mpv/m_property.h

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/*
* This file is part of MPlayer.
*
* MPlayer is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* MPlayer is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with MPlayer; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef MPLAYER_M_PROPERTY_H
#define MPLAYER_M_PROPERTY_H
#include <stdbool.h>
struct m_option;
extern const struct m_option_type m_option_type_dummy;
enum mp_property_action {
// Get the property type. This defines the fundamental data type read from
// or written to the property.
// If unimplemented, the m_option entry that defines the property is used.
// arg: m_option*
M_PROPERTY_GET_TYPE,
// Get the current value.
// arg: pointer to a variable of the type according to the property type
M_PROPERTY_GET,
// Set a new value. The property wrapper will make sure that only valid
// values are set (e.g. according to the property type's min/max range).
// If unimplemented, the property is read-only.
// arg: pointer to a variable of the type according to the property type
M_PROPERTY_SET,
// Get human readable string representing the current value.
// If unimplemented, the property wrapper uses the property type as
// fallback.
// arg: char**
M_PROPERTY_PRINT,
// Switch the property up/down by a given value.
// If unimplemented, the property wrapper uses the property type as
// fallback.
// arg: struct m_property_switch_arg*
M_PROPERTY_SWITCH,
// Get a string containing a parsable representation.
// Can't be overridden by property implementations.
// arg: char**
M_PROPERTY_GET_STRING,
// Set a new value from a string. The property wrapper parses this using the
// parse function provided by the property type.
// Can't be overridden by property implementations.
// arg: char*
M_PROPERTY_SET_STRING,
// Pass down an action to a sub-property.
// arg: struct m_property_action_arg*
M_PROPERTY_KEY_ACTION,
};
// Argument for M_PROPERTY_SWITCH
struct m_property_switch_arg {
double inc; // value to add to property, or cycle direction
bool wrap; // whether value should wrap around on over/underflow
};
// Argument for M_PROPERTY_KEY_ACTION
struct m_property_action_arg {
const char* key;
int action;
void* arg;
};
enum mp_property_return {
// Returned on success.
M_PROPERTY_OK = 1,
// Returned on error.
M_PROPERTY_ERROR = 0,
// Returned when the property can't be used, for example video related
// properties while playing audio only.
M_PROPERTY_UNAVAILABLE = -1,
// Returned if the requested action is not implemented.
M_PROPERTY_NOT_IMPLEMENTED = -2,
// Returned when asking for a property that doesn't exist.
M_PROPERTY_UNKNOWN = -3,
};
// Access a property.
// action: one of m_property_action
// ctx: opaque value passed through to property implementation
// returns: one of mp_property_return
int m_property_do(const struct m_option* prop_list, const char* property_name,
int action, void* arg, void *ctx);
// Print a list of properties.
void m_properties_print_help_list(const struct m_option* list);
// Expand a property string.
commands: change property expansion format string This affects property format strings like they are used in the "show_text" input command, for --playing-msg, and other places. To quote the documentation comment on m_properties_expand_string(): ${NAME} is expanded to the value of property NAME. If NAME starts with '=', use the raw value of the property. ${NAME:STR} expands to the property, or STR if the property is not available. ${?NAME:STR} expands to STR if the property is available. ${!NAME:STR} expands to STR if the property is not available. STR is recursively expanded using the same rules. "$$" can be used to escape "$", and "$}" to escape "}". "$>" disables parsing of "$" for the rest of the string. Most importantly, "?(property:str)" becomes "${?property:str}". Make the simple fallback case easier, e.g. "${property:fallback}" instead of "${property}?(!property:fallback)". Add the ability to escape the format meta characters. "$" is used for escaping, because escaping with "\" is taken by the commands parser in the layer below. "$>" can be used to disable interpretation of format strings (of course escapes by the commands parser can't be canceled). By default, properties which are unavailable or don't exist are turned into a string signaling the status (e.g. "(unavailable)"), instead of an empty string. If an empty string is desired, this has to be done explicitly: "${property:}" (the fallback part is an empty string). Raw properties still return an empty string on error. m_properties_expand_string() now returns a talloc'ed pointer, instead of a malloc'ed one.
2012-09-23 21:00:54 +00:00
// This function allows to print strings containing property values.
// ${NAME} is expanded to the value of property NAME.
// If NAME starts with '=', use the raw value of the property.
// ${NAME:STR} expands to the property, or STR if the property is not
// available.
// ${?NAME:STR} expands to STR if the property is available.
// ${!NAME:STR} expands to STR if the property is not available.
// General syntax: "${" ["?" | "!"] ["="] NAME ":" STR "}"
// STR is recursively expanded using the same rules.
// "$$" can be used to escape "$", and "$}" to escape "}".
// "$>" disables parsing of "$" for the rest of the string.
char* m_properties_expand_string(const struct m_option* prop_list, char *str,
void *ctx);
// Trivial helpers for implementing properties.
int m_property_int_ro(const struct m_option* prop, int action, void* arg,
int var);
int m_property_float_ro(const struct m_option* prop, int action, void* arg,
float var);
int m_property_double_ro(const struct m_option* prop, int action, void* arg,
double var);
#endif /* MPLAYER_M_PROPERTY_H */