Creates a matrix of alphanumeric fields. Therefore, all values of the matrixs fields are strings. The matrix is not a grid container like many systems have. It inherits from IupCanvas.

This is an additional control that depends on the CD library. It is included in the Controls Library.

It has two modes of operation: normal and callback mode. In normal mode, string values are stored in attributes for each cell. In callback mode these attributes are ignored and the cells are filled with strings returned by the "VALUE_CB" callback. So the existence of this callback defines the mode the matrix will operate.


Ihandle* IupMatrix(char *action_cb); [in C]
iup.matrix{} -> (elem: ihandle) [in Lua]
matrix(action_cb) [in LED]

action_cb: Name of the action generated when the user types something.

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








Column Size


Line Size


Number of Cells


Mark Attributes


Action Attributes


Text Editing Attributes


Canvas Attributes




ACTION_CB - Action generated when a keyboard event occurs.
- Action generated when any mouse button is pressed over a cell.
RELEASE_CB - Action generated when any mouse button is released over a cell.
MOUSEMOVE_CB - Action generated to notify the application that the mouse has moved over the matrix.
ENTERITEM_CB - Action generated when a matrix cell is selected, becoming the current cell.
- Action generated when a cell is no longer the current cell.
SCROLLTOP_CB - Action generated when the matrix is scrolled with the scrollbars or with the keyboard.


BGCOLOR_CB - Action generated to retrieve the background color of a cell when it needs to be redrawn.
FGCOLOR_CB - Action generated to retrieve the foreground color of a cell when it needs to be redrawn.
FONT_CB - Action generated to retrieve the font of a cell when it needs to be redrawn.
DRAW_CB - Action generated before the cell is drawn. Allow a custom cell draw.
DROPCHECK_CB - Action generated to determine if a dropdown feedback should be shown.


DROP_CB - Action generated to determine if a text field or a dropdown will be shown.
MENUDROP_CB - Action generated to determine if a popup menu will be shown. 
DROPSELECT_CB - Action generated when an element in the dropdown list is selected.
- Action generated when the current cell enters or leaves the edition mode.

Callback Mode

VALUE_CB - Action generated to verify the value of a cell.
VALUE_EDIT_CB - Action generated to notify the application that the value of a cell was edited.
MARK_CB - Action generated to verify the selection state of a cell.
- Action generated to notify the application that the selection state of a cell was changed.

Utility Functions

These functions can be used to help set and get attributes from the matrix:

void  IupSetAttributeId2(Ihandle* ih, const char* name, int lin, int col, const char* value);
char* IupGetAttributeId2(Ihandle* ih, const char* name, int lin, int col);
int   IupGetIntId2(Ihandle* ih, const char* name, int lin, int col);
float IupGetFloatId2(Ihandle* ih, const char* name, int lin, int col);
void  IupSetfAttributeId2(Ihandle* ih, const char* name, int lin, int col, const char* format, ...);
void  IupSetIntId2(Ihandle* ih, const char* name, int lin, int col, int value);
void  IupSetFloatId2(Ihandle* ih, const char* name, int lin, int col, float value);

They work just like the respective traditional set and get functions. But the attribute string is complemented with the L and C values. When only one value is needed then use the Iup*AttributeId functions. For ex:

IupSetAttribute(ih, "30:10", value)        => IupSetAttributeId2(ih, "", 30, 10, value)
IupSetAttribute(ih, "BGCOLOR30:10", value) => IupSetAttributeId2(ih, "BGCOLOR", 30, 10, value)
IupSetAttribute(ih, "ALIGNMENT10", value)  => IupSetAttributeId(ih, "ALIGNMENT", 10, value)

When one of the indices is the asterisk, use IUP_INVALID_ID as the parameter. For ex:

IupSetAttribute(ih, "BGCOLOR30:*", value) => IupSetAttributeId2(ih, "BGCOLOR", 30, IUP_INVALID_ID, value)

These functions are faster than the traditional functions because they do not need to parse the attribute name string and the application does not need to concatenate the attribute name with the id.

They are used by the additional methods in Lua:

elem:setcell(lin, col: number, value: string)
elem:getcell(lin, col: number) -> (cell: string)

But you can also use the traditional functions when typing:

elem["bgcolor"..l..":"..c] = v
elem["bgcolor30:10"] = v



Before mapped to the native system, all attributes are stored in the hash table, independently from the size of the matrix or its operation mode. The action attributes like ADDLIN and DELCOL will NOT work.

When the matrix is mapped, and it is NOT in callback mode, then the cell values and mark state are moved from the hash table to an internal storage at the matrix. Other cell attributes remains on the hash table. Cell values with indices greater than (NUMLIN,NUMCOL) are ignored. When in callback mode cell values stored in the hash table are ignored.

Callback Mode

Very large matrices can use the callback mode to store the cell values at the application, and not at the internal matrix storage. The idea is the following:

1 - Register the VALUE_CB callback
2 - No longer set the value of the cells. Store the cell value at the application. They will be retreived one by one by the callback.
3 - If the matrix can be edited, set the VALUE_EDIT_CB callback.
4 - When the matrix display must be updated, use the REDRAW attribute to force a matrix redraw.

A negative aspect is that, when VALUE_CB is defined, after it is mapped the matrix never verifies attributes of type L:C again.

If VALUE_CB is defined and VALUE_EDIT_CB is not defined when the matrix is mapped then READONLY will be set to YES.

Number of Cells

If you do not plan to use ADDLIN nor ADDCOL, and plan to set sparse cell values, then you must set NUMLIN and NUMCOL before mapping.


A matrix might have titles for lines and columns. Titles are always non scrollable, non editable and presented with a different default background color. A matrix will have a line of titles if an attribute of the "L:0" type is defined, where L is a line number, or if the HEIGHT0 attribute is defined. It will have a column of titles if an attribute of the "0:C" type is defined, where C is a column number, or if the WIDTH0 attribute is defined.

When allowed the width of a column can be changed by holding and dragging its title right border, see RESIZEMATRIX.

Any cell can have more than one text line, just use the \n control character. Multiple text lines will be considered when calculating the title cell size based on its contents. The contents of ordinary cells (not a title) do not affect the cell size.

Natural Size

The Natural size is calculated using only the title cells size plus the size of NUMCOL_VISIBLE and NUMLIN_VISIBLE cells, but it is also affected if SCROLBAR is enabled. The natural height is the sum of the line heights from line 0 to NUMLIN_VISIBLE (inclusive). The natural width is the sum of the column width from column 0 to NUMCOL_VISIBLE (inclusive). Notice that since NUMCOL_VISIBLE and NUMLIN_VISIBLE do not include the titles then NUMCOL_VISIBLE+1 columns and NUMLIN_VISIBLE+1 lines are included in the sum.

The height of a line L depends on several attributes, first it checks the HEIGHTL attribute, then checks RASTERHEIGHTL, then when USETITLESIZE=YES or not in callback mode the height of the title text for the line or if L=0 it searches for the highest column title, if still could not define a height then if L!=0 it will use HEIGHTDEF, if L=0 then height will be 0.

A similar approach is valid for the column width. The width of a column C first checks the WIDTHC attribute, then checks RASTERWIDTHC, then when USETITLESIZE=YES or not in callback mode the width of the title text for the column or if C=0 it searches for the widest line title, if still could not define a width then if C!=0 it will use WIDTHDEF, if C=0 then height will be 0.

Virtual Size

When the scrollbars are enabled if the matrix area is greater than the visible area then scrollbars will be displayed so the cells can be scrolled to be visible area. When dragging the scrollbar the position of cells is free, when clicking on its buttons it will move in cell steps, aligning to the left border of the cell.

By default EXPAND=Yes, so matrix will be automatically resized when the dialog is resized. So more columns and lines will be displayed. But the matrix Natural size will be used as minimum size. To remove the minimum size limitation set NUMCOL_VISIBLE and NUMLIN_VISIBLE to 0 after showing it for the first time.

Keyboard Navigation

Keyboard navigation through the matrix cells outside the edition mode is done by using the following keys:

When using the keyboard to change the focus cell if the limit of the visible area is reached then the cells are automatically scrolled. Also if a cell partially visible is edited then first it is scrolled to the visible area. Also while pressing together the Shift key and marks are enabled with MARKMULTIPLE=Yes then a continuous area will be selected (since 3.9).

When the matrix is outside the edition mode, pressing any character key makes the current key to enter in the edition mode, the old text is replaced by the new one being typed. If F2, Enter or Space is pressed, the current cell enters the edition mode with the current text of the cell. Double-clicking a cell also enters the edition mode (in Motif the user must click again to the edit control get the focus).

Inside the edition mode, the following keys are used for a text field:

The cell will also leave the edition mode if the user clicked in another cell or in another control, then the value will be confirmed. When pressing Enter to confirm the value the focus goes to the cell below the current cell, if at the last line then the focus goes to the cell on the left. The value confirmation depends on the EDITION_CB callback return code.

Marks (Selected Cells)

When a mark mode is set the cells can be marked using mouse.

A marked cell will have its background attenuated to indicate that it is marked. A title cell appears marked only when MARKMODE=LIN, COL or LINCOL.

Cells can be selected individually or can be restricted to lines or columns. Also multiple cells can be marked simultaneously in continuous or in segmented areas. Lines and columns are marked only when the user clicks in their respective titles, if MARKMODE=CELL then all the cells of the line or column will be marked. Continuous areas are marked holding and dragging the mouse or holding the Shift key when clicking at the end of the area. Segmented areas are marked or unmarked holding the Ctrl key, the mark state is inverted. Clicking on the cell 0:0 will select all the items depending on MARKMODE, except for LINCOL.

When there are cells marked, pressing the Del key remove the selected cells contents.


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See Also