Added a new ValueWithDefault class to juce_data_structures and extended ChoicePropertyComponent and TextPropertyComponent to use this class

modules/juce_data_structures/juce_data_structures.h

@@ -60,5 +60,6 @@
 #include "values/juce_ValueTree.h"
 #include "values/juce_ValueTreeSynchroniser.h"
 #include "values/juce_CachedValue.h"
+#include "values/juce_ValueWithDefault.h"
 #include "app_properties/juce_PropertiesFile.h"
 #include "app_properties/juce_ApplicationProperties.h"

modules/juce_data_structures/values/juce_ValueWithDefault.h

@@ -0,0 +1,163 @@
+/*
+  ==============================================================================
+
+   This file is part of the JUCE library.
+   Copyright (c) 2017 - ROLI Ltd.
+
+   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 5 End-User License
+   Agreement and JUCE 5 Privacy Policy (both updated and effective as of the
+   27th April 2017).
+
+   End User License Agreement: www.juce.com/juce-5-licence
+   Privacy Policy: www.juce.com/juce-5-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
+{
+
+//==============================================================================
+/**
+    This class acts as a wrapper around a property inside a ValueTree.
+
+    If the property inside the ValueTree is missing or empty the ValueWithDefault will automatically
+    return a default value, which can be specified when initialising the ValueWithDefault.
+*/
+class ValueWithDefault
+{
+public:
+    //==============================================================================
+    /** Creates an unitialised ValueWithDefault. Initialise it using one of the referTo() methods. */
+    ValueWithDefault()    : undoManager (nullptr) {}
+
+    /** Creates an ValueWithDefault object. The default value will be an empty var. */
+    ValueWithDefault (ValueTree& tree, const Identifier& propertyID,
+                      UndoManager* um)
+        : targetTree (tree),
+          targetProperty (propertyID),
+          undoManager (um),
+          defaultValue()
+    {
+    }
+
+    /** Creates an ValueWithDefault object. The default value will be defaultToUse. */
+    ValueWithDefault (ValueTree& tree, const Identifier& propertyID,
+                      UndoManager* um, const var& defaultToUse)
+        : targetTree (tree),
+          targetProperty (propertyID),
+          undoManager (um),
+          defaultValue (defaultToUse)
+    {
+    }
+
+    /** Creates a ValueWithDefault object from another ValueWithDefault object. */
+    ValueWithDefault (const ValueWithDefault& other)
+        : targetTree (other.targetTree),
+          targetProperty (other.targetProperty),
+          undoManager (other.undoManager),
+          defaultValue (other.defaultValue)
+    {
+    }
+
+    //==============================================================================
+    /** Returns the current value of the property. If the property does not exist or is empty,
+        returns the default value.
+    */
+    var get() const noexcept
+    {
+        if (isUsingDefault())
+            return defaultValue;
+
+        return targetTree[targetProperty];
+    }
+
+    /** Returns the current property as a Value object. */
+    Value getPropertyAsValue()     { return targetTree.getPropertyAsValue (targetProperty, undoManager); }
+
+    /** Returns the current default value. */
+    var getDefault() const         { return defaultValue; }
+
+    /** Sets the default value to a new var. */
+    void setDefault (const var& newDefault)
+    {
+        if (defaultValue != newDefault)
+            defaultValue = newDefault;
+    }
+
+    /** Returns true if the property does not exist or is empty. */
+    bool isUsingDefault() const
+    {
+        return ! targetTree.hasProperty (targetProperty);
+    }
+
+    /** Resets the property to an empty var. */
+    void resetToDefault() noexcept
+    {
+        targetTree.removeProperty (targetProperty, nullptr);
+    }
+
+    //==============================================================================
+    /** Sets the property and returns the new ValueWithDefault. This will modify the property in the referenced ValueTree. */
+    ValueWithDefault& operator= (const var& newValue)
+    {
+        setValue (newValue, undoManager);
+        return *this;
+    }
+
+    /** Sets the property. This will actually modify the property in the referenced ValueTree. */
+    void setValue (const var& newValue, UndoManager* undoManagerToUse)
+    {
+        targetTree.setProperty (targetProperty, newValue, undoManagerToUse);
+    }
+
+    //==============================================================================
+    /** Makes the ValueWithDefault refer to the specified property inside the given ValueTree. */
+    void referTo (ValueTree& tree, const Identifier& property, UndoManager* um)
+    {
+        referToWithDefault (tree, property, um, var());
+    }
+
+    /** Makes the ValueWithDefault refer to the specified property inside the given ValueTree,
+        and specifies a default value to use.
+     */
+    void referTo (ValueTree& tree, const Identifier& property, UndoManager* um, const var& defaultVal)
+    {
+        referToWithDefault (tree, property, um, defaultVal);
+    }
+
+    //==============================================================================
+    /** Returns a reference to the ValueTree containing the referenced property. */
+    ValueTree& getValueTree() noexcept                      { return targetTree; }
+
+    /** Returns the property ID of the referenced property. */
+    Identifier& getPropertyID() noexcept                    { return targetProperty; }
+
+private:
+    //==============================================================================
+    ValueTree targetTree;
+    Identifier targetProperty;
+    UndoManager* undoManager;
+    var defaultValue;
+
+    //==============================================================================
+    void referToWithDefault (ValueTree& v, const Identifier& i, UndoManager* um, const var& defaultVal)
+    {
+        targetTree = v;
+        targetProperty = i;
+        undoManager = um;
+        defaultValue = defaultVal;
+    }
+};
+
+} // namespace juce

modules/juce_gui_basics/properties/juce_ChoicePropertyComponent.cpp

@@ -27,30 +27,32 @@
 namespace juce
 {
 
+//==============================================================================
 class ChoicePropertyComponent::RemapperValueSource    : public Value::ValueSource,
                                                         private Value::Listener
 {
 public:
     RemapperValueSource (const Value& source, const Array<var>& map)
-       : sourceValue (source), mappings (map)
+       : sourceValue (source),
+         mappings (map)
     {
         sourceValue.addListener (this);
     }
 
-    var getValue() const
+    var getValue() const override
     {
-        const var targetValue (sourceValue.getValue());
+        auto targetValue = sourceValue.getValue();
 
-        for (int i = 0; i < mappings.size(); ++i)
-            if (mappings.getReference(i).equalsWithSameType (targetValue))
-                return i + 1;
+        for (auto& map : mappings)
+            if (map.equalsWithSameType (targetValue))
+                return mappings.indexOf (map) + 1;
 
         return mappings.indexOf (targetValue) + 1;
     }
 
-    void setValue (const var& newValue)
+    void setValue (const var& newValue) override
     {
-        const var remappedVal (mappings [static_cast<int> (newValue) - 1]);
+        auto remappedVal = mappings [static_cast<int> (newValue) - 1];
 
         if (! remappedVal.equalsWithSameType (sourceValue))
             sourceValue = remappedVal;
@@ -60,14 +62,66 @@ protected:
     Value sourceValue;
     Array<var> mappings;
 
-    void valueChanged (Value&)
-    {
-        sendChangeMessage (true);
-    }
+    void valueChanged (Value&) override    { sendChangeMessage (true); }
 
+    //==============================================================================
     JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (RemapperValueSource)
 };
 
+//==============================================================================
+class ChoicePropertyComponent::RemapperValueSourceWithDefault    : public Value::ValueSource,
+                                                                   private Value::Listener
+{
+public:
+    RemapperValueSourceWithDefault (const ValueWithDefault& vwd, const Array<var>& map)
+        : valueWithDefault (vwd),
+          sourceValue (valueWithDefault.getPropertyAsValue()),
+          mappings (map)
+    {
+        sourceValue.addListener (this);
+    }
+
+    var getValue() const override
+    {
+        if (valueWithDefault.isUsingDefault())
+            return -1;
+
+        auto targetValue = sourceValue.getValue();
+
+        for (auto map : mappings)
+            if (map.equalsWithSameType (targetValue))
+                return mappings.indexOf (map) + 1;
+
+        return mappings.indexOf (targetValue) + 1;
+    }
+
+    void setValue (const var& newValue) override
+    {
+        auto newValueInt = static_cast<int> (newValue);
+
+        if (newValueInt == -1)
+        {
+            valueWithDefault.resetToDefault();
+        }
+        else
+        {
+            auto remappedVal = mappings [newValueInt - 1];
+
+            if (! remappedVal.equalsWithSameType (sourceValue))
+                valueWithDefault = remappedVal;
+        }
+    }
+
+private:
+    ValueWithDefault valueWithDefault;
+    Value sourceValue;
+    Array<var> mappings;
+
+    void valueChanged (Value&) override    { sendChangeMessage (true); }
+
+    //==============================================================================
+    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (RemapperValueSourceWithDefault)
+};
 
 //==============================================================================
 ChoicePropertyComponent::ChoicePropertyComponent (const String& name)
@@ -76,24 +130,54 @@ ChoicePropertyComponent::ChoicePropertyComponent (const String& name)
 {
 }
 
-ChoicePropertyComponent::ChoicePropertyComponent (const Value& valueToControl,
-                                                  const String& name,
+ChoicePropertyComponent::ChoicePropertyComponent (const String& name,
                                                   const StringArray& choiceList,
                                                   const Array<var>& correspondingValues)
     : PropertyComponent (name),
-      choices (choiceList),
-      isCustomClass (false)
+      choices (choiceList)
 {
     // The array of corresponding values must contain one value for each of the items in
     // the choices array!
     jassert (correspondingValues.size() == choices.size());
 
+    ignoreUnused (correspondingValues);
+}
+
+ChoicePropertyComponent::ChoicePropertyComponent (const Value& valueToControl,
+                                                  const String& name,
+                                                  const StringArray& choiceList,
+                                                  const Array<var>& correspondingValues)
+    : ChoicePropertyComponent (name, choiceList, correspondingValues)
+{
     createComboBox();
 
     comboBox.getSelectedIdAsValue().referTo (Value (new RemapperValueSource (valueToControl,
                                                                              correspondingValues)));
 }
 
+ChoicePropertyComponent::ChoicePropertyComponent (ValueWithDefault valueToControl,
+                                                  const String& name,
+                                                  const StringArray& choiceList,
+                                                  const Array<var>& correspondingValues)
+    : ChoicePropertyComponent (name, choiceList, correspondingValues)
+{
+    createComboBoxWithDefault (choiceList [correspondingValues.indexOf (valueToControl.getDefault())]);
+
+    comboBox.getSelectedIdAsValue().referTo (Value (new RemapperValueSourceWithDefault (valueToControl,
+                                                                                        correspondingValues)));
+}
+
+ChoicePropertyComponent::ChoicePropertyComponent (ValueWithDefault valueToControl,
+                                                  const String& name)
+    : PropertyComponent (name),
+      choices ({ "Enabled", "Disabled" })
+{
+    createComboBoxWithDefault (valueToControl.getDefault() ? "Enabled" : "Disabled");
+
+    comboBox.getSelectedIdAsValue().referTo (Value (new RemapperValueSourceWithDefault (valueToControl,
+                                                                                       { true, false })));
+}
+
 ChoicePropertyComponent::~ChoicePropertyComponent()
 {
 }
@@ -103,10 +187,27 @@ void ChoicePropertyComponent::createComboBox()
 {
     addAndMakeVisible (comboBox);
 
-    for (int i = 0; i < choices.size(); ++i)
+    for (auto choice : choices)
+    {
+        if (choice.isNotEmpty())
+            comboBox.addItem (choice, choices.indexOf (choice) + 1);
+        else
+            comboBox.addSeparator();
+    }
+
+    comboBox.setEditableText (false);
+}
+
+void ChoicePropertyComponent::createComboBoxWithDefault (const String& defaultString)
+{
+    addAndMakeVisible (comboBox);
+
+    comboBox.addItem ("Default" + (defaultString.isNotEmpty() ? " (" + defaultString + ")" : ""), -1);
+
+    for (auto choice : choices)
     {
-        if (choices[i].isNotEmpty())
-            comboBox.addItem (choices[i], i + 1);
+        if (choice.isNotEmpty())
+            comboBox.addItem (choice, choices.indexOf (choice) + 1);
         else
             comboBox.addSeparator();
     }
@@ -149,7 +250,7 @@ void ChoicePropertyComponent::comboBoxChanged (ComboBox*)
 {
     if (isCustomClass)
     {
-        const int newIndex = comboBox.getSelectedId() - 1;
+        auto newIndex = comboBox.getSelectedId() - 1;
 
         if (newIndex != getIndex())
             setIndex (newIndex);

modules/juce_gui_basics/properties/juce_ChoicePropertyComponent.h

@@ -75,6 +75,31 @@ public:
                              const StringArray& choices,
                              const Array<var>& correspondingValues);
 
+    /** Creates the component using a ValueWithDefault object. This will add an item to the ComboBox for the
+        default value with an ID of -1.
+
+        @param valueToControl       the ValueWithDefault object that contains the Value object that the combo box will read and control
+        @param propertyName         the name of the property
+        @param choices              the list of possible values that the drop-down list will contain
+        @param correspondingValues  a list of values corresponding to each item in the 'choices' StringArray.
+                                    These are the values that will be read and written to the
+                                    valueToControl value. This array must contain the same number of items
+                                    as the choices array
+
+    */
+    ChoicePropertyComponent (ValueWithDefault valueToControl,
+                             const String& propertyName,
+                             const StringArray& choices,
+                             const Array<var>& correspondingValues);
+
+    /** Creates the component using a ValueWithDefault object, adding an item to the ComboBox for the
+        default value with an ID of -1 as well as adding separate "Enabled" and "Disabled" options.
+
+        This is useful for simple on/off choices that also need a default value.
+    */
+    ChoicePropertyComponent (ValueWithDefault valueToControl,
+                             const String& propertyName);
+
     /** Destructor. */
     ~ChoicePropertyComponent();
 
@@ -95,10 +120,9 @@ public:
     /** Returns the list of options. */
     const StringArray& getChoices() const;
 
-
     //==============================================================================
     /** @internal */
-    void refresh();
+    void refresh() override;
 
 protected:
     /** The list of options that will be shown in the combo box.
@@ -110,12 +134,19 @@ protected:
     StringArray choices;
 
 private:
+    /** Delegating constructor. */
+    ChoicePropertyComponent (const String&, const StringArray&, const Array<var>&);
+
     ComboBox comboBox;
-    bool isCustomClass;
+    bool isCustomClass = false;
 
     class RemapperValueSource;
+    class RemapperValueSourceWithDefault;
+
     void createComboBox();
-    void comboBoxChanged (ComboBox*);
+    void createComboBoxWithDefault (const String&);
+
+    void comboBoxChanged (ComboBox*) override;
 
     JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (ChoicePropertyComponent)
 };

modules/juce_gui_basics/properties/juce_TextPropertyComponent.cpp

@@ -27,6 +27,7 @@
 namespace juce
 {
 
+//==============================================================================
 class TextPropertyComponent::LabelComp  : public Label,
                                           public FileDragAndDropTarget
 {
@@ -85,11 +86,66 @@ public:
         interestedInFileDrag = isInterested;
     }
 
+    void setTextToDisplayWhenEmpty (const String& text, float alpha)
+    {
+        textToDisplayWhenEmpty = text;
+        alphaToUseForEmptyText = alpha;
+    }
+
+    void paintOverChildren (Graphics& g) override
+    {
+        if (getText().isEmpty() && ! isBeingEdited())
+        {
+            auto textArea = getBorderSize().subtractedFrom (getLocalBounds());
+            auto labelFont = owner.getLookAndFeel().getLabelFont (*this);
+
+            g.setColour (owner.findColour (TextPropertyComponent::textColourId).withAlpha (alphaToUseForEmptyText));
+            g.setFont (labelFont);
+
+            g.drawFittedText (textToDisplayWhenEmpty, textArea, getJustificationType(),
+                              jmax (1, (int) (textArea.getHeight() / labelFont.getHeight())),
+                              getMinimumHorizontalScale());
+        }
+    }
+
 private:
     TextPropertyComponent& owner;
+
     int maxChars;
     bool isMultiline;
     bool interestedInFileDrag = true;
+
+    String textToDisplayWhenEmpty;
+    float alphaToUseForEmptyText = 0.0f;
+};
+
+//==============================================================================
+class TextPropertyComponent::RemapperValueSourceWithDefault    : public Value::ValueSource
+{
+public:
+    RemapperValueSourceWithDefault (const ValueWithDefault& vwd)
+        : valueWithDefault (vwd)
+    {
+    }
+
+    var getValue() const override
+    {
+        return valueWithDefault.isUsingDefault() ? var() : valueWithDefault.get();
+    }
+
+    void setValue (const var& newValue) override
+    {
+        if (newValue.toString().isEmpty())
+            valueWithDefault.resetToDefault();
+        else
+            valueWithDefault = newValue;
+    }
+
+private:
+    ValueWithDefault valueWithDefault;
+
+    //==============================================================================
+    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (RemapperValueSourceWithDefault)
 };
 
 //==============================================================================
@@ -107,13 +163,22 @@ TextPropertyComponent::TextPropertyComponent (const Value& valueToControl,
                                               int maxNumChars,
                                               bool isMultiLine,
                                               bool isEditable)
-    : PropertyComponent (name)
+    : TextPropertyComponent (name, maxNumChars, isMultiLine, isEditable)
 {
-    createEditor (maxNumChars, isMultiLine, isEditable);
-
     textEditor->getTextValue().referTo (valueToControl);
 }
 
+TextPropertyComponent::TextPropertyComponent (const ValueWithDefault& valueToControl,
+                                              const String& name,
+                                              int maxNumChars,
+                                              bool isMultiLine,
+                                              bool isEditable)
+    : TextPropertyComponent (name, maxNumChars, isMultiLine, isEditable)
+{
+    textEditor->getTextValue().referTo (Value (new RemapperValueSourceWithDefault (valueToControl)));
+    textEditor->setTextToDisplayWhenEmpty (valueToControl.getDefault(), 0.5f);
+}
+
 TextPropertyComponent::~TextPropertyComponent()
 {
 }

modules/juce_gui_basics/properties/juce_TextPropertyComponent.h

@@ -70,6 +70,23 @@ public:
                            bool isMultiLine,
                            bool isEditable = true);
 
+    /** Creates a text property component with a default value.
+
+        @param valueToControl The ValueWithDefault that is controlled by the TextPropertyComponent
+        @param propertyName   The name of the property
+        @param maxNumChars    If not zero, then this specifies the maximum allowable length of
+                              the string. If zero, then the string will have no length limit.
+        @param isMultiLine    Sets whether the text editor allows carriage returns.
+        @param isEditable     Sets whether the text editor is editable. The default is true.
+
+        @see TextEditor, setEditable
+    */
+    TextPropertyComponent (const ValueWithDefault& valueToControl,
+                           const String& propertyName,
+                           int maxNumChars,
+                           bool isMultiLine,
+                           bool isEditable = true);
+
     /** Destructor. */
     ~TextPropertyComponent();
 
@@ -144,6 +161,8 @@ public:
     virtual void textWasEdited();
 
 private:
+    class RemapperValueSourceWithDefault;
+
     class LabelComp;
     friend class LabelComp;