juce_ValueTreePropertyWithDefault.h

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/*
  ==============================================================================
 
   This file is part of the JUCE library.
   Copyright (c) 2022 - Raw Material Software Limited
 
   JUCE is an open source library subject to commercial or open-source
   licensing.
 
   By using JUCE, you agree to the terms of both the JUCE 7 End-User License
   Agreement and JUCE Privacy Policy.
 
   End User License Agreement: www.juce.com/juce-7-licence
   Privacy Policy: www.juce.com/juce-privacy-policy
 
   Or: You may also use this code under the terms of the GPL v3 (see
   www.gnu.org/licenses).
 
   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
{
 
//==============================================================================
class JUCE_API  ValueTreePropertyWithDefault  : private Value::Listener
{
public:
    //==============================================================================
    ValueTreePropertyWithDefault() = default;

    ValueTreePropertyWithDefault (ValueTree& tree,
                                  const Identifier& propertyID,
                                  UndoManager* um)
    {
        referTo (tree, propertyID, um);
    }

    ValueTreePropertyWithDefault (ValueTree& tree,
                                  const Identifier& propertyID,
                                  UndoManager* um,
                                  var defaultToUse)
    {
        referTo (tree, propertyID, um, defaultToUse);
    }

    ValueTreePropertyWithDefault (ValueTree& tree,
                                  const Identifier& propertyID,
                                  UndoManager* um,
                                  var defaultToUse,
                                  StringRef arrayDelimiter)
    {
        referTo (tree, propertyID, um, defaultToUse, arrayDelimiter);
    }

    ValueTreePropertyWithDefault (const ValueTreePropertyWithDefault& other)
    {
        referToWithDefault (other.targetTree,
                            other.targetProperty,
                            other.undoManager,
                            other.defaultValue,
                            other.delimiter);
    }

    ~ValueTreePropertyWithDefault() override
    {
        defaultValue.removeListener (this);
    }
 
    //==============================================================================
    var get() const noexcept
    {
        if (isUsingDefault())
            return defaultValue;
 
        if (delimiter.isNotEmpty())
            return delimitedStringToVarArray (targetTree[targetProperty].toString(), delimiter);
 
        return targetTree[targetProperty];
    }

    Value getPropertyAsValue()               { return targetTree.getPropertyAsValue (targetProperty, undoManager); }

    var getDefault() const                   { return defaultValue; }

    void setDefault (const var& newDefault)  { defaultValue = newDefault; }

    bool isUsingDefault() const              { return ! targetTree.hasProperty (targetProperty); }

    void resetToDefault() noexcept           { targetTree.removeProperty (targetProperty, nullptr); }

    std::function<void()> onDefaultChange;
 
    //==============================================================================
    ValueTreePropertyWithDefault& operator= (const var& newValue)
    {
        setValue (newValue, undoManager);
        return *this;
    }

    void setValue (const var& newValue, UndoManager* undoManagerToUse)
    {
        if (auto* array = newValue.getArray())
            targetTree.setProperty (targetProperty, varArrayToDelimitedString (*array, delimiter), undoManagerToUse);
        else
            targetTree.setProperty (targetProperty, newValue, undoManagerToUse);
    }
 
    //==============================================================================
    void referTo (ValueTree tree,
                  const Identifier& property,
                  UndoManager* um)
    {
        referToWithDefault (tree,
                            property,
                            um,
                            Value (new SynchronousValueSource (var())),
                            {});
    }

    void referTo (ValueTree tree,
                  const Identifier& property,
                  UndoManager* um,
                  var defaultVal)
    {
        referToWithDefault (tree,
                            property,
                            um,
                            Value (new SynchronousValueSource (defaultVal)),
                            {});
    }

    void referTo (ValueTree tree,
                  const Identifier& property,
                  UndoManager* um,
                  var defaultVal,
                  StringRef arrayDelimiter)
    {
        referToWithDefault (tree,
                            property,
                            um,
                            Value (new SynchronousValueSource (defaultVal)),
                            arrayDelimiter);
    }
 
    //==============================================================================
    ValueTree& getValueTree() noexcept                      { return targetTree; }

    Identifier& getPropertyID() noexcept                    { return targetProperty; }

    UndoManager* getUndoManager() noexcept                  { return undoManager; }
 
    //==============================================================================
    ValueTreePropertyWithDefault& operator= (const ValueTreePropertyWithDefault& other)
    {
        referToWithDefault (other.targetTree,
                            other.targetProperty,
                            other.undoManager,
                            other.defaultValue,
                            other.delimiter);
 
        return *this;
    }
 
private:
    //==============================================================================
    class SynchronousValueSource  : public Value::ValueSource
    {
    public:
        explicit SynchronousValueSource (const var& initialValue)
            : value (initialValue)
        {
        }
 
        var getValue() const override
        {
            return value;
        }
 
        void setValue (const var& newValue) override
        {
            if (! newValue.equalsWithSameType (value))
            {
                value = newValue;
                sendChangeMessage (true);
            }
        }
 
    private:
        var value;
 
        JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (SynchronousValueSource)
    };
 
    //==============================================================================
    static String varArrayToDelimitedString (const Array<var>& input, StringRef delim)
    {
        // if you are trying to control a var that is an array then you need to
        // set a delimiter string that will be used when writing to XML!
        jassert (delim.isNotEmpty());
 
        StringArray elements;
 
        for (auto& v : input)
            elements.add (v.toString());
 
        return elements.joinIntoString (delim);
    }
 
    static Array<var> delimitedStringToVarArray (StringRef input, StringRef delim)
    {
        Array<var> arr;
 
        for (auto t : StringArray::fromTokens (input, delim, {}))
            arr.add (t);
 
        return arr;
    }
 
    void valueChanged (Value&) override
    {
        if (onDefaultChange != nullptr)
            onDefaultChange();
    }
 
    void referToWithDefault (ValueTree v,
                             const Identifier& i,
                             UndoManager* um,
                             const Value& defaultVal,
                             StringRef del)
    {
        targetTree = v;
        targetProperty = i;
        undoManager = um;
        defaultValue.referTo (defaultVal);
        delimiter = del;
 
        defaultValue.addListener (this);
    }
 
    //==============================================================================
    ValueTree targetTree;
    Identifier targetProperty;
    UndoManager* undoManager = nullptr;
    Value defaultValue;
    String delimiter;
 
    //==============================================================================
    JUCE_LEAK_DETECTOR (ValueTreePropertyWithDefault)
};
 
//==============================================================================
#ifndef DOXYGEN
using ValueWithDefault  [[deprecated ("This class has been renamed to better describe what is does. "
                                      "This declaration is here for backwards compatibility and new "
                                      "code should use the new class name.")]]
    = ValueTreePropertyWithDefault;
#endif
 
} // namespace juce