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Diffstat (limited to 'widget/nsIClipboardDragDropHooks.idl')
| -rw-r--r-- | widget/nsIClipboardDragDropHooks.idl | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/widget/nsIClipboardDragDropHooks.idl b/widget/nsIClipboardDragDropHooks.idl new file mode 100644 index 000000000..0810ff70f --- /dev/null +++ b/widget/nsIClipboardDragDropHooks.idl @@ -0,0 +1,101 @@ +/* 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 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "nsISupports.idl" + +interface nsITransferable; +interface nsIDragSession; +interface nsIDOMEvent; + + +/** + * 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. + */ + + +[scriptable,uuid(e03e6c5e-0d84-4c0b-8739-e6b8d51922de)] +interface nsIClipboardDragDropHooks : nsISupports +{ + /** + * Prevents the drag from starting + * + * @param event DOM event (drag gesture) + * + * @return TRUE drag can proceed + * @return FALSE drag is cancelled, does not go to OS + */ + boolean allowStartDrag(in nsIDOMEvent event); + + /** + * Tells gecko whether a drop is allowed on this content area + * + * @param event DOM event (drag over) + * @param session the drag session from which client can get + * the flavors present or the actual data + * + * @return TRUE indicates to OS that if a drop does happen on this + * browser, it will be accepted. + * @return FALSE indicates to OS drop is not allowed. On win32, this + * will change the cursor to "reject". + */ + boolean allowDrop(in nsIDOMEvent event, in nsIDragSession session); + + /** + * 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. + * + * @param event DOM event (drag drop); null if triggered by copy. + * @param trans the transferable holding the list of flavors + * and the data for each flavor + * + * @return TRUE copy/drag can proceed + * @return FALSE copy/drag is cancelled, does not go to OS + */ + boolean onCopyOrDrag(in nsIDOMEvent aEvent, in nsITransferable trans); + + /** + * Provide an alternative action to the built-in behavior when + * something is dropped on the browser or in an editor + * + * @param event DOM event (drag drop); null if triggered by paste. + * @param trans the transferable holding the list of flavors + * and the data for each flavor + * + * @return TRUE action was handled, do not perform built-in + * behavior + * @return FALSE action was not overridden, do built-in behavior + */ + boolean onPasteOrDrop(in nsIDOMEvent event, in nsITransferable trans); +}; + |