Cocos2d-x  v4
Properties Class Reference

Defines a properties file for loading text files. More...

Public Types

enum  Type
 Data types supported by the properties class.
 

Public Member Functions

 ~Properties ()
 Destructor.
 
const char * getNextProperty ()
 
PropertiesgetNextNamespace ()
 Get the next namespace.
 
void rewind ()
 Rewind the getNextProperty() and getNextNamespace() iterators to the beginning of the file.
 
PropertiesgetNamespace (const char *id, bool searchNames=false, bool recurse=true) const
 Get a specific namespace by ID or name. More...
 
const char * getNamespace () const
 Get the name of this Property's namespace. More...
 
const char * getId () const
 Get the ID of this Property's namespace. More...
 
bool exists (const char *name) const
 Check if a property with the given name is specified in this Properties object. More...
 
Type getType (const char *name=NULL) const
 Returns the type of a property. More...
 
const char * getString (const char *name=NULL, const char *defaultValue=NULL) const
 Get the value of the given property as a string. More...
 
bool setString (const char *name, const char *value)
 Sets the value of the property with the specified name. More...
 
bool getBool (const char *name=NULL, bool defaultValue=false) const
 Interpret the value of the given property as a boolean. More...
 
int getInt (const char *name=NULL) const
 Interpret the value of the given property as an integer. More...
 
float getFloat (const char *name=NULL) const
 Interpret the value of the given property as a floating-point number. More...
 
long getLong (const char *name=NULL) const
 Interpret the value of the given property as a long integer. More...
 
bool getMat4 (const char *name, Mat4 *out) const
 Interpret the value of the given property as a Matrix. More...
 
bool getVec2 (const char *name, Vec2 *out) const
 Interpret the value of the given property as a Vector2. More...
 
bool getVec3 (const char *name, Vec3 *out) const
 Interpret the value of the given property as a Vector3. More...
 
bool getVec4 (const char *name, Vec4 *out) const
 Interpret the value of the given property as a Vector4. More...
 
bool getQuaternionFromAxisAngle (const char *name, Quaternion *out) const
 Interpret the value of the given property as a Quaternion specified as an axis angle. More...
 
bool getColor (const char *name, Vec3 *out) const
 Interpret the value of the given property as an RGB color in hex and write this color to a Vector3. More...
 
bool getColor (const char *name, Vec4 *out) const
 Interpret the value of the given property as an RGBA color in hex and write this color to a Vector4. More...
 
bool getPath (const char *name, std::string *path) const
 Gets the file path for the given property if the file exists. More...
 
const char * getVariable (const char *name, const char *defaultValue=NULL) const
 Returns the value of a variable that is set in this Properties object. More...
 
void setVariable (const char *name, const char *value)
 Sets the value of the specified variable. More...
 

Static Public Member Functions

static PropertiescreateNonRefCounted (const std::string &url)
 Creates a Properties runtime settings from the specified URL, where the URL is of the format "<file-path>.<extension>#<namespace-id>/<namespace-id>/.../<namespace-id>" (and "#<namespace-id>/<namespace-id>/.../<namespace-id>" is optional). More...
 
static bool parseVec2 (const char *str, Vec2 *out)
 Attempts to parse the specified string as a Vector2 value. More...
 
static bool parseVec3 (const char *str, Vec3 *out)
 Attempts to parse the specified string as a Vector3 value. More...
 
static bool parseVec4 (const char *str, Vec4 *out)
 Attempts to parse the specified string as a Vector4 value. More...
 
static bool parseAxisAngle (const char *str, Quaternion *out)
 Attempts to parse the specified string as an axis-angle value. More...
 
static bool parseColor (const char *str, Vec3 *out)
 Attempts to parse the specified string as an RGB color value. More...
 
static bool parseColor (const char *str, Vec4 *out)
 Attempts to parse the specified string as an RGBA color value. More...
 

Detailed Description

Defines a properties file for loading text files.

A properties file has very simple syntax and can contain only namespaces and name/value pairs (the properties of a namespace).
The file can have any file extension a user specifies.

Here's an example of a simple file that uses all the available features of the markup language:

   // This is a comment.

   // This property is in the default namespace:
   integerProperty = 5

   // This line defines a namespace of type "mynamespace" without an ID:
   mynamespace
   {
       // This namespace can be retrieved by searching for its ID, "spriteTexture",
       // or by its name "texture":
       texture spriteTexture 
       {
           fileName = sprite.png
           width = 64
           height = 64
       }

       // This property is in the "space" namespace:
       booleanProperty = true

       // It's legal to have a name without a value if you leave out the '=' character:
       foo

       // In fact, the '=' character is optional if you'd rather write:
       bar 23

       // But don't write this or you'll get an error:
       // illegalProperty =

       // Or this:
       // = 15

       // Properties objects let you retrieve values as various types.
       floatProperty = 3.333
       stringProperty = This is a string.
       vector3Property = 1.0, 5.0, 3.55
       colorProperty = 1.0, 0.4, 0.0, 1.0
   }

Retrieving information out of a file like this could be done in two ways. If the available namespaces and name/value pairs are known in advance they can be queried by ID or name. For example, if the namespace "spriteTexture" and its properties are required then they can be retrieved with a call to getNamespace() followed by calls to getString() and getInt(). A namespace is stored and retrieved as a Properties object. Reading the spriteTexture properties out of the file above in this way could be done with the following code:

   // Create the top-level Properties object.
   Properties* properties = Properties::createNonRefCounted("example.properties");
   // Retrieve the "spriteTexture" namespace.
   Properties* spriteTexture = properties->getNamespace("spriteTexture");

   // Get the values of known texture properties out of the namespace.
   const char* fileName = spriteTexture->getString("fileName");
   int width = spriteTexture->getInt("width");
   int height = spriteTexture->getInt("height");

   // Deleting the top-level Properties object will clean up all nested namespaces.
   SAFE_DELETE(properties);

On the other hand, if the structure of the file is not known in advance its namespaces and name/value pairs can be retrieved one by one using the getNextNamespace() and getNextProperty() methods. The following method prints the contents of any properties file to the console:

   void printProperties(Properties* properties)
   {
       // Print the name and ID of the current namespace.
       const char* spacename = properties->getNamespace();
       const char* id = properties->getId();
       GP_WARN("Namespace: %s  ID: %s\n{", spacename, id);

       // Print all properties in this namespace.
       const char* name = properties->getNextProperty();
       const char* value = NULL;
       while (name != NULL)
       {
           value = properties->getString(name);
           GP_WARN("%s = %s", name, value);
           name = properties->getNextProperty();
       }
       GP_WARN("}\n");

       // Print the properties of every namespace within this one.
       Properties* space = properties->getNextNamespace();
       while (space != NULL)
       {
           printProperties(space);
           space = properties->getNextNamespace();
       }
   }

Note that this method does not keep track of the namespace hierarchy, but could be modified to do so. Also note that nothing in a properties file indicates the type of a property. If the type is unknown, its string can be retrieved and interpreted as necessary.

Member Function Documentation

◆ createNonRefCounted()

static Properties* createNonRefCounted ( const std::string &  url)
static

Creates a Properties runtime settings from the specified URL, where the URL is of the format "<file-path>.<extension>#<namespace-id>/<namespace-id>/.../<namespace-id>" (and "#<namespace-id>/<namespace-id>/.../<namespace-id>" is optional).

Parameters
urlThe URL to create the properties from.
Returns
The created Properties or NULL if there was an error. @script{create}

◆ getNextProperty()

const char* getNextProperty ( )
   Get the name of the next property.

   If a valid next property is returned, the value of the property can be
   retrieved using any of the get methods in this class, passing NULL for

the property name.

   @return The name of the next property, or NULL if there are no properties remaining.

◆ getNamespace() [1/2]

Properties* getNamespace ( const char *  id,
bool  searchNames = false,
bool  recurse = true 
) const

Get a specific namespace by ID or name.

This method will optionally perform a depth-first search on all namespaces and inner namespaces within this Property.

Parameters
idThe ID or name of the namespace to find.
searchNamesIf true, namespace names are used in the search, instead of namespace IDs. By default this parameter is false and namespace IDs are searched.
recurseIf true, perform a depth-first search, otherwise search only the immediate child namespaces.
Returns
A properties object with the given ID or name.

◆ getNamespace() [2/2]

const char* getNamespace ( ) const

Get the name of this Property's namespace.

Returns
The name of this Property's namespace.

◆ getId()

const char* getId ( ) const

Get the ID of this Property's namespace.

The ID should be a unique identifier, but its uniqueness is not enforced.

Returns
The ID of this Property's namespace.

◆ exists()

bool exists ( const char *  name) const

Check if a property with the given name is specified in this Properties object.

Parameters
nameThe name of the property to query.
Returns
True if the property exists, false otherwise.

◆ getType()

Type getType ( const char *  name = NULL) const

Returns the type of a property.

Parameters
nameThe name of the property to interpret, or NULL to return the current property's type.
Returns
The type of the property.

◆ getString()

const char* getString ( const char *  name = NULL,
const char *  defaultValue = NULL 
) const

Get the value of the given property as a string.

This can always be retrieved, whatever the intended type of the property.

Parameters
nameThe name of the property to interpret, or NULL to return the current property's value.
defaultValueThe default value to return if the specified property does not exist.
Returns
The value of the given property as a string, or the empty string if no property with that name exists.

◆ setString()

bool setString ( const char *  name,
const char *  value 
)

Sets the value of the property with the specified name.

If there is no property in this namespace with the current name, one is added. Otherwise, the value of the first property with the specified name is updated.

If name is NULL, the value current property (see getNextProperty) is set, unless there is no current property, in which case false is returned.

Parameters
nameThe name of the property to set.
valueThe property value.
Returns
True if the property was set, false otherwise.

◆ getBool()

bool getBool ( const char *  name = NULL,
bool  defaultValue = false 
) const

Interpret the value of the given property as a boolean.

Parameters
nameThe name of the property to interpret, or NULL to return the current property's value.
defaultValuethe default value to return if the specified property does not exist within the properties file.
Returns
true if the property exists and its value is "true", otherwise false.

◆ getInt()

int getInt ( const char *  name = NULL) const

Interpret the value of the given property as an integer.

If the property does not exist, zero will be returned. If the property exists but could not be scanned, an error will be logged and zero will be returned.

Parameters
nameThe name of the property to interpret, or NULL to return the current property's value.
Returns
The value of the given property interpreted as an integer. Zero if the property does not exist or could not be scanned.

◆ getFloat()

float getFloat ( const char *  name = NULL) const

Interpret the value of the given property as a floating-point number.

If the property does not exist, zero will be returned. If the property exists but could not be scanned, an error will be logged and zero will be returned.

Parameters
nameThe name of the property to interpret, or NULL to return the current property's value.
Returns
The value of the given property interpreted as a float. Zero if the property does not exist or could not be scanned.

◆ getLong()

long getLong ( const char *  name = NULL) const

Interpret the value of the given property as a long integer.

If the property does not exist, zero will be returned. If the property exists but could not be scanned, an error will be logged and zero will be returned.

Parameters
nameThe name of the property to interpret, or NULL to return the current property's value.
Returns
The value of the given property interpreted as a long. Zero if the property does not exist or could not be scanned.

◆ getMat4()

bool getMat4 ( const char *  name,
Mat4 out 
) const

Interpret the value of the given property as a Matrix.

If the property does not exist, out will be set to the identity matrix. If the property exists but could not be scanned, an error will be logged and out will be set to the identity matrix.

Parameters
nameThe name of the property to interpret, or NULL to return the current property's value.
outThe matrix to set to this property's interpreted value.
Returns
True on success, false if the property does not exist or could not be scanned.

◆ getVec2()

bool getVec2 ( const char *  name,
Vec2 out 
) const

Interpret the value of the given property as a Vector2.

If the property does not exist, out will be set to Vector2(0.0f, 0.0f). If the property exists but could not be scanned, an error will be logged and out will be set to Vector2(0.0f, 0.0f).

Parameters
nameThe name of the property to interpret, or NULL to return the current property's value.
outThe vector to set to this property's interpreted value.
Returns
True on success, false if the property does not exist or could not be scanned.

◆ getVec3()

bool getVec3 ( const char *  name,
Vec3 out 
) const

Interpret the value of the given property as a Vector3.

If the property does not exist, out will be set to Vector3(0.0f, 0.0f, 0.0f). If the property exists but could not be scanned, an error will be logged and out will be set to Vector3(0.0f, 0.0f, 0.0f).

Parameters
nameThe name of the property to interpret, or NULL to return the current property's value.
outThe vector to set to this property's interpreted value.
Returns
True on success, false if the property does not exist or could not be scanned.

◆ getVec4()

bool getVec4 ( const char *  name,
Vec4 out 
) const

Interpret the value of the given property as a Vector4.

If the property does not exist, out will be set to Vector4(0.0f, 0.0f, 0.0f, 0.0f). If the property exists but could not be scanned, an error will be logged and out will be set to Vector4(0.0f, 0.0f, 0.0f, 0.0f).

Parameters
nameThe name of the property to interpret, or NULL to return the current property's value.
outThe vector to set to this property's interpreted value.
Returns
True on success, false if the property does not exist or could not be scanned.

◆ getQuaternionFromAxisAngle()

bool getQuaternionFromAxisAngle ( const char *  name,
Quaternion out 
) const

Interpret the value of the given property as a Quaternion specified as an axis angle.

If the property does not exist, out will be set to Quaternion(). If the property exists but could not be scanned, an error will be logged and out will be set to Quaternion().

Parameters
nameThe name of the property to interpret, or NULL to return the current property's value.
outThe quaternion to set to this property's interpreted value.
Returns
True on success, false if the property does not exist or could not be scanned.

◆ getColor() [1/2]

bool getColor ( const char *  name,
Vec3 out 
) const

Interpret the value of the given property as an RGB color in hex and write this color to a Vector3.

E.g. 0xff0000 represents red and sets the vector to (1, 0, 0). If the property does not exist, out will be set to Vector3(0.0f, 0.0f, 0.0f). If the property exists but could not be scanned, an error will be logged and out will be set to Vector3(0.0f, 0.0f, 0.0f).

Parameters
nameThe name of the property to interpret, or NULL to return the current property's value.
outThe vector to set to this property's interpreted value.
Returns
True on success, false if the property does not exist or could not be scanned.

◆ getColor() [2/2]

bool getColor ( const char *  name,
Vec4 out 
) const

Interpret the value of the given property as an RGBA color in hex and write this color to a Vector4.

E.g. 0xff0000ff represents opaque red and sets the vector to (1, 0, 0, 1). If the property does not exist, out will be set to Vector4(0.0f, 0.0f, 0.0f, 0.0f). If the property exists but could not be scanned, an error will be logged and out will be set to Vector4(0.0f, 0.0f, 0.0f, 0.0f).

Parameters
nameThe name of the property to interpret, or NULL to return the current property's value.
outThe vector to set to this property's interpreted value.
Returns
True on success, false if the property does not exist or could not be scanned.

◆ getPath()

bool getPath ( const char *  name,
std::string *  path 
) const

Gets the file path for the given property if the file exists.

This method will first search for the file relative to the working directory. If the file is not found then it will search relative to the directory the bundle file is in.

Parameters
nameThe name of the property.
pathThe string to copy the path to if the file exists.
Returns
True if the property exists and the file exists, false otherwise.

@script{ignore}

◆ getVariable()

const char* getVariable ( const char *  name,
const char *  defaultValue = NULL 
) const

Returns the value of a variable that is set in this Properties object.

Variables take on the format ${name} and are inherited from parent Property objects.

Parameters
nameName of the variable to get.
defaultValueValue to return if the variable is not found.
Returns
The value of the specified variable, or defaultValue if not found.

◆ setVariable()

void setVariable ( const char *  name,
const char *  value 
)

Sets the value of the specified variable.

Parameters
nameName of the variable to set.
valueThe value to set.

◆ parseVec2()

static bool parseVec2 ( const char *  str,
Vec2 out 
)
static

Attempts to parse the specified string as a Vector2 value.

On error, false is returned and the output is set to all zero values.

Parameters
strThe string to parse.
outThe value to populate if successful.
Returns
True if a valid Vector2 was parsed, false otherwise.

◆ parseVec3()

static bool parseVec3 ( const char *  str,
Vec3 out 
)
static

Attempts to parse the specified string as a Vector3 value.

On error, false is returned and the output is set to all zero values.

Parameters
strThe string to parse.
outThe value to populate if successful.
Returns
True if a valid Vector3 was parsed, false otherwise.

◆ parseVec4()

static bool parseVec4 ( const char *  str,
Vec4 out 
)
static

Attempts to parse the specified string as a Vector4 value.

On error, false is returned and the output is set to all zero values.

Parameters
strThe string to parse.
outThe value to populate if successful.
Returns
True if a valid Vector4 was parsed, false otherwise.

◆ parseAxisAngle()

static bool parseAxisAngle ( const char *  str,
Quaternion out 
)
static

Attempts to parse the specified string as an axis-angle value.

The specified string is expected to contain four comma-separated values, where the first three values represents the axis and the fourth value represents the angle, in degrees.

On error, false is returned and the output is set to all zero values.

Parameters
strThe string to parse.
outA Quaternion populated with the orientation of the axis-angle, if successful.
Returns
True if a valid axis-angle was parsed, false otherwise.

◆ parseColor() [1/2]

static bool parseColor ( const char *  str,
Vec3 out 
)
static

Attempts to parse the specified string as an RGB color value.

Parameters
strThe string to parse.
outThe value to populate if successful.
Returns
True if a valid RGB color was parsed, false otherwise.

◆ parseColor() [2/2]

static bool parseColor ( const char *  str,
Vec4 out 
)
static

Attempts to parse the specified string as an RGBA color value.

Parameters
strThe string to parse.
outThe value to populate if successful.
Returns
True if a valid RGBA color was parsed, false otherwise.

The documentation for this class was generated from the following file: