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+/**
+ * Copyright 2009 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS-IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import("blob");
+
+jimport("java.awt.image.BufferedImage");
+jimport("org.apache.sanselan.Sanselan");
+jimport("org.apache.sanselan.ImageFormat");
+
+if (java.lang.System.getProperty("java.awt.headless") == null) {
+ // If the system property isn't set either way, then default to "headless" mode,
+ // so that we don't start calling the window manager when the AWT classes
+ // are loaded. For example, on OS X the java process is given a Dock icon
+ // when we create our first BufferedImage.
+ java.lang.System.setProperty("java.awt.headless", "true");
+}
+
+/**
+ * Encodes the given pixel data into an image blob, ready to be served to
+ * the client. Pixels are specified as 32-bit ints in the format AARRGGBB,
+ * and the order is across rows first, then down columns. If useTransparency
+ * is true, then all pixels should have an alpha channel as their
+ * most-significant byte, with 0xff being fully opaque. If useTransparency
+ * is false, all pixels are fully opaque and the high byte is ignored.
+ * Supported formats: GIF.
+ * <p>
+ * For example, to create a GIF image consisting of a green pixel followed
+ * by a transparent pixel to the right of it, use:
+ * imageBlobFromPixels(2, 1, [0xff00ff00, 0x00000000], true, "gif")
+ */
+
+function pixelsToImageBlob(width, height, pixelArrayARGB, useTransparency, format) {
+ var image = _makeBufferedImage(width, height);
+ var array = _makePixelArray(width, height);
+ var alphaMask = (useTransparency ? 0x00000000 : 0xff000000);
+
+ for(var i=0; i<array.length; i++) {
+ // bitwise operations cause a JS number to become a signed 32-bit int
+ array[i] = (pixelArrayARGB[i] | alphaMask);
+ }
+
+ _setImagePixels(image, array);
+
+ if (format.toLowerCase() == "gif") {
+ return _bufferedImage2gifBlob(image);
+ }
+ return null;
+}
+
+/**
+ * Creates a blob of image data in a format readable by a web browser
+ * that consists of a solid, opaque color and has the given width
+ * and height. The sixHexDigits must be a number, such as
+ * 0x12fda3, or a string, such as "12fda3".
+ */
+function solidColorImageBlob(width, height, sixHexDigits) {
+ var image = _makeBufferedImage(width, height);
+ var array = _makePixelArray(width, height);
+
+ var pixel = 0xffffff;
+ if ((typeof sixHexDigits) == "number") {
+ pixel = sixHexDigits;
+ }
+ else if ((typeof sixHexDigits) == "string") {
+ pixel = Number("0x"+sixHexDigits);
+ }
+
+ // bitwise operations cause a JS number to become a signed 32-bit int
+ pixel = ((pixel & 0xffffff) | 0xff000000);
+
+ java.util.Arrays.fill(array, pixel);
+ _setImagePixels(image, array);
+
+ return _bufferedImage2gifBlob(image);
+}
+
+function _makeBufferedImage(width, height) {
+ return new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
+}
+
+function _makePixelArray(width, height) {
+ return java.lang.reflect.Array.newInstance(java.lang.Integer.TYPE,
+ width*height);
+}
+
+function _setImagePixels(image, array) {
+ var width = image.getWidth();
+ var height = image.getHeight();
+
+ image.setRGB(0, 0, width, height, array, 0, width);
+}
+
+function _bufferedImage2gifBlob(image) {
+ // Use the Apache Sanselan image library because it nails transparent GIFs.
+ var bytes = Sanselan.writeImageToBytes(image, ImageFormat.IMAGE_FORMAT_GIF, null);
+ return blob.byteArrayToBlob("image/gif", bytes);
+}