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OpenSpace/include/openspace/properties/property.h

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/*****************************************************************************************
* *
* OpenSpace *
* *
* Copyright (c) 2014-2017 *
* *
* Permission is hereby granted, free of charge, to any person obtaining a copy of this *
* software and associated documentation files (the "Software"), to deal in the Software *
* without restriction, including without limitation the rights to use, copy, modify, *
* merge, publish, distribute, sublicense, and/or sell copies of the Software, and to *
* permit persons to whom the Software is furnished to do so, subject to the following *
* conditions: *
* *
* The above copyright notice and this permission notice shall be included in all copies *
* or substantial portions of the Software. *
* *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, *
* INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A *
* PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT *
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF *
* CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE *
* OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. *
****************************************************************************************/
#ifndef __OPENSPACE_CORE___PROPERTY___H__
#define __OPENSPACE_CORE___PROPERTY___H__
#include <openspace/properties/propertydelegate.h>
#include <ghoul/misc/dictionary.h>
#include <functional>
#include <string>
struct lua_State;
namespace openspace {
namespace properties {
class PropertyOwner;
/**
* A property encapsulates a value which should be user-changeable. A property almost
* always belongs to a PropertyOwner who has taken ownership (setPropertyOwner) of the
* Property. Per PropertyOwner, the <code>identifier</code> needs to be unique and can be
* used as a URI. This class is an abstract base class and each subclass (most notable
* TemplateProperty) needs to implement the methods Property::className, Property::get,
* Property::set, Property::type(), Property::getLuaValue, Property::setLuaValue,
* Property::getStringValue, Property::setStringValue and Property::typeLua to make full
* use of the infrastructure.
* The most common types can be implemented by creating a specialized instantiation of
* TemplateProperty, which provides default implementations for these methods.
*
* The onChange method can be used by the PropertyOwner to listen to changes that happen
* to the Property. The parameter is a function object that gets called after new value
* has been set.
* The metaData allows the developer to specify additional information about the Property
* which might be used in GUI representations. One example would be a glm::vec4 property,
* (Vec4Property) that can either represent a 4-dimensional position, a powerscaled
* coordinate, a light position, or other things, requiring different GUI representations.
* \see TemplateProperty
* \see PropertyOwner
*/
class Property {
public:
/**
* The visibility classes for Property%s. The classes are strictly ordered as
* All > Developer > User > Hidden
*/
enum class Visibility {
All = 3, ///< Visible for all types, no matter what
Developer = 2, ///< Visible in Developer mode
User = 1, ///< Visible in User mode
Hidden = 0 ///< Never visible
};
/**
* The constructor for the property. The <code>identifier</code> needs to be unique
* for each PropertyOwner. The <code>guiName</code> will be stored in the metaData
* to be accessed by the GUI elements using the <code>guiName</code> key. The default
* visibility settings is <code>true</code>, whereas the default read-only state is
* <code>false</code>.
* \param identifier A unique identifier for this property. It has to be unique to the
* PropertyOwner and cannot contain any <code>.</code>s
* \param guiName The human-readable GUI name for this Property
* \pre \p identifier must not be empty
* \pre \p guiName must not be empty
*/
Property(std::string identifier, std::string guiName,
Visibility visibility = Visibility::All);
/**
* The destructor taking care of deallocating all unused memory. This method will not
* remove the Property from the PropertyOwner.
*/
virtual ~Property();
/**
* This method returns the class name of the Property. The method is used by the
* TemplateFactory to create new instances of Propertys. The returned value is almost
* always identical to the C++ class name of the derived class.
* \return The class name of the Property
*/
virtual std::string className() const = 0;
/**
* This method returns the encapsulated value of the Property to the caller. The type
* that is returned is determined by the type function and is up to the developer of
* the derived class. The default implementation returns an empty ghoul::any object.
* \return The value that is encapsulated by this Property, or an empty ghoul::any
* object if the method was not overritten.
*/
virtual ghoul::any get() const;
/**
* Sets the value encapsulated by this Property to the <code>value</code> passed to
* this function. It is the caller's responsibility to ensure that the type contained
* in <code>value</code> is compatible with the concrete subclass of the Property. The
* method Property::type will return the desired type for the Property. The default
* implementation of this method ignores the input.
* \param value The new value that should be stored in this Property
*/
virtual void set(ghoul::any value);
/**
* This method returns the type that is requested by this Property for the set method.
* The default implementation returns the type of <code>void</code>.
* \return The type that is requested by this Property's Property::set method
*/
virtual const std::type_info& type() const;
/**
* This method encodes the encapsulated value of this Property at the top of the Lua
* stack. The specific details of this serialization is up to the property developer
* as long as the rest of the stack is unchanged. The implementation has to be
* synchronized with the Property::setLuaValue method. The default implementation is a
* no-op.
* \param state The Lua state to which the value will be encoded
* \return <code>true</code> if the encoding succeeded, <code>false</code> otherwise
*/
virtual bool getLuaValue(lua_State* state) const;
/**
* This method sets the value encapsulated by this Property by deserializing the value
* on top of the passed Lua stack. The specific details of the deserialization are up
* to the Property developer, but they must only depend on the top element of the
* stack and must leave all other elements unchanged. The implementation has to be
* synchronized with the Property::getLuaValue method. The default implementation is a
* no-op.
* \param state The Lua state from which the value will be decoded
* \return <code>true</code> if the decoding and setting of the value succeeded,
* <code>false</code> otherwise
*/
virtual bool setLuaValue(lua_State* state);
/**
* Returns the Lua type that will be put onto the stack in the Property::getLua method
* and which will be consumed by the Property::setLuaValue method. The returned value
* can belong to the set of Lua types: <code>LUA_TNONE</code>, <code>LUA_TNIL</code>,
* <code>LUA_TBOOLEAN</code>, <code>LUA_TLIGHTUSERDATA</code>,
* <code>LUA_TNUMBER</code>, <code>LUA_TSTRING</code>, <code>LUA_TTABLE</code>,
* <code>LUA_TFUNCTION</code>, <code>LUA_TUSERDATA</code>, or
* <code>LUA_TTHREAD</code>. The default implementation will return
* <code>LUA_TNONE</code>.
* \return The Lua type that will be consumed or produced by the Property::getLuaValue
* and Property::setLuaValue methods.
*/
virtual int typeLua() const;
/**
* This method encodes the encapsulated value of this Property as a
* <code>std::string</code>. The specific details of this serialization is up to the
* property developer. The implementation has to be synchronized with the
Property::setStringValue method. The default implementation is a no-op.
* \param value The value to which the Property will be encoded
* \return <code>true</code> if the encoding succeeded, <code>false</code> otherwise
*/
virtual bool getStringValue(std::string& value) const;
/**
* This method sets the value encapsulated by this Property by deserializing the
* passed <code>std::string</code>. The specific details of the deserialization are up
* to the Property developer. The implementation has to be synchronized with the
* Property::getLuaValue method. The default implementation is a no-op.
* \param value The value from which the Property will be decoded
* \return <code>true</code> if the decoding and setting of the value succeeded,
* <code>false</code> otherwise
*/
virtual bool setStringValue(std::string value);
/**
* This method registers a <code>callback</code> function that will be called every
* time if either Property:set or Property::setLuaValue was called with a value that
* is different from the previously stored value. The callback can be removed by
* passing an empty <code>std::function<void()></code> object.
* \param callback The callback function that is called when the encapsulated type has
* been successfully changed by either the Property::set or Property::setLuaValue
* methods.
*/
virtual void onChange(std::function<void()> callback);
/**
* This method returns the unique identifier of this Property.
* \return The unique identifier of this Property
*/
const std::string& identifier() const;
/**
* Returns the fully qualified name for this Property that uniquely identifies this
* Property within OpenSpace. It consists of the <code>identifier</code> preceded by
* all levels of PropertyOwner%s separated with <code>.</code>; for example:
* <code>owner1.owner2.identifier</code>.
* \return The fully qualified identifier for this Property
*/
std::string fullyQualifiedIdentifier() const;
/**
* Returns the PropertyOwner of this Property or <code>nullptr</code>, if it does not
* have an owner.
*\ return The Property of this Property
*/
PropertyOwner* owner() const;
/**
* Assigned the Property to a new PropertyOwner. This method does not inform the
* PropertyOwner of this action.
* \param owner The new PropertyOwner for this Property
*/
void setPropertyOwner(PropertyOwner* owner);
/**
* Returns the human-readable GUI name for this Property that has been set in the
* constructor. This method returns the same value as accessing the metaData object
* and requesting the <code>std::string</code> stored for the <code>guiName</code>
* key.
* \return The human-readable GUI name for this Property
*/
std::string guiName() const;
/**
* Returns the description for this Property that contains all necessary information
* required for creating a GUI representation. The format of the description is a
* valid Lua table, i.e., it is surrounded by a pair of <code>{</code> and
* <code>}</code> with key,value pairs between. Each value can either be a number, a
* string, a bool, or another table. The general values set by this base function
* are: <code>Identifier</code>, <code>Name</code>, <code>Type</code>. All other
* values are specific to the type and are added in a specific subclass, which require
* the subclass to call this method first.
* \return The descriptive text for the Property that can be used for constructing a
* GUI representation
*/
virtual std::string description() const;
/**
* Sets the identifier of the group that this Property belongs to. Property groups can
* be used, for example, by GUI application to visually group different properties,
* but it has no impact on the Property itself. The default value for the groupID is
* <code>""</code>.
* \param groupId The group id that this property should belong to
*/
void setGroupIdentifier(std::string groupId);
/**
* Returns the group idenfier that this Property belongs to, or <code>""</code> if it
* belongs to no group.
* \return The group identifier that this Property belongs to
*/
std::string groupIdentifier() const;
/**
* Sets a hint about the visibility of the Property. Each application accessing the
* properties is free to ignore this hint. It is stored in the metaData Dictionary
* with the key: <code>Visibility</code>.
* \param visibility The new visibility of the Property
*/
void setVisibility(Visibility visibility);
/**
* Returns this Property%'s visibility setting
* \return This Property%'s visibility setting
*/
Visibility visibility() const;
/**
* This method determines if this Property should be read-only in external
* applications. This setting is only a hint and does not need to be followed by GUI
* applications and does not have any effect on the Property::set,
* Property::setLuaValue, or Property::setStringValue methods. The value is stored in
* the metaData Dictionary with the key: <code>isReadOnly</code>. The default value is
* <code>false</code>.
* \param state <code>true</code> if the Property should be read only,
* <code>false</code> otherwise
*/
void setReadOnly(bool state);
/**
* This method allows the developer to give hints to the GUI about different
* representations for the GUI. The same Property (for example Vec4Property) can be
* used in different ways, each requiring a different input method. These values are
* stored in the metaData object using the <code>views.</code> prefix in front of the
* <code>option</code> parameter. See Property::ViewOptions for a default list of
* possible options. As these are only hints, the GUI is free to ignore any suggestion
* by the developer.
* \param option The view option that should be modified
* \param value Determines if the view option should be active (<code>true</code>) or
* deactivated (<code>false</code>)
*/
void setViewOption(std::string option, bool value = true);
/**
* Default view options that can be used in the Property::setViewOption method. The
* values are: Property::ViewOptions::Color = <code>color</code>,
* Property::ViewOptions::LightPosition = <code>lightPosition</code>,
* Property::ViewOptions::PowerScaledScalar = <code>powerScaledScalar</code>, and
* Property::ViewOptions::PowerScaledCoordinate = <code>powerScaledCoordinate</code>.
*/
struct ViewOptions {
static const char* Color;
static const char* LightPosition;
static const char* PowerScaledScalar;
static const char* PowerScaledCoordinate;
};
/**
* Returns the metaData that contains all information for external applications to
* correctly display information about the Property. No information that is stored in
* this Dictionary is necessary for the programmatic use of the Property.
* \return The Dictionary containing all meta data information about this Property
*/
const ghoul::Dictionary& metaData() const;
protected:
static const char* IdentifierKey;
static const char* NameKey;
static const char* TypeKey;
static const char* MetaDataKey;
/**
* Creates the information that is general to every Property and adds the
* <code>Identifier</code>, <code>Name</code>, <code>Type</code>, and
* <code>MetaData</code> keys and their values. The meta data is handles by the
* generateMetaDataDescription method, which has to be overloaded if a concrete base
* class wants to add meta data that is not curated by the Property class
* \return The base description common to all Property classes
*/
std::string generateBaseDescription() const;
/**
* Creates the information for the <code>MetaData</code> key-part of the Lua
* description for the Property. The result can be included as one key-value pair in
* the description text generated by subclasses. Only the metadata curated by the
* Property class is used in this method.
* \return The metadata information text for the property
*/
virtual std::string generateMetaDataDescription() const;
/**
* Creates the information that is specific to each subclass of Property%s. If a
* subclass needs to add additional information into the description, it has to
* override this method and return the string containing all of the additional
* information. The base implementation of the #description method will return the Lua
* script:
* <code>return { generateBaseDescription(), generateMetaDataDescription(),</code>
* <code>generateAdditionalDescription()}</code>, which #generateMetaDataDescription
* and this method being the override points to customize the behavior.
* \return The information specific to each subclass of Property
*/
virtual std::string generateAdditionalDescription() const;
/**
* This method must be called by all subclasses whenever the encapsulated value has
* changed and a potential listener has to be informed.
*/
void notifyListener();
/// The PropetyOwner this Property belongs to, or <code>nullptr</code>
PropertyOwner* _owner;
/// The identifier for this Property
std::string _identifier;
/// The Dictionary containing all meta data necessary for external applications
ghoul::Dictionary _metaData;
/// The callback function that will be invoked whenever the encapsulated value changes
std::function<void()> _onChangeCallback;
};
} // namespace properties
} // namespace openspace
#endif // __OPENSPACE_CORE___PROPERTY___H__