| import LRU from '../../core/LRU'; |
| var globalImageCache = new LRU(50); |
| /** |
| * @param {string|HTMLImageElement|HTMLCanvasElement|Canvas} newImageOrSrc |
| * @return {HTMLImageElement|HTMLCanvasElement|Canvas} image |
| */ |
| |
| export 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 |
| */ |
| |
| export 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 && (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; |
| } |
| |
| export function isImageReady(image) { |
| return image && image.width && image.height; |
| } |