88 lines
2.7 KiB
JavaScript
88 lines
2.7 KiB
JavaScript
var LRU = require("../../core/LRU");
|
|
|
|
var globalImageCache = new LRU(50);
|
|
/**
|
|
* @param {string|HTMLImageElement|HTMLCanvasElement|Canvas} newImageOrSrc
|
|
* @return {HTMLImageElement|HTMLCanvasElement|Canvas} image
|
|
*/
|
|
|
|
function findExistImage(newImageOrSrc) {
|
|
if (typeof newImageOrSrc === 'string') {
|
|
var cachedImgObj = globalImageCache.get(newImageOrSrc);
|
|
return cachedImgObj && cachedImgObj.image;
|
|
} else {
|
|
return newImageOrSrc;
|
|
}
|
|
}
|
|
/**
|
|
* Caution: User should cache loaded images, but not just count on LRU.
|
|
* Consider if required images more than LRU size, will dead loop occur?
|
|
*
|
|
* @param {string|HTMLImageElement|HTMLCanvasElement|Canvas} newImageOrSrc
|
|
* @param {HTMLImageElement|HTMLCanvasElement|Canvas} image Existent image.
|
|
* @param {module:zrender/Element} [hostEl] For calling `dirty`.
|
|
* @param {Function} [cb] params: (image, cbPayload)
|
|
* @param {Object} [cbPayload] Payload on cb calling.
|
|
* @return {HTMLImageElement|HTMLCanvasElement|Canvas} image
|
|
*/
|
|
|
|
|
|
function createOrUpdateImage(newImageOrSrc, image, hostEl, cb, cbPayload) {
|
|
if (!newImageOrSrc) {
|
|
return image;
|
|
} else if (typeof newImageOrSrc === 'string') {
|
|
// Image should not be loaded repeatly.
|
|
if (image && image.__zrImageSrc === newImageOrSrc || !hostEl) {
|
|
return image;
|
|
} // Only when there is no existent image or existent image src
|
|
// is different, this method is responsible for load.
|
|
|
|
|
|
var cachedImgObj = globalImageCache.get(newImageOrSrc);
|
|
var pendingWrap = {
|
|
hostEl: hostEl,
|
|
cb: cb,
|
|
cbPayload: cbPayload
|
|
};
|
|
|
|
if (cachedImgObj) {
|
|
image = cachedImgObj.image;
|
|
!isImageReady(image) && cachedImgObj.pending.push(pendingWrap);
|
|
} else {
|
|
image = new Image();
|
|
image.onload = image.onerror = imageOnLoad;
|
|
globalImageCache.put(newImageOrSrc, image.__cachedImgObj = {
|
|
image: image,
|
|
pending: [pendingWrap]
|
|
});
|
|
image.src = image.__zrImageSrc = newImageOrSrc;
|
|
}
|
|
|
|
return image;
|
|
} // newImageOrSrc is an HTMLImageElement or HTMLCanvasElement or Canvas
|
|
else {
|
|
return newImageOrSrc;
|
|
}
|
|
}
|
|
|
|
function imageOnLoad() {
|
|
var cachedImgObj = this.__cachedImgObj;
|
|
this.onload = this.onerror = this.__cachedImgObj = null;
|
|
|
|
for (var i = 0; i < cachedImgObj.pending.length; i++) {
|
|
var pendingWrap = cachedImgObj.pending[i];
|
|
var cb = pendingWrap.cb;
|
|
cb && cb(this, pendingWrap.cbPayload);
|
|
pendingWrap.hostEl.dirty();
|
|
}
|
|
|
|
cachedImgObj.pending.length = 0;
|
|
}
|
|
|
|
function isImageReady(image) {
|
|
return image && image.width && image.height;
|
|
}
|
|
|
|
exports.findExistImage = findExistImage;
|
|
exports.createOrUpdateImage = createOrUpdateImage;
|
|
exports.isImageReady = isImageReady; |