IupSplit (since 3.1)

Creates a void container that split its client area in two. Allows the provided controls to be enclosed in a box that allows expanding and contracting the element size in one direction, but when one is expanded the other is contracted.

It does not have a native representation, but it contains also a IupFlatSeparator to implement the bar handler.


Ihandle* IupSplit(Ihandle* child1, Ihandle* child2); [in C]
iup.split{child1, child2: ihandle} -> (ih: ihandle) [in Lua]
split(child1, child2) [in LED]

child1: Identifier of an interface element that will be at left or top. It can be NULL (nil in Lua), or empty in LED.
child2: Identifier of an interface element that will be at right or bottom. It can be NULL (nil in Lua), or empty in LED.

Returns: the identifier of the created element, or NULL if an error occurs.


AUTOHIDE (non inheritable): if the child client area is smaller than the bar size, then automatically hide the child. Default: NO.

BARSIZE (non inheritable): controls the size of the bar handler. Default: 5.

COLOR: Changes the color of the bar grip affordance. Default: "160 160 160".

ORIENTATION (creation only) (non inheritable): Indicates the orientation of the bar handler. The direction of the resize is perpendicular to the orientation. Possible values are "VERTICAL" or "HORIZONTAL". Default: "VERTICAL".

EXPAND (non inheritable): The default value is "YES".

LAYOUTDRAG (non inheritable): When the bar is moved automatically update the children layout. Default: YES. If set to NO then the layout will be updated only when the mouse drag is released.

MINMAX (non inheritable): sets minimum and maximum crop values for VALUE, in the format "%d:%d" [min:max]. The min value can not be less than 0, and the max value can not be larger than 1000. This will constrain the interactive change of the bar handler. Default: "0:1000". (Since 3.2)

SHOWGRIP (non inheritable): Shows the bar grip affordance. Default: YES. When set to NO, the BARSIZE is set to 3. When set to NO, COLOR is used to fill the grip area (since 3.11.1) if defined, if COLOR is not defined the area is filled with the parent background color. If set to "LINES" then instead of the traditional grip appearance, it will be two parallel lines (since 3.11.1).

VALUE (non inheritable): The proportion of the left or top (child1) client area relative to the full available area. It is an integer between 0 and 1000. If not defined or set to NULL, the Native size of the two children will define its initial size.

WID (read-only): returns -1 if mapped.



VALUECHANGED_CB: Called after the value was interactively changed by the user. (since 3.12)

int function(Ihandle *ih); [in C]
ih:valuechanged_cb() -> (ret: number) [in Lua]

ih: identifier of the element that activated the event.


The controls that you want to be resized must have the EXPAND=YES attribute set. See the Layout Guide for mode details on sizes.

If you set the MINMAX attribute for a direct child, IupSplit will respect that size. Nested children will also have their size limits respected.

The IupFlatSeparator bar handler is always the first child of the split. It can be obtained using IupGetChild or IupGetNextChild.

The IupSplit control looks just like the IupSbox, but internally is very different. While the IupSbox controls only one element and can push other elements outside the dialog, the IupSplit balance its internal size and never push other elements outside its boundaries.

When AUTOHIDE=Yes the control will set FLOATING=IGNORE and VISIBLE=NO for the child to be auto-hidden, then back to FLOATING=NO and VISIBLE=Yes when shown. So if the child has several children with different combinations of VISIBLE it is recommended that this child to be a native container like IupBackgroundBox or IupFrame, so the VISIBLE attribute will be not be propagated to its children.

The container can be created with no elements and be dynamic filled using IupAppend or IupInsert.


Browse for Example Files

Natural Size

After Moving the Split Bar