MapItemView Transitions (QML)

How to use transitions together with MapItemView .

MapItemView 过渡 演示如何使用 Map item to render a map. It shows the minimum amount of code needed to display the map, and can be used as a basis for further experimentation.

运行范例

要运行范例从 Qt Creator ，打开欢迎模式，然后选择范例从范例。更多信息，拜访构建和运行范例 .

QML 代码

在 main.qml , two MapItemView elements are used, to add to the map the administrative districts for the Oslo region, and to add a marker upon long-press.

MapItemView {
    id: mivMarker
    add: Transition {
        NumberAnimation {
            property: "slideIn"
            from: 50
            to: 0
            duration: 500
            easing.type: Easing.OutBounce
            easing.amplitude: 3.0
        }
    }
    remove: Transition {
        NumberAnimation {
            property: "opacity"
            to: 0.1
            duration: 50
        }
    }
    model: ListModel {
        id: markerModel
    }
    delegate: Component {
        MapQuickItem {
            coordinate: QtPositioning.coordinate(latitude, longitude)
            anchorPoint: Qt.point(e1.width * 0.5, e1.height + slideIn)
            property real slideIn : 0
            sourceItem: Shape {
                id: e1
                vendorExtensionsEnabled: false
                width: 32
                height: 32
                visible: true
                transform: Scale {
                    origin.y: e1.height * 0.5
                    yScale: -1
                }
                ShapePath {
                    id: c_sp1
                    strokeWidth: -1
                    fillColor: Qt.rgba(1,0,1,1.0)
                    property real half: e1.width * 0.5
                    property real quarter: e1.width * 0.25
                    property point center: Qt.point(e1.x + e1.width * 0.5 , e1.y + e1.height * 0.5)
                    property point top: Qt.point(center.x, center.y - half )
                    property point bottomLeft: Qt.point(center.x - half, center.y + half )
                    property point bottomRight: Qt.point(center.x + half, center.y + half )
                    startX: center.x;
                    startY: center.y + half
                    PathLine { x: c_sp1.bottomLeft.x; y: c_sp1.bottomLeft.y }
                    PathLine { x: c_sp1.top.x; y: c_sp1.top.y }
                    PathLine { x: c_sp1.bottomRight.x; y: c_sp1.bottomRight.y }
                    PathLine { x: c_sp1.center.x; y: c_sp1.center.y + c_sp1.half }
                }
            }
        }
    }
}

The marker view specifies both the add and the remove transition, to create a bouncing marker effect.

MapItemView {
    id: miv
    model: OsloListModel {
        id: osloListModel
    }
    add: Transition {
        NumberAnimation {
            property: "animationScale"
            from: 0.2
            to: 1
            duration: 800
            easing.type: Easing.OutCubic
        }
    }
    delegate: Component {
        MapPolygon {
            function fromMercator(l, centroid) {
                var res = []
                for (var i  = 0; i < l.length; i++) {
                    var vtx = l[i]
                    var offset = Qt.point((vtx.x - centroid.x) * animationScale,
                                          (vtx.y - centroid.y) * animationScale)
                    var pt = Qt.point(centroid.x + offset.x, centroid.y + offset.y)
                    res.push( QtPositioning.mercatorToCoord(pt) )
                }
                return res;
            }
            path: fromMercator(osloListModel.geometries[name+"_"+adminLevel]
                               , osloListModel.centroids[name+"_"+adminLevel] )
            color: ((adminLevel > 4) ? "lightsteelblue" : 'firebrick')
            property real animationScale : 1
            opacity: ((adminLevel < 9) ? 0.1 : 0.8)
            visible: true
        }
    }
}

The administrative districts view specifies only the add transition, to create a district growing effect.

要求

The example requires a working internet connection to download OpenStreetMap map tiles. An optional system proxy should be picked up automatically.

范例工程 @ code.qt.io