693 lines
21 KiB
C++
693 lines
21 KiB
C++
// fg_props.hxx - Declarations and inline methods for property handling.
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// Written by David Megginson, started 2000.
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//
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// This file is in the Public Domain, and comes with no warranty.
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#ifndef __FG_PROPS_HXX
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#define __FG_PROPS_HXX 1
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#include <simgear/debug/logstream.hxx>
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#include <simgear/misc/props.hxx>
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#include <simgear/misc/props_io.hxx>
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#include "globals.hxx"
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////////////////////////////////////////////////////////////////////////
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// Property management.
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////////////////////////////////////////////////////////////////////////
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/**
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* Initialize the default FlightGear properties.
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*
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* These are mostly properties that haven't been claimed by a
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* specific module yet. This function should be invoked once,
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* while the program is starting (and after the global property
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* tree has been created).
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*/
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extern void fgInitProps (); // fixme: how are they untied?
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/**
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* Update the default FlightGear properties.
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*
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* This function should be invoked once in each loop to update all
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* of the default properties.
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*/
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extern void fgUpdateProps ();
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/**
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* Save a flight to disk.
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*
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* This function saves all of the archivable properties to a stream
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* so that the current flight can be restored later.
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*
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* @param output The output stream to write the XML save file to.
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* @param write_all If true, write all properties rather than
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* just the ones flagged as archivable.
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* @return true if the flight was saved successfully.
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*/
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extern bool fgSaveFlight (ostream &output, bool write_all = false);
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/**
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* Load a flight from disk.
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*
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* This function loads an XML save file from a stream to restore
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* a flight.
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*
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* @param input The input stream to read the XML from.
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* @return true if the flight was restored successfully.
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*/
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extern bool fgLoadFlight (istream &input);
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/**
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* Load properties from a file relative to $FG_ROOT.
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*
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* @param file The file name relative to $FG_ROOT.
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*/
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extern void fgLoadProps (const char * path, SGPropertyNode * props);
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////////////////////////////////////////////////////////////////////////
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// Convenience functions for getting property values.
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////////////////////////////////////////////////////////////////////////
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/**
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* Get a property node.
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*
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* @param path The path of the node, relative to root.
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* @param create true to create the node if it doesn't exist.
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* @return The node, or 0 if none exists and none was created.
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*/
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extern SGPropertyNode * fgGetNode (const char * path, bool create = false);
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/**
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* Get a property node with separate index.
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*
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* This method separates the index from the path string, to make it
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* easier to iterate through multiple components without using sprintf
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* to add indices. For example, fgGetNode("foo[1]/bar", 3) will
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* return the same result as fgGetNode("foo[1]/bar[3]").
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*
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* @param path The path of the node, relative to root.
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* @param index The index for the last member of the path (overrides
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* any given in the string).
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* @param create true to create the node if it doesn't exist.
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* @return The node, or 0 if none exists and none was created.
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*/
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extern SGPropertyNode * fgGetNode (const char * path,
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int index, bool create = false);
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/**
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* Test whether a given node exists.
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*
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* @param path The path of the node, relative to root.
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* @return true if the node exists, false otherwise.
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*/
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extern bool fgHasNode (const char * path);
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/**
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* Add a listener to a node.
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*
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* @param listener The listener to add to the node.
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* @param path The path of the node, relative to root.
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* @param index The index for the last member of the path (overrides
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* any given in the string).
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*/
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extern void fgAddChangeListener (SGPropertyChangeListener * listener,
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const char * path);
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/**
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* Add a listener to a node.
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*
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* @param listener The listener to add to the node.
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* @param path The path of the node, relative to root.
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* @param index The index for the last member of the path (overrides
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* any given in the string).
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*/
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extern void fgAddChangeListener (SGPropertyChangeListener * listener,
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const char * path, int index);
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/**
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* Get a bool value for a property.
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*
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* This method is convenient but inefficient. It should be used
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* infrequently (i.e. for initializing, loading, saving, etc.),
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* not in the main loop. If you need to get a value frequently,
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* it is better to look up the node itself using fgGetNode and then
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* use the node's getBoolValue() method, to avoid the lookup overhead.
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*
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* @param name The property name.
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* @param defaultValue The default value to return if the property
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* does not exist.
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* @return The property's value as a bool, or the default value provided.
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*/
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extern bool fgGetBool (const char * name, bool defaultValue = false);
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/**
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* Get an int value for a property.
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*
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* This method is convenient but inefficient. It should be used
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* infrequently (i.e. for initializing, loading, saving, etc.),
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* not in the main loop. If you need to get a value frequently,
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* it is better to look up the node itself using fgGetNode and then
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* use the node's getIntValue() method, to avoid the lookup overhead.
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*
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* @param name The property name.
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* @param defaultValue The default value to return if the property
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* does not exist.
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* @return The property's value as an int, or the default value provided.
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*/
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extern int fgGetInt (const char * name, int defaultValue = 0);
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/**
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* Get a long value for a property.
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*
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* This method is convenient but inefficient. It should be used
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* infrequently (i.e. for initializing, loading, saving, etc.),
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* not in the main loop. If you need to get a value frequently,
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* it is better to look up the node itself using fgGetNode and then
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* use the node's getLongValue() method, to avoid the lookup overhead.
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*
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* @param name The property name.
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* @param defaultValue The default value to return if the property
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* does not exist.
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* @return The property's value as a long, or the default value provided.
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*/
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extern int fgGetLong (const char * name, long defaultValue = 0L);
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/**
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* Get a float value for a property.
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*
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* This method is convenient but inefficient. It should be used
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* infrequently (i.e. for initializing, loading, saving, etc.),
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* not in the main loop. If you need to get a value frequently,
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* it is better to look up the node itself using fgGetNode and then
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* use the node's getFloatValue() method, to avoid the lookup overhead.
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*
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* @param name The property name.
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* @param defaultValue The default value to return if the property
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* does not exist.
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* @return The property's value as a float, or the default value provided.
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*/
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extern float fgGetFloat (const char * name, float defaultValue = 0.0);
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/**
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* Get a double value for a property.
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*
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* This method is convenient but inefficient. It should be used
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* infrequently (i.e. for initializing, loading, saving, etc.),
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* not in the main loop. If you need to get a value frequently,
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* it is better to look up the node itself using fgGetNode and then
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* use the node's getDoubleValue() method, to avoid the lookup overhead.
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*
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* @param name The property name.
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* @param defaultValue The default value to return if the property
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* does not exist.
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* @return The property's value as a double, or the default value provided.
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*/
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extern double fgGetDouble (const char * name, double defaultValue = 0.0);
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/**
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* Get a string value for a property.
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*
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* This method is convenient but inefficient. It should be used
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* infrequently (i.e. for initializing, loading, saving, etc.),
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* not in the main loop. If you need to get a value frequently,
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* it is better to look up the node itself using fgGetNode and then
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* use the node's getStringValue() method, to avoid the lookup overhead.
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*
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* @param name The property name.
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* @param defaultValue The default value to return if the property
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* does not exist.
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* @return The property's value as a string, or the default value provided.
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*/
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extern const char * fgGetString (const char * name,
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const char * defaultValue = "");
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/**
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* Set a bool value for a property.
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*
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* Assign a bool value to a property. If the property does not
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* yet exist, it will be created and its type will be set to
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* BOOL; if it has a type of UNKNOWN, the type will also be set to
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* BOOL; otherwise, the bool value will be converted to the property's
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* type.
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*
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* @param name The property name.
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* @param val The new value for the property.
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* @return true if the assignment succeeded, false otherwise.
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*/
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extern bool fgSetBool (const char * name, bool val);
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/**
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* Set an int value for a property.
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*
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* Assign an int value to a property. If the property does not
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* yet exist, it will be created and its type will be set to
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* INT; if it has a type of UNKNOWN, the type will also be set to
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* INT; otherwise, the bool value will be converted to the property's
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* type.
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*
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* @param name The property name.
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* @param val The new value for the property.
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* @return true if the assignment succeeded, false otherwise.
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*/
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extern bool fgSetInt (const char * name, int val);
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/**
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* Set a long value for a property.
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*
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* Assign a long value to a property. If the property does not
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* yet exist, it will be created and its type will be set to
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* LONG; if it has a type of UNKNOWN, the type will also be set to
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* LONG; otherwise, the bool value will be converted to the property's
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* type.
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*
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* @param name The property name.
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* @param val The new value for the property.
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* @return true if the assignment succeeded, false otherwise.
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*/
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extern bool fgSetLong (const char * name, long val);
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/**
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* Set a float value for a property.
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*
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* Assign a float value to a property. If the property does not
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* yet exist, it will be created and its type will be set to
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* FLOAT; if it has a type of UNKNOWN, the type will also be set to
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* FLOAT; otherwise, the bool value will be converted to the property's
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* type.
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*
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* @param name The property name.
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* @param val The new value for the property.
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* @return true if the assignment succeeded, false otherwise.
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*/
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extern bool fgSetFloat (const char * name, float val);
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/**
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* Set a double value for a property.
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*
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* Assign a double value to a property. If the property does not
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* yet exist, it will be created and its type will be set to
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* DOUBLE; if it has a type of UNKNOWN, the type will also be set to
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* DOUBLE; otherwise, the double value will be converted to the property's
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* type.
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*
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* @param name The property name.
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* @param val The new value for the property.
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* @return true if the assignment succeeded, false otherwise.
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*/
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extern bool fgSetDouble (const char * name, double val);
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/**
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* Set a string value for a property.
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*
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* Assign a string value to a property. If the property does not
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* yet exist, it will be created and its type will be set to
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* STRING; if it has a type of UNKNOWN, the type will also be set to
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* STRING; otherwise, the string value will be converted to the property's
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* type.
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*
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* @param name The property name.
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* @param val The new value for the property.
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* @return true if the assignment succeeded, false otherwise.
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*/
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extern bool fgSetString (const char * name, const char * val);
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////////////////////////////////////////////////////////////////////////
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// Convenience functions for setting property attributes.
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////////////////////////////////////////////////////////////////////////
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/**
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* Set the state of the archive attribute for a property.
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*
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* If the archive attribute is true, the property will be written
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* when a flight is saved; if it is false, the property will be
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* skipped.
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*
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* A warning message will be printed if the property does not exist.
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*
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* @param name The property name.
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* @param state The state of the archive attribute (defaults to true).
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*/
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extern void fgSetArchivable (const char * name, bool state = true);
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/**
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* Set the state of the read attribute for a property.
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*
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* If the read attribute is true, the property value will be readable;
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* if it is false, the property value will always be the default value
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* for its type.
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*
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* A warning message will be printed if the property does not exist.
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*
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* @param name The property name.
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* @param state The state of the read attribute (defaults to true).
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*/
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extern void fgSetReadable (const char * name, bool state = true);
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/**
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* Set the state of the write attribute for a property.
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*
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* If the write attribute is true, the property value may be modified
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* (depending on how it is tied); if the write attribute is false, the
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* property value may not be modified.
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*
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* A warning message will be printed if the property does not exist.
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*
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* @param name The property name.
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* @param state The state of the write attribute (defaults to true).
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*/
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extern void fgSetWritable (const char * name, bool state = true);
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////////////////////////////////////////////////////////////////////////
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// Convenience functions for tying properties, with logging.
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////////////////////////////////////////////////////////////////////////
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/**
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* Untie a property from an external data source.
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*
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* Classes should use this function to release control of any
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* properties they are managing.
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*/
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extern void fgUntie (const char * name);
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/**
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* Tie a property to a pair of simple functions.
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*
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* Every time the property value is queried, the getter (if any) will
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* be invoked; every time the property value is modified, the setter
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* (if any) will be invoked. The getter can be 0 to make the property
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* unreadable, and the setter can be 0 to make the property
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* unmodifiable.
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*
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* @param name The property name to tie (full path).
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* @param getter The getter function, or 0 if the value is unreadable.
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* @param setter The setter function, or 0 if the value is unmodifiable.
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* @param useDefault true if the setter should be invoked with any existing
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* property value should be; false if the old value should be
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* discarded; defaults to true.
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*/
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template <class V>
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inline void
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fgTie (const char * name, V (*getter)(), void (*setter)(V) = 0,
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bool useDefault = true)
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{
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if (!globals->get_props()->tie(name, SGRawValueFunctions<V>(getter, setter),
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useDefault))
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SG_LOG(SG_GENERAL, SG_WARN,
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"Failed to tie property " << name << " to functions");
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}
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/**
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* Tie a property to a pair of indexed functions.
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*
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* Every time the property value is queried, the getter (if any) will
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* be invoked with the index provided; every time the property value
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* is modified, the setter (if any) will be invoked with the index
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* provided. The getter can be 0 to make the property unreadable, and
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* the setter can be 0 to make the property unmodifiable.
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*
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* @param name The property name to tie (full path).
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* @param index The integer argument to pass to the getter and
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* setter functions.
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* @param getter The getter function, or 0 if the value is unreadable.
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* @param setter The setter function, or 0 if the value is unmodifiable.
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* @param useDefault true if the setter should be invoked with any existing
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* property value should be; false if the old value should be
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* discarded; defaults to true.
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*/
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template <class V>
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inline void
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fgTie (const char * name, int index, V (*getter)(int),
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void (*setter)(int, V) = 0, bool useDefault = true)
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{
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if (!globals->get_props()->tie(name,
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SGRawValueFunctionsIndexed<V>(index,
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getter,
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setter),
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useDefault))
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SG_LOG(SG_GENERAL, SG_WARN,
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"Failed to tie property " << name << " to indexed functions");
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}
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/**
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* Tie a property to a pair of object methods.
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*
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* Every time the property value is queried, the getter (if any) will
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* be invoked; every time the property value is modified, the setter
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* (if any) will be invoked. The getter can be 0 to make the property
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* unreadable, and the setter can be 0 to make the property
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* unmodifiable.
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*
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* @param name The property name to tie (full path).
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* @param obj The object whose methods should be invoked.
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* @param getter The object's getter method, or 0 if the value is
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* unreadable.
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* @param setter The object's setter method, or 0 if the value is
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* unmodifiable.
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* @param useDefault true if the setter should be invoked with any existing
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* property value should be; false if the old value should be
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* discarded; defaults to true.
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*/
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template <class T, class V>
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inline void
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fgTie (const char * name, T * obj, V (T::*getter)() const,
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void (T::*setter)(V) = 0, bool useDefault = true)
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{
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if (!globals->get_props()->tie(name,
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SGRawValueMethods<T,V>(*obj, getter, setter),
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useDefault))
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SG_LOG(SG_GENERAL, SG_WARN,
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"Failed to tie property " << name << " to object methods");
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}
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/**
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* Tie a property to a pair of indexed object methods.
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*
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* Every time the property value is queried, the getter (if any) will
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* be invoked with the index provided; every time the property value
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* is modified, the setter (if any) will be invoked with the index
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* provided. The getter can be 0 to make the property unreadable, and
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* the setter can be 0 to make the property unmodifiable.
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*
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* @param name The property name to tie (full path).
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* @param obj The object whose methods should be invoked.
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* @param index The integer argument to pass to the getter and
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* setter methods.
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* @param getter The getter method, or 0 if the value is unreadable.
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* @param setter The setter method, or 0 if the value is unmodifiable.
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* @param useDefault true if the setter should be invoked with any existing
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* property value should be; false if the old value should be
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* discarded; defaults to true.
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*/
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template <class T, class V>
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inline void
|
||
fgTie (const char * name, T * obj, int index,
|
||
V (T::*getter)(int) const, void (T::*setter)(int, V) = 0,
|
||
bool useDefault = true)
|
||
{
|
||
if (!globals->get_props()->tie(name,
|
||
SGRawValueMethodsIndexed<T,V>(*obj,
|
||
index,
|
||
getter,
|
||
setter),
|
||
useDefault))
|
||
SG_LOG(SG_GENERAL, SG_WARN,
|
||
"Failed to tie property " << name << " to indexed object methods");
|
||
}
|
||
|
||
|
||
|
||
////////////////////////////////////////////////////////////////////////
|
||
// Conditions.
|
||
////////////////////////////////////////////////////////////////////////
|
||
|
||
|
||
/**
|
||
* An encoded condition.
|
||
*
|
||
* This class encodes a single condition of some sort, possibly
|
||
* connected with properties.
|
||
*
|
||
* This class should migrate to somewhere more general.
|
||
*/
|
||
class FGCondition
|
||
{
|
||
public:
|
||
FGCondition ();
|
||
virtual ~FGCondition ();
|
||
virtual bool test () const = 0;
|
||
};
|
||
|
||
|
||
/**
|
||
* Condition for a single property.
|
||
*
|
||
* This condition is true only if the property returns a boolean
|
||
* true value.
|
||
*/
|
||
class FGPropertyCondition : public FGCondition
|
||
{
|
||
public:
|
||
FGPropertyCondition (const char * propname);
|
||
virtual ~FGPropertyCondition ();
|
||
virtual bool test () const { return _node->getBoolValue(); }
|
||
private:
|
||
const SGPropertyNode * _node;
|
||
};
|
||
|
||
|
||
/**
|
||
* Condition for a 'not' operator.
|
||
*
|
||
* This condition is true only if the child condition is false.
|
||
*/
|
||
class FGNotCondition : public FGCondition
|
||
{
|
||
public:
|
||
// transfer pointer ownership
|
||
FGNotCondition (FGCondition * condition);
|
||
virtual ~FGNotCondition ();
|
||
virtual bool test () const;
|
||
private:
|
||
FGCondition * _condition;
|
||
};
|
||
|
||
|
||
/**
|
||
* Condition for an 'and' group.
|
||
*
|
||
* This condition is true only if all of the conditions
|
||
* in the group are true.
|
||
*/
|
||
class FGAndCondition : public FGCondition
|
||
{
|
||
public:
|
||
FGAndCondition ();
|
||
virtual ~FGAndCondition ();
|
||
virtual bool test () const;
|
||
// transfer pointer ownership
|
||
virtual void addCondition (FGCondition * condition);
|
||
private:
|
||
vector<FGCondition *> _conditions;
|
||
};
|
||
|
||
|
||
/**
|
||
* Condition for an 'or' group.
|
||
*
|
||
* This condition is true if at least one of the conditions in the
|
||
* group is true.
|
||
*/
|
||
class FGOrCondition : public FGCondition
|
||
{
|
||
public:
|
||
FGOrCondition ();
|
||
virtual ~FGOrCondition ();
|
||
virtual bool test () const;
|
||
// transfer pointer ownership
|
||
virtual void addCondition (FGCondition * condition);
|
||
private:
|
||
vector<FGCondition *> _conditions;
|
||
};
|
||
|
||
|
||
/**
|
||
* Abstract base class for property comparison conditions.
|
||
*/
|
||
class FGComparisonCondition : public FGCondition
|
||
{
|
||
public:
|
||
enum Type {
|
||
LESS_THAN,
|
||
GREATER_THAN,
|
||
EQUALS
|
||
};
|
||
FGComparisonCondition (Type type, bool reverse = false);
|
||
virtual ~FGComparisonCondition ();
|
||
virtual bool test () const;
|
||
virtual void setLeftProperty (const char * propname);
|
||
virtual void setRightProperty (const char * propname);
|
||
// will make a local copy
|
||
virtual void setRightValue (const SGPropertyNode * value);
|
||
private:
|
||
Type _type;
|
||
bool _reverse;
|
||
const SGPropertyNode * _left_property;
|
||
const SGPropertyNode * _right_property;
|
||
const SGPropertyNode * _right_value;
|
||
};
|
||
|
||
|
||
/**
|
||
* Base class for a conditional components.
|
||
*
|
||
* This class manages the conditions and tests; the component should
|
||
* invoke the test() method whenever it needs to decide whether to
|
||
* active itself, draw itself, and so on.
|
||
*/
|
||
class FGConditional
|
||
{
|
||
public:
|
||
FGConditional ();
|
||
virtual ~FGConditional ();
|
||
// transfer pointer ownership
|
||
virtual void setCondition (FGCondition * condition);
|
||
virtual const FGCondition * getCondition () const { return _condition; }
|
||
virtual bool test () const;
|
||
private:
|
||
FGCondition * _condition;
|
||
};
|
||
|
||
|
||
/**
|
||
* Global function to make a condition out of properties.
|
||
*
|
||
* The top-level is always an implicit 'and' group, whatever the
|
||
* node's name (it should usually be "condition").
|
||
*
|
||
* @param node The top-level condition node (usually named "condition").
|
||
* @return A pointer to a newly-allocated condition; it is the
|
||
* responsibility of the caller to delete the condition when
|
||
* it is no longer needed.
|
||
*/
|
||
FGCondition * fgReadCondition (const SGPropertyNode * node);
|
||
|
||
|
||
#endif // __FG_PROPS_HXX
|
||
|