Public Member Functions

nsIClipboardDragDropHooks Interface Reference

Interfaces for overriding the built-in drag, drop, copy, and paste implementations in the content area and editors. More...

import "nsIClipboardDragDropHooks.idl";

List of all members.

Public Member Functions

boolean allowStartDrag (in nsIDOMEvent event)
 Prevents the drag from starting.
boolean allowDrop (in nsIDOMEvent event, in nsIDragSession session)
 Tells gecko whether a drop is allowed on this content area.
boolean onCopyOrDrag (in nsIDOMEvent aEvent, in nsITransferable trans)
 Alter the flavors or data presented to the OS Used for drag and copy actions Because this can be called many times, it is highly recommended that the implementation be very efficient so user feedback is not negatively impacted.
boolean onPasteOrDrop (in nsIDOMEvent event, in nsITransferable trans)
 Provide an alternative action to the built-in behavior when something is dropped on the browser or in an editor.

Detailed Description

Interfaces for overriding the built-in drag, drop, copy, and paste implementations in the content area and editors.

Use this to do things such as prevent a drag from starting, adding or removing data and flavors, or preventing the drop.

Embedders who want to have these hooks made available should implement nsIClipboardDragDropHooks and use the command manager to send the appropriate commands with these parameters/settings: command: cmd_clipboardDragDropHook

params value type possible values "addhook" isupports nsIClipboardDragDropHooks as nsISupports "removehook" isupports nsIClipboardDragDropHooks as nsISupports

Notes: * Overrides/hooks need to be added to each window (as appropriate). Adding them to the first window does not enable them for every window. * If more than one implementation is set for a window, the hooks will be called in the order they are added. * Adding the same hook to the same window will not add a second call. Each hook can only be called once per user action/api. * Not all hooks are guaranteed to be called. If there are multiple hooks set for a window, any of them has an opportunity to cancel the action so no further processing will occur. * If any errors occur (without setting the boolean result) the default action will occur. * AllowDrop will be called MANY times during drag so ensure that it is efficient.


Member Function Documentation

boolean nsIClipboardDragDropHooks::allowDrop ( in nsIDOMEvent  event,
in nsIDragSession  session 
)

Tells gecko whether a drop is allowed on this content area.

Parameters:
event DOM event (drag over)
session the drag session from which client can get the flavors present or the actual data
Returns:
TRUE indicates to OS that if a drop does happen on this browser, it will be accepted.
FALSE indicates to OS drop is not allowed. On win32, this will change the cursor to "reject".
boolean nsIClipboardDragDropHooks::allowStartDrag ( in nsIDOMEvent  event  ) 

Prevents the drag from starting.

Parameters:
event DOM event (drag gesture)
Returns:
TRUE drag can proceed
FALSE drag is cancelled, does not go to OS
boolean nsIClipboardDragDropHooks::onCopyOrDrag ( in nsIDOMEvent  aEvent,
in nsITransferable  trans 
)

Alter the flavors or data presented to the OS Used for drag and copy actions Because this can be called many times, it is highly recommended that the implementation be very efficient so user feedback is not negatively impacted.

Parameters:
event DOM event (drag drop); null if triggered by copy.
trans the transferable holding the list of flavors and the data for each flavor
Returns:
TRUE copy/drag can proceed
FALSE copy/drag is cancelled, does not go to OS
boolean nsIClipboardDragDropHooks::onPasteOrDrop ( in nsIDOMEvent  event,
in nsITransferable  trans 
)

Provide an alternative action to the built-in behavior when something is dropped on the browser or in an editor.

Parameters:
event DOM event (drag drop); null if triggered by paste.
trans the transferable holding the list of flavors and the data for each flavor
Returns:
TRUE action was handled, do not perform built-in behavior
FALSE action was not overridden, do built-in behavior

The documentation for this interface was generated from the following file: