QML Dynamic View Ordering Tutorial 4 - Sorting Items | Qt Quick 5.13.0

Qt 5.13 | Qt Quick | QML Dynamic View Ordering Tutorial 4 - Sorting Items

Qt 5.13.0 Reference Documentation

QML Dynamic View Ordering Tutorial 3 - Moving Dragged Items

# QML Dynamic View Ordering Tutorial 4 - Sorting Items

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      import QtQuick 2.0
      import QtQml.Models 2.1

      Rectangle {
          id: root

          width: 300; height: 400

          Component {
              id: dragDelegate

              MouseArea {
                  id: dragArea

                  property bool held: false

                  anchors { left: parent.left; right: parent.right }
                  height: content.height

                  enabled: visualModel.sortOrder == visualModel.lessThan.length

                  drag.target: held ? content : undefined
                  drag.axis: Drag.YAxis

                  onPressAndHold: held = true
                  onReleased: held = false

                  Rectangle {
                      id: content

                      anchors {
                          horizontalCenter: parent.horizontalCenter
                          verticalCenter: parent.verticalCenter
                      }
                      width: dragArea.width; height: column.implicitHeight + 4

                      border.width: 1
                      border.color: "lightsteelblue"

                      color: dragArea.held ? "lightsteelblue" : "white"
                      Behavior on color { ColorAnimation { duration: 100 } }

                      radius: 2

                      Drag.active: dragArea.held
                      Drag.source: dragArea
                      Drag.hotSpot.x: width / 2
                      Drag.hotSpot.y: height / 2

                      states: State {
                          when: dragArea.held

                          ParentChange { target: content; parent: root }
                          AnchorChanges {
                              target: content
                              anchors { horizontalCenter: undefined; verticalCenter: undefined }
                          }
                      }

                      Column {
                          id: column
                          anchors { fill: parent; margins: 2 }

                          Text { text: 'Name: ' + name }
                          Text { text: 'Type: ' + type }
                          Text { text: 'Age: ' + age }
                          Text { text: 'Size: ' + size }
                      }
                  }

                  DropArea {
                      anchors { fill: parent; margins: 10 }

                      onEntered: {
                          visualModel.items.move(
                                  drag.source.DelegateModel.itemsIndex,
                                  dragArea.DelegateModel.itemsIndex)
                      }
                  }
              }
          }
          DelegateModel {
              id: visualModel
              property var lessThan: [
                  function(left, right) { return left.name < right.name },
                  function(left, right) { return left.type < right.type },
                  function(left, right) { return left.age < right.age },
                  function(left, right) {
                      if (left.size == "Small")
                          return true
                      else if (right.size == "Small")
                          return false
                      else if (left.size == "Medium")
                          return true
                      else
                          return false
                  }
              ]

              property int sortOrder: orderSelector.selectedIndex
              onSortOrderChanged: items.setGroups(0, items.count, "unsorted")

              function insertPosition(lessThan, item) {
                  var lower = 0
                  var upper = items.count
                  while (lower < upper) {
                      var middle = Math.floor(lower + (upper - lower) / 2)
                      var result = lessThan(item.model, items.get(middle).model);
                      if (result) {
                          upper = middle
                      } else {
                          lower = middle + 1
                      }
                  }
                  return lower
              }

              function sort(lessThan) {
                  while (unsortedItems.count > 0) {
                      var item = unsortedItems.get(0)
                      var index = insertPosition(lessThan, item)

                      item.groups = "items"
                      items.move(item.itemsIndex, index)
                  }
              }

              items.includeByDefault: false
              groups: DelegateModelGroup {
                  id: unsortedItems
                  name: "unsorted"

                  includeByDefault: true
                  onChanged: {
                      if (visualModel.sortOrder == visualModel.lessThan.length)
                          setGroups(0, count, "items")
                      else
                          visualModel.sort(visualModel.lessThan[visualModel.sortOrder])
                  }
              }
              model: PetsModel {}
              delegate: dragDelegate
          }
          ListView {
              id: view

              anchors {
                  left: parent.left; top: parent.top; right: parent.right; bottom: orderSelector.top;
                  margins: 2
              }

              model: visualModel

              spacing: 4
              cacheBuffer: 50
          }

          ListSelector {
              id: orderSelector

              anchors { left: parent.left; right: parent.right; bottom: parent.bottom; margins: 2 }

              label: "Sort By"
              list: [ "Name", "Type", "Age", "Size", "Custom" ]
          }
      }