Signals for entered/exited events in TabView

Question

I have a TabView, which has 3 Tabs, Say tab1, tab2, tab3. Each Tab has some widgets. I want to have some kind of signalling mechanism, so that when I enter tab3, I want to set the state of some of the widgets (e.g. a TextField) within tab3 and when I leave it, I want to reset their state.

Any pointers on how to achieve this? When I read Qt 5.3 documentation about TabView and Tab, I did not find any signals exposed by them.

Signalling can be within tab3 or between Tabview and tab3. I am fine with either of these.

score 6 · Accepted Answer · answered Dec 10 '14 at 11:11

6

Use onVisibleChanged Try this:

TabView {

    Tab {
        onVisibleChanged: console.log("hello1 "+visible)
        title: "Red"
        Rectangle { color: "red" }
    }
    Tab {
        onVisibleChanged: console.log("hello2 "+visible)
        title: "Blue"
        Rectangle { color: "blue" }
    }
    Tab {
        onVisibleChanged: console.log("hello3 "+visible)
        title: "Green"
        Rectangle { color: "green" }
    }
}

answered Dec 10 '14 at 11:11

Jablonski

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47

I was about to answer my own question, but you were quick. onVisibleChanged, onFocusChanged both worked for me. My qtcreator automatically gave me hints the moment I started typing on (keyword). But I do not see them as part of qt5.3 documentation under Tab. – Sandeep Dec 10 '14 at 11:25
1

@Sandeep Because Tab inherits this property: http://qt-project.org/doc/qt-5/qml-qtquick-item.html#visible-prop So you can use it, but there is no explicit description in doc, you can use this instead: http://qt-project.org/doc/qt-5/qml-qtquick-controls-tab-members.html – Jablonski Dec 10 '14 at 11:39

score 0 · Answer 2 · edited Sep 26 '15 at 02:27

On a tab change, visibility of TWO tabs changes, on the leaving tab (from false to true) and on the entering tab (from true to false). These events are not always serialized. I had to add:

onVisibleChanged: {
    if (!this.activeFocus){
        // ...
    }
}

But, if you do not actually click on tab but activate it by setting tab's active to true, the solution above is not enough. You'd have to use TabView.currentIndex to compare it with the static, i.e. declarative tab index. If onVisibleChanged is called for the new active tab, then the indexes should be equal.

Here is as example:

function refreshButtons(tabIndexStatic){
    if (tabStepsView.currentIndex !== tabIndexStatic)
        return;
    buttonPrev.visible      = tabIndexStatic !== 0
    buttonNext.visible      = tabIndexStatic !== tabStepsView.count - 1
    buttonConvert.visible   = tabIndexStatic === tabStepsView.count - 1
    }
    Tab {
        title: qsTr("Tab 0")
        onVisibleChanged: parent.refreshButtons(0)

        // ...
    }
    Tab {
        title: qsTr("Tab 1")
        onVisibleChanged: parent.refreshButtons(1);
        // ...
    }
    Tab {
        title: "Tab 2"
        onVisibleChanged: tabStepsView.refreshButtons(2)
        // ...
    }
}

Signals for entered/exited events in TabView

2 Answers2