Class: DropTarget

• Inheritance
• Description
• Class protocol
  • instance creation
• Instance protocol
  • accessing
  • actions
  • instance creation
  • private
  • queries

Inheritance:

   Object
   |
   +--DropTarget

Package:

stx:libview2

Category:

Interface-DragAndDrop

Version:

rev: 1.13 date: 2021/01/20 13:12:43

user: cg

file: DropTarget.st directory: libview2

module: stx stc-classLibrary: libview2

Description:

this class keeps the current target of the drop operation; 
the object responsible for the widget under the current mouse position.
Usually a dropTarget object is created by the D&D manager automatically,
but a view may redefine the dropTarget method (or set its dropTarget instVar),
to provide a customized droptarget (with different selectors).

receiver        <Object>        receiver to which the requests are sent. 
                                The widget or an application.

argument        <Object>        user defined argument

enterSelector   <Symbol>        sent the first time to the drop target when entering
                                the widget. Nil, when defaulted from D&D manager.

leaveSelector   <Symbol>        sent the last time to the drop target when leaving
                                the widget. Nil, when defaulted from D&D manager.

overSelector    <Symbol>        sent all the time to the drop target when moveing the
                                mouse over the widget. Nil, when defaulted from D&D manager.

dropSelector    <Symbol>        sent to the drop target to drop the collection of
                                objects. #drop: when defaulted from D&D manager.

canDropSelector <Symbol>        sent to the drop target to ask if the context could
                                be dropped. #canDrop: when defaulted from D&D manager.

copyright
COPYRIGHT (c) 1998 by eXept Software AG / Claus Gittinger
             All Rights Reserved

This software is furnished under a license and may be used
only in accordance with the terms of that license and with the
inclusion of the above copyright notice.   This software may not
be provided or otherwise made available to, or used by, any
other person.  No title to or ownership of the software is
hereby transferred.

Class protocol:

 receiver: aReceiver

 receiver: aReceiver argument: anArgument

 receiver: aReceiver argument: anArgument dropSelector: aSelector

 receiver: aReceiver argument: anArgument dropSelector: s1 canDropSelector: s2

Instance protocol:

 argument

returns the user defined argument; this argument is used for a drop action
with two arguments, the context and the argument

 argument: something

set the user defined argument; this argument is passed for a drop action
with two arguments, the context and the argument

 canDropSelector

selector called to get a feedback if context is droppable.
the arguments to the selector are:
0 nothing
1 aDropContext
2 aDropContext and the argument

 canDropSelector: aSelectorOrNil

selector called to get a feedback if context is droppable.
the arguments to the selector are:
0 nothing
1 aDropContext
2 aDropContext and the argument

 dropSelector

return the selector of the message which is sent to the drop target
when the objects are to be dropped (i.e. when the mouse button is released).

Depending on the number of arguments of the selector,
the arguments of the message are:
0 nothing
1 aDropContext
2 aDropContext and the argument

 dropSelector: aSelectorOrNil

specify the selector of the message which is sent to the drop target
when the objects are to be dropped (i.e. when the mouse button is released).

Depending on the number of arguments of the selector,
the arguments of the message are:
0 nothing
1 aDropContext
2 aDropContext and the argument

 enterSelector

return the selector of the message which is sent to the drop target
when entering the widget for the first time.

Depending on the number of arguments of the selector,
the arguments of the message are:
0 nothing
1 aDropContext
2 aDropContext and the argument

 enterSelector: aSelectorOrNil

specify the selector of the message which is sent to the drop target
when entering the widget for the first time.

Depending on the number of arguments of the selector,
the arguments of the message are:
0 nothing
1 aDropContext
2 aDropContext and the argument

 keyPressSelector

return the selector of the message which is sent to the drop target
when a key is pressed during the drag operation.
By default, keyboard input is ignored,
(except for escape, shift, cmd, ctrl etc., which are handled by the d&d manager).
Apps which want to react on keypress, must return a dropTarget with the
keyPressSelector set.

 keyPressSelector: aSelectorOrNil

set the selector of the message which is sent to the drop target
when a key is pressed during the drag operation.
By default, keyboard input is ignored,
(except for escape, shift, cmd, ctrl etc., which are handled by the d&d manager).
Apps which want to react on keypress, must return a dropTarget with the
keyPressSelector set.

 leaveSelector

return the selector of the message which is sent to the drop target
when leaving the widget.

Depending on the number of arguments of the selector,
the arguments of the message are:
0 nothing
1 aDropContext
2 aDropContext and the argument

 leaveSelector: aSelectorOrNil

specify the selector of the message which is sent to the drop target
when leaving the widget.

Depending on the number of arguments of the selector,
the arguments of the message are:
0 nothing
1 aDropContext
2 aDropContext and the argument

 oldDropAPI: aBoolean

for backward compatibility

 overSelector

send all the time to the drop target when moveing the mouse over the widget

Depending on the number of arguments of the selector,
the arguments of the message are:
0 nothing
1 aDropContext
2 aDropContext and the argument

 overSelector: aSelectorOrNil

specify the selector of the message which is sent to the drop target
when the mouse is moved over the widget.

Depending on the number of arguments of the selector,
the arguments of the message are:
0 nothing
1 aDropContext
2 aDropContext and the argument

 receiver

returns the receiver to which the requests are sent: a widget or an application.

 receiver: viewOrApp

define the receiver to which the requests are sent.
The argument is a widget or an application.

 drop: aDropContext

sent, when the mouse button is released within the current widget.
Forwarded via dropSelector to the receiver

 enter: aContext

sent, when entering a widget.
Forwarded via enterSelector (unless nil) to the receiver

 keyPress: aContext key: aKey

sent, whenever a key is pressed while over a widget.
Forwarded via dropKeyPressSelector (unless nil) to the receiver

 leave: aContext

sent, when leaving a widget.
Forwarded via leaveSelector (unless nil) to the receiver

 over: aContext

sent, whenever the mouse is moved over a widget.
Forwarded via overSelector (unless nil) to the receiver

 receiver: aReceiver argument: anArgument

set the receiver and a user defined argument

 receiver: aReceiver argument: anArgument dropSelector: s1 canDropSelector: s2

set the receiver and a user defined argument

 receiverPerform: aSelector withContext: aContext

let the receiver perform the selector

** This is an obsolete interface - do not use it (it may vanish in future versions) **

 canDrop: aDropContext

sent to the receiver to ask if the context is droppable