JUCE/modules/juce_gui_basics/menus/juce_BurgerMenuComponent.cpp

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

   This file is part of the JUCE 6 technical preview.
   Copyright (c) 2020 - Raw Material Software Limited

   You may use this code under the terms of the GPL v3
   (see www.gnu.org/licenses).

   For this technical preview, this file is not subject to commercial licensing.

   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
{

//==============================================================================
struct CustomMenuBarItemHolder    : public Component
{
    CustomMenuBarItemHolder (const ReferenceCountedObjectPtr<PopupMenu::CustomComponent>& customComponent)
    {
        setInterceptsMouseClicks (false, true);
        update (customComponent);
    }

    void update (const ReferenceCountedObjectPtr<PopupMenu::CustomComponent>& newComponent)
    {
        jassert (newComponent != nullptr);

        if (newComponent != custom)
        {
            if (custom != nullptr)
                removeChildComponent (custom.get());

            custom = newComponent;
            addAndMakeVisible (*custom);
            resized();
        }
    }

    void resized() override
    {
        custom->setBounds (getLocalBounds());
    }

    ReferenceCountedObjectPtr<PopupMenu::CustomComponent> custom;

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (CustomMenuBarItemHolder)
};

//==============================================================================
BurgerMenuComponent::BurgerMenuComponent (MenuBarModel* modelToUse)
{
    auto& lf = getLookAndFeel();

    listBox.setRowHeight (roundToInt (lf.getPopupMenuFont().getHeight() * 2.0f));
    listBox.addMouseListener (this, true);

    setModel (modelToUse);
    addAndMakeVisible (listBox);
}

BurgerMenuComponent::~BurgerMenuComponent()
{
    if (model != nullptr)
        model->removeListener (this);
}

void BurgerMenuComponent::setModel (MenuBarModel* newModel)
{
    if (newModel != model)
    {
        if (model != nullptr)
            model->removeListener (this);

        model = newModel;

        if (model != nullptr)
            model->addListener (this);

        refresh();
        listBox.updateContent();
    }
}

MenuBarModel* BurgerMenuComponent::getModel() const noexcept
{
    return model;
}

void BurgerMenuComponent::refresh()
{
    lastRowClicked = inputSourceIndexOfLastClick = -1;

    rows.clear();

    if (model != nullptr)
    {
        auto menuBarNames = model->getMenuBarNames();

        for (auto menuIdx = 0; menuIdx < menuBarNames.size(); ++menuIdx)
        {
            PopupMenu::Item menuItem;
            menuItem.text = menuBarNames[menuIdx];

            String ignore;
            auto menu = model->getMenuForIndex (menuIdx, ignore);

            rows.add (Row { true, menuIdx, menuItem });
            addMenuBarItemsForMenu (menu, menuIdx);
        }
    }
}

void BurgerMenuComponent::addMenuBarItemsForMenu (PopupMenu& menu, int menuIdx)
{
    for (PopupMenu::MenuItemIterator it (menu); it.next();)
    {
        auto& item = it.getItem();

        if (item.isSeparator)
            continue;

        if (hasSubMenu (item))
            addMenuBarItemsForMenu (*item.subMenu, menuIdx);
        else
            rows.add (Row {false, menuIdx, it.getItem()});
    }
}

int BurgerMenuComponent::getNumRows()
{
    return rows.size();
}

void BurgerMenuComponent::paint (Graphics& g)
{
    getLookAndFeel().drawPopupMenuBackground (g, getWidth(), getHeight());
}

void BurgerMenuComponent::paintListBoxItem (int rowIndex, Graphics& g, int w, int h, bool highlight)
{
    auto& lf = getLookAndFeel();
    Rectangle<int> r (w, h);

    auto row = (rowIndex < rows.size() ? rows.getReference (rowIndex)
                                       : Row { true, 0, {} });

    g.fillAll (findColour (PopupMenu::backgroundColourId));

    if (row.isMenuHeader)
    {
        lf.drawPopupMenuSectionHeader (g, r.reduced (20, 0), row.item.text);
        g.setColour (Colours::grey);
        g.fillRect (r.withHeight (1));
    }
    else
    {
        auto& item = row.item;
        auto* colour = item.colour != Colour() ? &item.colour : nullptr;

        if (item.customComponent == nullptr)
            lf.drawPopupMenuItem (g, r.reduced (20, 0),
                                  item.isSeparator,
                                  item.isEnabled,
                                  highlight,
                                  item.isTicked,
                                  hasSubMenu (item),
                                  item.text,
                                  item.shortcutKeyDescription,
                                  item.image.get(),
                                  colour);
    }
}

bool BurgerMenuComponent::hasSubMenu (const PopupMenu::Item& item)
{
    return item.subMenu != nullptr && (item.itemID == 0 || item.subMenu->getNumItems() > 0);
}

void BurgerMenuComponent::listBoxItemClicked (int rowIndex, const MouseEvent& e)
{
    auto row = rowIndex < rows.size() ? rows.getReference (rowIndex)
                                      : Row { true, 0, {} };

    if (! row.isMenuHeader)
    {
        lastRowClicked = rowIndex;
        inputSourceIndexOfLastClick = e.source.getIndex();
    }
}

Component* BurgerMenuComponent::refreshComponentForRow (int rowIndex, bool isRowSelected, Component* existing)
{
    auto row = rowIndex < rows.size() ? rows.getReference (rowIndex)
                                      : Row { true, 0, {} };

    auto hasCustomComponent = (row.item.customComponent != nullptr);

    if (existing == nullptr && hasCustomComponent)
        return new CustomMenuBarItemHolder (row.item.customComponent);

    if (existing != nullptr)
    {
        auto* componentToUpdate = dynamic_cast<CustomMenuBarItemHolder*> (existing);
        jassert (componentToUpdate != nullptr);

        if (hasCustomComponent && componentToUpdate != nullptr)
        {
            row.item.customComponent->setHighlighted (isRowSelected);
            componentToUpdate->update (row.item.customComponent);
        }
        else
        {
            delete existing;
            existing = nullptr;
        }
    }

    return existing;
}

void BurgerMenuComponent::resized()
{
    listBox.setBounds (getLocalBounds());
}

void BurgerMenuComponent::menuBarItemsChanged (MenuBarModel* menuBarModel)
{
    setModel (menuBarModel);
}

void BurgerMenuComponent::menuCommandInvoked (MenuBarModel*, const ApplicationCommandTarget::InvocationInfo&)
{
}

void BurgerMenuComponent::mouseUp (const MouseEvent& event)
{
    auto rowIndex = listBox.getSelectedRow();

    if (rowIndex == lastRowClicked && rowIndex < rows.size()
         && event.source.getIndex() == inputSourceIndexOfLastClick)
    {
        auto& row = rows.getReference (rowIndex);

        if (! row.isMenuHeader)
        {
            listBox.selectRow (-1);

            lastRowClicked = -1;
            inputSourceIndexOfLastClick = -1;

            topLevelIndexClicked = row.topLevelMenuIndex;
            auto& item = row.item;

            if (auto* managerOfChosenCommand = item.commandManager)
            {
                ApplicationCommandTarget::InvocationInfo info (item.itemID);
                info.invocationMethod = ApplicationCommandTarget::InvocationInfo::fromMenu;

                managerOfChosenCommand->invoke (info, true);
            }

            postCommandMessage (item.itemID);
        }
    }
}

void BurgerMenuComponent::handleCommandMessage (int commandID)
{
    if (model != nullptr)
    {
        model->menuItemSelected (commandID, topLevelIndexClicked);
        topLevelIndexClicked = -1;

        refresh();
        listBox.updateContent();
    }
}

} // namespace juce