QML技术问询：如何创建双向及环形SwipeView？能否用Tumbler承载元素？

Hey there! Let's break down your QML questions and walk through practical solutions using your existing code as a starting point:

Great news: The default SwipeView already supports bidirectional swiping out of the box (left/right for horizontal orientation, up/down for vertical). If you're looking to enable swiping in both directions along a single axis, here's how to tweak your code:

SwipeView {
    id: view
    spacing: 20
    currentIndex: 0
    clip: true
    anchors.fill: parent
    
    // Uncomment this line for vertical bidirectional swiping
    // orientation: Qt.Vertical

    // Add your content pages here
    Page { Text { text: "First Page"; anchors.centerIn: parent } }
    Page { Text { text: "Second Page"; anchors.centerIn: parent } }
    Page { Text { text: "Third Page"; anchors.centerIn: parent } }
}

By default, it’s set to horizontal orientation, so users can swipe left and right freely. Switch to vertical orientation if you want up/down swiping instead.

The stock SwipeView doesn’t have a built-in wrap-around feature, but we can add it by listening to currentIndex changes and resetting it when it goes out of bounds. Here’s how to modify your code for this behavior:

SwipeView {
    id: view
    spacing: 20
    currentIndex: 0
    clip: true
    anchors.fill: parent

    // Sample content pages
    Page { Text { text: "Page 1"; anchors.centerIn: parent } }
    Page { Text { text: "Page 2"; anchors.centerIn: parent } }
    Page { Text { text: "Page 3"; anchors.centerIn: parent } }

    onCurrentIndexChanged: {
        // Wrap around when swiping past the last page
        if (currentIndex === count) {
            currentIndex = 0;
        }
        // Wrap around when swiping before the first page
        else if (currentIndex === -1) {
            currentIndex = count - 1;
        }
    }

    // Optional: Add smooth animation to avoid abrupt jumps
    Behavior on currentIndex {
        NumberAnimation { duration: 200 }
    }
}

When users swipe past the last page, currentIndex will briefly equal count (one past the last valid index) — we catch that and reset to 0. Similarly, swiping before the first page sets currentIndex to -1, which we switch to the last page index. The Behavior ensures the transition feels smooth instead of a hard jump.

Absolutely! You can use Tumbler to load different QML components, just like you’re doing with PathView. The key is to use a Loader as the TumblerColumn delegate. Here’s how to adapt your existing model for Tumbler:

Tumbler {
    id: tumbler
    anchors.fill: parent
    // Reuse your existing model of QML component paths
    model: ["qrc:/QML/Widget/AnalogClock.qml", "qrc:/QML/Widget/Clock.qml", "qrc:/QML/Widget/Widget.qml"]

    TumblerColumn {
        width: parent.width
        // Match the item height to your widget's needs
        height: tumbler.itemHeight

        delegate: Loader {
            width: parent.width
            height: parent.height
            source: modelData
        }
    }

    // Adjust item height to fit your widgets properly
    itemHeight: parent.height
    snapMode: Tumbler.SnapToItem
}

This setup lets the Tumbler load each of your custom widgets as users scroll. The snapMode ensures the scroll stops on a full item, and setting itemHeight to match your widgets prevents clipping. Keep in mind that Tumbler is optimized for vertical scrolling selection, whereas PathView is better for custom path-based layouts — choose whichever fits your UI flow better.

内容的提问来源于stack exchange，提问作者Anupam Srivastava