Name: dragEnd

Type: message

Syntax: dragEnd

Summary:

Sent to the <object(glossary)> a <drag and drop> started from, when the

data is dropped.

Introduced: 2.0

Associations: field, button, graphic, scrollbar, player, image

OS: mac, windows, linux

Platforms: desktop, server

Example:

on dragEnd -- remove data being dragged

delete the dragSource

end dragEnd

Description:

Handle the <dragEnd> <message> to perform an action when the user drops

data, or <trap> the <message> to prevent text from being deleted from a

<field(keyword)> when it's dragged to another <field(keyword)>.

The <dragEnd> <message> is sent to the <control> that the drag started

from. If the data is not dropped onto a <control> that accepts it, the

<dragEnd> <message> is still sent.

LiveCode automatically handles the mechanics of dragging and dropping

text between and within unlocked fields. To support this type of drag

and drop operation, you don't need to do any scripting: the text is

deleted from the source field automatically when LiveCode receives the

<dragEnd> <message>.

To prevent the dragged text from being automatically deleted from the

source field when it's dropped onto another unlocked field, trap the

<dragEnd> <message>. If you don't want text from a particular

<field(keyword)> to be deleted after dragging, place a <dragEnd>

<handler> in the <field(keyword)> that does not contain a <pass>

<control structure>:

on dragEnd -- in script of field or one of its owners

-- do nothing, but trap the message

end dragEnd

On the other hand, if you want to perform some action when text is

dragged from an unlocked field and then dropped, you need to pass the

<dragEnd> <message> once you're done with it in order to allow the

deletion to take place:

on dragEnd

set the textColor of me to "gray"

pass dragEnd -- needed for text removal to occur

end dragEnd

To make changes to the original data in a locked field or a control

other than a field when a drop is completed, handle the <dragEnd>

message. For these objects, if you want the dragged data to be removed

(or changed), your <dragEnd> <handler> must delete the dragged text from

the source <object(glossary)> (or perform whatever action you want to do

on a drop); the behavior is not automated as it is for <unlock|unlocked>

<field(object)|fields>.

References: pass (control structure), dragSource (function),

dragDestination (function), object (glossary), handler (glossary),

message (glossary), unlock (glossary), control structure (glossary),

drag and drop (glossary), control (glossary), trap (glossary),

field (keyword), dragEnd (message), dragDrop (message),

mouseRelease (message), field (object), dragImage (property),

acceptDrop (property)

Tags: ui