Class: DropContext

• Inheritance
• Description
• Related information
• Class protocol
  • constants
• Instance protocol
  • accessing
  • accessing-source
  • accessing-target
  • actions
  • change & update
  • drag & drop manager interface
  • queries
• Private classes

Inheritance:

   Object
   |
   +--DropContext

Package:

stx:libview2

Category:

Interface-DragAndDrop

Version:

rev: 1.20 date: 2018/06/15 00:48:47

user: cg

file: DropContext.st directory: libview2

module: stx stc-classLibrary: libview2

Author:

Claus Atzkern

Description:

instance, which keeps information about the current drag & drop operation.

dropObjects         <Collection>    collection of dropObjects.
rootPoint           <Point>         the current mouse position on the screen (root view).

Related information:

    DragAndDropManager
    DropObject
    DropSource
    DropTarget

Class protocol:

 dragTypeCopy

 dragTypeDefault

 dragTypeLink

 dragTypeMove

Instance protocol:

 dragHandler

 dragHandler: aHandler

 dragType

the type of drag - modified by pressing one of Shift, Ctrl or Alt

 dragType: aSymbol

the type of drag - modified by pressing one of Shift, Ctrl or Alt

 dropInfo

a hook for additional info

 dropObjects

returns the collection of dropobjects

 manager: something

 rootPoint

returns the absolute point on the screen (rootPoint)

 dropSource

returns the drop source or nil

 sourceWidget

returns the source widget the drag is started from

 dropTarget

returns the drop target or nil

 targetId

returns the id of the target widget

 targetPoint

returns the point on the target widget (in LOGICAL coordinates)

usage example(s):

the targetPoint is in LOGICAL coordinates NOT in device coordinates

 targetPointInDeviceCoordinates

returns the point on the target widget (in DEVICE coordinates)

 targetWidget

returns the widget assigned to the current dropTarget

 doDrop

evaluate the drop operation; set the feedBack

 exchangeDragHandler: aHandler

make the new handler to the active handler

 passiveAction: aBlock

 saveDraw: aBlock

evaluate aBlock with the drag temporarily being undrawn
(i.e. restore original picture, evaluate the block, and draw dragged objects again).
Return blocks value.

 contentsWillChange

called by the dropTarget-widget if the contents will change during a
dragAndDrop operation

 dropObjects: something

set the collection of dropobjects

 dropSource: aDropSource

set the dropSource

 dropTarget: aDropTargetOrNil

set a new drop target

 rootPoint: something

set the absolute point on the screen (rootPoint);
called by the drag and drop manager

 sourceWidget: aView

set the source widget the drag is started from

 targetWidget: aViewOrNil id: anId

set a new drop widget

 canDrop

returns true if the current dropTarget can drop the objects

 clearHasDroppedFlagToSuppressFeedBack

can be used from within a targets drop code,
to signal that no feedBack should be send to the
dropSource (because the drop did not happen)

 hasDropped

 isAlienView

returns true if current dropTarget is not an ST/X view

 isRootView

returns true if the current target widget is the root view (screen)

Private classes:

    DragType
    DragTypeCopy
    DragTypeLink
    DragTypeMove