桌面/移动端事件支持

我们可以使用 on() 方法给图形添加桌面/移动端事件。例如：我们可以使用 “mousedown touchstart” 的事件组合，同时在桌面端和移动端绑定mousedown事件，同理 mouseup 可以使用 “mouseup touchend” 事件组合，双击可以使用 “dblclick dbltap” 事件组合。

说明：观察 mousedown、mouseup、touchstart、touchend 事件在桌面端和移动端的执行情况。

Konva Desktop_and_Mobile Demoview raw

<!DOCTYPE html>
<html>
  <head>
    <script src="https://unpkg.com/konva@4.0.18/konva.min.js"></script>
    <meta charset="utf-8" />
    <title>Konva Desktop and Mobile Events Support Demo</title>
    <style>
      body {
        margin: 0;
        padding: 0;
        overflow: hidden;
        background-color: #f0f0f0;
      }
    </style>
  </head>

  <body>
    <div id="container"></div>
    <script>
      function writeMessage(message) {
        text.text(message);
        layer.draw();
      }

      var stage = new Konva.Stage({
        container: 'container',
        width: window.innerWidth,
        height: window.innerHeight
      });

      var layer = new Konva.Layer();

      var text = new Konva.Text({
        x: 10,
        y: 10,
        fontFamily: 'Calibri',
        fontSize: 20,
        text: '',
        fill: 'black'
      });

      var circle = new Konva.Circle({
        x: stage.width() / 2,
        y: stage.height() / 2 + 10,
        radius: 70,
        fill: 'red',
        stroke: 'black',
        strokeWidth: 4
      });

      /*
       * mousedown and touchstart are desktop and
       * mobile equivalents so they are often times
       * used together
       */
      circle.on('mousedown touchstart', function() {
        writeMessage('Mousedown or touchstart');
      });
      /*
       * mouseup and touchend are desktop and
       * mobile equivalents so they are often times
       * used together
       */
      circle.on('mouseup touchend', function() {
        writeMessage('Mouseup or touchend');
      });

      layer.add(circle);
      layer.add(text);

      // add the layer to the stage
      stage.add(layer);
    </script>
  </body>
</html>