juce_gui_basics/menus/juce_BurgerMenuComponent.cpp

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

   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.

   By using JUCE, you agree to the terms of both the JUCE 6 End-User License
   Agreement and JUCE Privacy Policy (both effective as of the 16th June 2020).

   End User License Agreement: www.juce.com/juce-6-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
{

//==============================================================================
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)
{
    lookAndFeelChanged();
    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();
    }
}

void BurgerMenuComponent::lookAndFeelChanged()
{
    listBox.setRowHeight (roundToInt (getLookAndFeel().getPopupMenuFont().getHeight() * 2.0f));
}

} // namespace juce