michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: "use strict";
michael@0: 
michael@0: this.EXPORTED_SYMBOLS = ["LightweightThemeImageOptimizer"];
michael@0: 
michael@0: const Cu = Components.utils;
michael@0: const Ci = Components.interfaces;
michael@0: 
michael@0: Cu.import("resource://gre/modules/XPCOMUtils.jsm");
michael@0: 
michael@0: XPCOMUtils.defineLazyModuleGetter(this, "Services",
michael@0:   "resource://gre/modules/Services.jsm");
michael@0: 
michael@0: XPCOMUtils.defineLazyModuleGetter(this, "FileUtils",
michael@0:   "resource://gre/modules/FileUtils.jsm");
michael@0: 
michael@0: const ORIGIN_TOP_RIGHT = 1;
michael@0: const ORIGIN_BOTTOM_LEFT = 2;
michael@0: 
michael@0: this.LightweightThemeImageOptimizer = {
michael@0:   optimize: function LWTIO_optimize(aThemeData, aScreen) {
michael@0:     let data = Utils.createCopy(aThemeData);
michael@0:     if (!data.headerURL) {
michael@0:       return data;
michael@0:     }
michael@0: 
michael@0:     data.headerURL = ImageCropper.getCroppedImageURL(
michael@0:       data.headerURL, aScreen, ORIGIN_TOP_RIGHT);
michael@0: 
michael@0:     if (data.footerURL) {
michael@0:       data.footerURL = ImageCropper.getCroppedImageURL(
michael@0:         data.footerURL, aScreen, ORIGIN_BOTTOM_LEFT);
michael@0:     }
michael@0: 
michael@0:     return data;
michael@0:   },
michael@0: 
michael@0:   purge: function LWTIO_purge() {
michael@0:     let dir = FileUtils.getDir("ProfD", ["lwtheme"]);
michael@0:     dir.followLinks = false;
michael@0:     try {
michael@0:       dir.remove(true);
michael@0:     } catch (e) {}
michael@0:   }
michael@0: };
michael@0: 
michael@0: Object.freeze(LightweightThemeImageOptimizer);
michael@0: 
michael@0: let ImageCropper = {
michael@0:   _inProgress: {},
michael@0: 
michael@0:   getCroppedImageURL:
michael@0:   function ImageCropper_getCroppedImageURL(aImageURL, aScreen, aOrigin) {
michael@0:     // We can crop local files, only.
michael@0:     if (!aImageURL.startsWith("file://")) {
michael@0:       return aImageURL;
michael@0:     }
michael@0: 
michael@0:     // Generate the cropped image's file name using its
michael@0:     // base name and the current screen size.
michael@0:     let uri = Services.io.newURI(aImageURL, null, null);
michael@0:     let file = uri.QueryInterface(Ci.nsIFileURL).file;
michael@0: 
michael@0:     // Make sure the source file exists.
michael@0:     if (!file.exists()) {
michael@0:       return aImageURL;
michael@0:     }
michael@0: 
michael@0:     let fileName = file.leafName + "-" + aScreen.width + "x" + aScreen.height;
michael@0:     let croppedFile = FileUtils.getFile("ProfD", ["lwtheme", fileName]);
michael@0: 
michael@0:     // If we have a local file that is not in progress, return it.
michael@0:     if (croppedFile.exists() && !(croppedFile.path in this._inProgress)) {
michael@0:       let fileURI = Services.io.newFileURI(croppedFile);
michael@0: 
michael@0:       // Copy the query part to avoid wrong caching.
michael@0:       fileURI.QueryInterface(Ci.nsIURL).query = uri.query;
michael@0:       return fileURI.spec;
michael@0:     }
michael@0: 
michael@0:     // Crop the given image in the background.
michael@0:     this._crop(uri, croppedFile, aScreen, aOrigin);
michael@0: 
michael@0:     // Return the original image while we're waiting for the cropped version
michael@0:     // to be written to disk.
michael@0:     return aImageURL;
michael@0:   },
michael@0: 
michael@0:   _crop: function ImageCropper_crop(aURI, aTargetFile, aScreen, aOrigin) {
michael@0:     let inProgress = this._inProgress;
michael@0:     inProgress[aTargetFile.path] = true;
michael@0: 
michael@0:     function resetInProgress() {
michael@0:       delete inProgress[aTargetFile.path];
michael@0:     }
michael@0: 
michael@0:     ImageFile.read(aURI, function crop_readImageFile(aInputStream, aContentType) {
michael@0:       if (aInputStream && aContentType) {
michael@0:         let image = ImageTools.decode(aInputStream, aContentType);
michael@0:         if (image && image.width && image.height) {
michael@0:           let stream = ImageTools.encode(image, aScreen, aOrigin, aContentType);
michael@0:           if (stream) {
michael@0:             ImageFile.write(aTargetFile, stream, resetInProgress);
michael@0:             return;
michael@0:           }
michael@0:         }
michael@0:       }
michael@0: 
michael@0:       resetInProgress();
michael@0:     });
michael@0:   }
michael@0: };
michael@0: 
michael@0: let ImageFile = {
michael@0:   read: function ImageFile_read(aURI, aCallback) {
michael@0:     this._netUtil.asyncFetch(aURI, function read_asyncFetch(aInputStream, aStatus, aRequest) {
michael@0:       if (Components.isSuccessCode(aStatus) && aRequest instanceof Ci.nsIChannel) {
michael@0:         let channel = aRequest.QueryInterface(Ci.nsIChannel);
michael@0:         aCallback(aInputStream, channel.contentType);
michael@0:       } else {
michael@0:         aCallback();
michael@0:       }
michael@0:     });
michael@0:   },
michael@0: 
michael@0:   write: function ImageFile_write(aFile, aInputStream, aCallback) {
michael@0:     let fos = FileUtils.openSafeFileOutputStream(aFile);
michael@0:     this._netUtil.asyncCopy(aInputStream, fos, function write_asyncCopy(aResult) {
michael@0:       FileUtils.closeSafeFileOutputStream(fos);
michael@0: 
michael@0:       // Remove the file if writing was not successful.
michael@0:       if (!Components.isSuccessCode(aResult)) {
michael@0:         try {
michael@0:           aFile.remove(false);
michael@0:         } catch (e) {}
michael@0:       }
michael@0: 
michael@0:       aCallback();
michael@0:     });
michael@0:   }
michael@0: };
michael@0: 
michael@0: XPCOMUtils.defineLazyModuleGetter(ImageFile, "_netUtil",
michael@0:   "resource://gre/modules/NetUtil.jsm", "NetUtil");
michael@0: 
michael@0: let ImageTools = {
michael@0:   decode: function ImageTools_decode(aInputStream, aContentType) {
michael@0:     let outParam = {value: null};
michael@0: 
michael@0:     try {
michael@0:       this._imgTools.decodeImageData(aInputStream, aContentType, outParam);
michael@0:     } catch (e) {}
michael@0: 
michael@0:     return outParam.value;
michael@0:   },
michael@0: 
michael@0:   encode: function ImageTools_encode(aImage, aScreen, aOrigin, aContentType) {
michael@0:     let stream;
michael@0:     let width = Math.min(aImage.width, aScreen.width);
michael@0:     let height = Math.min(aImage.height, aScreen.height);
michael@0:     let x = aOrigin == ORIGIN_TOP_RIGHT ? aImage.width - width : 0;
michael@0: 
michael@0:     try {
michael@0:       stream = this._imgTools.encodeCroppedImage(aImage, aContentType, x, 0,
michael@0:                                                  width, height);
michael@0:     } catch (e) {}
michael@0: 
michael@0:     return stream;
michael@0:   }
michael@0: };
michael@0: 
michael@0: XPCOMUtils.defineLazyServiceGetter(ImageTools, "_imgTools",
michael@0:   "@mozilla.org/image/tools;1", "imgITools");
michael@0: 
michael@0: let Utils = {
michael@0:   createCopy: function Utils_createCopy(aData) {
michael@0:     let copy = {};
michael@0:     for (let [k, v] in Iterator(aData)) {
michael@0:       copy[k] = v;
michael@0:     }
michael@0:     return copy;
michael@0:   }
michael@0: };