ImageGrid/ui (gen4)/features/ui-partial-ribbons-precache.js
2018-11-08 21:10:58 +03:00

246 lines
6.7 KiB
JavaScript
Executable File

/**********************************************************************
*
*
*
**********************************************************************/
((typeof define)[0]=='u'?function(f){module.exports=f(require)}:define)
(function(require){ var module={} // make module AMD/node compatible...
/*********************************************************************/
var actions = require('lib/actions')
var features = require('lib/features')
var core = require('features/core')
/*********************************************************************/
var PreCacheActions = actions.Actions({
config: {
// How many non-adjacent images to preload...
'preload-radius': 5,
// Sources to preload...
'preload-sources': ['bookmark', 'marked'],
},
// NOTE: this will not work from chrome when loading from a local fs...
// XXX experimental...
startCacheWorker: ['Interface/',
function(){
// a worker is started already...
if(this.cacheWorker != null){
return
}
var b = new Blob([[
'addEventListener(\'message\', function(e) {',
' var urls = e.data',
' urls = urls.constructor !== Array ? [urls] : urls',
' var l = urls.length',
' urls.forEach(function(url){',
' var xhr = new XMLHttpRequest()',
' xhr.responseType = \'blob\'',
/*
' xhr.onload = xhr.onerror = function(){',
' l -= 1',
' if(l <= 0){',
' postMessage({status: \'done.\', urls: urls})',
' }',
' }',
*/
' xhr.open(\'GET\', url, true)',
' xhr.send()',
' })',
'}, false)',
].join('\n')])
var url = URL.createObjectURL(b)
this.cacheWorker = new Worker(url)
this.cacheWorker.url = url
}],
stopCacheWorker: ['Interface/',
function(){
if(this.cacheWorker){
this.cacheWorker.terminate()
URL.revokeObjectURL(this.cacheWorker.url)
delete this.cacheWorker
}
}],
// Pre-load images...
//
// Sources supported:
// <tag> - pre-load images tagged with <tag>
// (default: ['bookmark', 'marked'])
// <ribbon-gid> - pre-cache from a specific ribbon
// 'ribbon' - pre-cache from current ribbon
// 'order' - pre-cache from images in order
//
// NOTE: workers when loaded from file:// in a browser context
// will not have access to local images...
//
// XXX need a clear strategy to run this...
// XXX might be a good idea to make the worker queue the lists...
// ...this will need careful prioritization logic...
// - avoid loading the same url too often
// - load the most probable urls first
// - next targets
// - next/prev
// .preCacheJumpTargets(target, 'ribbon', this.screenwidth)
// - next/prev marked/bookmarked/order
// .preCacheJumpTargets(target, 'marked')
// .preCacheJumpTargets(target, 'bookmarked')
// .preCacheJumpTargets(target, 'order')
// - next/prev screen
// .preCacheJumpTargets(target, 'ribbon',
// this.config['preload-radius'] * this.screenwidth)
// - next/prev ribbon
// .preCacheJumpTargets(target, this.data.getRibbon(target, 1))
// .preCacheJumpTargets(target, this.data.getRibbon(target, -1))
// - next blocks
// - what resize ribbon does...
// XXX coordinate this with .resizeRibbon(..)
// XXX make this support an explicit list of gids....
// XXX should this be here???
preCacheJumpTargets: ['- Interface/Pre-cache potential jump target images',
function(target, sources, radius, size){
target = target instanceof jQuery
? this.ribbons.elemGID(target)
// NOTE: data.getImage(..) can return null at start or end
// of ribbon, thus we need to account for this...
: (this.data.getImage(target)
|| this.data.getImage(target, 'after'))
sources = sources || this.config['preload-sources'] || ['bookmark', 'marked']
sources = sources.constructor !== Array ? [sources] : sources
radius = radius || this.config['preload-radius'] || 9
var that = this
// get preview...
var _getPreview = function(c){
return that.images[c]
&& that.images.getBestPreview(c, size, true).url
}
// get a set of paths...
// NOTE: we are also ordering the resulting gids by their
// distance from target...
var _get = function(i, lst, source, radius, oddity, step){
var found = oddity
var max = source.length
for(var j = i+step; (step > 0 && j < max) || (step < 0 && j >= 0); j += step){
var c = source[j]
if(c == null || that.images[c] == null){
continue
}
// build the URL...
lst[found] = _getPreview(c)
found += 2
if(found >= radius*2){
break
}
}
}
// run the actual preload...
var _run = function(){
sources.forEach(function(tag){
// order...
if(tag == 'order'){
var source = that.data.order
// current ribbon...
}else if(tag == 'ribbon'){
var source = that.data.ribbons[that.data.getRibbon()]
// ribbon-gid...
} else if(tag in that.data.ribbons){
var source = that.data.ribbons[tag]
// nothing tagged then nothing to do...
} else if(that.data.tags == null
|| that.data.tags[tag] == null
|| that.data.tags[tag].length == 0){
return
// tag...
} else {
var source = that.data.tags[tag]
}
size = size || that.ribbons.getVisibleImageSize()
var i = that.data.order.indexOf(target)
var lst = []
// get the list of URLs before and after current...
_get(i ,lst, source, radius, 0, 1)
_get(i, lst, source, radius, 1, -1)
// get target preview in case the target is not loaded...
var p = _getPreview(that.data.getImage(target))
p && lst.splice(0, 0, p)
// web worker...
if(that.cacheWorker != null){
that.cacheWorker.postMessage(lst)
// async inline...
} else {
// do the actual preloading...
lst.forEach(function(url){
var img = new Image()
img.src = url
})
}
})
}
if(that.cacheWorker != null){
_run()
} else {
setTimeout(_run, 0)
}
}],
})
var PreCache =
module.PreCache = core.ImageGridFeatures.Feature({
title: '',
doc: '',
tag: 'ui-partial-ribbons-precache',
depends: [
'ui',
],
actions: PreCacheActions,
handlers: [
['focusImage.post',
function(_, target){
this.preCacheJumpTargets(target) }],
/*/
['resizing.pre',
function(unit, size){
this.preCacheJumpTargets() }],
//*/
],
})
/**********************************************************************
* vim:set ts=4 sw=4 : */ return module })