QML ListView 的可见项

Question

I'm trying to get all visible items (ie only items visible by eyes) of QML ListView, but i'm not shure how to realize this functionality. Maybe is some working approach exists? Thank you in advance.

Answer 1

indexAt( real x, real y ) can be used to calculate an index range of visible items.

https://doc.qt.io/qt-5/qml-qtquick-listview.html#indexAt-method

I'm not aware of a function that'll give you an index range for visible items. You'll have to come up with your own implementation based on item sizes and your specific layout.

Here's one possible implementation:

ListView {
    id: listView

    function getVisibleIndexRange() {
        var center_x = listView.x + listView.width / 2
        return [indexAt( center_x, listView.y + listView.contentY + 10),
                indexAt( center_x, listView.y + listView.contentY + listView.height - 10)]
    }
}

This is the implementation I'm using:

    id: listView

    onContentXChanged: {
        var idx = 0
        if ( listView.atXBeginning ) {
            idx = 0
        }
        else if ( listView.atXEnd ) {
            idx = listViewModel.count - 1
        }
        else {
            idx = listView.indexAt( listView.contentX + listView.width / 2,
                                    listView.y + listView.height / 2 )
        }

        //Do things with idx
    }