NAME

AG_Config — agar configuration interface

SYNOPSIS

#include <agar/core.h>

DESCRIPTION

The AG_Config object records configuration settings global to an Agar application. This includes user preferences which are to be preserved after the application has exited.

Library or application-specific data may also be stored in the configuration object as AG_Variable(3) values. Variable names should not start with "ag_", the prefix is reserved for internal Agar settings.

Note that our AG_Variable(3) system implements pointers (or "bindings"), so it is always possible for a parameter value to be specified as a pointer to an external piece of data.

INHERITANCE HIERARCHY

AG_Object(3) -> AG_Config.

INTERFACE

AG_Config *
AG_ConfigObject(void);

int
AG_ConfigLoad(void);

int
AG_ConfigSave(void);

int
AG_ConfigFind(AG_ConfigPathGroup group, const char *filename, char *dst, AG_Size dst_size);

void
AG_ConfigAddPath(AG_ConfigPathGroup group, const char *format, ...);

void
AG_ConfigAddPathS(AG_ConfigPathGroup group, const char *pathname);

void
AG_ConfigSetPath(AG_ConfigPathGroup group, int index, const char *format, ...);

void
AG_ConfigSetPathS(AG_ConfigPathGroup group, int index, const char *pathname);

void
AG_ConfigDelPath(AG_ConfigPathGroup group, const char *format, ...);

void
AG_ConfigDelPathS(AG_ConfigPathGroup group, const char *pathname);

AG_ConfigObject() returns a pointer to the global agConfig object.

AG_ConfigLoad() loads the configuration data from disk, returning 0 on sucess or -1 on failure. It is equivalent to calling AG_ObjectLoad(3) on the agConfig object. Note that AG_ConfigLoad() must be called after the initialization of all Agar libraries (i.e., if an application uses Agar-GUI, then the AG_ConfigLoad() call must follow AG_InitGraphics()).

The AG_ConfigSave() function saves the configuration data to disk, returning 0 on success or -1 on failure. It is equivalent to calling AG_ObjectSave(3) on the agConfig object.

The AG_ConfigFind() function searches a list of registered paths for the given file. group may be AG_CONFIG_PATH_DATA (for object and data files), or AG_CONFIG_PATH_FONTS (for fonts). If filename is found and and the file is accessible, then its absolute pathname is copied into the fixed-size buffer dst_path (limited to dst_len bytes), and AG_ConfigFind() returns 0. If the file cannot be found, it returns -1.

AG_ConfigAddPath() adds the specified directory to the list of AG_ConfigFind() search paths.

AG_ConfigSetPath() sets the path at index idx. If there is no such entry but idx is (last)-1, then the entry is created. Otherwise AG_ConfigFind() will fail and return -1.

AG_ConfigDelPath() removes the given directory from the list of registered search paths.

EXAMPLES

The following code sets an integer option and a string. The configuration is then immediately saved to disk:

AG_SetInt(agConfig, "my-setting", 1);
AG_SetString(agConfig, "my-string", "Foo bar");
AG_ConfigSave();

The following Agar-GUI code displays a checkbox controlling the value of "my-setting":

AG_Checkbox *cb;

cb = AG_CheckboxNew(win, 0, "My setting");
AG_BindVariable(cb, "state", agConfig, "my-setting");

The following code binds "my-ext-setting" to an external variable, and then reads the configuration from disk. If the saved configuration has "my-ext-setting" defined, then the variable will be set accordingly:

int myExtSetting = 0;

AG_BindInt(agConfig, "my-ext-setting", &myExtSetting);
AG_ConfigLoad();

The following code prints the currently configured paths:

char path[AG_PATHNAME_MAX];
int i, j;

for (i = 0; i < AG_CONFIG_PATH_LAST; i++) {
	for (j = 0; ; j++) {
		if (AG_ConfigGetPath(i,j, path, sizeof(path))==0) {
			break;
		}
		AG_LabelNew(win, 0, "%s[%d] = %s",
		    agConfigPathGroupNames[i], j, path);
	}
}

SEE ALSO

AG_Intro(3), AG_Object(3)

HISTORY

The AG_Config interface first appeared in Agar 1.0. AG_ConfigFind(), AG_ConfigAddPath(), AG_ConfigSetPath() and AG_ConfigDelPath() were introduced in Agar 1.6.0.