learning_cesium/css/Timeline/TimelineTrack.js

60 lines
2.4 KiB
JavaScript

define([
'../../Core/Color',
'../../Core/defined',
'../../Core/JulianDate'
], function(
Color,
defined,
JulianDate) {
'use strict';
/**
* @private
*/
function TimelineTrack(interval, pixelHeight, color, backgroundColor) {
this.interval = interval;
this.height = pixelHeight;
this.color = color || new Color(0.5, 0.5, 0.5, 1.0);
this.backgroundColor = backgroundColor || new Color(0.0, 0.0, 0.0, 0.0);
}
TimelineTrack.prototype.render = function(context, renderState) {
var startInterval = this.interval.start;
var stopInterval = this.interval.stop;
var spanStart = renderState.startJulian;
var spanStop = JulianDate.addSeconds(renderState.startJulian, renderState.duration, new JulianDate());
if (JulianDate.lessThan(startInterval, spanStart) && JulianDate.greaterThan(stopInterval, spanStop)) {
//The track takes up the entire visible span.
context.fillStyle = this.color.toCssColorString();
context.fillRect(0, renderState.y, renderState.timeBarWidth, this.height);
} else if (JulianDate.lessThanOrEquals(startInterval, spanStop) && JulianDate.greaterThanOrEquals(stopInterval, spanStart)) {
//The track only takes up some of the visible span, compute that span.
var x;
var start, stop;
for (x = 0; x < renderState.timeBarWidth; ++x) {
var currentTime = JulianDate.addSeconds(renderState.startJulian, (x / renderState.timeBarWidth) * renderState.duration, new JulianDate());
if (!defined(start) && JulianDate.greaterThanOrEquals(currentTime, startInterval)) {
start = x;
} else if (!defined(stop) && JulianDate.greaterThanOrEquals(currentTime, stopInterval)) {
stop = x;
}
}
context.fillStyle = this.backgroundColor.toCssColorString();
context.fillRect(0, renderState.y, renderState.timeBarWidth, this.height);
if (defined(start)) {
if (!defined(stop)) {
stop = renderState.timeBarWidth;
}
context.fillStyle = this.color.toCssColorString();
context.fillRect(start, renderState.y, Math.max(stop - start, 1), this.height);
}
}
};
return TimelineTrack;
});