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/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
////////////////////////////////////////////////////////////////////////
//
// 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:
//
////////////////////////////////////////////////////////////////////////
/**
* 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 = Cc["@mozilla.org/supports-string;1"]
.createInstance(Ci.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 nsIArray 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 array = aRetrievalFunc(aFlavourSet);
var dataArray = [];
// 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 (let i = 0; i < array.length; i++)
{
let trans = array.queryElementAt(i, Ci.nsITransferable);
if (!trans)
continue;
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 = Ci.nsITransferable;
var trans = Cc[kXferableContractID].createInstance(kXferableIID);
trans.init(null);
return trans;
}
};
/**
* 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(Ci[this.flavour.dataIIDKey]);
var supports = this.supports;
if (supports instanceof Ci.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 Ci.nsISupportsString) ? aData.toString() : aData).split("\n")[0];
case "application/x-moz-file":
var fileHandler = Services.io.getProtocolHandler("file")
.QueryInterface(Ci.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 = Ci.nsIDragService;
this._mDS = Cc[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 = Ci.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 Ci.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.from(types).includes(modtype)) {
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 = Services.io.newURI(aDraggedText);
} catch (e) {
}
if (!uri)
return;
// aDraggedText is a URI, do the security check.
let secMan = Services.scriptSecurityManager;
if (!aDragSession)
aDragSession = this.mDragService.getCurrentSession();
var sourceDoc = aDragSession.sourceDocument;
// are always allowed.
var principal = sourceDoc ? sourceDoc.nodePrincipal
try {
secMan.checkLoadURIStrWithPrincipal(principal, aDraggedText,
Ci.nsIScriptSecurityManager.STANDARD);
} catch (e) {
// Stop event propagation right here.
aEvent.stopPropagation();
throw "Drop of " + aDraggedText + " denied.";
}
}
};