AutoScroller.qml Example File | Qt Virtual Keyboard 5.9

Qt 5.9 | Qt Virtual Keyboard | Qt Quick Virtual Keyboard - Basic Example | AutoScroller.qml Example File

Qt 5.9.4 Reference Documentation

# AutoScroller.qml Example File

basic/content/AutoScroller.qml

      /****************************************************************************
      **
      ** Copyright (C) 2016 The Qt Company Ltd.
      ** Contact: https://www.qt.io/licensing/
      **
      ** This file is part of the Qt Virtual Keyboard module of the Qt Toolkit.
      **
      ** $QT_BEGIN_LICENSE:GPL$
      ** Commercial License Usage
      ** Licensees holding valid commercial Qt licenses may use this file in
      ** accordance with the commercial license agreement provided with the
      ** Software or, alternatively, in accordance with the terms contained in
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      ** information use the contact form at https://www.qt.io/contact-us.
      **
      ** GNU General Public License Usage
      ** Alternatively, this file may be used under the terms of the GNU
      ** General Public License version 3 or (at your option) any later version
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      ** the Free Software Foundation and appearing in the file LICENSE.GPL3
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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()
          }
      }