Polymer elements added to third_party/polymer.

third_party/polymer/components/paper-ripple/paper-ripple.html

+<!--
+Copyright (c) 2014 The Polymer Project Authors. All rights reserved.
+This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
+The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
+The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt
+Code distributed by Google as part of the polymer project is also
+subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
+-->
+
+<!--
+`paper-ripple` provides a visual effect that other paper elements can
+use to simulate a rippling effect emanating from the point of contact.  The
+effect can be visualized as a concentric circle with motion.
+
+Example:
+
+    <paper-ripple></paper-ripple>
+
+`paper-ripple` listens to "down" and "up" events so it would display ripple
+effect when touches on it.  You can also defeat the default behavior and 
+manually route the down and up actions to the ripple element.  Note that it is
+important if you call downAction() you will have to make sure to call upAction()
+so that `paper-ripple` would end the animation loop.
+
+Example:
+
+    <paper-ripple id="ripple" style="pointer-events: none;"></paper-ripple>
+    ...
+    downAction: function(e) {
+      this.$.ripple.downAction({x: e.x, y: e.y});
+    },
+    upAction: function(e) {
+      this.$.ripple.upAction();
+    }
+
+Styling ripple effect:
+
+  Use CSS color property to style the ripple:
+
+    paper-ripple {
+      color: #4285f4;
+    }
+
+  Note that CSS color property is inherited so it is not required to set it on
+  the `paper-ripple` element directly.
+
+Apply `recenteringTouch` class to make the recentering rippling effect.
+
+    <paper-ripple class="recenteringTouch"></paper-ripple>
+
+Apply `circle` class to make the rippling effect within a circle.
+
+    <paper-ripple class="circle"></paper-ripple>
+
+@group Paper Elements
+@element paper-ripple
+@homepage github.io
+-->
+
+<link rel="import" href="../polymer/polymer.html" >
+
+<polymer-element name="paper-ripple" attributes="initialOpacity opacityDecayVelocity">
+<template>
+
+  <style>
+
+    :host {
+      display: block;
+      position: relative;
+    }
+
+    #canvas {
+      pointer-events: none;
+      position: absolute;
+      top: 0;
+      left: 0;
+      width: 100%;
+      height: 100%;
+    }
+
+    :host(.circle) #canvas {
+      border-radius: 50%;
+    }
+
+  </style>
+
+</template>
+<script>
+
+  (function() {
+
+    var waveMaxRadius = 150;
+    //
+    // INK EQUATIONS
+    //
+    function waveRadiusFn(touchDownMs, touchUpMs, anim) {
+      // Convert from ms to s.
+      var touchDown = touchDownMs / 1000;
+      var touchUp = touchUpMs / 1000;
+      var totalElapsed = touchDown + touchUp;
+      var ww = anim.width, hh = anim.height;
+      // use diagonal size of container to avoid floating point math sadness
+      var waveRadius = Math.min(Math.sqrt(ww * ww + hh * hh), waveMaxRadius) * 1.1 + 5;
+      var duration = 1.1 - .2 * (waveRadius / waveMaxRadius);
+      var tt = (totalElapsed / duration);
+
+      var size = waveRadius * (1 - Math.pow(80, -tt));
+      return Math.abs(size);
+    }
+
+    function waveOpacityFn(td, tu, anim) {
+      // Convert from ms to s.
+      var touchDown = td / 1000;
+      var touchUp = tu / 1000;
+      var totalElapsed = touchDown + touchUp;
+
+      if (tu <= 0) {  // before touch up
+        return anim.initialOpacity;
+      }
+      return Math.max(0, anim.initialOpacity - touchUp * anim.opacityDecayVelocity);
+    }
+
+    function waveOuterOpacityFn(td, tu, anim) {
+      // Convert from ms to s.
+      var touchDown = td / 1000;
+      var touchUp = tu / 1000;
+
+      // Linear increase in background opacity, capped at the opacity
+      // of the wavefront (waveOpacity).
+      var outerOpacity = touchDown * 0.3;
+      var waveOpacity = waveOpacityFn(td, tu, anim);
+      return Math.max(0, Math.min(outerOpacity, waveOpacity));
+    }
+
+    // Determines whether the wave should be completely removed.
+    function waveDidFinish(wave, radius, anim) {
+      var waveOpacity = waveOpacityFn(wave.tDown, wave.tUp, anim);
+      // If the wave opacity is 0 and the radius exceeds the bounds
+      // of the element, then this is finished.
+      if (waveOpacity < 0.01 && radius >= Math.min(wave.maxRadius, waveMaxRadius)) {
+        return true;
+      }
+      return false;
+    };
+
+    function waveAtMaximum(wave, radius, anim) {
+      var waveOpacity = waveOpacityFn(wave.tDown, wave.tUp, anim);
+      if (waveOpacity >= anim.initialOpacity && radius >= Math.min(wave.maxRadius, waveMaxRadius)) {
+        return true;
+      }
+      return false;
+    }
+
+    //
+    // DRAWING
+    //
+    function drawRipple(ctx, x, y, radius, innerColor, outerColor) {
+      if (outerColor) {
+        ctx.fillStyle = outerColor;
+        ctx.fillRect(0,0,ctx.canvas.width, ctx.canvas.height);
+      }
+      ctx.beginPath();
+      ctx.arc(x, y, radius, 0, 2 * Math.PI, false);
+      ctx.fillStyle = innerColor;
+      ctx.fill();
+    }
+
+    //
+    // SETUP
+    //
+    function createWave(elem) {
+      var elementStyle = window.getComputedStyle(elem);
+      var fgColor = elementStyle.color;
+
+      var wave = {
+        waveColor: fgColor,
+        maxRadius: 0,
+        isMouseDown: false,
+        mouseDownStart: 0.0,
+        mouseUpStart: 0.0,
+        tDown: 0,
+        tUp: 0
+      };
+      return wave;
+    }
+
+    function removeWaveFromScope(scope, wave) {
+      if (scope.waves) {
+        var pos = scope.waves.indexOf(wave);
+        scope.waves.splice(pos, 1);
+      }
+    };
+
+    // Shortcuts.
+    var pow = Math.pow;
+    var now = Date.now;
+    if (window.performance && performance.now) {
+      now = performance.now.bind(performance);
+    }
+
+    function cssColorWithAlpha(cssColor, alpha) {
+        var parts = cssColor.match(/^rgb\((\d+),\s*(\d+),\s*(\d+)\)$/);
+        if (typeof alpha == 'undefined') {
+            alpha = 1;
+        }
+        if (!parts) {
+          return 'rgba(255, 255, 255, ' + alpha + ')';
+        }
+        return 'rgba(' + parts[1] + ', ' + parts[2] + ', ' + parts[3] + ', ' + alpha + ')';
+    }
+
+    function dist(p1, p2) {
+      return Math.sqrt(pow(p1.x - p2.x, 2) + pow(p1.y - p2.y, 2));
+    }
+
+    function distanceFromPointToFurthestCorner(point, size) {
+      var tl_d = dist(point, {x: 0, y: 0});
+      var tr_d = dist(point, {x: size.w, y: 0});
+      var bl_d = dist(point, {x: 0, y: size.h});
+      var br_d = dist(point, {x: size.w, y: size.h});
+      return Math.max(tl_d, tr_d, bl_d, br_d);
+    }
+
+    Polymer('paper-ripple', {
+
+      /**
+       * The initial opacity set on the wave.
+       *
+       * @attribute initialOpacity
+       * @type number
+       * @default 0.25
+       */
+      initialOpacity: 0.25,
+
+      /**
+       * How fast (opacity per second) the wave fades out.
+       *
+       * @attribute opacityDecayVelocity
+       * @type number
+       * @default 0.8
+       */
+      opacityDecayVelocity: 0.8,
+
+      backgroundFill: true,
+      pixelDensity: 2,
+
+      eventDelegates: {
+        down: 'downAction',
+        up: 'upAction'
+      },
+
+      attached: function() {
+        // create the canvas element manually becase ios
+        // does not render the canvas element if it is not created in the
+        // main document (component templates are created in a
+        // different document). See:
+        // https://bugs.webkit.org/show_bug.cgi?id=109073.
+        if (!this.$.canvas) {
+          var canvas = document.createElement('canvas');
+          canvas.id = 'canvas';
+          this.shadowRoot.appendChild(canvas);
+          this.$.canvas = canvas;
+        }
+      },
+
+      ready: function() {
+        this.waves = [];
+      },
+
+      setupCanvas: function() {
+        this.$.canvas.setAttribute('width', this.$.canvas.clientWidth * this.pixelDensity + "px");
+        this.$.canvas.setAttribute('height', this.$.canvas.clientHeight * this.pixelDensity + "px");
+        var ctx = this.$.canvas.getContext('2d');
+        ctx.scale(this.pixelDensity, this.pixelDensity);
+        if (!this._loop) {
+          this._loop = this.animate.bind(this, ctx);
+        }
+      },
+
+      downAction: function(e) {
+        this.setupCanvas();
+        var wave = createWave(this.$.canvas);
+
+        this.cancelled = false;
+        wave.isMouseDown = true;
+        wave.tDown = 0.0;
+        wave.tUp = 0.0;
+        wave.mouseUpStart = 0.0;
+        wave.mouseDownStart = now();
+
+        var width = this.$.canvas.width / 2; // Retina canvas
+        var height = this.$.canvas.height / 2;
+        var rect = this.getBoundingClientRect();
+        var touchX = e.x - rect.left;
+        var touchY = e.y - rect.top;
+
+        wave.startPosition = {x:touchX, y:touchY};
+
+        if (this.classList.contains("recenteringTouch")) {
+          wave.endPosition = {x: width / 2,  y: height / 2};
+          wave.slideDistance = dist(wave.startPosition, wave.endPosition);
+        }
+        wave.containerSize = Math.max(width, height);
+        wave.maxRadius = distanceFromPointToFurthestCorner(wave.startPosition, {w: width, h: height});
+        this.waves.push(wave);
+        requestAnimationFrame(this._loop);
+      },
+
+      upAction: function() {
+        for (var i = 0; i < this.waves.length; i++) {
+          // Declare the next wave that has mouse down to be mouse'ed up.
+          var wave = this.waves[i];
+          if (wave.isMouseDown) {
+            wave.isMouseDown = false
+            wave.mouseUpStart = now();
+            wave.mouseDownStart = 0;
+            wave.tUp = 0.0;
+            break;
+          }
+        }
+        this._loop && requestAnimationFrame(this._loop);
+      },
+
+      cancel: function() {
+        this.cancelled = true;
+      },
+
+      animate: function(ctx) {
+        var shouldRenderNextFrame = false;
+
+        // Clear the canvas
+        ctx.clearRect(0, 0, ctx.canvas.width, ctx.canvas.height);
+
+        var deleteTheseWaves = [];
+        // The oldest wave's touch down duration
+        var longestTouchDownDuration = 0;
+        var longestTouchUpDuration = 0;
+        // Save the last known wave color
+        var lastWaveColor = null;
+        // wave animation values
+        var anim = {
+          initialOpacity: this.initialOpacity,
+          opacityDecayVelocity: this.opacityDecayVelocity,
+          height: ctx.canvas.height,
+          width: ctx.canvas.width
+        }
+
+        for (var i = 0; i < this.waves.length; i++) {
+          var wave = this.waves[i];
+
+          if (wave.mouseDownStart > 0) {
+            wave.tDown = now() - wave.mouseDownStart;
+          }
+          if (wave.mouseUpStart > 0) {
+            wave.tUp = now() - wave.mouseUpStart;
+          }
+
+          // Determine how long the touch has been up or down.
+          var tUp = wave.tUp;
+          var tDown = wave.tDown;
+          longestTouchDownDuration = Math.max(longestTouchDownDuration, tDown);
+          longestTouchUpDuration = Math.max(longestTouchUpDuration, tUp);
+
+          // Obtain the instantenous size and alpha of the ripple.
+          var radius = waveRadiusFn(tDown, tUp, anim);
+          var waveAlpha =  waveOpacityFn(tDown, tUp, anim);
+          var waveColor = cssColorWithAlpha(wave.waveColor, waveAlpha);
+          lastWaveColor = wave.waveColor;
+
+          // Position of the ripple.
+          var x = wave.startPosition.x;
+          var y = wave.startPosition.y;
+
+          // Ripple gravitational pull to the center of the canvas.
+          if (wave.endPosition) {
+
+            // This translates from the origin to the center of the view  based on the max dimension of  
+            var translateFraction = Math.min(1, radius / wave.containerSize * 2 / Math.sqrt(2) );
+
+            x += translateFraction * (wave.endPosition.x - wave.startPosition.x);
+            y += translateFraction * (wave.endPosition.y - wave.startPosition.y);
+          }
+
+          // If we do a background fill fade too, work out the correct color.
+          var bgFillColor = null;
+          if (this.backgroundFill) {
+            var bgFillAlpha = waveOuterOpacityFn(tDown, tUp, anim);
+            bgFillColor = cssColorWithAlpha(wave.waveColor, bgFillAlpha);
+          }
+
+          // Draw the ripple.
+          drawRipple(ctx, x, y, radius, waveColor, bgFillColor);
+
+          // Determine whether there is any more rendering to be done.
+          var maximumWave = waveAtMaximum(wave, radius, anim);
+          var waveDissipated = waveDidFinish(wave, radius, anim);
+          var shouldKeepWave = !waveDissipated || maximumWave;
+          var shouldRenderWaveAgain = !waveDissipated && !maximumWave;
+          shouldRenderNextFrame = shouldRenderNextFrame || shouldRenderWaveAgain;
+          if (!shouldKeepWave || this.cancelled) {
+            deleteTheseWaves.push(wave);
+          }
+       }
+
+        if (shouldRenderNextFrame) {
+          requestAnimationFrame(this._loop);
+        }
+
+        for (var i = 0; i < deleteTheseWaves.length; ++i) {
+          var wave = deleteTheseWaves[i];
+          removeWaveFromScope(this, wave);
+        }
+
+        if (!this.waves.length) {
+          // If there is nothing to draw, clear any drawn waves now because
+          // we're not going to get another requestAnimationFrame any more.
+          ctx.clearRect(0, 0, ctx.canvas.width, ctx.canvas.height);
+          this._loop = null;
+        }
+      }
+
+    });
+
+  })();
+
+</script>
+</polymer-element>