/toolkit/content/nsDragAndDrop.js
http://github.com/zpao/v8monkey · JavaScript · 635 lines · 363 code · 65 blank · 207 comment · 58 complexity · 1f8334d82e61994cb741c5e2e86ebe89 MD5 · raw file
- # -*- Mode: Java; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
- # ***** BEGIN LICENSE BLOCK *****
- # Version: MPL 1.1/GPL 2.0/LGPL 2.1
- #
- # The contents of this file are subject to the Mozilla Public License Version
- # 1.1 (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.mozilla.org/MPL/
- #
- # Software distributed under the License is distributed on an "AS IS" basis,
- # WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
- # for the specific language governing rights and limitations under the
- # License.
- #
- # The Original Code is mozilla.org code.
- #
- # The Initial Developer of the Original Code is
- # Netscape Communications Corporation.
- # Portions created by the Initial Developer are Copyright (C) 1998
- # the Initial Developer. All Rights Reserved.
- #
- # Contributor(s):
- # Ben Goodger <ben@netscape.com> (Original Author)
- # Pierre Chanial <pierrechanial@netscape.net>
- #
- # Alternatively, the contents of this file may be used under the terms of
- # either the GNU General Public License Version 2 or later (the "GPL"), or
- # the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
- # in which case the provisions of the GPL or the LGPL are applicable instead
- # of those above. If you wish to allow use of your version of this file only
- # under the terms of either the GPL or the LGPL, and not to allow others to
- # use your version of this file under the terms of the MPL, indicate your
- # decision by deleting the provisions above and replace them with the notice
- # and other provisions required by the GPL or the LGPL. If you do not delete
- # the provisions above, a recipient may use your version of this file under
- # the terms of any one of the MPL, the GPL or the LGPL.
- #
- # ***** END LICENSE BLOCK *****
- ////////////////////////////////////////////////////////////////////////
- //
- // USE OF THIS API FOR DRAG AND DROP IS DEPRECATED!
- // Do not use this file for new code.
- //
- // For documentation about what to use instead, see:
- // http://developer.mozilla.org/En/DragDrop/Drag_and_Drop
- //
- ////////////////////////////////////////////////////////////////////////
- /**
- * nsTransferable - a wrapper for nsITransferable that simplifies
- * javascript clipboard and drag&drop. for use in
- * these situations you should use the nsClipboard
- * and nsDragAndDrop wrappers for more convenience
- **/
-
- var nsTransferable = {
- /**
- * nsITransferable set (TransferData aTransferData) ;
- *
- * Creates a transferable with data for a list of supported types ("flavours")
- *
- * @param TransferData aTransferData
- * a javascript object in the format described above
- **/
- set: function (aTransferDataSet)
- {
- var trans = this.createTransferable();
- for (var i = 0; i < aTransferDataSet.dataList.length; ++i)
- {
- var currData = aTransferDataSet.dataList[i];
- var currFlavour = currData.flavour.contentType;
- trans.addDataFlavor(currFlavour);
- var supports = null; // nsISupports data
- var length = 0;
- if (currData.flavour.dataIIDKey == "nsISupportsString")
- {
- supports = Components.classes["@mozilla.org/supports-string;1"]
- .createInstance(Components.interfaces.nsISupportsString);
- supports.data = currData.supports;
- length = supports.data.length;
- }
- else
- {
- // non-string data.
- supports = currData.supports;
- length = 0; // kFlavorHasDataProvider
- }
- trans.setTransferData(currFlavour, supports, length * 2);
- }
- return trans;
- },
-
- /**
- * TransferData/TransferDataSet get (FlavourSet aFlavourSet,
- * Function aRetrievalFunc, Boolean aAnyFlag) ;
- *
- * Retrieves data from the transferable provided in aRetrievalFunc, formatted
- * for more convenient access.
- *
- * @param FlavourSet aFlavourSet
- * a FlavourSet object that contains a list of supported flavours.
- * @param Function aRetrievalFunc
- * a reference to a function that returns a nsISupportsArray of nsITransferables
- * for each item from the specified source (clipboard/drag&drop etc)
- * @param Boolean aAnyFlag
- * a flag specifying whether or not a specific flavour is requested. If false,
- * data of the type of the first flavour in the flavourlist parameter is returned,
- * otherwise the best flavour supported will be returned.
- **/
- get: function (aFlavourSet, aRetrievalFunc, aAnyFlag)
- {
- if (!aRetrievalFunc)
- throw "No data retrieval handler provided!";
-
- var supportsArray = aRetrievalFunc(aFlavourSet);
- var dataArray = [];
- var count = supportsArray.Count();
-
- // Iterate over the number of items returned from aRetrievalFunc. For
- // clipboard operations, this is 1, for drag and drop (where multiple
- // items may have been dragged) this could be >1.
- for (var i = 0; i < count; i++)
- {
- var trans = supportsArray.GetElementAt(i);
- if (!trans) continue;
- trans = trans.QueryInterface(Components.interfaces.nsITransferable);
-
- var data = { };
- var length = { };
-
- var currData = null;
- if (aAnyFlag)
- {
- var flavour = { };
- trans.getAnyTransferData(flavour, data, length);
- if (data && flavour)
- {
- var selectedFlavour = aFlavourSet.flavourTable[flavour.value];
- if (selectedFlavour)
- dataArray[i] = FlavourToXfer(data.value, length.value, selectedFlavour);
- }
- }
- else
- {
- var firstFlavour = aFlavourSet.flavours[0];
- trans.getTransferData(firstFlavour, data, length);
- if (data && firstFlavour)
- dataArray[i] = FlavourToXfer(data.value, length.value, firstFlavour);
- }
- }
- return new TransferDataSet(dataArray);
- },
- /**
- * nsITransferable createTransferable (void) ;
- *
- * Creates and returns a transferable object.
- **/
- createTransferable: function ()
- {
- const kXferableContractID = "@mozilla.org/widget/transferable;1";
- const kXferableIID = Components.interfaces.nsITransferable;
- return Components.classes[kXferableContractID].createInstance(kXferableIID);
- }
- };
- /**
- * A FlavourSet is a simple type that represents a collection of Flavour objects.
- * FlavourSet is constructed from an array of Flavours, and stores this list as
- * an array and a hashtable. The rationale for the dual storage is as follows:
- *
- * Array: Ordering is important when adding data flavours to a transferable.
- * Flavours added first are deemed to be 'preferred' by the client.
- * Hash: Convenient lookup of flavour data using the content type (MIME type)
- * of data as a key.
- */
- function FlavourSet(aFlavourList)
- {
- this.flavours = aFlavourList || [];
- this.flavourTable = { };
- this._XferID = "FlavourSet";
-
- for (var i = 0; i < this.flavours.length; ++i)
- this.flavourTable[this.flavours[i].contentType] = this.flavours[i];
- }
- FlavourSet.prototype = {
- appendFlavour: function (aFlavour, aFlavourIIDKey)
- {
- var flavour = new Flavour (aFlavour, aFlavourIIDKey);
- this.flavours.push(flavour);
- this.flavourTable[flavour.contentType] = flavour;
- }
- };
- /**
- * A Flavour is a simple type that represents a data type that can be handled.
- * It takes a content type (MIME type) which is used when storing data on the
- * system clipboard/drag and drop, and an IIDKey (string interface name
- * which is used to QI data to an appropriate form. The default interface is
- * assumed to be wide-string.
- */
- function Flavour(aContentType, aDataIIDKey)
- {
- this.contentType = aContentType;
- this.dataIIDKey = aDataIIDKey || "nsISupportsString";
- this._XferID = "Flavour";
- }
- function TransferDataBase() {}
- TransferDataBase.prototype = {
- push: function (aItems)
- {
- this.dataList.push(aItems);
- },
- get first ()
- {
- return "dataList" in this && this.dataList.length ? this.dataList[0] : null;
- }
- };
- /**
- * TransferDataSet is a list (array) of TransferData objects, which represents
- * data dragged from one or more elements.
- */
- function TransferDataSet(aTransferDataList)
- {
- this.dataList = aTransferDataList || [];
- this._XferID = "TransferDataSet";
- }
- TransferDataSet.prototype = TransferDataBase.prototype;
- /**
- * TransferData is a list (array) of FlavourData for all the applicable content
- * types associated with a drag from a single item.
- */
- function TransferData(aFlavourDataList)
- {
- this.dataList = aFlavourDataList || [];
- this._XferID = "TransferData";
- }
- TransferData.prototype = {
- __proto__: TransferDataBase.prototype,
-
- addDataForFlavour: function (aFlavourString, aData, aLength, aDataIIDKey)
- {
- this.dataList.push(new FlavourData(aData, aLength,
- new Flavour(aFlavourString, aDataIIDKey)));
- }
- };
- /**
- * FlavourData is a type that represents data retrieved from the system
- * clipboard or drag and drop. It is constructed internally by the Transferable
- * using the raw (nsISupports) data from the clipboard, the length of the data,
- * and an object of type Flavour representing the type. Clients implementing
- * IDragDropObserver receive an object of this type in their implementation of
- * onDrop. They access the 'data' property to retrieve data, which is either data
- * QI'ed to a usable form, or unicode string.
- */
- function FlavourData(aData, aLength, aFlavour)
- {
- this.supports = aData;
- this.contentLength = aLength;
- this.flavour = aFlavour || null;
-
- this._XferID = "FlavourData";
- }
- FlavourData.prototype = {
- get data ()
- {
- if (this.flavour &&
- this.flavour.dataIIDKey != "nsISupportsString")
- return this.supports.QueryInterface(Components.interfaces[this.flavour.dataIIDKey]);
- var supports = this.supports;
- if (supports instanceof Components.interfaces.nsISupportsString)
- return supports.data.substring(0, this.contentLength/2);
-
- return supports;
- }
- }
- /**
- * Create a TransferData object with a single FlavourData entry. Used when
- * unwrapping data of a specific flavour from the drag service.
- */
- function FlavourToXfer(aData, aLength, aFlavour)
- {
- return new TransferData([new FlavourData(aData, aLength, aFlavour)]);
- }
- var transferUtils = {
- retrieveURLFromData: function (aData, flavour)
- {
- switch (flavour) {
- case "text/unicode":
- case "text/plain":
- case "text/x-moz-text-internal":
- return aData.replace(/^\s+|\s+$/g, "");
- case "text/x-moz-url":
- return ((aData instanceof Components.interfaces.nsISupportsString) ? aData.toString() : aData).split("\n")[0];
- case "application/x-moz-file":
- var ioService = Components.classes["@mozilla.org/network/io-service;1"]
- .getService(Components.interfaces.nsIIOService);
- var fileHandler = ioService.getProtocolHandler("file")
- .QueryInterface(Components.interfaces.nsIFileProtocolHandler);
- return fileHandler.getURLSpecFromFile(aData);
- }
- return null;
- }
- }
- /**
- * nsDragAndDrop - a convenience wrapper for nsTransferable, nsITransferable
- * and nsIDragService/nsIDragSession.
- *
- * Use: map the handler functions to the 'ondraggesture', 'ondragover' and
- * 'ondragdrop' event handlers on your XML element, e.g.
- * <xmlelement ondraggesture="nsDragAndDrop.startDrag(event, observer);"
- * ondragover="nsDragAndDrop.dragOver(event, observer);"
- * ondragdrop="nsDragAndDrop.drop(event, observer);"/>
- *
- * You need to create an observer js object with the following member
- * functions:
- * Object onDragStart (event) // called when drag initiated,
- * // returns flavour list with data
- * // to stuff into transferable
- * void onDragOver (Object flavour) // called when element is dragged
- * // over, so that it can perform
- * // any drag-over feedback for provided
- * // flavour
- * void onDrop (Object data) // formatted data object dropped.
- * Object getSupportedFlavours () // returns a flavour list so that
- * // nsTransferable can determine
- * // whether or not to accept drop.
- **/
- var nsDragAndDrop = {
-
- _mDS: null,
- get mDragService()
- {
- if (!this._mDS)
- {
- const kDSContractID = "@mozilla.org/widget/dragservice;1";
- const kDSIID = Components.interfaces.nsIDragService;
- this._mDS = Components.classes[kDSContractID].getService(kDSIID);
- }
- return this._mDS;
- },
- /**
- * void startDrag (DOMEvent aEvent, Object aDragDropObserver) ;
- *
- * called when a drag on an element is started.
- *
- * @param DOMEvent aEvent
- * the DOM event fired by the drag init
- * @param Object aDragDropObserver
- * javascript object of format described above that specifies
- * the way in which the element responds to drag events.
- **/
- startDrag: function (aEvent, aDragDropObserver)
- {
- if (!("onDragStart" in aDragDropObserver))
- return;
- const kDSIID = Components.interfaces.nsIDragService;
- var dragAction = { action: kDSIID.DRAGDROP_ACTION_COPY + kDSIID.DRAGDROP_ACTION_MOVE + kDSIID.DRAGDROP_ACTION_LINK };
- var transferData = { data: null };
- try
- {
- aDragDropObserver.onDragStart(aEvent, transferData, dragAction);
- }
- catch (e)
- {
- return; // not a draggable item, bail!
- }
- if (!transferData.data) return;
- transferData = transferData.data;
- var dt = aEvent.dataTransfer;
- var count = 0;
- do {
- var tds = transferData._XferID == "TransferData"
- ? transferData
- : transferData.dataList[count]
- for (var i = 0; i < tds.dataList.length; ++i)
- {
- var currData = tds.dataList[i];
- var currFlavour = currData.flavour.contentType;
- var value = currData.supports;
- if (value instanceof Components.interfaces.nsISupportsString)
- value = value.toString();
- dt.mozSetDataAt(currFlavour, value, count);
- }
- count++;
- }
- while (transferData._XferID == "TransferDataSet" &&
- count < transferData.dataList.length);
- dt.effectAllowed = "all";
- // a drag targeted at a tree should instead use the treechildren so that
- // the current selection is used as the drag feedback
- dt.addElement(aEvent.originalTarget.localName == "treechildren" ?
- aEvent.originalTarget : aEvent.target);
- aEvent.stopPropagation();
- },
- /**
- * void dragOver (DOMEvent aEvent, Object aDragDropObserver) ;
- *
- * called when a drag passes over this element
- *
- * @param DOMEvent aEvent
- * the DOM event fired by passing over the element
- * @param Object aDragDropObserver
- * javascript object of format described above that specifies
- * the way in which the element responds to drag events.
- **/
- dragOver: function (aEvent, aDragDropObserver)
- {
- if (!("onDragOver" in aDragDropObserver))
- return;
- if (!this.checkCanDrop(aEvent, aDragDropObserver))
- return;
- var flavourSet = aDragDropObserver.getSupportedFlavours();
- for (var flavour in flavourSet.flavourTable)
- {
- if (this.mDragSession.isDataFlavorSupported(flavour))
- {
- aDragDropObserver.onDragOver(aEvent,
- flavourSet.flavourTable[flavour],
- this.mDragSession);
- aEvent.stopPropagation();
- aEvent.preventDefault();
- break;
- }
- }
- },
- mDragSession: null,
- /**
- * void drop (DOMEvent aEvent, Object aDragDropObserver) ;
- *
- * called when the user drops on the element
- *
- * @param DOMEvent aEvent
- * the DOM event fired by the drop
- * @param Object aDragDropObserver
- * javascript object of format described above that specifies
- * the way in which the element responds to drag events.
- **/
- drop: function (aEvent, aDragDropObserver)
- {
- if (!("onDrop" in aDragDropObserver))
- return;
- if (!this.checkCanDrop(aEvent, aDragDropObserver))
- return;
- var flavourSet = aDragDropObserver.getSupportedFlavours();
- var dt = aEvent.dataTransfer;
- var dataArray = [];
- var count = dt.mozItemCount;
- for (var i = 0; i < count; ++i) {
- var types = dt.mozTypesAt(i);
- for (var j = 0; j < flavourSet.flavours.length; j++) {
- var type = flavourSet.flavours[j].contentType;
- // dataTransfer uses text/plain but older code used text/unicode, so
- // switch this for compatibility
- var modtype = (type == "text/unicode") ? "text/plain" : type;
- if (Array.indexOf(types, modtype) >= 0) {
- var data = dt.mozGetDataAt(modtype, i);
- if (data) {
- // Non-strings need some non-zero value used for their data length.
- const kNonStringDataLength = 4;
- var length = (typeof data == "string") ? data.length : kNonStringDataLength;
- dataArray[i] = FlavourToXfer(data, length, flavourSet.flavourTable[type]);
- break;
- }
- }
- }
- }
- var transferData = new TransferDataSet(dataArray)
- // hand over to the client to respond to dropped data
- var multiple = "canHandleMultipleItems" in aDragDropObserver && aDragDropObserver.canHandleMultipleItems;
- var dropData = multiple ? transferData : transferData.first.first;
- aDragDropObserver.onDrop(aEvent, dropData, this.mDragSession);
- aEvent.stopPropagation();
- },
- /**
- * void dragExit (DOMEvent aEvent, Object aDragDropObserver) ;
- *
- * called when a drag leaves this element
- *
- * @param DOMEvent aEvent
- * the DOM event fired by leaving the element
- * @param Object aDragDropObserver
- * javascript object of format described above that specifies
- * the way in which the element responds to drag events.
- **/
- dragExit: function (aEvent, aDragDropObserver)
- {
- if (!this.checkCanDrop(aEvent, aDragDropObserver))
- return;
- if ("onDragExit" in aDragDropObserver)
- aDragDropObserver.onDragExit(aEvent, this.mDragSession);
- },
-
- /**
- * void dragEnter (DOMEvent aEvent, Object aDragDropObserver) ;
- *
- * called when a drag enters in this element
- *
- * @param DOMEvent aEvent
- * the DOM event fired by entering in the element
- * @param Object aDragDropObserver
- * javascript object of format described above that specifies
- * the way in which the element responds to drag events.
- **/
- dragEnter: function (aEvent, aDragDropObserver)
- {
- if (!this.checkCanDrop(aEvent, aDragDropObserver))
- return;
- if ("onDragEnter" in aDragDropObserver)
- aDragDropObserver.onDragEnter(aEvent, this.mDragSession);
- },
- /**
- * Boolean checkCanDrop (DOMEvent aEvent, Object aDragDropObserver) ;
- *
- * Sets the canDrop attribute for the drag session.
- * returns false if there is no current drag session.
- *
- * @param DOMEvent aEvent
- * the DOM event fired by the drop
- * @param Object aDragDropObserver
- * javascript object of format described above that specifies
- * the way in which the element responds to drag events.
- **/
- checkCanDrop: function (aEvent, aDragDropObserver)
- {
- if (!this.mDragSession)
- this.mDragSession = this.mDragService.getCurrentSession();
- if (!this.mDragSession)
- return false;
- this.mDragSession.canDrop = this.mDragSession.sourceNode != aEvent.target;
- if ("canDrop" in aDragDropObserver)
- this.mDragSession.canDrop &= aDragDropObserver.canDrop(aEvent, this.mDragSession);
- return true;
- },
- /**
- * Do a security check for drag n' drop. Make sure the source document
- * can load the dragged link.
- *
- * @param DOMEvent aEvent
- * the DOM event fired by leaving the element
- * @param Object aDragDropObserver
- * javascript object of format described above that specifies
- * the way in which the element responds to drag events.
- * @param String aDraggedText
- * the text being dragged
- **/
- dragDropSecurityCheck: function (aEvent, aDragSession, aDraggedText)
- {
- // Strip leading and trailing whitespace, then try to create a
- // URI from the dropped string. If that succeeds, we're
- // dropping a URI and we need to do a security check to make
- // sure the source document can load the dropped URI. We don't
- // so much care about creating the real URI here
- // (i.e. encoding differences etc don't matter), we just want
- // to know if aDraggedText really is a URI.
- aDraggedText = aDraggedText.replace(/^\s*|\s*$/g, '');
- var uri;
- try {
- uri = Components.classes["@mozilla.org/network/io-service;1"]
- .getService(Components.interfaces.nsIIOService)
- .newURI(aDraggedText, null, null);
- } catch (e) {
- }
- if (!uri)
- return;
- // aDraggedText is a URI, do the security check.
- const nsIScriptSecurityManager = Components.interfaces
- .nsIScriptSecurityManager;
- var secMan = Components.classes["@mozilla.org/scriptsecuritymanager;1"]
- .getService(nsIScriptSecurityManager);
- if (!aDragSession)
- aDragSession = this.mDragService.getCurrentSession();
- var sourceDoc = aDragSession.sourceDocument;
- // Use "file:///" as the default sourceURI so that drops of file:// URIs
- // are always allowed.
- var sourceURI = sourceDoc ? sourceDoc.documentURI : "file:///";
- try {
- secMan.checkLoadURIStr(sourceURI, aDraggedText,
- nsIScriptSecurityManager.STANDARD);
- } catch (e) {
- // Stop event propagation right here.
- aEvent.stopPropagation();
- throw "Drop of " + aDraggedText + " denied.";
- }
- }
- };