4D Doc Center : SET DRAG ICON

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4D v14.3

SET DRAG ICON


SET DRAG ICON ( icon {; horOffset {; vertOffset}} )

Parameter	Type	Description
icon	Picture	Icon to use during drag
horOffset	Longint	Horizontal offset from left edge of picture with respect to cursor position (>0 = to the left, <0 = to the right)
vertOffset	Longint	Vertical offset from top edge of picture with respect to cursor position (>0 = upwards, <0 = downwards)

Description

The SET DRAG ICON command associates the icon picture with the cursor during drag and drop operations that are managed by programming.

This command can only be called in the context of the On Begin Drag Over form event (see the Form event command).

In the icon parameter, pass the picture to use. Its maximum size is 256x256 pixels. If one of its dimensions exceeds 256 pixels, it is automatically resized.

In horOffset and vertOffset, you can pass offset values in pixels:

for horOffset, you pass the horizontal offset from the left edge of the icon with respect to the cursor position. Pass a positive value to apply this offset towards the left or a negative value to apply it towards the right.
for vertOffset, you pass the vertical offset from the top edge of the icon with respect to the cursor position. Pass a positive value to apply this offset upwards or a negative value to apply it downwards.

If you omit this parameter, the cursor is placed at the center of the icon.

Example

In a form, a user can generate a label by dragging and dropping a row. In the object method of the list box, you can write:

 If(Form event=On Begin Drag Over)

    READ PICTURE FILE(Get 4D folder(Current resources folder)+"splash.png";vpict)

    CREATE THUMBNAIL(vpict;vpict;48;48)

    SET DRAG ICON(vpict)

 End if

When you drag a row, the picture appears as shown here:

Note that you can modify the position of the cursor with respect to the picture:

SET DRAG ICON(vpict;0;0)