JUCE/modules/juce_core/containers/juce_DynamicObject.h

/*
  ==============================================================================

   This file is part of the JUCE library.
   Copyright (c) 2020 - Raw Material Software Limited

   JUCE is an open source library subject to commercial or open-source
   licensing.

   The code included in this file is provided under the terms of the ISC license
   http://www.isc.org/downloads/software-support-policy/isc-license. Permission
   To use, copy, modify, and/or distribute this software for any purpose with or
   without fee is hereby granted provided that the above copyright notice and
   this permission notice appear in all copies.

   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
   DISCLAIMED.

  ==============================================================================
*/

namespace juce
{

//==============================================================================
/**
    Represents a dynamically implemented object.

    This class is primarily intended for wrapping scripting language objects,
    but could be used for other purposes.

    An instance of a DynamicObject can be used to store named properties, and
    by subclassing hasMethod() and invokeMethod(), you can give your object
    methods.

    @tags{Core}
*/
class JUCE_API  DynamicObject  : public ReferenceCountedObject
{
public:
    //==============================================================================
    DynamicObject();
    DynamicObject (const DynamicObject&);
    ~DynamicObject() override;

    using Ptr = ReferenceCountedObjectPtr<DynamicObject>;

    //==============================================================================
    /** Returns true if the object has a property with this name.
        Note that if the property is actually a method, this will return false.
    */
    virtual bool hasProperty (const Identifier& propertyName) const;

    /** Returns a named property.
        This returns var() if no such property exists.
    */
    virtual const var& getProperty (const Identifier& propertyName) const;

    /** Sets a named property. */
    virtual void setProperty (const Identifier& propertyName, const var& newValue);

    /** Removes a named property. */
    virtual void removeProperty (const Identifier& propertyName);

    //==============================================================================
    /** Checks whether this object has the specified method.

        The default implementation of this just checks whether there's a property
        with this name that's actually a method, but this can be overridden for
        building objects with dynamic invocation.
    */
    virtual bool hasMethod (const Identifier& methodName) const;

    /** Invokes a named method on this object.

        The default implementation looks up the named property, and if it's a method
        call, then it invokes it.

        This method is virtual to allow more dynamic invocation to used for objects
        where the methods may not already be set as properties.
    */
    virtual var invokeMethod (Identifier methodName,
                              const var::NativeFunctionArgs& args);

    /** Adds a method to the class.

        This is basically the same as calling setProperty (methodName, (var::NativeFunction) myFunction), but
        helps to avoid accidentally invoking the wrong type of var constructor. It also makes
        the code easier to read.
    */
    void setMethod (Identifier methodName, var::NativeFunction function);

    //==============================================================================
    /** Removes all properties and methods from the object. */
    void clear();

    /** Returns the NamedValueSet that holds the object's properties. */
    NamedValueSet& getProperties() noexcept     { return properties; }

    /** Calls var::clone() on all the properties that this object contains. */
    void cloneAllProperties();

    //==============================================================================
    /** Returns a clone of this object.
        The default implementation of this method just returns a new DynamicObject
        with a (deep) copy of all of its properties. Subclasses can override this to
        implement their own custom copy routines.
    */
    virtual Ptr clone();

    //==============================================================================
    /** Writes this object to a text stream in JSON format.
        This method is used by JSON::toString and JSON::writeToStream, and you should
        never need to call it directly, but it's virtual so that custom object types
        can stringify themselves appropriately.
    */
    virtual void writeAsJSON (OutputStream&, int indentLevel, bool allOnOneLine, int maximumDecimalPlaces);

private:
    //==============================================================================
    NamedValueSet properties;

   #if JUCE_CATCH_DEPRECATED_CODE_MISUSE
    // This method has been deprecated - use var::invoke instead
    virtual void invokeMethod (const Identifier&, const var*, int) {}
   #endif

    JUCE_LEAK_DETECTOR (DynamicObject)
};

} // namespace juce