oxjs/source/Ox.UI/js/Video/VideoPreview.js
2012-06-10 20:18:03 +02:00

172 lines
5.8 KiB
JavaScript

'use strict';
/*@
Ox.VideoPreview <f> Video Preview
([options[, self]]) -> <o:Ox.Element> Video Preview
options <o> Options
self <o> Shared private variable
@*/
Ox.VideoPreview = function(options, self) {
self = self || {};
var that = Ox.Element({}, self)
.defaults({
duration: 0,
getFrame: null,
fps: 25,
frameRatio: 16/9,
height: 256,
position: void 0,
scaleToFill: false,
timeline: '',
width: 256
})
.options(options || {})
.update({
height: function() {
that.css({height: self.options.height + 'px'});
self.$frame.css(getFrameCSS());
},
position: function() {
self.$frame.attr({src: self.options.getFrame(self.options.position)});
},
width: function() {
that.css({width: self.options.width + 'px'});
stopLoading();
self.$frame.attr({src: self.options.getFrame()})
.css(getFrameCSS());
self.$timeline && self.$timeline.css({width: self.options.width + 'px'});
}
})
.addClass('OxVideoPreview')
.css({
width: self.options.width + 'px',
height: self.options.height + 'px'
});
self.loaded = [];
self.queue = [];
self.$frameElement = $('<div>')
.addClass('OxFrame')
.appendTo(that.$element)
self.$frame = $('<img>')
.attr({src: self.options.getFrame(self.options.position)})
.css(getFrameCSS())
.appendTo(self.$frameElement);
if (self.options.timeline) {
self.$timeline = $('<img>')
.addClass('OxTimeline')
.attr({src: self.options.timeline})
.css({width: self.options.width + 'px'})
.appendTo(that.$element);
}
self.$interface = Ox.Element({
tooltip: function(event) {
// e.offsetX does not work in Firefox
var position = getPosition(event.clientX - that.offset().left);
self.$frame.attr({src: getClosestFrame(position)});
self.timeout && clearTimeout(self.timeout);
self.timeout = setTimeout(function() {
self.$frame.attr({src: self.options.getFrame(position)});
}, 250);
return Ox.formatDuration(position, 2);
}
})
.addClass('OxInterface')
.on({
click: click,
mouseenter: startLoading,
mouseleave: function() {
stopLoading();
self.$frame.attr({src: self.options.getFrame(self.options.position)});
}
})
.appendTo(that.$element);
function click(e) {
that.triggerEvent('click', {
// e.offsetX does not work in Firefox
position: getPosition(e.clientX - that.offset().left)
});
}
function getClosestFrame(position) {
return self.loaded.length == 0
? self.options.getFrame(self.options.position)
: self.loaded.sort(function(a, b) {
return Math.abs(a.position - position) - Math.abs(b.position - position);
})[0].frame;
}
function getFrameCSS() {
var css = {},
elementWidth = self.options.width,
elementHeight = self.options.height - (self.options.timeline ? 16 : 0),
elementRatio = elementWidth / elementHeight,
frameRatio = self.options.frameRatio,
frameIsWider = frameRatio > elementRatio;
if (self.options.scaleToFill) {
css.width = frameIsWider ? elementHeight * frameRatio : elementWidth;
css.height = frameIsWider ? elementHeight : elementWidth / frameRatio;
css.marginLeft = frameIsWider ? (elementWidth - css.width) / 2 : 0;
css.marginTop = frameIsWider ? 0 : (elementHeight - css.height) / 2;
} else {
css.width = frameIsWider ? elementWidth : elementHeight * frameRatio;
css.height = frameIsWider ? elementWidth / frameRatio : elementHeight;
css.marginLeft = frameIsWider ? 0 : (elementWidth - css.width) / 2;
css.marginTop = frameIsWider ? (elementHeight - css.height) / 2 : 0;
}
return Ox.map(css, function(value) {
return Math.round(value) + 'px';
});
}
function getPosition(x) {
return Math.round(
self.options.duration * x / self.options.width * self.options.fps
) / self.options.fps;
}
function startLoading() {
var last,
steps = [Math.round(self.options.width / 2)];
while ((last = steps[steps.length - 1]) > 1) {
steps.push(Math.round(last / 2));
}
steps.forEach(function(step) {
Ox.loop(0, self.options.width, step, function(x) {
var position = getPosition(x),
frame = self.options.getFrame(position);
if (!self.loaded.some(function(image) {
return image.frame == frame;
}) && !self.queue.some(function(image) {
return image.frame == frame;
})) {
self.queue.push({frame: frame, position: position});
}
});
});
self.queue.length && loadFrame();
function loadFrame() {
var image = self.queue.shift();
$('<img>')
.load(function() {
self.loaded.push(image);
self.queue.length && loadFrame();
})
.attr({src: image.frame})
}
}
function stopLoading() {
self.queue = [];
self.timeout && clearTimeout(self.timeout);
}
return that;
};