamicallyDragItemComponent

        Rectangle {
            x: 50
            y: 130
            width: 200
            height: 200
            color: fordegroundDragHandler.active ? "red" : "blue"
            opacity: 0.6

            DragHandler {
                id: fordegroundDragHandler
            }
        }
    }

    Switch {
        id: dynamicallyCreation

        anchors.bottom: parent.bottom
        text: "Dynamically creation of fordeground DragItem"
    }
}

      You may notice several problems (you have to start the sample application again for each case).

      1. Steps to reproduce:

      • Press and hold on rectangle with number 1
      • Wait for longPress and activation of DragHandler (Drag enabled: 1)
      • Drag (without releasing the mouse button before that)

      or

      • Activate switch Dynamically creation of...
      • Press and hold on rectangle with number 1
      • Wait for creation of blue rectangle
      • Drag (without releasing the mouse button before that)

      Result:  Orange and not blue rectangle will be dragged

       

      2. Steps to reproduce:

      • Press and hold on rectangle with number 2
      • Drag in direction of rectangle with number 3

      or

      • Press and hold on rectangle with number 2
      • Wait for longPress and activation of DragHandler (Drag enabled: 1)
      • Drag in direction of rectangle with number 4

      or

      • Press and hold on rectangle with number 4
      • Wait for longPress and activation of DragHandler (Drag enabled: 1)
      • Drag blue reactangle  (without releasing the mouse button before that)

      or

      • Activate switch Dynamically creation of...
      • Press and hold on rectangle with number 4
      • Wait for creation of blue rectangle
      • Drag blue reactangle (without releasing the mouse button before that)

      Result:  Dragged rectangle (DragHandler target) skip with its top left corner to place where drag begins, instead of smoothly dragging.

        1. DelayedDragHandlerCreationOrActivation.zip
          3 kB
        No reviews matched the request. Check your Options in the drop-down menu of this sections header.

            qt.team.quick.subscriptions Qt Quick and Widgets Team
            permotion88 Karol Polak
            Votes:
            1 Vote for this issue
            Watchers:
            2 Start watching this issue

              Created:
              Updated:

                There are no open Gerrit changes