m_property.h

   1
   2 /// \defgroup Properties
   3 ///
   4 /// Properties provide an interface to query and set the state of various
   5 /// things in MPlayer. The API is based on the \ref Options API like the
   6 /// \ref Config, but instead of using variables, properties use an ioctl like
   7 /// function. The function is used to perform various actions like get and set
   8 /// (see \ref PropertyActions).
   9 ///@{
  10
  11 /// \file
  12
  13 /// \defgroup PropertyActions Property actions
  14 /// \ingroup Properties
  15 ///@{
  16
  17 /// Get the current value.
  18 /** \param arg Pointer to a variable of the right type.
  19  */
  20 #define M_PROPERTY_GET         0
  21
  22 /// Get a string representing the current value.
  23 /** Set the variable to a newly allocated string or NULL.
  24  *  \param arg Pointer to a char* variable.
  25  */
  26 #define M_PROPERTY_PRINT       1
  27
  28 /// Set a new value.
  29 /** The variable is updated to the value actually set.
  30  *  \param arg Pointer to a variable of the right type.
  31  */
  32 #define M_PROPERTY_SET         2
  33
  34 /// Set a new value from a string.
  35 /** \param arg String containing the value.
  36  */
  37 #define M_PROPERTY_PARSE       3
  38
  39 /// Increment the current value.
  40 /** The sign of the argument is also taken into account if applicable.
  41  *  \param arg Pointer to a variable of the right type or NULL.
  42  */
  43 #define M_PROPERTY_STEP_UP     4
  44
  45 /// Decrement the current value.
  46 /** The sign of the argument is also taken into account if applicable.
  47  *  \param arg Pointer to a variable of the right type or NULL.
  48  */
  49 #define M_PROPERTY_STEP_DOWN   5
  50
  51 ///@}
  52
  53 /// \defgroup PropertyActionsReturn Property actions return code
  54 /// \ingroup Properties
  55 /// \brief  Return values for the control function.
  56 ///@{
  57
  58 /// Returned on success.
  59 #define M_PROPERTY_OK                1
  60
  61 /// Returned on error.
  62 #define M_PROPERTY_ERROR             0
  63
  64 /// \brief Returned when the property can't be used, for example something about
  65 /// the subs while playing audio only
  66 #define M_PROPERTY_UNAVAILABLE      -1
  67
  68 /// Returned if the requested action is not implemented.
  69 #define M_PROPERTY_NOT_IMPLEMENTED  -2
  70
  71 /// Returned when asking for a property that doesn't exist.
  72 #define M_PROPERTY_UNKNOWN          -3
  73
  74 /// Returned when the action can't be done (like setting the volume when edl mute).
  75 #define M_PROPERTY_DISABLED         -4
  76
  77 ///@}
  78
  79 /// \ingroup Properties
  80 /// \brief Property action callback.
  81 typedef int(*m_property_ctrl_f)(m_option_t* prop,int action,void* arg);
  82
  83 /// Do an action on a property.
  84 /** \param prop The property.
  85  *  \param action See \ref PropertyActions.
  86  *  \param arg Argument, usually a pointer to the data type used by the property.
  87  *  \return See \ref PropertyActionsReturn.
  88  */
  89 int m_property_do(m_option_t* prop, int action, void* arg);
  90
  91 /// Print the current value of a property.
  92 /** \param prop The property.
  93  *  \return A newly allocated string with the current value or NULL on error.
  94  */
  95 char* m_property_print(m_option_t* prop);
  96
  97 /// Set a property.
  98 /** \param prop The property.
  99  *  \param txt The value to set.
 100  *  \return 1 on success, 0 on error.
 101  */
 102 int m_property_parse(m_option_t* prop, char* txt);
 103
 104 /// Print a list of properties.
 105 void m_properties_print_help_list(m_option_t* list);
 106
 107 /// Expand a property string.
 108 /** This function allows to print strings containing property values.
 109  *  ${NAME} is expanded to the value of property NAME or an empty
 110  *  string in case of error. $(NAME:STR) expand STR only if the property
 111  *  NAME is available.
 112  *
 113  *  \param prop_list An array of \ref m_option describing the available
 114  *                   properties.
 115  *  \param str The string to expand.
 116  *  \return The newly allocated expanded string.
 117  */
 118 char* m_properties_expand_string(m_option_t* prop_list,char* str);
 119
 120 // Helpers to use MPlayer's properties
 121
 122 /// Get an MPlayer property.
 123 m_option_t*  mp_property_find(const char* name);
 124
 125 /// Do an action with an MPlayer property.
 126 int mp_property_do(const char* name,int action, void* val);
 127
 128 /// \defgroup PropertyImplHelper Property implementation helpers
 129 /// \ingroup Properties
 130 /// \brief Helper functions for common property types.
 131 ///@{
 132
 133 /// Clamp a value according to \ref m_option::min and \ref m_option::max.
 134 #define M_PROPERTY_CLAMP(prop,val) do {                                 \
 135         if(((prop)->flags & M_OPT_MIN) && (val) < (prop)->min)          \
 136             (val) = (prop)->min;                                        \
 137         else if(((prop)->flags & M_OPT_MAX) && (val) > (prop)->max)     \
 138             (val) = (prop)->max;                                        \
 139     } while(0)
 140
 141 /// Implement get.
 142 int m_property_int_ro(m_option_t* prop,int action,
 143                       void* arg,int var);
 144
 145 /// Implement set, get and step up/down.
 146 int m_property_int_range(m_option_t* prop,int action,
 147                          void* arg,int* var);
 148
 149 /// Same as m_property_int_range but cycle.
 150 int m_property_choice(m_option_t* prop,int action,
 151                       void* arg,int* var);
 152
 153 /// Switch betwen min and max.
 154 int m_property_flag(m_option_t* prop,int action,
 155                     void* arg,int* var);
 156
 157 /// Implement get, print.
 158 int m_property_float_ro(m_option_t* prop,int action,
 159                         void* arg,float var);
 160
 161 /// Implement set, get and step up/down
 162 int m_property_float_range(m_option_t* prop,int action,
 163                            void* arg,float* var);
 164
 165 /// float with a print function which print the time in ms
 166 int m_property_delay(m_option_t* prop,int action,
 167                      void* arg,float* var);
 168
 169 /// Implement get, print
 170 int m_property_double_ro(m_option_t* prop,int action,
 171                          void* arg,double var);
 172
 173 /// get/print the string
 174 int m_property_string_ro(m_option_t* prop,int action,void* arg, char* str);
 175
 176 ///@}
 177
 178 ///@}