examples/Utilities/ValueTreesDemo.h

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

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

   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.

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

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

/*******************************************************************************
 The block below describes the properties of this PIP. A PIP is a short snippet
 of code that can be read by the Projucer and used to generate a JUCE project.

 BEGIN_JUCE_PIP_METADATA

 name:             ValueTreesDemo
 version:          1.0.0
 vendor:           JUCE
 website:          http://juce.com
 description:      Showcases value tree features.

 dependencies:     juce_core, juce_data_structures, juce_events, juce_graphics,
                   juce_gui_basics
 exporters:        xcode_mac, vs2019, linux_make, androidstudio, xcode_iphone

 moduleFlags:      JUCE_STRICT_REFCOUNTEDPOINTER=1

 type:             Component
 mainClass:        ValueTreesDemo

 useLocalCopy:     1

 END_JUCE_PIP_METADATA

*******************************************************************************/

#pragma once

#include "../Assets/DemoUtilities.h"

//==============================================================================
class ValueTreeItem  : public TreeViewItem,
                       private ValueTree::Listener
{
public:
    ValueTreeItem (const ValueTree& v, UndoManager& um)
        : tree (v), undoManager (um)
    {
        tree.addListener (this);
    }

    String getUniqueName() const override
    {
        return tree["name"].toString();
    }

    bool mightContainSubItems() override
    {
        return tree.getNumChildren() > 0;
    }

    void paintItem (Graphics& g, int width, int height) override
    {
        if (isSelected())
            g.fillAll (getUIColourIfAvailable (LookAndFeel_V4::ColourScheme::UIColour::highlightedFill,
                                               Colours::teal));

        g.setColour (getUIColourIfAvailable (LookAndFeel_V4::ColourScheme::UIColour::defaultText,
                                             Colours::black));
        g.setFont (15.0f);

        g.drawText (tree["name"].toString(),
                    4, 0, width - 4, height,
                    Justification::centredLeft, true);
    }

    void itemOpennessChanged (bool isNowOpen) override
    {
        if (isNowOpen && getNumSubItems() == 0)
            refreshSubItems();
        else
            clearSubItems();
    }

    var getDragSourceDescription() override
    {
        return "Drag Demo";
    }

    bool isInterestedInDragSource (const DragAndDropTarget::SourceDetails& dragSourceDetails) override
    {
        return dragSourceDetails.description == "Drag Demo";
    }

    void itemDropped (const DragAndDropTarget::SourceDetails&, int insertIndex) override
    {
        OwnedArray<ValueTree> selectedTrees;
        getSelectedTreeViewItems (*getOwnerView(), selectedTrees);

        moveItems (*getOwnerView(), selectedTrees, tree, insertIndex, undoManager);
    }

    static void moveItems (TreeView& treeView, const OwnedArray<ValueTree>& items,
                           ValueTree newParent, int insertIndex, UndoManager& undoManager)
    {
        if (items.size() > 0)
        {
            std::unique_ptr<XmlElement> oldOpenness (treeView.getOpennessState (false));

            for (auto* v : items)
            {
                if (v->getParent().isValid() && newParent != *v && ! newParent.isAChildOf (*v))
                {
                    if (v->getParent() == newParent && newParent.indexOf (*v) < insertIndex)
                        --insertIndex;

                    v->getParent().removeChild (*v, &undoManager);
                    newParent.addChild (*v, insertIndex, &undoManager);
                }
            }

            if (oldOpenness.get() != nullptr)
                treeView.restoreOpennessState (*oldOpenness, false);
        }
    }

    static void getSelectedTreeViewItems (TreeView& treeView, OwnedArray<ValueTree>& items)
    {
        auto numSelected = treeView.getNumSelectedItems();

        for (int i = 0; i < numSelected; ++i)
            if (auto* vti = dynamic_cast<ValueTreeItem*> (treeView.getSelectedItem (i)))
                items.add (new ValueTree (vti->tree));
    }

private:
    ValueTree tree;
    UndoManager& undoManager;

    void refreshSubItems()
    {
        clearSubItems();

        for (int i = 0; i < tree.getNumChildren(); ++i)
            addSubItem (new ValueTreeItem (tree.getChild (i), undoManager));
    }

    void valueTreePropertyChanged (ValueTree&, const Identifier&) override
    {
        repaintItem();
    }

    void valueTreeChildAdded (ValueTree& parentTree, ValueTree&) override         { treeChildrenChanged (parentTree); }
    void valueTreeChildRemoved (ValueTree& parentTree, ValueTree&, int) override  { treeChildrenChanged (parentTree); }
    void valueTreeChildOrderChanged (ValueTree& parentTree, int, int) override    { treeChildrenChanged (parentTree); }
    void valueTreeParentChanged (ValueTree&) override {}

    void treeChildrenChanged (const ValueTree& parentTree)
    {
        if (parentTree == tree)
        {
            refreshSubItems();
            treeHasChanged();
            setOpen (true);
        }
    }

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (ValueTreeItem)
};

//==============================================================================
class ValueTreesDemo   : public Component,
                         public DragAndDropContainer,
                         private Timer
{
public:
    ValueTreesDemo()
    {
        addAndMakeVisible (tree);

        tree.setDefaultOpenness (true);
        tree.setMultiSelectEnabled (true);
        rootItem.reset (new ValueTreeItem (createRootValueTree(), undoManager));
        tree.setRootItem (rootItem.get());

        addAndMakeVisible (undoButton);
        addAndMakeVisible (redoButton);
        undoButton.onClick = [this] { undoManager.undo(); };
        redoButton.onClick = [this] { undoManager.redo(); };

        startTimer (500);

        setSize (500, 500);
    }

    ~ValueTreesDemo() override
    {
        tree.setRootItem (nullptr);
    }

    void paint (Graphics& g) override
    {
        g.fillAll (getUIColourIfAvailable (LookAndFeel_V4::ColourScheme::UIColour::windowBackground));
    }

    void resized() override
    {
        auto r = getLocalBounds().reduced (8);

        auto buttons = r.removeFromBottom (22);
        undoButton.setBounds (buttons.removeFromLeft (100));
        buttons.removeFromLeft (6);
        redoButton.setBounds (buttons.removeFromLeft (100));

        r.removeFromBottom (4);
        tree.setBounds (r);
    }

    static ValueTree createTree (const String& desc)
    {
        ValueTree t ("Item");
        t.setProperty ("name", desc, nullptr);
        return t;
    }

    static ValueTree createRootValueTree()
    {
        auto vt = createTree ("This demo displays a ValueTree as a treeview.");
        vt.appendChild (createTree ("You can drag around the nodes to rearrange them"),               nullptr);
        vt.appendChild (createTree ("..and press 'delete' or 'backspace' to delete them"),            nullptr);
        vt.appendChild (createTree ("Then, you can use the undo/redo buttons to undo these changes"), nullptr);

        int n = 1;
        vt.appendChild (createRandomTree (n, 0), nullptr);

        return vt;
    }

    static ValueTree createRandomTree (int& counter, int depth)
    {
        auto t = createTree ("Item " + String (counter++));

        if (depth < 3)
            for (int i = 1 + Random::getSystemRandom().nextInt (7); --i >= 0;)
                t.appendChild (createRandomTree (counter, depth + 1), nullptr);

        return t;
    }

    void deleteSelectedItems()
    {
        OwnedArray<ValueTree> selectedItems;
        ValueTreeItem::getSelectedTreeViewItems (tree, selectedItems);

        for (auto* v : selectedItems)
        {
            if (v->getParent().isValid())
                v->getParent().removeChild (*v, &undoManager);
        }
    }

    bool keyPressed (const KeyPress& key) override
    {
        if (key == KeyPress::deleteKey || key == KeyPress::backspaceKey)
        {
            deleteSelectedItems();
            return true;
        }

        if (key == KeyPress ('z', ModifierKeys::commandModifier, 0))
        {
            undoManager.undo();
            return true;
        }

        if (key == KeyPress ('z', ModifierKeys::commandModifier | ModifierKeys::shiftModifier, 0))
        {
            undoManager.redo();
            return true;
        }

        return Component::keyPressed (key);
    }

private:
    TreeView tree;
    TextButton undoButton  { "Undo" },
               redoButton  { "Redo" };

    std::unique_ptr<ValueTreeItem> rootItem;
    UndoManager undoManager;

    void timerCallback() override
    {
        undoManager.beginNewTransaction();
    }

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (ValueTreesDemo)
};