如何编写firefox插件_火狐插件怎么写

                
javascript.options.showInConsole = true //把 JavaScript 的出错信息显示在错误控制台
nglayout.debug.disable_xul_cache = true //禁用 XUL 缓存，使得对窗口和对话框的修改不需要重新加载 XUL 文件
browser.dom.window.dump.enabled  = true //允许使用 dump() 语句向标准控制台输出信息
javascript.options.strict        = true //在错误控制台中启用严格的 JavaScript 警告信息

                
<?xml version="1.0"?>
<?xml-stylesheet href="chrome://global/skin/" type="text/css"?>
<window
  id="batchimagesdownloader-mainwindow" title="Batch Images Downloader"
  orient="horizontal" οnlοad="mainWindowOnLoad();"
  xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
  <vbox flex="1">
    <vbox flex="1">
      <label value="Images on this web page:" />
      <spacer style="height: 5px"/>
      <hbox height="500" width="750" style="overflow:auto;">
        <grid>
          <columns>
            <column/>
            <column/>
            <column/>
          </columns>
          <rows id="imagesContainer"></rows> <!-- 显示图片的表格 -->
        </grid>
      </hbox>
    </vbox>
    <spacer style="height: 10px"/>
    <hbox>
      <spacer flex="1"/>
      <button id="mainWindow-add-button" label="OK" default="true" 
	    oncommand="download();"/>
      <button id="mainWindow-cancel-button" label="Cancel" oncommand="close();"/>
    </hbox>
    <spacer style="height: 5px"/>
  </vbox>
</window>

                
<menupopup id="menu_ToolsPopup">
  <menuitem id="batchimagesdownloader-show" label="Batch Images Downloader" 
              oncommand="BatchImagesDownloader.show(event);"/>
</menupopup>

                
var BatchImagesDownloader = {
  show : function() {
    var doc = window.getBrowser().selectedBrowser.contentDocument;
    var imageNodes = doc.getElementsByTagName("img"); //获取所有的 img 节点
    var params = {"imageNodes" : imageNodes};
    this.openWindow("BatchImagesDownloader.mainWindow", 
	  "chrome://batchimagesdownloader/content/mainWindow.xul", 
	  "chrome=yes,centerscreen", params);
  },
  
  //打开一个新的窗口，或是使得已经创建的窗口获得焦点
  openWindow : function(windowName, url, flags, params) {
    var windowsMediator = Components.classes["@mozilla.org/appshell/window-mediator;1"]
	  .getService(Components.interfaces.nsIWindowMediator);
    var aWindow = windowsMediator.getMostRecentWindow(windowName);
    if (aWindow) { 
      aWindow.focus();
    }	  
    else {
      aWindow = window.openDialog(url, windowName, flags, params);
    }
    return aWindow;
  }
};

                
const COLUMNS_PER_ROW = 3;	//每行显示3张图片
function mainWindowOnLoad() {
  var params = window.arguments[0];
  var imageNodes = params.imageNodes;
  displayImages(imageNodes);
}

function displayImages(imageNodes) {
  imageNodes = imageNodes || [];
  var cols = COLUMNS_PER_ROW, row, image, hbox, checkbox;
  var rows = document.getElementById("imagesContainer");
  for (var i = 0, n = imageNodes.length; i < n; i++) {
    var imageNode = imageNodes[i];
    var imageSrc = imageNode.getAttribute("src");
    if (imageSrc == "") {
      continue;
    }
    if (cols >= COLUMNS_PER_ROW) {
      row = document.createElementNS(XUL_NS, "row"); //开始新的一行
      row.setAttribute("align", "center");
      rows.appendChild(row);
      cols = 0;
    }
    else {
      hbox = document.createElementNS(XUL_NS, "hbox");
      hbox.setAttribute("style", "padding:5px 5px 5px 5px;");
      image = document.createElementNS(XUL_NS, "image");//创建 XUL 图像元素来显示图片
      image.setAttribute("src", imageSrc);
      checkbox = document.createElementNS(XUL_NS, "checkbox");//创建 XUL 复选框元素以供用户选择
      checkbox.setAttribute("imageUrl", imageSrc);
      hbox.appendChild(checkbox);
      hbox.appendChild(image);
      row.appendChild(hbox);
      cols++;
    }
  }
}

                
<hbox>
  <label value="Save images to" />
  <textbox id="mainWindow-save-path" readonly="true" style="min-width: 15em;" flex="1"/>
  <button label="Browse..." oncommand="selectSaveDirectory();"/>
</hbox>
<spacer style="height: 10px"/>
<progressmeter mode="determined" id="downloadProgress" 
  value="0" style="visibility:hidden;"/>

                
var saveDirectory = getDefaultSaveDirectory();
function selectSaveDirectory() {
  const nsIFilePicker = Components.interfaces.nsIFilePicker;
  var fp = Components.classes["@mozilla.org/filepicker;1"].createInstance(nsIFilePicker);
  fp.init(window, "", nsIFilePicker.modeGetFolder);
  var result = fp.show(); //显示目录选择对话框
  if (result == nsIFilePicker.returnOK) {
    var file = fp.file;
    saveDirectory = file;
    byId("mainWindow-save-path").value = file.path;//把目录的路径显示在文本框中
  }
}
	
//获得默认的图片保存目录，也就是当前用户的根目录
function getDefaultSaveDirectory() {
  var file = Components.classes["@mozilla.org/file/directory_service;1"]
                .getService(Components.interfaces.nsIProperties)
                .get("Home", Components.interfaces.nsIFile);
  return file;
}

                
function downloadSingleImage(uri, callback) {
  var ios = Components.classes["@mozilla.org/network/io-service;1"]
              .getService(Components.interfaces.nsIIOService);
  var imageURI = ios.newURI(uri, null, null); //创建图像的 URI
  var imageFileName = uri.substring(uri.lastIndexOf("/") + 1);
  var channel = ios.newChannelFromURI(imageURI);  //创建读取 URI 指定的数据流的通道
  var observer = {
    onStreamComplete : function(loader, context, status, length, result) {
      var file = Components.classes["@mozilla.org/file/local;1"]
                    .createInstance(Components.interfaces.nsILocalFile);
      file.initWithFile(saveDirectory);  //图片保存的目录
      file.appendRelativePath(imageFileName);
      var stream = Components.classes["@mozilla.org/network/safe-file-output-stream;1"]
                     .createInstance(Components.interfaces.nsIFileOutputStream);
      stream.init(file, -1, -1, 0);
      var bstream = Components.classes["@mozilla.org/binaryoutputstream;1"]
                      .createInstance(Components.interfaces.nsIBinaryOutputStream);
      bstream.setOutputStream(stream);        
      bstream.writeByteArray(result, length); //把图片流的全部字节写入输出文件流中
      if (stream instanceof Components.interfaces.nsISafeOutputStream) {
        stream.finish();
      } 
      else {
        stream.close();
      }
      if (typeof callback == "function") {
        callback();
      }
    }
  };
  var streamLoader = Components.classes["@mozilla.org/network/stream-loader;1"]
             .createInstance(Components.interfaces.nsIStreamLoader);
  streamLoader.init(channel, observer, null);
}

                
function download() {
  var rows = document.getElementById("imagesContainer");
  var checkboxes = rows.getElementsByTagName("checkbox");
  var imageUrls = [];
  for (var i = 0, n = checkboxes.length; i < n; i++) {
    if (checkboxes[i].checked) {
      imageUrls.push(checkboxes[i].getAttribute("imageUrl")); //用户选择的图片的 URL
    }
  }
  var progressmeter = byId("downloadProgress");
  progressmeter.style.visibility = "visible";
  var total = imageUrls.length, step = 100 / total, current = 0;
  for (var i = 0; i < total; i++) {
    downloadSingleImage(imageUrls[i], function() {
      var value = parseInt(progressmeter.value); //更新进度条
      progressmeter.value = value + step;
    });
  }
  close();
}