Common methods for objects

Implementation of the Drag-and-Drop feature

The implementation of the Drag-and-Drop features allow user to extend this ability to remove data in same window or another one . The action of holding a mouse button down and moving a control is called Dragging, and the action of releasing the button is called dropping .

Let exist dialog. It contain TREE  and LISTBOX objects. We'll remove element of the TREE object to the object LISTBOX.

PIC. 1

In order that object LISTBOX react to Darg-and-Drop  operation it's necessary set relation between interface objects. Action Drag for object TREE is named, for example "111", and action Drop for object LISTBOX   we assign the same name. Each object can execute action Drag with one name only, but take action Drop from several different named objects.

In moment Drag-and-Drop operation generate following events:
OnDrop              - Drag the selection over a valid drop target and release the mouse.
OnDragHover - Drag the selection over a valid drop target.
OnDragMove  - Drag the selected text or object.
OnDragLeave - Drag the selection over a valid drop target, and then move that selection out again without dropping it.

Data formed on event represent on the pucture 2.

fig.2

RETURNS DYNAMIC array:

ID	Description	For what events fill
1	dialog (screen) name	for all
2	object name	for all
3	message type 50 message from screen objects 51 message from dialog objects	for all
4	dialog identifier	for all
5	object identifier in dialog	for all
6	message name	for all
7	Drop-action name	for all
	object element description, above which there was an event
8,1	number	except OnDragLeave
8,2	text	except OnDragLeave
9	flag, Whence event has come: D - dialog, S - screen	except OnDragLeave
10	sourse dialog identifier	except OnDragLeave
11	object identifier in sourse dialog	except OnDragLeave
12	X- coordinate of the point from which the selection is dragged	except OnDragLeave
13	Y-coordinate of the point  whether the selection being dragged is over the drag source	except OnDragLeave
14	window identifier value (hwnd)	except OnDragLeave
	object element description, which moves
15,1	element number	for all
15,2	text	for all

Methods

SetDragName	Sets name of a Drag-action
SetDropName	Sets name of a Drop-action
AddDropName	Adds Drop-action name
DeleteDropName	Deletes Drop-action name
SetDropDelay	Sets value of the time interval after what event OnDragHover begin
SetDropScrollInterval	Sets interval value of the scrolling  object window.
SetDropScrollMargin	Sets space value from the top and bottom window border

Common methods description