d3-progress-meter/d3-progress-meter.html

<link rel="import" href="../polymer/polymer.html">

<script src="../d3/d3.min.js"></script>

<!--
An animated chart that shows the progress as a meter

### Example

```html
<d3-progress-meter radius="100" percentage="0.35" current-text="70" goal-text="Goal: 200" type-text="transactions"></d3-progress-meter>
```


@demo demo/index.html
-->
<dom-module id="d3-progress-meter">

	<template>
		<style>
			:host {
				display: inline-block;
			}
			#background {
				/* var(--paper-grey-300) */
				fill: #e0e0e0;
			}
			#progress.low {
				/* var(--paper-red-500) */
				fill: #f44336;
			}
			#progress.medium {
				/* var(--paper-yellow-500) */
				fill: #ffeb3b;
			}
			#progress.high {
				/* var(--paper-green-500) */
				fill: #4caf50;
			}
			#current,#goal,#type {
				font-family: Arial, sans-serif;
			}
			#current {
				font-weight: bold;
			}
			#type {
				margin-top: 5px;
				text-align: center;
				text-transform: uppercase;
				white-space: nowrap;
				overflow-x: hidden;
				text-overflow: ellipsis;
			}
		</style>
		
		<svg width$=[[_diameter]] height$=[[_diameter]]>
			<g transform$=[[_transform]]>
				<g>
					<path id="background"></path>
					<path id="progress" class$=[[_progressLevel]]></path>
					<text id="current" dy="-.2em" text-anchor="middle">[[currentText]]</text>
					<text id="goal" dy="1.5em" text-anchor="middle">[[goalText]]</text>
				</g>
			</g>
		</svg>
		<div id="type">[[typeText]]</div>
	</template>

</dom-module>
	
<script>
(function() {

	Polymer({
		is: 'd3-progress-meter',
		properties: {
			/**
			 * Radius of the meter. The element will have twice the size of the radius
			 */
			radius: {
				type: Number,
				value: 100,
				observer: '_radiusChanged'
			},

			/**
			 * Progress in percent
			 */
			percentage: {
				type: Number,
				observer: '_percentageChanged'
			},

			/**
			 * Large number showing current progress
			 */
			currentText: String,

			/**
			 * Small text indicating when progress will be 100%
			 */
			goalText: String,

			/**
			 * Bottom text describing for what progress is measured
			 */
			typeText: String,

			/**
			 * Amount of progress made (absolute number)
			 */
			_progress: {
				type: Number,
				value: 0
			},

			_diameter: {
				type: Number,
				computed: '_computeDiameter(radius)'
			},
			_transform: {
				type: String,
				computed: '_computeTransform(radius)'
			},
			_progressLevel: {
				type: Number,
				computed: '_computeProgressLevel(percentage)'
			}
		},
		
		_computeDiameter: function(radius) {
			return 2 * radius;
		},
		_computeTransform: function(radius) {
			return "translate(" + radius + ", " + radius + ")";
		},
		_computeProgressLevel: function(percentage) {
			if (percentage <= .33) {
				return 'low';
			}

			if (percentage <= .66) {
				return 'medium';
			}

			return 'high';
		},
		_radiusChanged: function(oldVal, newVal) {
			this._onRadiusChanged();
			this._onPercentageChanged();
		},
		_percentageChanged: function(oldVal, newVal) {
			this._onPercentageChanged();
		},
		_onRadiusChanged: function() {
			this.progressArc = d3.svg.arc()
						.startAngle(0)
						.innerRadius(9/10 * this.radius)
						.outerRadius(this.radius);

			this.backgroundArc = d3.svg.arc()
						.startAngle(0)
						.innerRadius(0.825 * this.radius)
						.outerRadius(0.85 * this.radius);

			this.$.current.style.fontSize = this.radius/2 + 'px';
			this.$.goal.style.fontSize = this.radius/5 + 'px';
			this.$.type.style.fontSize = this.radius/4 + 'px';
			this.$.type.style.width = 2 * this.radius + 'px';
			this.$.background.setAttribute('d', this.backgroundArc.endAngle(2 * Math.PI)());
		},
		_onPercentageChanged: function() {
			if (typeof this.percentage == 'undefined') {
				return;
			}
			this.percentage = Math.min(1, Math.max(0, this.percentage));
			
			var i = d3.interpolate(this._progress, this.percentage);
			d3.select(this).transition().tween(this.$.progress, function() {
				return function(t) {
					this._progress = i(t);
					this.$.progress.setAttribute('d', this.progressArc.endAngle(2 * Math.PI * this._progress)());
				}.bind(this);
			}.bind(this));
		}
	});

})();
</script>