Drawer bug?

igor_stravinsky

I've got a Quick Controls 2 app that has a structure that looks like this:

Flippable
     Front
         StackView
              Page 1
                 ListView w/ScrollBar
              Page 2
     Back
         Tab View
             Tab 1
             Tab 2
                 Drawer

I've been chasing a bug in which the ListView's scroll bar was unresponsive to mouse input. After much experimentation, I discovered that the Drawer's dragMargin, which was set to Qt.styleHints.startDragDistance was the culprit. It created a dead zone on the right side of every view (not just Tab 2), which was unresponsive to clicks.

Is this the expected behavior of a Drawer? I would have thought that the dragMargin would only apply to the Tab2 view, not to every view in the app.
Are Drawers intended to be global?

igor_stravinsky

Here's a simple example of the bug:

main.qml

import QtQuick 2.10
import QtQuick.Window 2.10
import QtQuick.Controls 2.3

Window {
    visible: true
    width: 640
    height: 480
    title: qsTr("Hello World")

    Flipable {
        id: flipable
        anchors.fill:parent

        property bool flipped: false

        front: Front{}
        back: Back{}

        states: State {
            name: "back"
            PropertyChanges { target: rotation; angle: 180 }
            when: flipable.flipped
        }

        transform: Rotation {
            id: rotation
            origin{ x: flipable.width/2;y: flipable.height/2 }
            axis{ x: 0;y: -1;z: 0 }    // set axis.y to 1 to rotate around y-axis
            angle: 0    // the default angle
        }

        transitions: Transition {
            NumberAnimation { target: rotation; property: "angle"; duration: 2000 }
        }


    }

    RoundButton{
        height:40
        width:40
        radius:20
        anchors.right: parent.right
        anchors.bottom: parent.bottom
        text:"flip"

        onClicked: flipable.flipped = !flipable.flipped
    }
}

Front.qml:

import QtQuick 2.10
import QtQuick.Controls 2.3

Item {
    id:frontSide
    anchors.fill:parent

    ListView {
        anchors.fill:parent

        model: 100

        delegate: ItemDelegate {
            Text { text: "Item number: " + index }
            width: parent.width
        }

        ScrollBar.vertical: ScrollBar {
            policy:ScrollBar.AlwaysOn
            width:10
        }
    }

}

Back.qml:

import QtQuick 2.10
import QtQuick.Controls 2.3

Item {
    id:backSide
    anchors.fill:parent

    Drawer{
        id:theDrawer
        x: parent.width
        y: 0
        height: parent.height
        width: parent.width/2
        edge: Qt.RightEdge
        dragMargin: Qt.styleHints.startDragDistance

        Text{
            anchors.centerIn: parent
            text:"I'm a drawer!"
        }

    }
}

The code demonstrates that the scroll bar on the front side doesn't respond to clicks because of the dragMargin of the drawer on the back

jpnurmi

It's a known problem: QTBUG-59141. In your scenario, you can mitigate the problem by setting Drawer::interactive to false when applicable.