单击 \ 轻拂一个 Flickable 的空白区域，该区域与另一个 Flickable 部分重叠

Question

我有一个场景"editor"可以在底部滑动，并停靠在它的右侧，有一个场景"outliner"可以在它上面滑动，显示了场景结构树。

  Flickable {
    id: editor
    anchors.fill: parent
    contentWidth: 5000
    contentHeight: 5000
    Repeater {
      model: 500
      delegate: Rectangle {
        width: Math.random() * 200 + 50
        height: width
        x: Math.random() * editor.contentWidth
        y: Math.random() * editor.contentHeight
        color: Qt.rgba(Math.random(), Math.random(), Math.random(), 1)
        border.color: "black"
      }
    }
  }

  Flickable {
    id: outliner
    anchors.right: editor.right
    width: contentWidth
    height: parent.height
    contentWidth: contentItem.childrenRect.width
    contentHeight: contentItem.childrenRect.height
    Column {
      Repeater {
        model: 500
        delegate: Rectangle {
          width: Math.random() * 200 + 50
          x: outliner.contentWidth - width
          height: 50
          color: Qt.rgba(Math.random(), Math.random(), Math.random(), 1)
          border.color: "black"
        }
      }
    }
  }

自然地，我希望能够轻拂两者来导航两者，因为它们都比可用的屏幕空间大。

问题是，即使我从大纲项目不占据的位置轻拂，大纲轻拂将简单地阻止编辑器轻拂。我不想这样，我想要的是仅当轻弹发生在大纲项目顶部时才轻弹大纲，否则我想跳到编辑器，这样我就可以单击并将其从该区域轻弹到对了。

由于 Flickable 的工作方式，我没能做到。它将首先检查拖动，只有当点击不超过拖动阈值时，它才会让点击下层元素。所以我想不出只有在那个位置有物体的情况下才轻弹的方法。

有什么方法可以让事件处理按照我的意愿进行吗？

Answer 1

您可以通过检查场景中的每个印刷机来做到这一点，如果印刷机下方有大纲代表。如果不是，请将 outliner 标记为非交互式。在 editor.

中有移动后立即重新启用它

像这样：

import QtQuick 2.7
import QtQuick.Window 2.2
import QtQuick.Controls 2.0

ApplicationWindow {
    id: app
    visible: true
    width: 600
    height: 480
    Item { // a common parent not containing the MouseArea to be able to call childAt on press
        id: flickablesParent
        anchors.fill: parent
        Flickable {
            id: editor
            anchors.fill: parent
            contentWidth: 5000
            contentHeight: 5000
            onMovementStarted: outliner.interactive = true //re-enable the outliner user interaction so it can be flicked again.
            Repeater {
                model: 500
                delegate: Rectangle {
                    width: Math.random() * 200 + 50
                    height: width
                    x: Math.random() * editor.contentWidth
                    y: Math.random() * editor.contentHeight
                    color: Qt.rgba(Math.random(), Math.random(), Math.random(), 1)
                    border.color: "black"
                }
            }
        }

        Flickable {
            id: outliner
            anchors.right: editor.right
            width: contentWidth
            height: parent.height
            contentWidth: contentItem.childrenRect.width
            contentHeight: contentItem.childrenRect.height

            Column {
                id: column // set an id so it can be referenced in the MouseArea
                Repeater {
                    model: 500
                    delegate: Rectangle {
                        width: Math.random() * 200 + 50
                        x: outliner.contentWidth - width
                        height: 50
                        color: Qt.rgba(Math.random(), Math.random(), Math.random(), 1)
                        border.color: "black"
                    }
                }
            }
        }
    }
    MouseArea {
        id: dispatcher
        anchors.fill: parent
        onPressed: {
            var flickable = flickablesParent.childAt(mouse.x, mouse.y); //find out on what flickable we pressed (the check could be ommited but I guess it's more performant with)
            if (flickable === outliner) {
                var mappedPos = mapToItem(column, mouse.x, mouse.y);
                var delegate = column.childAt(mappedPos.x, mappedPos.y);
                if (!delegate)
                    outliner.interactive = false; //if there's no delegate where we pressed in the column, we disable the interactions of the outliner flickable.
            }
            mouse.accepted = false; // let the underlying Flickable deal with this event
        }
    }
}

编辑：您真的不需要在 onMovementStarted 中重新启用大纲视图，您也可以在 MouseArea onPressed 中重新启用。

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onPressed: {
    var flickable = flickablesParent.childAt(mouse.x, mouse.y); //find out on what flickable we pressed (the check could be ommited but I guess it's more performant with)
    if (flickable === outliner) {
        var mappedPos = mapToItem(column, mouse.x, mouse.y);
        var delegate = column.childAt(mappedPos.x, mappedPos.y);
        outliner.interactive = delegate ? true : false;
    }
    mouse.accepted = false; // let the underlying Flickable deal with this event
}

Answer 2

Mkay, I think I did it, the key was to disable the interactivity for the outliner, then intercept input via a MouseArea in the delegate, then carefully time and measure the manual dragging delta and if fast enough, schedule a manual flick on release.

Getting it to both stop an ongoing flick on press and subsequently launching another flick from the next drag turned out to be problematic after a flick has just been cancelled, but by delaying each flick to the next event loop cycle I got it working.

I also added wheel support and such.

If anyone experiences problems with it on any platform, do let me know in the comments.

// the editor code is the same from the OP
  Flickable {
    id: outliner
    anchors.right: editor.right
    width: contentWidth
    height: parent.height
    contentWidth: contentItem.childrenRect.width
    contentHeight: contentItem.childrenRect.height
    interactive: false
    property int ly: 0
    property real lt: 0
    property int dy: 0
    function go(yy) {
      dy = contentY - (contentY -= yy - ly)
      ly = yy
      lt = Date.now()
    }
    Timer { 
      id: trigger
      interval: 1
      onTriggered: outliner.flick(0, outliner.dy * 150)
    }
    Column {
      Repeater {
        model: 500
        delegate: Rectangle {
          width: Math.random() * 200 + 50
          x: outliner.contentWidth - width
          height: 50
          color: Qt.rgba(Math.random(), Math.random(), Math.random(), 1)
          border.color: "black"
          MouseArea {
            anchors.fill: parent
            Drag.active: drag.active
            drag.target: Item { id: dummy }
            onPressed: {
              dummy.y = 0
              if (outliner.flicking) outliner.cancelFlick()
            }
            onWheel: outliner.flick(0, wheel.angleDelta.y * 10)
            onPositionChanged: {
              if (drag.active) outliner.go(dummy.y)
            }
            onReleased: {
              if (Date.now() - outliner.lt < 50) trigger.start()
              outliner.ly = 0
              outliner.returnToBounds()
            }
          }
        }
      }
    }
  }

单击 \ 轻拂一个 Flickable 的空白区域，该区域与另一个 Flickable 部分重叠

Click \ flick through emptry area of a Flickable that partially overlaps another Flickable

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