[mobile] add missed source

apps/common/mobile/utils/CThumbnailLoader.js

@@ -0,0 +1,98 @@
+
+class CThumbnailLoader {
+    constructor() {
+        this.binaryFormat = null;
+        this.data = null;
+        this.width = 0;
+        this.heightOne = 0;
+    }
+
+    load(url, callback) {
+        if (!callback)
+            return;
+
+        let xhr = new XMLHttpRequest();
+        xhr.open('GET', url + ".bin", true);
+        xhr.responseType = 'arraybuffer';
+
+        if (xhr.overrideMimeType)
+            xhr.overrideMimeType('text/plain; charset=x-user-defined');
+        else xhr.setRequestHeader('Accept-Charset', 'x-user-defined');
+
+        xhr.onload = e => {
+            // TODO: check errors
+            this.binaryFormat = e.target.response;
+            callback();
+        };
+
+        xhr.send(null);
+    }
+
+    #openBinary(arrayBuffer) {
+        //var t1 = performance.now();
+
+        const binaryAlpha = new Uint8Array(arrayBuffer);
+        this.width      = (binaryAlpha[0] << 24) | (binaryAlpha[1] << 16) | (binaryAlpha[2] << 8) | (binaryAlpha[3] << 0);
+        this.heightOne  = (binaryAlpha[4] << 24) | (binaryAlpha[5] << 16) | (binaryAlpha[6] << 8) | (binaryAlpha[7] << 0);
+        const count     = (binaryAlpha[8] << 24) | (binaryAlpha[9] << 16) | (binaryAlpha[10] << 8) | (binaryAlpha[11] << 0);
+        const height    = count * this.heightOne;
+
+        this.data = new Uint8ClampedArray(4 * this.width * height);
+
+        var binaryIndex = 12;
+        var imagePixels = this.data;
+        var index = 0;
+
+        var len0 = 0;
+        var tmpValue = 0;
+        while (binaryIndex < binaryAlpha.length) {
+            tmpValue = binaryAlpha[binaryIndex++];
+            if (0 == tmpValue) {
+                len0 = binaryAlpha[binaryIndex++];
+                while (len0 > 0) {
+                    len0--;
+                    imagePixels[index] = imagePixels[index + 1] = imagePixels[index + 2] = 255;
+                    imagePixels[index + 3] = 0; // this value is already 0.
+                    index += 4;
+                }
+            } else {
+                imagePixels[index] = imagePixels[index + 1] = imagePixels[index + 2] = 255 - tmpValue;
+                imagePixels[index + 3] = tmpValue;
+                index += 4;
+            }
+        }
+
+        //var t2 = performance.now();
+        //console.log(t2 - t1);
+    };
+
+    getImage = function(index, canvas, ctx) {
+        //var t1 = performance.now();
+        if (!canvas) {
+            canvas = document.createElement("canvas");
+            canvas.width = this.width;
+            canvas.height = this.heightOne;
+            canvas.style.width = iconWidth + "px";
+            canvas.style.height = iconHeight + "px";
+
+            ctx = canvas.getContext("2d");
+        }
+
+        if (!this.data) {
+            this.#openBinary(this.binaryFormat);
+            delete this.binaryFormat;
+        }
+
+        let dataTmp = ctx.createImageData(this.width, this.heightOne);
+        const sizeImage = 4 * this.width * this.heightOne;
+        dataTmp.data.set(new Uint8ClampedArray(this.data.buffer, index * sizeImage, sizeImage));
+        ctx.putImageData(dataTmp, 0, 0);
+
+        //var t2 = performance.now();
+        //console.log(t2 - t1);
+
+        return canvas;
+    };
+};
+
+export default CThumbnailLoader;