FocusScope and activeFocus since Qt 4.8.2

SergeQt

Hi, everyone.

We have a problem that appeared with the correction in QDeclarativeItem::hasActiveFocus() in 4.8.2 release.

The documentation http://qt-project.org/doc/qt-4.8/qdeclarativefocus.html states that: “Both the focus scope and the sub-focused item will have activeFocus property set.”

Our code relies on this, and it doesn't seem to be true anymore. Did we miss something?

Here is an example (two files) to illustrate the behavior. The enclosing box doesn't show 'activeFocus=true' at any time in 4.8.2 and 4.8.3, as it did before.

(Windows 7)

@
// test.qml, to be loaded with qmlviewer
import QtQuick 1.0

Item {

width: 800
height: 600
focus: true

Keys.onUpPressed: container1_focusScope.focus = true
Keys.onDownPressed: container2_focusScope.focus = true

ListView_FocusScope {
    id: container1_focusScope

    anchors.top: parent.top
    anchors.topMargin: 50
}


ListView_FocusScope {
    id: container2_focusScope

    anchors.bottom: parent.bottom
    anchors.bottomMargin: 50
}

}
@

@
// ListView_FocusScope.qml
import QtQuick 1.0

ListView {

width: 580
height: 200
anchors.horizontalCenter: parent.horizontalCenter
spacing: 10
orientation: ListView.Horizontal
model: 3

delegate: Rectangle {

    width: 180
    height: 80
    anchors.verticalCenter: parent.verticalCenter
    color: activeFocus ? "red" : "black"

    // text to display "focus" value
    Text {
        text: "focus="+parent.focus
        font.pixelSize: 16
        font.bold: true
        color: "white"
        font.underline: parent.focus ? true : false
    }

    // text to display "activeFocus" value
    Text {
        text: "activeFocus="+parent.activeFocus
        anchors.top: parent.top
        anchors.topMargin: 20
        font.pixelSize: 16
        font.bold: true
        color: "white"
        font.underline: parent.activeFocus ? true : false
    }
}

// background
Rectangle {
    z: -1
    anchors.fill: parent
    color: "grey"
}

// text to display "focus" value
Text {
    text: "focus="+parent.focus
    font.pixelSize: 16
    font.bold: true
    color: "white"
    font.underline: parent.focus ? true : false
}

// text to display "activeFocus" value
Text {
    text: "activeFocus="+parent.activeFocus
    anchors.top: parent.top
    anchors.topMargin: 20
    font.pixelSize: 16
    font.bold: true
    color: "white"
    font.underline: parent.activeFocus ? true : false
}

}
@

trollixx

I had similar issues recently and the workaround was to use Item::forceActiveFocus() to set focus on the component.

benoute

Same issue here on 4.8.2 and 4.8.3 on Linux and Mac.

This seems to be a bug in Qt since The "Key Interaction: Focus Example" demo code that comes with Qt and demonstrates how FocusScope works no longer behave correctly since 4.8.2: once the "context" menu on the left is opened, it does not disappear after a right click (its visibility depends on the activeFocus property of mainView FocusScope which does not switch to "true" when one of its children gets focus)

It seems that the active focus is correctly proxied to the children but the intermediate focus scope do not get active focus set.

SergeQt

I tried to use forceActiveFocus() in various places in our code but to no avail. Trollixx, could you share more about your workaround? I am really interested in making this thing work.

wimvalcke

There is indeed a serious bug in QML regarding scopes
The following example shows this. It uses a similar principle as the focus example demo. Left click on the 'Change focus' will change the focus to the right rectangle. Pressing 'right mouse button' in the 'change focus area' will dump out all the activeFocus properties. Each time it seems that the activeFocus properties are correct. When changing the focus to the right rectangle it becomes green and the state change makes both rectangles moving to the right. Pressing 'left arrow' key changes the focus back to the left rectangle. But the state change is not performed, despite the 'when' property should be false ! (check this with 'right mouse button')
@import QtQuick 1.1

Rectangle {
width: 600
height: 480
id: main

function showFocusStatus() {
    console.log("--------------------")
    console.log("scope1 active focus", scope1.activeFocus)
    console.log("scope2 active focus", scope2.activeFocus)
    console.log("rect1 active focus", rect1.activeFocus)
    console.log("rect2 active focus", rect2.activeFocus)
    console.log("State is", main.state)
    console.log("--------------------")
}

FocusScope {
    id: scope1
    x: 10
    y: 10
    width: rect1.width
    height: rect1.height
    focus: true
    onActiveFocusChanged: {
        console.log("Active focus for scope1 changed to " + focus)
    }

    Rectangle {
        id: rect1
        width: 200
        height: 200
        focus: true
        color: {
            if (activeFocus)
                "green"
            else
                "red"
        }
    }
}

FocusScope {
    id: scope2
    focus: false
    width: rect2.width
    height: rect2.height
    anchors.top: scope1.top
    anchors.left: scope1.right
    anchors.leftMargin: 20
    onActiveFocusChanged: {
        console.log("Active focus for scope2 changed to " + focus)
    }
    Rectangle {
        id: rect2
        width: 200
        height: 200
        focus: true
        color: {
            if (activeFocus)
                "green"
            else
                "red"
        }
        Keys.onLeftPressed: {
            //scope1.focus = true
            scope1.forceActiveFocus()
        }
    }
}

Rectangle {
    property int focusRect: 1
    id: button
    width: parent.width
    height: 30
    color: "steelblue"
    anchors.bottom: parent.bottom
    Text {
        anchors.centerIn: parent
        text: "Change focus"
        color: "white"
        font.pointSize: 20
    }

    MouseArea {
        anchors.fill: parent
        acceptedButtons: Qt.LeftButton | Qt.RightButton
        onClicked: {
            if (mouse.button == Qt.LeftButton) {
                //scope2.focus = true
                scope2.forceActiveFocus()
                console.log("Changing focus to rect2")
            } else {
                main.showFocusStatus()
            }
        }
    }
}

states: [
    State {
        name: "rightActive"
        when: !scope1.activeFocus
        StateChangeScript{script: console.log("Entered right active state")}
        PropertyChanges {
            target: scope1
            x: 60
        }
    }
]

onStateChanged: {
    console.log("State changed to <" + state + ">")
}

}
@
To be continued...

Wim.

wimvalcke

I can confirm that the previous QML program works correct with Qt4.7.4. All the strange issues just disappear when using the qmlviewer from Qt 4.7.4. I really hope that the Qt guys put some more effort in not breaking things in newer releases that worked in older releases. Has this bug been already reported ? For me this thing must be solved ASAP as is seems to be a fundamental part of QML.

Wim.

Qt Academy Launch in California!

FocusScope and activeFocus since Qt 4.8.2