DragHandler QML Type

Rectangle {
    id: canvas
    width: 640
    height: 480
    color: "#333"
    property int highestZ: 0

    Repeater {
        model: FolderListModel { nameFilters: ["*.qml"] }

        delegate: Rectangle {
            required property string fileName
            required property url fileUrl
            required property int index

            id: frame
            x: index * 30; y: index * 30
            width: 320; height: 240
            property bool dragging: ldh.active || rdh.active
            onDraggingChanged: if (dragging) z = ++canvas.highestZ
            border { width: 2; color: dragging ? "red" : "steelblue" }
            color: "beige"
            clip: true

            TextEdit {
                // drag to select text
                id: textEdit
                textDocument.source: frame.fileUrl
                x: 3; y: 3

                BoundaryRule on y {
                    id: ybr
                    minimum: textEdit.parent.height - textEdit.height; maximum: 0
                    minimumOvershoot: 200; maximumOvershoot: 200
                    overshootFilter: BoundaryRule.Peak
                }
            }

            DragHandler {
                id: rdh
                // right-drag to position the "window"
                acceptedButtons: Qt.RightButton
            }

            WheelHandler {
                target: textEdit
                property: "y"
                onActiveChanged: if (!active) ybr.returnToBounds()
            }

            Rectangle {
                anchors.right: parent.right
                width: titleText.implicitWidth + 12
                height: titleText.implicitHeight + 6
                border { width: 2; color: parent.border.color }
                bottomLeftRadius: 6
                Text {
                    id: titleText
                    color: "saddlebrown"
                    anchors.centerIn: parent
                    text: frame.fileName
                    textFormat: Text.PlainText
                }
                DragHandler {
                    id: ldh
                    // left-drag to position the "window"
                    target: frame
                }
            }
        }
    }
}

GridView {
    id: root
    width: 320
    height: 480
    cellWidth: 80
    cellHeight: 80
    interactive: false

    displaced: Transition {
        NumberAnimation {
            properties: "x,y"
            easing.type: Easing.OutQuad
        }
    }

    model: DelegateModel {
        id: visualModel
        model: 24
        property var dropTarget: undefined
        property bool copy: false
        delegate: DropArea {
            id: delegateRoot

            width: 80
            height: 80

            onEntered: drag => {
                if (visualModel.copy) {
                    if (drag.source !== icon)
                        visualModel.dropTarget = icon
                } else {
                    visualModel.items.move(drag.source.DelegateModel.itemsIndex, icon.DelegateModel.itemsIndex)
                }
            }

            Rectangle {
                id: icon
                objectName: DelegateModel.itemsIndex

                property string text
                Component.onCompleted: {
                    color = Qt.rgba(0.2 + (48 - DelegateModel.itemsIndex) * Math.random() / 48,
                                    0.3 + DelegateModel.itemsIndex * Math.random() / 48,
                                    0.4 * Math.random(),
                                    1.0)
                    text = DelegateModel.itemsIndex
                }
                border.color: visualModel.dropTarget === this ? "black" : "transparent"
                border.width: 2
                radius: 3
                width: 72
                height: 72
                anchors {
                    horizontalCenter: parent.horizontalCenter
                    verticalCenter: parent.verticalCenter
                }

                states: [
                    State {
                        when: dragHandler.active || controlDragHandler.active
                        ParentChange {
                            target: icon
                            parent: root
                        }

                        AnchorChanges {
                            target: icon
                            anchors {
                                horizontalCenter: undefined
                                verticalCenter: undefined
                            }
                        }
                    }
                ]

                Text {
                    anchors.centerIn: parent
                    color: "white"
                    font.pointSize: 14
                    text: controlDragHandler.active ? "+" : icon.text
                }

                DragHandler {
                    id: dragHandler
                    acceptedModifiers: Qt.NoModifier
                    onActiveChanged: if (!active) visualModel.dropTarget = undefined
                }

                DragHandler {
                    id: controlDragHandler
                    acceptedModifiers: Qt.ControlModifier
                    onActiveChanged: {
                        visualModel.copy = active
                        if (!active) {
                            visualModel.dropTarget.text = icon.text
                            visualModel.dropTarget.color = icon.color
                            visualModel.dropTarget = undefined
                        }
                    }
                }

                Drag.active: dragHandler.active || controlDragHandler.active
                Drag.source: icon
                Drag.hotSpot.x: 36
                Drag.hotSpot.y: 36
            }
        }
    }
}

Rectangle {
    width: 24
    height: 24
    border.color: "steelblue"
    Text {
        text: "it's\ntiny"
        font.pixelSize: 7
        rotation: -45
        anchors.centerIn: parent
    }

    DragHandler {
        margin: 12
    }
}

import QtQuick

Rectangle {
    width: 50; height: 200

    Rectangle {
        id: knob
        width: parent.width; height: width; radius: width / 2
        anchors.centerIn: parent
        color: "lightsteelblue"

        Rectangle {
            antialiasing: true
            width: 4; height: 20
            x: parent.width / 2 - 2
        }

        WheelHandler {
            property: "rotation"
        }
    }

    DragHandler {
        target: null
        dragThreshold: 0
        yAxis.onActiveValueChanged: (delta)=> { knob.rotation -= delta }
    }
}