Qt 5.6 | Qt 3D | Qt 3D: Audio Visualizer Example | main.qml Example File

Qt 5.6.3 Reference Documentation

# main.qml Example File

audio-visualizer-qml/main.qml

      /****************************************************************************
      **
      ** Copyright (C) 2016 The Qt Company Ltd.
      ** Contact: http://www.qt.io/licensing/
      **
      ** This file is part of the Qt3D module of the Qt Toolkit.
      **
      ** $QT_BEGIN_LICENSE:LGPL3$
      ** 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
      ** a written agreement between you and The Qt Company. For licensing terms
      ** and conditions see http://www.qt.io/terms-conditions. For further
      ** information use the contact form at http://www.qt.io/contact-us.
      **
      ** GNU Lesser General Public License Usage
      ** Alternatively, this file may be used under the terms of the GNU Lesser
      ** General Public License version 3 as published by the Free Software
      ** Foundation and appearing in the file LICENSE.LGPLv3 included in the
      ** packaging of this file. Please review the following information to
      ** ensure the GNU Lesser General Public License version 3 requirements
      ** will be met: https://www.gnu.org/licenses/lgpl.html.
      **
      ** GNU General Public License Usage
      ** Alternatively, this file may be used under the terms of the GNU
      ** General Public License version 2.0 or later as published by the Free
      ** Software Foundation and appearing in the file LICENSE.GPL included in
      ** the packaging of this file. Please review the following information to
      ** ensure the GNU General Public License version 2.0 requirements will be
      ** met: http://www.gnu.org/licenses/gpl-2.0.html.
      **
      ** $QT_END_LICENSE$
      **
      ****************************************************************************/

      import QtQuick 2.0
      import QtQuick.Scene3D 2.0
      import QtQuick.Layouts 1.2
      import QtMultimedia 5.0

      Item {
          id: mainview
          width: 1215
          height: 720
          visible: true
          property bool isHoverEnabled: false

          property variant magnitudeArray: null
          property int millisecondsPerBar: 68
          property string magnitudeDataSourceFile: "qrc:/music/visualization.raw"
          property int mediaLatencyOffset: 68

          state: "stopped"
          states: [
              State {
                  name: "playing"
                  PropertyChanges {
                      target: playButtonImage
                      source: {
                          if (playButtonMouseArea.containsMouse)
                              "qrc:/images/pausehoverpressed.png"
                          else
                              "qrc:/images/pausenormal.png"
                      }
                  }
                  PropertyChanges {
                      target: stopButtonImage
                      source: "qrc:/images/stopnormal.png"
                  }
              },
              State {
                  name: "paused"
                  PropertyChanges {
                      target: playButtonImage
                      source: {
                          if (playButtonMouseArea.containsMouse)
                              "qrc:/images/playhoverpressed.png"
                          else
                              "qrc:/images/playnormal.png"
                      }
                  }
                  PropertyChanges {
                      target: stopButtonImage
                      source: "qrc:/images/stopnormal.png"
                  }
              },
              State {
                  name: "stopped"
                  PropertyChanges {
                      target: playButtonImage
                      source: "qrc:/images/playnormal.png"
                  }
                  PropertyChanges {
                      target: stopButtonImage
                      source: "qrc:/images/stopdisabled.png"
                  }
              }
          ]

          Component.onCompleted: isHoverEnabled = touchSettings.isHoverEnabled()

          MediaPlayer {
              id: mediaPlayer
              autoPlay: true
              volume: 0.5
              source: "qrc:/music/tiltshifted_lost_neon_sun.mp3"

              onStatusChanged: {
                  if (status == MediaPlayer.EndOfMedia) //{
                      state = "stopped"
              }

              onError: console.error("error with audio " + mediaPlayer.error)

              onDurationChanged: {
                  // Load the pre-calculated magnitude data for the visualizer
                  var request = new XMLHttpRequest()
                  request.responseType = 'arraybuffer'
                  request.onreadystatechange = function() {
                          if (request.readyState === XMLHttpRequest.DONE) {
                              if (request.status == 200 || request.status == 0) {
                                  var arrayBuffer = request.response
                                  if (arrayBuffer) {
                                      magnitudeArray = new Uint16Array(arrayBuffer)
                                      visualizer.startVisualization()
                                    }
                              } else {
                                  console.warn("Couldn't load magnitude data for bars.")
                              }
                              request = null
                          }
                      };

                  request.open('GET', magnitudeDataSourceFile, true)
                  request.send(null)
              }

              function getNextAudioLevel(offsetMs) {
                  if (magnitudeArray === null)
                      return 0.0;

                  // Calculate the integer index position in to the magnitude array
                  var index = ((mediaPlayer.position + offsetMs) /
                               mainview.millisecondsPerBar) | 0;

                  if (index < 0 || index >= magnitudeArray.length)
                      return 0.0;

                  return (magnitudeArray[index] / 63274.0);
              }
          }

          Image {
              id: coverImage
              anchors.fill: parent
              source: "qrc:/images/albumcover.png"
          }

          Scene3D {
              anchors.fill: parent

              Visualizer {
                  id: visualizer
                  animationState: mainview.state
                  numberOfBars: 120
                  barRotationTimeMs: 8160 // 68 ms per bar
              }
          }

          Rectangle {
              id: blackBottomRect
              color: "black"
              width: parent.width
              height: 0.14 * mainview.height
              anchors.bottom: parent.bottom
          }

          // Duration of played content
          Text {
              text: formatDuration(mediaPlayer.position)
              color: "#80C342"
              x: parent.width / 6
              y: mainview.height - mainview.height / 8
              font.pixelSize: 12
          }

          // Duration of the content left
          Text {
              text: "-" + formatDuration(mediaPlayer.duration - mediaPlayer.position)
              color: "#80C342"
              x: parent.width - parent.width / 6
              y: mainview.height - mainview.height / 8
              font.pixelSize: 12
          }

          function formatDuration(milliseconds) {
              var minutes = Math.floor(milliseconds / 60000)
              milliseconds -= minutes * 60000
              var seconds = milliseconds / 1000
              seconds = Math.round(seconds)
              if (seconds < 10)
                  return minutes + ":0" + seconds
              else
                  return minutes + ":" + seconds
          }

          property int buttonHorizontalMargin: 10
          Rectangle {
              id: playButton
              height: 54
              width: 54
              anchors.bottom: parent.bottom
              anchors.bottomMargin: width
              x: parent.width / 2 - width - buttonHorizontalMargin
              color: "transparent"

              Image {
                  id: playButtonImage
                  source: "qrc:/images/pausenormal.png"
              }

              MouseArea {
                  id: playButtonMouseArea
                  anchors.fill: parent
                  hoverEnabled: isHoverEnabled
                  onClicked: {
                      if (mainview.state == 'paused' || mainview.state == 'stopped')
                          mainview.state = 'playing'
                      else
                          mainview.state = 'paused'
                  }
                  onEntered: {
                      if (mainview.state == 'playing')
                          playButtonImage.source = "qrc:/images/pausehoverpressed.png"
                      else
                          playButtonImage.source = "qrc:/images/playhoverpressed.png"
                  }
                  onExited: {
                      if (mainview.state == 'playing')
                          playButtonImage.source = "qrc:/images/pausenormal.png"
                      else
                          playButtonImage.source = "qrc:/images/playnormal.png"
                  }
              }
          }

          Rectangle {
              id: stopButton
              height: 54
              width: 54
              anchors.bottom: parent.bottom
              anchors.bottomMargin: width
              x: parent.width / 2 + buttonHorizontalMargin
              color: "transparent"

              Image {
                  id: stopButtonImage
                  source: "qrc:/images/stopnormal.png"
              }

              MouseArea {
                  anchors.fill: parent
                  hoverEnabled: isHoverEnabled
                  onClicked: mainview.state = 'stopped'
                  onEntered: {
                      if (mainview.state != 'stopped')
                          stopButtonImage.source = "qrc:/images/stophoverpressed.png"
                  }
                  onExited: {
                      if (mainview.state != 'stopped')
                          stopButtonImage.source = "qrc:/images/stopnormal.png"
                  }
              }
          }
      }