IUP/Controls/IupCanvas

Creates an interface element that is a canvas - a working area for your application.

Creation

iup.canvas{} -> (elem: ihandle)

This function returns the identifier of the created canvas, or nil if an error occurs.

Attributes

BGCOLOR: Border color

SIZE: Size of the canvas. Default: size of one character.

SCROLLBAR: Associates a horizontal and/or vertical scrollbar to the canvas.

DX: Size of the thumb in the horizontal scrollbar.

DY: Size of the thumb in the vertical scrollbar.

POSX: Position of the thumb in the horizontal scrollbar.

POSY: Position of the thumb in the vertical scrollbar.

XMIN: Minimum value of the horizontal scrollbar.

XMAX: Maximum value of the horizontal scrollbar.

YMIN: Minimum value of the vertical scrollbar.

YMAX: Maximum value of the vertical scrollbar.

BORDER: Shows a border around the canvas. It can only be changed before the element is mapped. Default: "YES".

EXPAND: The default value is "YES".

Callbacks

ACTION: Action generated when the canvas needs to be redrawn. Also receives as parameters the scrollbar position:

elem:action(x, y: number) -> (ret: number)

x: Thumb position in the horizontal scrollbar.

y: Thumb position in the vertical scrollbar.

This action is also generated right after the dialog is viewed by means of functions IupShow, IupShowXY or IupPopup.

BUTTON_CB: Action generated when any mouse button is pressed or released.

ENTERWINDOW_CB: Action generated when the mouse enters the canvas.

LEAVEWINDOW_CB: Action generated when the mouse leaves the canvas.

MOTION_CB: Action generated when the mouse is moved.

KEYPRESS_CB: Action generated when a key is pressed or released.

SCROLL_CB: Called when the scrollbar is manipulated.

MAP_CB: Called right after the element is mapped.

Note

Note that some keys might remove the focus from the canvas. To avoid this, return IGNORE in the K_ANY callback.