ObjcAttach()

NAME

ObjcAttach() - attach a variable or a function at an object.

PROTOTYPAGE

int ObjcAttach( int mode, WINDOW *win, int index, int type, void *data, ...);

PARAMETERS

mode:

OC_FORM:

if the object is in a window formular,

OC_TOOLBAR:

object is in a toolbar,

OC_MENU:

object is in a window menu,

win:

a window descriptor or NULL,

index:

object index to attach,

type:

BIND_VAR:

attach a variable,

BIND_BIT:

attach a specific bit of a variable,

BIND_FUNC:

attach a function.

data:

data or function address to attach,

...:

additional parameter depending on type parameter : in BIND_BIT mode, this parameter specifies the bit to attach in data. In BIND_FUNC mode, this parameter can specify an optional user data pointer which pass to the binded function.

return:

a negative code error.

DESCRIPTION

ObjcAttach() attaches a function or a variable at an object from a window formular, a toolbar or a menu. The rules are differents if you use a formular and a toolbar or a menu.

With formulars or toolbars, only EXIT or TOUCHEXIT objects can be attached at a function. When the user selects these objects, the function is invoked. Only SELECTABLE objects can be attached at a variable. If the object has the RADIO flag, the variable attached - always an integer variable - is filled with the index of the selected RADIO object at the RADIO level. If the object is not a RADIO object, the variable is filled with 1 if the object is selected, 0 else with the BIND_VAR mode. The BIND_BIT mode allows the object to be attached with a specific bit of the variable. This bit is specified by the bit parameter.

With menu, an item of the menu can be attached at a function or at a variable. When an item is linked to a variable, it is checked or unchecked when the user selects it. The variable linked is filled with 1 or 0 (or a specific bit with the BIND_BIT mode) when the item is checked or unchecked. Notice desktop menu is addressed if win parameter is set to NULL.

A function linked with to an object in a formular or a toolbar has the following interface:

     	void func ( WINDOW *win, int index, int mode, void *data);

where win is the host window, index is the index of the attached object and mode can be OC_FORM, OC_TOOLBAR or OC_MENU. If an user data pointer is specified with ObjcAttach(), this pointer can be read as a fourth parameter of the binded function (data in our example).

A function linked to a menu object has an additionnal parameter - title - which indicated the menu title index selected. This parameter is required by MenuTNormal():

     	void func ( WINDOW *win, int index, int mode, int title, void *data);

The fifth parameter data is an optional user pointer data specified in ObjcAttach().

EXAMPLES

     	{
     		static int radio = RAD1;
     #define OPTION1	0x1	/* bit 0 */
     #define OPTION2 0x2	/* bit 1 */
     #define OPTION3 0x4 /* bit 2 */
     		static int options = 0;
     
     		/* Before : create the form with FormCreate() */
     		/* Then attach the objects  */
     
     		/* 3 radio buttons in a formular */
     		ObjcAttach( OC_FORM, win, RAD1, BIND_VAR, &radio, 0);
     		ObjcAttach( OC_FORM, win, RAD2, BIND_VAR, &radio, 0);
     		ObjcAttach( OC_FORM, win, RAD3, BIND_VAR, &radio, 0);
     
     		/* some checkboxes ... */
     		ObjcAttach( OC_FORM, win, BUT1, BIND_BIT, &options, OPTION1);
     		ObjcAttach( OC_FORM, win, BUT2, BIND_BIT, &options, OPTION2);
     		ObjcAttach( OC_FORM, win, BUT3, BIND_BIT, &options, OPTION3);
     
     		/* An example of function linked to an object   *
     		 * see after for the definition of the function */
     		ObjcAttach( OC_FORM, win, OK, BIND_FUNC, ButOk, 0);
     
     	}
     
     	/* Function linked to OK object */
     	void ButOk( WINDOW *win, int index, int mode) {
     		/* Unselect the object ... */
     		ObjcChange( mode, win, index, NORMAL, 0);
     		/* ... and destroy the window */
     		ApplWrite( app.id, WM_DESTROY, win->handle);
     	}
     }