-// props.hxx - interface definition for a property list.
-// Started Fall 2000 by David Megginson, david@megginson.com
-// This code is released into the Public Domain.
-//
-// See props.html for documentation [replace with URL when available].
-//
-// $Id$
+/**
+ * \file props.hxx
+ * Interface definition for a property list.
+ * Started Fall 2000 by David Megginson, david@megginson.com
+ * This code is released into the Public Domain.
+ *
+ * See props.html for documentation [replace with URL when available].
+ *
+ * $Id$
+ */
#ifndef __PROPS_HXX
#define __PROPS_HXX
-#ifdef HAVE_CONFIG_H
-#include <config.h>
-#endif
-
#include <simgear/compiler.h>
#include <stdio.h>
#undef ALIAS
#endif
-#ifdef UNKNOWN
-#pragma warn A sloppy coder has defined UNKNOWN as a macro!
-#undef UNKNOWN
+#ifdef UNSPECIFIED
+#pragma warn A sloppy coder has defined UNSPECIFIED as a macro!
+#undef UNSPECIFIED
#endif
#ifdef BOOL
/**
* Abstract base class for a raw value.
*
- * Unlike values, raw values are not persistent -- the raw value can
- * change frequently, but the changes are not visible to the application.
+ * The property manager is implemented in three layers. The {@link
+ * SGPropertyNode} is the highest and most abstract layer,
+ * representing * an LValue/RValue pair: it * records the position
+ * of the property in the property tree and * contains facilities
+ * for navigation to other nodes. Each node * may contain an {@link
+ * SGValue}, which is guaranteed persistent: the * {@link SGValue}
+ * will not change during a session, even if the * property is bound
+ * and unbound multiple times. The SGValue is the * abstraction of
+ * an RValue: it allows for conversion among all of the different
+ * types, and can be bound to external pointers, functions, methods,
+ * or other data sources. Every SGValue contains an SGRawValue of
+ * a specific type. The SGRawValue (this class) may change frequently
+ * during a session as a value is retyped or bound and unbound to
+ * various data source, but the abstract SGValue layer insulates
+ * the application from those changes. The raw value contains no
+ * facilities for data binding or for type conversion: it is simply
+ * the abstraction of a primitive data type (or a compound data
+ * type, in the case of a string).
*
* The SGValue class always keeps a *copy* of a raw value, not the
* original one passed to it; if you override a derived class but do
- * not replace the clone() method, strange things will happen.
+ * not replace the {@link #clone} method, strange things will happen.
*
- * All raw values must implement getValue, setValue, and clone for the
- * appropriate type.
- */
+ * All raw values must implement {@link #getValue}, {@link #setValue},
+ * and {@link #clone} for the appropriate type.
+ *
+ * @see SGValue
+ * @see SGPropertyNode */
template <class T>
class SGRawValue
{
public:
+
+ /**
+ * The default underlying value for this type.
+ *
+ * Every raw value has a default; the default is false for a
+ * boolean, 0 for the various numeric values, and "" for a string.
+ * If additional types of raw values are added in the future, they
+ * may need different kinds of default values (such as epoch for a
+ * date type). The default value is used when creating new values.
+ */
static const T DefaultValue; // Default for this kind of raw value.
+
+ /**
+ * Constructor.
+ *
+ * Use the default value for this type.
+ */
SGRawValue () {}
+
+
+ /**
+ * Destructor.
+ */
virtual ~SGRawValue () {}
+
+
+ /**
+ * Return the underlying value.
+ *
+ * @return The actual value for the property.
+ * @see #setValue
+ */
virtual T getValue () const = 0;
+
+
+ /**
+ * Assign a new underlying value.
+ *
+ * If the new value cannot be set (because this is a read-only
+ * raw value, or because the new value is not acceptable for
+ * some reason) this method returns false and leaves the original
+ * value unchanged.
+ *
+ * @param value The actual value for the property.
+ * @return true if the value was set successfully, false otherwise.
+ * @see #getValue
+ */
virtual bool setValue (T value) = 0;
+
+
+ /**
+ * Create a new deep copy of this raw value.
+ *
+ * The copy will contain its own version of the underlying value
+ * as well.
+ *
+ * @return A deep copy of the current object.
+ */
virtual SGRawValue * clone () const = 0;
};
/**
- * A value managed internally.
+ * An unbound raw value, stored internally.
*
* Instances of this class are created automatically, by default,
* by the SGValue class; ordinarily the application should not
class SGRawValueInternal : public SGRawValue<T>
{
public:
+
+ /**
+ * Default constructor.
+ *
+ * Initialize with the default value for this type.
+ */
SGRawValueInternal () {}
+
+ /**
+ * Explicit value constructor.
+ *
+ * Initialize with the underlying value provided.
+ *
+ * @param value The initial value for this property.
+ */
SGRawValueInternal (T value) : _value(value) {}
+
+ /**
+ * Destructor.
+ */
virtual ~SGRawValueInternal () {}
+
+ /**
+ * Get the underlying value.
+ */
virtual T getValue () const { return _value; }
+
+ /**
+ * Set the underlying value.
+ */
virtual bool setValue (T value) { _value = value; return true; }
+
+ /**
+ * Create a deep copy of this raw value.
+ */
virtual SGRawValue<T> * clone () const {
return new SGRawValueInternal<T>(_value);
}
+
private:
T _value;
};
/**
- * A value managed through a direct pointer.
+ * A raw value bound to a pointer.
*
* This is the most efficient way to tie an external value, but also
* the most dangerous, because there is no way for the supplier to
* perform bounds checking and derived calculations except by polling
- * the variable to see if it has changed.
+ * the variable to see if it has changed. There is no default
+ * constructor, because this class would be meaningless without a
+ * pointer.
*/
template <class T>
class SGRawValuePointer : public SGRawValue<T>
{
public:
+
+ /**
+ * Explicit pointer constructor.
+ *
+ * Create a new raw value bound to the value of the variable
+ * referenced by the pointer.
+ *
+ * @param ptr The pointer to the variable to which this raw value
+ * will be bound.
+ */
SGRawValuePointer (T * ptr) : _ptr(ptr) {}
+
+ /**
+ * Destructor.
+ */
virtual ~SGRawValuePointer () {}
+
+ /**
+ * Get the underlying value.
+ *
+ * This method will dereference the pointer and return the
+ * variable's value.
+ */
virtual T getValue () const { return *_ptr; }
+
+ /**
+ * Set the underlying value.
+ *
+ * This method will dereference the pointer and change the
+ * variable's value.
+ */
virtual bool setValue (T value) { *_ptr = value; return true; }
+
+ /**
+ * Create a copy of this raw value.
+ *
+ * The copy will use the same external pointer as the original.
+ */
virtual SGRawValue<T> * clone () const {
return new SGRawValuePointer<T>(_ptr);
}
+
private:
T * _ptr;
};
class SGRawValueFunctions : public SGRawValue<T>
{
public:
+
+ /**
+ * The template type of a static getter function.
+ */
typedef T (*getter_t)();
+
+ /**
+ * The template type of a static setter function.
+ */
typedef void (*setter_t)(T);
+
+ /**
+ * Explicit constructor.
+ *
+ * Create a new raw value bound to the getter and setter supplied.
+ *
+ * @param getter A static function for getting a value, or 0
+ * to read-disable the value.
+ * @param setter A static function for setting a value, or 0
+ * to write-disable the value.
+ */
SGRawValueFunctions (getter_t getter = 0, setter_t setter = 0)
: _getter(getter), _setter(setter) {}
+
+ /**
+ * Destructor.
+ */
virtual ~SGRawValueFunctions () {}
+
+ /**
+ * Get the underlying value.
+ *
+ * This method will invoke the getter function to get a value.
+ * If no getter function was supplied, this method will always
+ * return the default value for the type.
+ */
virtual T getValue () const {
if (_getter) return (*_getter)();
else return SGRawValue<T>::DefaultValue;
}
+
+ /**
+ * Set the underlying value.
+ *
+ * This method will invoke the setter function to change the
+ * underlying value. If no setter function was supplied, this
+ * method will return false.
+ */
virtual bool setValue (T value) {
if (_setter) { (*_setter)(value); return true; }
else return false;
}
+
+ /**
+ * Create a copy of this raw value, bound to the same functions.
+ */
virtual SGRawValue<T> * clone () const {
return new SGRawValueFunctions<T>(_getter,_setter);
}
+
private:
getter_t _getter;
setter_t _setter;
/**
- * An indexed value managed through static functions.
+ * An indexed value bound to static functions.
*
* A read-only value will not have a setter; a write-only value will
- * not have a getter.
+ * not have a getter. An indexed value is useful for binding one
+ * of a list of possible values (such as multiple engines for a
+ * plane). The index is hard-coded at creation time.
*/
template <class T>
class SGRawValueFunctionsIndexed : public SGRawValue<T>
\f
-////////////////////////////////////////////////////////////////////////
-// A cooked value.
-//
-// This is the value that property-list clients see. It is a
-// persistent layer over the possibly-changing raw value; once a
-// client gets an SGValue from the property manager, the pointer
-// will be good for the life of the property manager itself, no
-// matter how often the pointer is tied or untied.
-////////////////////////////////////////////////////////////////////////
-
-class SGValue
+/**
+ * A node in a property tree.
+ */
+class SGPropertyNode
{
+
public:
+
+
+ /**
+ * Property value types.
+ */
enum Type {
+ NONE,
+ ALIAS,
BOOL,
INT,
LONG,
FLOAT,
DOUBLE,
STRING,
- UNKNOWN
+ UNSPECIFIED
};
- SGValue ();
- SGValue (const SGValue &value);
- ~SGValue ();
-
- Type getType () const;
- SGValue * getAlias ();
- const SGValue * getAlias () const;
- bool alias (SGValue * alias);
- bool unalias ();
- bool isAlias () const { return _type == ALIAS; }
- bool getBoolValue () const;
- int getIntValue () const;
- long getLongValue () const;
- float getFloatValue () const;
- double getDoubleValue () const;
- string getStringValue () const;
+ /**
+ * Access mode attributes.
+ *
+ * <p>The ARCHIVE attribute is strictly advisory, and controls
+ * whether the property should normally be saved and restored.</p>
+ */
+ enum Attribute {
+ READ = 1,
+ WRITE = 2,
+ ARCHIVE = 4
+ };
- bool setBoolValue (bool value);
- bool setIntValue (int value);
- bool setLongValue (long value);
- bool setFloatValue (float value);
- bool setDoubleValue (double value);
- bool setStringValue (string value);
- bool setUnknownValue (string value);
- bool isTied () const { return _tied; }
+ /**
+ * Default constructor.
+ */
+ SGPropertyNode ();
- bool tie (const SGRawValue<bool> &rawValue, bool useDefault = true);
- bool tie (const SGRawValue<int> &rawValue, bool useDefault = true);
- bool tie (const SGRawValue<long> &rawValue, bool useDefault = true);
- bool tie (const SGRawValue<float> &rawValue, bool useDefault = true);
- bool tie (const SGRawValue<double> &rawValue, bool useDefault = true);
- bool tie (const SGRawValue<string> &rawValue, bool useDefault = true);
- bool untie ();
+ /**
+ * Copy constructor.
+ */
+ SGPropertyNode (const SGPropertyNode &node);
-private:
- enum {
- ALIAS = -1
- };
+ /**
+ * Destructor.
+ */
+ virtual ~SGPropertyNode ();
- void clear_value ();
- int _type;
- bool _tied;
- // The right kind of pointer...
- union {
- SGValue * alias;
- SGRawValue<bool> * bool_val;
- SGRawValue<int> * int_val;
- SGRawValue<long> * long_val;
- SGRawValue<float> * float_val;
- SGRawValue<double> * double_val;
- SGRawValue<string> * string_val;
- } _value;
+ //
+ // Basic properties.
+ //
-};
+ /**
+ * Test whether this node contains a primitive leaf value.
+ */
+ bool hasValue () const { return (_type != NONE); }
-\f
-////////////////////////////////////////////////////////////////////////
-// A node in a property tree.
-////////////////////////////////////////////////////////////////////////
+ /**
+ * Get the node's simple (XML) name.
+ */
+ const string &getName () const { return _name; }
-class SGPropertyNode
-{
-public:
+ /**
+ * Get the node's integer index.
+ */
+ const int getIndex () const { return _index; }
- SGPropertyNode ();
- virtual ~SGPropertyNode ();
- // Basic properties.
- bool hasValue () const { return (_value != 0); }
- SGValue * getValue () { return _value; }
- SGValue * getValue (bool create);
- const SGValue * getValue () const { return _value; }
- const string &getName () const { return _name; }
- const int getIndex () const { return _index; }
+ /**
+ * Get a non-const pointer to the node's parent.
+ */
SGPropertyNode * getParent () { return _parent; }
+
+
+ /**
+ * Get a const pointer to the node's parent.
+ */
const SGPropertyNode * getParent () const { return _parent; }
- // Alias support.
- bool alias (SGPropertyNode * target);
- bool alias (const string &path);
- bool unalias ();
- bool isAlias () const;
- SGPropertyNode * getAliasTarget ();
- const SGPropertyNode * getAliasTarget () const;
- // Children.
+ //
+ // Children.
+ //
+
+
+ /**
+ * Get the number of child nodes.
+ */
const int nChildren () const { return _children.size(); }
+
+
+ /**
+ * Get a child node by position (*NOT* index).
+ */
SGPropertyNode * getChild (int position);
+
+
+ /**
+ * Get a const child node by position (*NOT* index).
+ */
const SGPropertyNode * getChild (int position) const;
+
+
+ /**
+ * Get a child node by name and index.
+ */
SGPropertyNode * getChild (const string &name, int index = 0,
bool create = false);
+
+
+ /**
+ * Get a const child node by name and index.
+ */
const SGPropertyNode * getChild (const string &name, int index = 0) const;
+
+ /**
+ * Get a vector of all children with the specified name.
+ */
vector<SGPropertyNode *> getChildren (const string &name);
+
+
+ /**
+ * Get a vector all all children (const) with the specified name.
+ */
vector<const SGPropertyNode *> getChildren (const string &name) const;
- // Path information.
+
+ //
+ // Alias support.
+ //
+
+
+ /**
+ * Alias this node's leaf value to another's.
+ */
+ bool alias (SGPropertyNode * target);
+
+
+ /**
+ * Alias this node's leaf value to another's by relative path.
+ */
+ bool alias (const string &path);
+
+
+ /**
+ * Remove any alias for this node.
+ */
+ bool unalias ();
+
+
+ /**
+ * Test whether the node's leaf value is aliased to another's.
+ */
+ bool isAlias () const { return (_type == ALIAS); }
+
+
+ /**
+ * Get a non-const pointer to the current alias target, if any.
+ */
+ SGPropertyNode * getAliasTarget ();
+
+
+ /**
+ * Get a const pointer to the current alias target, if any.
+ */
+ const SGPropertyNode * getAliasTarget () const;
+
+
+ //
+ // Path information.
+ //
+
+
+ /**
+ * Get the path to this node from the root.
+ */
string getPath (bool simplify = false) const;
- // Relative or absolute paths.
+
+ /**
+ * Get a pointer to the root node.
+ */
SGPropertyNode * getRootNode ();
+
+
+ /**
+ * Get a const pointer to the root node.
+ */
const SGPropertyNode * getRootNode () const;
+
+
+ /**
+ * Get a pointer to another node by relative path.
+ */
SGPropertyNode * getNode (const string &relative_path, bool create = false);
+
+
+ /**
+ * Get a const pointer to another node by relative path.
+ */
const SGPropertyNode * getNode (const string &relative_path) const;
- // Value-related stuff.
- SGValue::Type getType () const;
+
+ //
+ // Access Mode.
+ //
+
+ /**
+ * Check a single mode attribute for the property node.
+ */
+ bool getAttribute (Attribute attr) const { return (bool)(_attr & attr); }
+
+
+ /**
+ * Set a single mode attribute for the property node.
+ */
+ void setAttribute (Attribute attr, bool state) {
+ (state ? _attr |= attr : _attr &= ~attr);
+ }
+
+
+ /**
+ * Get all of the mode attributes for the property node.
+ */
+ int getAttributes () const { return _attr; }
+
+
+ /**
+ * Set all of the mode attributes for the property node.
+ */
+ void setAttributes (int attr) { _attr = attr; }
+
+ //
+ // Leaf Value (primitive).
+ //
+
+
+ /**
+ * Get the type of leaf value, if any, for this node.
+ */
+ Type getType () const;
+
+
+ /**
+ * Get a bool value for this node.
+ */
bool getBoolValue () const;
+
+
+ /**
+ * Get an int value for this node.
+ */
int getIntValue () const;
+
+
+ /**
+ * Get a long int value for this node.
+ */
long getLongValue () const;
+
+
+ /**
+ * Get a float value for this node.
+ */
float getFloatValue () const;
+
+
+ /**
+ * Get a double value for this node.
+ */
double getDoubleValue () const;
+
+
+ /**
+ * Get a string value for this node.
+ */
string getStringValue () const;
+
+
+ /**
+ * Set a bool value for this node.
+ */
bool setBoolValue (bool value);
+
+
+ /**
+ * Set an int value for this node.
+ */
bool setIntValue (int value);
+
+
+ /**
+ * Set a long int value for this node.
+ */
bool setLongValue (long value);
+
+
+ /**
+ * Set a float value for this node.
+ */
bool setFloatValue (float value);
+
+
+ /**
+ * Set a double value for this node.
+ */
bool setDoubleValue (double value);
+
+
+ /**
+ * Set a string value for this node.
+ */
bool setStringValue (string value);
- bool setUnknownValue (string value);
- bool isTied () const;
+ /**
+ * Set a value of unspecified type for this node.
+ */
+ bool setUnspecifiedValue (string value);
+
+
+ //
+ // Data binding.
+ //
+
+
+ /**
+ * Test whether this node is bound to an external data source.
+ */
+ bool isTied () const { return _tied; }
+
+
+ /**
+ * Bind this node to an external bool source.
+ */
bool tie (const SGRawValue<bool> &rawValue, bool useDefault = true);
+
+
+ /**
+ * Bind this node to an external int source.
+ */
bool tie (const SGRawValue<int> &rawValue, bool useDefault = true);
+
+
+ /**
+ * Bind this node to an external long int source.
+ */
bool tie (const SGRawValue<long> &rawValue, bool useDefault = true);
+
+
+ /**
+ * Bind this node to an external float source.
+ */
bool tie (const SGRawValue<float> &rawValue, bool useDefault = true);
+
+
+ /**
+ * Bind this node to an external double source.
+ */
bool tie (const SGRawValue<double> &rawValue, bool useDefault = true);
+
+
+ /**
+ * Bind this node to an external string source.
+ */
bool tie (const SGRawValue<string> &rawValue, bool useDefault = true);
+
+ /**
+ * Unbind this node from any external data source.
+ */
bool untie ();
- // Values from paths.
+
+ //
+ // Convenience methods using paths.
+ // TODO: add attribute methods
+ //
+
+
+ /**
+ * Get another node's type.
+ */
+ Type getType (const string &relative_path) const;
+
+
+ /**
+ * Test whether another node has a leaf value.
+ */
bool hasValue (const string &relative_path) const;
- SGValue * getValue (const string &relative_path, bool create = false);
- const SGValue * getValue (const string &relative_path) const;
- SGValue::Type getType (const string &relative_path) const;
-
+
+ /**
+ * Get another node's value as a bool.
+ */
bool getBoolValue (const string &relative_path,
bool defaultValue = false) const;
+
+
+ /**
+ * Get another node's value as an int.
+ */
int getIntValue (const string &relative_path,
int defaultValue = 0) const;
+
+
+ /**
+ * Get another node's value as a long int.
+ */
long getLongValue (const string &relative_path,
long defaultValue = 0L) const;
+
+
+ /**
+ * Get another node's value as a float.
+ */
float getFloatValue (const string &relative_path,
float defaultValue = 0.0) const;
+
+
+ /**
+ * Get another node's value as a double.
+ */
double getDoubleValue (const string &relative_path,
double defaultValue = 0.0L) const;
+
+
+ /**
+ * Get another node's value as a string.
+ */
string getStringValue (const string &relative_path,
string defaultValue = "") const;
+
+ /**
+ * Set another node's value as a bool.
+ */
bool setBoolValue (const string &relative_path, bool value);
+
+
+ /**
+ * Set another node's value as an int.
+ */
bool setIntValue (const string &relative_path, int value);
+
+
+ /**
+ * Set another node's value as a long int.
+ */
bool setLongValue (const string &relative_path, long value);
+
+
+ /**
+ * Set another node's value as a float.
+ */
bool setFloatValue (const string &relative_path, float value);
+
+
+ /**
+ * Set another node's value as a double.
+ */
bool setDoubleValue (const string &relative_path, double value);
+
+
+ /**
+ * Set another node's value as a string.
+ */
bool setStringValue (const string &relative_path, string value);
- bool setUnknownValue (const string &relative_path, string value);
+
+ /**
+ * Set another node's value with no specified type.
+ */
+ bool setUnspecifiedValue (const string &relative_path, string value);
+
+
+ /**
+ * Test whether another node is bound to an external data source.
+ */
bool isTied (const string &relative_path) const;
+
+ /**
+ * Bind another node to an external bool source.
+ */
bool tie (const string &relative_path, const SGRawValue<bool> &rawValue,
bool useDefault = true);
+
+
+ /**
+ * Bind another node to an external int source.
+ */
bool tie (const string &relative_path, const SGRawValue<int> &rawValue,
bool useDefault = true);
+
+
+ /**
+ * Bind another node to an external long int source.
+ */
bool tie (const string &relative_path, const SGRawValue<long> &rawValue,
bool useDefault = true);
+
+
+ /**
+ * Bind another node to an external float source.
+ */
bool tie (const string &relative_path, const SGRawValue<float> &rawValue,
bool useDefault = true);
+
+
+ /**
+ * Bind another node to an external double source.
+ */
bool tie (const string &relative_path, const SGRawValue<double> &rawValue,
bool useDefault = true);
+
+
+ /**
+ * Bind another node to an external string source.
+ */
bool tie (const string &relative_path, const SGRawValue<string> &rawValue,
bool useDefault = true);
+
+ /**
+ * Unbind another node from any external data source.
+ */
bool untie (const string &relative_path);
+
protected:
+
+ /**
+ * Protected constructor for making new nodes on demand.
+ */
SGPropertyNode (const string &name, int index, SGPropertyNode * parent);
+
private:
- SGPropertyNode (const SGPropertyNode &node) {}
- SGValue * _value;
+ /**
+ * Clear any existing value and set the type to NONE.
+ */
+ void clear_value ();
+
string _name;
int _index;
SGPropertyNode * _parent;
vector<SGPropertyNode *> _children;
- mutable SGPropertyNode * _target;
+
+
+ Type _type;
+ bool _tied;
+ int _attr;
+
+ // The right kind of pointer...
+ union {
+ SGPropertyNode * alias;
+ SGRawValue<bool> * bool_val;
+ SGRawValue<int> * int_val;
+ SGRawValue<long> * long_val;
+ SGRawValue<float> * float_val;
+ SGRawValue<double> * double_val;
+ SGRawValue<string> * string_val;
+ } _value;
+
};
// I/O functions.
////////////////////////////////////////////////////////////////////////
-bool readProperties (istream &input, SGPropertyNode * start_node,
+
+/**
+ * Read properties from an XML input stream.
+ */
+void readProperties (istream &input, SGPropertyNode * start_node,
const string &base = "");
-bool readProperties (const string &file, SGPropertyNode * start_node);
-bool writeProperties (ostream &output, const SGPropertyNode * start_node);
-bool writeProperties (const string &file, const SGPropertyNode * start_node);
+
+
+/**
+ * Read properties from an XML file.
+ */
+void readProperties (const string &file, SGPropertyNode * start_node);
+
+
+/**
+ * Write properties to an XML output stream.
+ */
+void writeProperties (ostream &output, const SGPropertyNode * start_node);
+
+
+/**
+ * Write properties to an XML file.
+ */
+void writeProperties (const string &file, const SGPropertyNode * start_node);
+
+
+/**
+ * Copy properties from one node to another.
+ */
bool copyProperties (const SGPropertyNode *in, SGPropertyNode *out);