AutoScroller.qml Example File

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  ** Contact: https://www.qt.io/licensing/
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  ** This file is part of the Qt Virtual Keyboard module of the Qt Toolkit.
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  import QtQuick 2.0
  import QtQuick.VirtualKeyboard 2.1

  Item {

      property var innerFlickable
      property var outerFlickable
      property var inputItem: InputContext.inputItem

      onInputItemChanged: {
          innerFlickable = null
          outerFlickable = null
          if (inputItem !== null) {
              var parent_ = inputItem.parent
              while (parent_) {
                  if (parent_.maximumFlickVelocity) {
                      if (innerFlickable) {
                          outerFlickable = parent_
                          break
                      } else {
                          innerFlickable = parent_
                      }
                  }
                  parent_ = parent_.parent
              }
              delayedLoading.triggered()
          }
      }

      function ensureVisible(flickable) {
          if (Qt.inputMethod.visible && inputItem && flickable && flickable.visible && flickable.interactive) {

              var verticallyFlickable = (flickable.flickableDirection === Flickable.HorizontalAndVerticalFlick || flickable.flickableDirection === Flickable.VerticalFlick
                                         || (flickable.flickableDirection === Flickable.AutoFlickDirection && flickable.contentHeight > flickable.height))
              var horizontallyFlickable = (flickable.flickableDirection === Flickable.HorizontalAndVerticalFlick || flickable.flickableDirection === Flickable.HorizontalFlick
                                           || (flickable.flickableDirection === Flickable.AutoFlickDirection && flickable.contentWidth > flickable.width))

              if ((!verticallyFlickable && !horizontallyFlickable) || !inputItem.hasOwnProperty("cursorRectangle"))
                  return

              var cursorRectangle = flickable.contentItem.mapFromItem(inputItem, inputItem.cursorRectangle.x, inputItem.cursorRectangle.y)

              var oldContentY = flickable.contentY
              if (verticallyFlickable) {
                  var scrollMarginVertical = (flickable && flickable.scrollMarginVertical) ? flickable.scrollMarginVertical : 10
                  if (flickable.contentY >= cursorRectangle.y  - scrollMarginVertical)
                      flickable.contentY = Math.max(0, cursorRectangle.y  - scrollMarginVertical)
                  else if (flickable.contentY + flickable.height <= cursorRectangle.y  + inputItem.cursorRectangle.height + scrollMarginVertical)
                      flickable.contentY = Math.min(flickable.contentHeight - flickable.height, cursorRectangle.y + inputItem.cursorRectangle.height - flickable.height + scrollMarginVertical)
              }
              if (horizontallyFlickable) {
                  var scrollMarginHorizontal = (flickable && flickable.scrollMarginHorizontal) ? flickable.scrollMarginHorizontal : 10
                  if (flickable.contentX >= cursorRectangle.x - scrollMarginHorizontal)
                      flickable.contentX = Math.max(0, cursorRectangle.x - scrollMarginHorizontal)
                  else if (flickable.contentX + flickable.width <= cursorRectangle.x + inputItem.cursorRectangle.width + scrollMarginHorizontal)
                      flickable.contentX = Math.min(flickable.contentWidth - flickable.width, cursorRectangle.x + inputItem.cursorRectangle.width - flickable.width + scrollMarginHorizontal)
              }
          }
      }
      Timer {
          id: delayedLoading
          interval: 10
          onTriggered: {
              ensureVisible(innerFlickable)
              ensureVisible(outerFlickable)
          }
      }
      Connections {
          ignoreUnknownSignals: true
          target: inputItem && !Qt.inputMethod.animating ? Qt.inputMethod : null
          onKeyboardRectangleChanged: delayedLoading.triggered()
      }
      Connections {
          ignoreUnknownSignals: true
          target: inputItem && inputItem.activeFocus ? inputItem : null
          onCursorRectangleChanged: delayedLoading.triggered()
      }
  }