diff --git a/src/Main/fg_props.hxx b/src/Main/fg_props.hxx index 2eae51b8f..75bf0b69b 100644 --- a/src/Main/fg_props.hxx +++ b/src/Main/fg_props.hxx @@ -1,3 +1,8 @@ +// fg_props.hxx - Declarations and inline methods for property handling. +// Written by David Megginson, started 2000. +// +// This file is in the Public Domain, and comes with no warranty. + #ifndef __FG_PROPS_HXX #define __FG_PROPS_HXX 1 @@ -10,9 +15,48 @@ // Property management. //////////////////////////////////////////////////////////////////////// + +/** + * Initialize the default FlightGear properties. + * + * These are mostly properties that haven't been claimed by a + * specific module yet. This function should be invoked once, + * while the program is starting (and after the global property + * tree has been created). + */ extern void fgInitProps (); // fixme: how are they untied? + + +/** + * Update the default FlightGear properties. + * + * This function should be invoked once in each loop to update all + * of the default properties. + */ extern void fgUpdateProps (); + + +/** + * Save a flight to disk. + * + * This function saves all of the archivable properties to a stream + * so that the current flight can be restored later. + * + * @param output The output stream to write the XML save file to. + * @return true if the flight was saved successfully. + */ extern bool fgSaveFlight (ostream &output); + + +/** + * Load a flight from disk. + * + * This function loads an XML save file from a stream to restore + * a flight. + * + * @param input The input stream to read the XML from. + * @return true if the flight was restored successfully. + */ extern bool fgLoadFlight (istream &input); @@ -49,72 +93,333 @@ fgHasNode (const string &path) } +/** + * Get a bool value for a property. + * + * This method is convenient but inefficient. It should be used + * infrequently (i.e. for initializing, loading, saving, etc.), + * not in the main loop. If you need to get a value frequently, + * it is better to look up the node itself using fgGetNode and then + * use the node's getBoolValue() method, to avoid the lookup overhead. + * + * @param name The property name. + * @param defaultValue The default value to return if the property + * does not exist. + * @return The property's value as a bool, or the default value provided. + */ inline bool fgGetBool (const string &name, bool defaultValue = false) { return globals->get_props()->getBoolValue(name, defaultValue); } + +/** + * Get an int value for a property. + * + * This method is convenient but inefficient. It should be used + * infrequently (i.e. for initializing, loading, saving, etc.), + * not in the main loop. If you need to get a value frequently, + * it is better to look up the node itself using fgGetNode and then + * use the node's getIntValue() method, to avoid the lookup overhead. + * + * @param name The property name. + * @param defaultValue The default value to return if the property + * does not exist. + * @return The property's value as an int, or the default value provided. + */ inline int fgGetInt (const string &name, int defaultValue = 0) { return globals->get_props()->getIntValue(name, defaultValue); } + +/** + * Get a long value for a property. + * + * This method is convenient but inefficient. It should be used + * infrequently (i.e. for initializing, loading, saving, etc.), + * not in the main loop. If you need to get a value frequently, + * it is better to look up the node itself using fgGetNode and then + * use the node's getLongValue() method, to avoid the lookup overhead. + * + * @param name The property name. + * @param defaultValue The default value to return if the property + * does not exist. + * @return The property's value as a long, or the default value provided. + */ inline int fgGetLong (const string &name, long defaultValue = 0L) { return globals->get_props()->getLongValue(name, defaultValue); } + +/** + * Get a float value for a property. + * + * This method is convenient but inefficient. It should be used + * infrequently (i.e. for initializing, loading, saving, etc.), + * not in the main loop. If you need to get a value frequently, + * it is better to look up the node itself using fgGetNode and then + * use the node's getFloatValue() method, to avoid the lookup overhead. + * + * @param name The property name. + * @param defaultValue The default value to return if the property + * does not exist. + * @return The property's value as a float, or the default value provided. + */ inline float fgGetFloat (const string &name, float defaultValue = 0.0) { return globals->get_props()->getFloatValue(name, defaultValue); } + +/** + * Get a double value for a property. + * + * This method is convenient but inefficient. It should be used + * infrequently (i.e. for initializing, loading, saving, etc.), + * not in the main loop. If you need to get a value frequently, + * it is better to look up the node itself using fgGetNode and then + * use the node's getDoubleValue() method, to avoid the lookup overhead. + * + * @param name The property name. + * @param defaultValue The default value to return if the property + * does not exist. + * @return The property's value as a double, or the default value provided. + */ inline double fgGetDouble (const string &name, double defaultValue = 0.0) { return globals->get_props()->getDoubleValue(name, defaultValue); } + +/** + * Get a string value for a property. + * + * This method is convenient but inefficient. It should be used + * infrequently (i.e. for initializing, loading, saving, etc.), + * not in the main loop. If you need to get a value frequently, + * it is better to look up the node itself using fgGetNode and then + * use the node's getStringValue() method, to avoid the lookup overhead. + * + * @param name The property name. + * @param defaultValue The default value to return if the property + * does not exist. + * @return The property's value as a string, or the default value provided. + */ inline string fgGetString (const string &name, string defaultValue = "") { return globals->get_props()->getStringValue(name, defaultValue); } + +/** + * Set a bool value for a property. + * + * Assign a bool value to a property. If the property does not + * yet exist, it will be created and its type will be set to + * BOOL; if it has a type of UNKNOWN, the type will also be set to + * BOOL; otherwise, the bool value will be converted to the property's + * type. + * + * @param name The property name. + * @param val The new value for the property. + * @return true if the assignment succeeded, false otherwise. + */ inline bool fgSetBool (const string &name, bool val) { return globals->get_props()->setBoolValue(name, val); } + +/** + * Set an int value for a property. + * + * Assign an int value to a property. If the property does not + * yet exist, it will be created and its type will be set to + * INT; if it has a type of UNKNOWN, the type will also be set to + * INT; otherwise, the bool value will be converted to the property's + * type. + * + * @param name The property name. + * @param val The new value for the property. + * @return true if the assignment succeeded, false otherwise. + */ inline bool fgSetInt (const string &name, int val) { return globals->get_props()->setIntValue(name, val); } + +/** + * Set a long value for a property. + * + * Assign a long value to a property. If the property does not + * yet exist, it will be created and its type will be set to + * LONG; if it has a type of UNKNOWN, the type will also be set to + * LONG; otherwise, the bool value will be converted to the property's + * type. + * + * @param name The property name. + * @param val The new value for the property. + * @return true if the assignment succeeded, false otherwise. + */ inline bool fgSetLong (const string &name, long val) { return globals->get_props()->setLongValue(name, val); } + +/** + * Set a float value for a property. + * + * Assign a float value to a property. If the property does not + * yet exist, it will be created and its type will be set to + * FLOAT; if it has a type of UNKNOWN, the type will also be set to + * FLOAT; otherwise, the bool value will be converted to the property's + * type. + * + * @param name The property name. + * @param val The new value for the property. + * @return true if the assignment succeeded, false otherwise. + */ inline bool fgSetFloat (const string &name, float val) { return globals->get_props()->setFloatValue(name, val); } + +/** + * Set a double value for a property. + * + * Assign a double value to a property. If the property does not + * yet exist, it will be created and its type will be set to + * DOUBLE; if it has a type of UNKNOWN, the type will also be set to + * DOUBLE; otherwise, the double value will be converted to the property's + * type. + * + * @param name The property name. + * @param val The new value for the property. + * @return true if the assignment succeeded, false otherwise. + */ inline bool fgSetDouble (const string &name, double val) { return globals->get_props()->setDoubleValue(name, val); } + +/** + * Set a string value for a property. + * + * Assign a string value to a property. If the property does not + * yet exist, it will be created and its type will be set to + * STRING; if it has a type of UNKNOWN, the type will also be set to + * STRING; otherwise, the string value will be converted to the property's + * type. + * + * @param name The property name. + * @param val The new value for the property. + * @return true if the assignment succeeded, false otherwise. + */ inline bool fgSetString (const string &name, const string &val) { return globals->get_props()->setStringValue(name, val); } + +//////////////////////////////////////////////////////////////////////// +// Convenience functions for setting property attributes. +//////////////////////////////////////////////////////////////////////// + + +/** + * Set the state of the archive attribute for a property. + * + * If the archive attribute is true, the property will be written + * when a flight is saved; if it is false, the property will be + * skipped. + * + * A warning message will be printed if the property does not exist. + * + * @param name The property name. + * @param state The state of the archive attribute (defaults to true). + */ +inline void +fgSetArchivable (const string &name, bool state = true) +{ + SGPropertyNode * node = globals->get_props()->getNode(name); + if (node == 0) + SG_LOG(SG_GENERAL, SG_ALERT, + "Attempt to set archive flag for non-existant property " + << name); + else + node->setAttribute(SGPropertyNode::ARCHIVE, state); +} + + +/** + * Set the state of the read attribute for a property. + * + * If the read attribute is true, the property value will be readable; + * if it is false, the property value will always be the default value + * for its type. + * + * A warning message will be printed if the property does not exist. + * + * @param name The property name. + * @param state The state of the read attribute (defaults to true). + */ +inline void +fgSetReadable (const string &name, bool state = true) +{ + SGPropertyNode * node = globals->get_props()->getNode(name); + if (node == 0) + SG_LOG(SG_GENERAL, SG_ALERT, + "Attempt to set read flag for non-existant property " + << name); + else + node->setAttribute(SGPropertyNode::READ, state); +} + + +/** + * Set the state of the write attribute for a property. + * + * If the write attribute is true, the property value may be modified + * (depending on how it is tied); if the write attribute is false, the + * property value may not be modified. + * + * A warning message will be printed if the property does not exist. + * + * @param name The property name. + * @param state The state of the write attribute (defaults to true). + */ +inline void +fgSetWritable (const string &name, bool state = true) +{ + SGPropertyNode * node = globals->get_props()->getNode(name); + if (node == 0) + SG_LOG(SG_GENERAL, SG_ALERT, + "Attempt to set write flag for non-existant property " + << name); + else + node->setAttribute(SGPropertyNode::WRITE, state); +} + + //////////////////////////////////////////////////////////////////////// // Convenience functions for tying properties, with logging. //////////////////////////////////////////////////////////////////////// + +/** + * Untie a property from an external data source. + * + * Classes should use this function to release control of any + * properties they are managing. + */ inline void fgUntie (const string &name) { @@ -124,6 +429,19 @@ fgUntie (const string &name) // Templates cause ambiguity here + +/** + * Tie a property to an external bool variable. + * + * The property's value will automatically mirror the variable's + * value, and vice-versa, until the property is untied. + * + * @param name The property name to tie (full path). + * @param pointer A pointer to the variable. + * @param useDefault true if any existing property value should be + * copied to the variable; false if the variable should not + * be modified; defaults to true. + */ inline void fgTie (const string &name, bool *pointer, bool useDefault = true) { @@ -133,6 +451,19 @@ fgTie (const string &name, bool *pointer, bool useDefault = true) "Failed to tie property " << name << " to a pointer"); } + +/** + * Tie a property to an external int variable. + * + * The property's value will automatically mirror the variable's + * value, and vice-versa, until the property is untied. + * + * @param name The property name to tie (full path). + * @param pointer A pointer to the variable. + * @param useDefault true if any existing property value should be + * copied to the variable; false if the variable should not + * be modified; defaults to true. + */ inline void fgTie (const string &name, int *pointer, bool useDefault = true) { @@ -142,6 +473,19 @@ fgTie (const string &name, int *pointer, bool useDefault = true) "Failed to tie property " << name << " to a pointer"); } + +/** + * Tie a property to an external long variable. + * + * The property's value will automatically mirror the variable's + * value, and vice-versa, until the property is untied. + * + * @param name The property name to tie (full path). + * @param pointer A pointer to the variable. + * @param useDefault true if any existing property value should be + * copied to the variable; false if the variable should not + * be modified; defaults to true. + */ inline void fgTie (const string &name, long *pointer, bool useDefault = true) { @@ -151,6 +495,19 @@ fgTie (const string &name, long *pointer, bool useDefault = true) "Failed to tie property " << name << " to a pointer"); } + +/** + * Tie a property to an external float variable. + * + * The property's value will automatically mirror the variable's + * value, and vice-versa, until the property is untied. + * + * @param name The property name to tie (full path). + * @param pointer A pointer to the variable. + * @param useDefault true if any existing property value should be + * copied to the variable; false if the variable should not + * be modified; defaults to true. + */ inline void fgTie (const string &name, float *pointer, bool useDefault = true) { @@ -160,6 +517,19 @@ fgTie (const string &name, float *pointer, bool useDefault = true) "Failed to tie property " << name << " to a pointer"); } + +/** + * Tie a property to an external double variable. + * + * The property's value will automatically mirror the variable's + * value, and vice-versa, until the property is untied. + * + * @param name The property name to tie (full path). + * @param pointer A pointer to the variable. + * @param useDefault true if any existing property value should be + * copied to the variable; false if the variable should not + * be modified; defaults to true. + */ inline void fgTie (const string &name, double *pointer, bool useDefault = true) { @@ -169,6 +539,19 @@ fgTie (const string &name, double *pointer, bool useDefault = true) "Failed to tie property " << name << " to a pointer"); } + +/** + * Tie a property to an external string variable. + * + * The property's value will automatically mirror the variable's + * value, and vice-versa, until the property is untied. + * + * @param name The property name to tie (full path). + * @param pointer A pointer to the variable. + * @param useDefault true if any existing property value should be + * copied to the variable; false if the variable should not + * be modified; defaults to true. + */ inline void fgTie (const string &name, string *pointer, bool useDefault = true) { @@ -178,6 +561,23 @@ fgTie (const string &name, string *pointer, bool useDefault = true) "Failed to tie property " << name << " to a pointer"); } + +/** + * Tie a property to a pair of simple functions. + * + * Every time the property value is queried, the getter (if any) will + * be invoked; every time the property value is modified, the setter + * (if any) will be invoked. The getter can be 0 to make the property + * unreadable, and the setter can be 0 to make the property + * unmodifiable. + * + * @param name The property name to tie (full path). + * @param getter The getter function, or 0 if the value is unreadable. + * @param setter The setter function, or 0 if the value is unmodifiable. + * @param useDefault true if the setter should be invoked with any existing + * property value should be; false if the old value should be + * discarded; defaults to true. + */ template inline void fgTie (const string &name, V (*getter)(), void (*setter)(V) = 0, @@ -189,6 +589,25 @@ fgTie (const string &name, V (*getter)(), void (*setter)(V) = 0, "Failed to tie property " << name << " to functions"); } + +/** + * Tie a property to a pair of indexed functions. + * + * Every time the property value is queried, the getter (if any) will + * be invoked with the index provided; every time the property value + * is modified, the setter (if any) will be invoked with the index + * provided. The getter can be 0 to make the property unreadable, and + * the setter can be 0 to make the property unmodifiable. + * + * @param name The property name to tie (full path). + * @param index The integer argument to pass to the getter and + * setter functions. + * @param getter The getter function, or 0 if the value is unreadable. + * @param setter The setter function, or 0 if the value is unmodifiable. + * @param useDefault true if the setter should be invoked with any existing + * property value should be; false if the old value should be + * discarded; defaults to true. + */ template inline void fgTie (const string &name, int index, V (*getter)(int), @@ -203,6 +622,26 @@ fgTie (const string &name, int index, V (*getter)(int), "Failed to tie property " << name << " to indexed functions"); } + +/** + * Tie a property to a pair of object methods. + * + * Every time the property value is queried, the getter (if any) will + * be invoked; every time the property value is modified, the setter + * (if any) will be invoked. The getter can be 0 to make the property + * unreadable, and the setter can be 0 to make the property + * unmodifiable. + * + * @param name The property name to tie (full path). + * @param obj The object whose methods should be invoked. + * @param getter The object's getter method, or 0 if the value is + * unreadable. + * @param setter The object's setter method, or 0 if the value is + * unmodifiable. + * @param useDefault true if the setter should be invoked with any existing + * property value should be; false if the old value should be + * discarded; defaults to true. + */ template inline void fgTie (const string &name, T * obj, V (T::*getter)() const, @@ -215,6 +654,26 @@ fgTie (const string &name, T * obj, V (T::*getter)() const, "Failed to tie property " << name << " to object methods"); } + +/** + * Tie a property to a pair of indexed object methods. + * + * Every time the property value is queried, the getter (if any) will + * be invoked with the index provided; every time the property value + * is modified, the setter (if any) will be invoked with the index + * provided. The getter can be 0 to make the property unreadable, and + * the setter can be 0 to make the property unmodifiable. + * + * @param name The property name to tie (full path). + * @param obj The object whose methods should be invoked. + * @param index The integer argument to pass to the getter and + * setter methods. + * @param getter The getter method, or 0 if the value is unreadable. + * @param setter The setter method, or 0 if the value is unmodifiable. + * @param useDefault true if the setter should be invoked with any existing + * property value should be; false if the old value should be + * discarded; defaults to true. + */ template inline void fgTie (const string &name, T * obj, int index,