Qt 5.7 | Qt Quick | Qt Quick Demo - Tweet Search | FlipBar.qml Example File

Qt 5.7.1 Reference Documentation

# FlipBar.qml Example File

demos/tweetsearch/content/FlipBar.qml

      /****************************************************************************
      **
      ** Copyright (C) 2015 The Qt Company Ltd.
      ** Contact: http://www.qt.io/licensing/
      **
      ** This file is part of the examples of the Qt Toolkit.
      **
      ** $QT_BEGIN_LICENSE:BSD$
      ** You may use this file under the terms of the BSD license as follows:
      **
      ** "Redistribution and use in source and binary forms, with or without
      ** modification, are permitted provided that the following conditions are
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      **   * Redistributions of source code must retain the above copyright
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      **     notice, this list of conditions and the following disclaimer in
      **     the documentation and/or other materials provided with the
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      **     contributors may be used to endorse or promote products derived
      **     from this software without specific prior written permission.
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      import QtQuick 2.0

      Item {
          id: container
          property int animDuration: 300
          property Item front: Item {}
          property Item back: Item {}
          property real factor: 0.1 // amount the edges fold in for the 3D effect
          property alias delta: effect.delta
          property Item cur: frontShown ? front : back
          property Item noncur: frontShown ? back : front

          function swap() {
              var tmp = front;
              front = back;
              back = tmp;
              resync();
          }

          width: cur.width
          height: cur.height
          onFrontChanged: resync();
          onBackChanged: resync();

          function resync() {//TODO: Are the items ever actually visible?
              back.parent = container;
              front.parent = container;
              frontShown ? back.visible = false : front.visible = false;
          }

          property bool frontShown: true

          onFrontShownChanged: {
              back.visible = !frontShown
              front.visible = frontShown
          }

          function flipUp(start) {
              effect.visible = true;
              effect.sourceA = effect.source1
              effect.sourceB = effect.source2
              if (start == undefined)
                  start = 1.0;
              deltaAnim.from = start;
              deltaAnim.to = 0.0
              dAnim.start();
              frontShown = false;
          }

          function flipDown(start) {
              effect.visible = true;
              effect.sourceA = effect.source1
              effect.sourceB = effect.source2
              if (start == undefined)
                  start = 0.0;
              deltaAnim.from = start;
              deltaAnim.to = 1.0
              dAnim.start();
              frontShown = true;
          }

          ShaderEffect {
              id: effect
              width: cur.width
              height: cur.height
              property real factor: container.factor * width
              property real delta: 1.0

              mesh: GridMesh { resolution: Qt.size(8,2) }

              SequentialAnimation on delta {
                  id: dAnim
                  running: false
                  NumberAnimation {
                  id: deltaAnim
                  duration: animDuration//expose anim
                  }
              }

              property variant sourceA: source1
              property variant sourceB: source1
              property variant source1: ShaderEffectSource {
                  sourceItem: front
                  hideSource: effect.visible
              }

              property variant source2: ShaderEffectSource {
                  sourceItem: back
                  hideSource: effect.visible
              }

              fragmentShader: "
                  uniform lowp float qt_Opacity;
                  uniform sampler2D sourceA;
                  uniform sampler2D sourceB;
                  uniform highp float delta;
                  varying highp vec2 qt_TexCoord0;
                  void main() {
                      highp vec4 tex = vec4(qt_TexCoord0.x, qt_TexCoord0.y * 2.0, qt_TexCoord0.x, (qt_TexCoord0.y-0.5) * 2.0);
                      highp float shade = clamp(delta*2.0, 0.5, 1.0);
                      highp vec4 col;
                      if (qt_TexCoord0.y < 0.5) {
                          col = texture2D(sourceA, tex.xy) * (shade);
                      } else {
                          col = texture2D(sourceB, tex.zw) * (1.5 - shade);
                          col.w = 1.0;
                      }
                      gl_FragColor = col * qt_Opacity;
                  }
              "
              property real h: height
              vertexShader: "
              uniform highp float delta;
              uniform highp float factor;
              uniform highp float h;
              uniform highp mat4 qt_Matrix;
              attribute highp vec4 qt_Vertex;
              attribute highp vec2 qt_MultiTexCoord0;
              varying highp vec2 qt_TexCoord0;
              void main() {
                  highp vec4 pos = qt_Vertex;
                  if (qt_MultiTexCoord0.y == 0.0)
                      pos.x += factor * (1. - delta) * (qt_MultiTexCoord0.x * -2.0 + 1.0);
                  else if (qt_MultiTexCoord0.y == 1.0)
                      pos.x += factor * (delta) * (qt_MultiTexCoord0.x * -2.0 + 1.0);
                  else
                      pos.y = delta * h;
                  gl_Position = qt_Matrix * pos;
                  qt_TexCoord0 = qt_MultiTexCoord0;
              }"

          }
      }