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DragGadget()

USAGE

void DragGadget(Window, DragInfo)

FUNCTION

This lets you take a normal Intuition BOOLGADGET style Gadget and drag it to a new location. The Gadget must be rendered with Intuition Image structure, because it is the Image that will be dragged.

There are several options to dragging the Gadget:

• You can specify a bounding box to move within. Bounding boxes may overlap since the hit box is only the Gadget itself.
• You can specify that Gadget only be displayed in one window, or that it can move across windows. This allows the user to select an item in one window and move it to another. Ofcourse, the Gadget is not suddenly transferred to the other window's Gadget list, nor is the other window notified, but the illusion has been created, so now software can back it up. An example of Gadgets that move from window to window would be the disk and file icons that Workbench uses.
• You can specify wether the Gadget has a transparent or solid backround. If transparent, all pen 0 parts of the image are transparent.
• you can specify wether you want the Gadget to move to the new location once the user lets up the mouse, or that it bounce back to its original locaiton.

Before calling DragGadget the first time, you must initialise a DragInfo structure.

The fields that need to be set in the DragInfo structure are:



Gadget	This is a pointer to the Gadget you wish to drag.
LeftEdge	This is the left edge of the bounding box that describes the region this Gadget can move within.
TopEdge	This is the top edge of the bounding box that describes the region this Gadget can move within.
RightEdge	This is the right edge of the bounding box that describes the region this Gadget can move within.
BottomEdge	This is the bottom edge of the bounding box that describes the region this Gadget can move within.
Flags	There are several flags you can set to influence the behavior of the Drag Gadget. DRAG_INWINDOW indicates you wish to have the Gadget displayed only within the rastport of your window. DRAG_OUTLINE indicates you'd the pen 0 color in the Gadget Image to be transparent. DRAG_MOVEGADGET indicates that you'd like the Gadget to stay where the user moves it. Be careful. If the bounding box is outside the window, the user can move the Gadget out of the window, too. And then it's somewhat hard to get back.
XPos, YPos	These coordinates indicate where the Gadget is now in the window. You need not set these, but you may need to read them at some point.
UpdateRoutine	You can supply a function that is called every time the Gadget moves. This function is passed two parameters: The window and the DragInfo structure (which, in turn, points to the Gadget). If you don't need to supply a routine, set this to NULL. Such a routine is particulary useful if you need to provide some sort of real time update while the Gadget moves.


INPUTS

Window = Pointer to the window this Gadget belongs to.
DragInfo = Initialised DragInfo structure.

RESULT

none (void)



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