menu.h

/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

/*
 * This code is based on the CRAB engine
 *
 * Copyright (c) Arvind Raja Yadav
 *
 * Licensed under MIT
 *
 */

//=============================================================================
// Author:   Arvind
// Purpose:  Menu class
//=============================================================================
#ifndef CRAB_MENU_H
#define CRAB_MENU_H

#include "crab/crab.h"
#include "crab/metaengine.h"
#include "crab/ui/button.h"

namespace Crab {

namespace pyrodactyl {
namespace ui {
template<typename T>
class Menu {
protected:
    // The index of current selected option and highlighted option
    int _hoverIndex;

    // The order in which a keyboard or gamepad traverses the menu
    Common::Array<uint> _path;

    // Are keyboard buttons enabled?
    bool _useKeyboard;

    // Has a key been pressed?
    enum InputDevice {
        KEYBOARD,
        MOUSE
    } _latestInput;

    // Do the paths use horizontal, vertical or both types of input for keyboard traversal
    enum PathType {
        PATH_DEFAULT,
        PATH_HORIZONTAL,
        PATH_VERTICAL
    } _pathType;

    //------------------------------------------------------------------------
    // Purpose: Find the next element in our path
    //------------------------------------------------------------------------
    void next() {
        if (_hoverIndex == -1) {
            for (uint pos = 0; pos < _path.size(); pos++)
                if (_element[_path[pos]]._visible == true) {
                    _hoverIndex = _path[pos];
                    break;
                }
        } else {
            uint curpos = 0;
            for (; curpos < _path.size(); curpos++)
                if ((int)_path[curpos] == _hoverIndex)
                    break;

            for (uint nextloc = (curpos + 1) % _element.size(); nextloc != curpos; nextloc = (nextloc + 1) % _element.size())
                if (_element[nextloc]._visible == true) {
                    _hoverIndex = _path[nextloc];
                    break;
                }
        }
    }

    //------------------------------------------------------------------------
    // Purpose: Find the previous element in our path
    //------------------------------------------------------------------------
    void prev() {
        if (_hoverIndex == -1) {
            for (uint pos = 0; pos < _path.size(); pos++)
                if (_element[_path[pos]]._visible == true) {
                    _hoverIndex = _path[pos];
                    break;
                }
        } else {
            uint curpos = 0;
            for (; curpos < _path.size(); curpos++)
                if ((int)_path[curpos] == _hoverIndex)
                    break;

            if (curpos == 0)
                return;         // There is no previous element

            int nextloc = curpos - 1;
            while (nextloc != (int)curpos) {
                if (nextloc < 0)
                    nextloc = _element.size() - 1;

                if (_element[nextloc]._visible == true) {
                    _hoverIndex = _path[nextloc];
                    break;
                }

                nextloc--;
            }
        }
    }

    //------------------------------------------------------------------------
    // Purpose: Handle keyboard input
    //------------------------------------------------------------------------
    int handleKeyboard(const Common::Event &event) {
        using namespace pyrodactyl::input;

        if (g_engine->_inputManager->getKeyBindingMode() != KBM_UI) {
            g_engine->_inputManager->setKeyBindingMode(KBM_UI);
        }

        if (!_element.empty()) {
            if (_pathType != PATH_HORIZONTAL) {
                if (g_engine->_inputManager->state(IU_DOWN)) {
                    next();
                    _latestInput = KEYBOARD;
                } else if (g_engine->_inputManager->state(IU_UP)) {
                    prev();
                    _latestInput = KEYBOARD;
                }
            }

            if (_pathType != PATH_VERTICAL) {
                if (g_engine->_inputManager->state(IU_RIGHT)) {
                    next();
                    _latestInput = KEYBOARD;
                } else if (g_engine->_inputManager->state(IU_LEFT)) {
                    prev();
                    _latestInput = KEYBOARD;
                }
            }

            if (g_engine->_inputManager->state(IU_ACCEPT) && _hoverIndex != -1)
                return _hoverIndex;

            // We pressed a key, which means we have to update the hovering status
            if (_latestInput == KEYBOARD) {
                // Update hover status of keys according to the current index
                int i = 0;
                for (auto it = _element.begin(); it != _element.end(); ++it, ++i)
                    it->_hoverKey = (i == _hoverIndex);
            }
        }

        return -1;
    }

public:
    // The collection of buttons in the menu
    Common::Array<T> _element;

    Menu() {
        _hoverIndex = -1;
        _useKeyboard = false;
        _latestInput = MOUSE;
        _pathType = PATH_DEFAULT;
    }
    ~Menu() {}

    void reset() {
        _latestInput = MOUSE;
        _hoverIndex = -1;
        for (auto &b : _element)
            b.reset();
    }

    void setUI() {
        for (auto &i : _element)
            i.setUI();
    }

    //------------------------------------------------------------------------
    // Purpose: Load the menu from a file
    //------------------------------------------------------------------------
    void load(rapidxml::xml_node<char> *node) {
        if (nodeValid(node)) {
            for (auto n = node->first_node(); n != nullptr; n = n->next_sibling()) {
                T b;
                b.load(n);
                _element.push_back(b);
            }

            loadBool(_useKeyboard, "keyboard", node, false);
            assignPaths();
        }
    }

    //------------------------------------------------------------------------
    // Purpose: Event Handling
    // The reason this function doesn't declare its own Event object is because
    // a menu might not be the only object in a game state
    //------------------------------------------------------------------------
    int handleEvents(const Common::Event &event, const int &xOffset = 0, const int &yOffset = 0) {
        // The keyboard/joystick event handling bit
        if (_useKeyboard) {
            int result = handleKeyboard(event);

            // We have accepted a menu option using the keyboard
            if (result != -1) {
                // Reset the menu state
                reset();
                g_engine->_inputManager->setKeyBindingMode(pyrodactyl::input::KBM_GAME);
                return result;
            }
        }

        // Check if we have moved or clicked the mouse
        if (Common::isMouseEvent(event)) {
            // Since the player is moving the mouse, we have to recalculate hover index at every opportunity
            _hoverIndex = -1;
            _latestInput = MOUSE;
        }

        // The mouse and hotkey event handling bit
        int i = 0;
        for (auto it = _element.begin(); it != _element.end(); ++it, ++i) {
            // We clicked on a button using the mouse
            if (it->handleEvents(event, xOffset, yOffset) == BUAC_LCLICK) {
                // Reset the menu state
                reset();
                g_engine->_inputManager->setKeyBindingMode(pyrodactyl::input::KBM_GAME);
                return i;
            }

            // We did not click a button, however we did hover over the button
            // However if we are use keyboard to browse through the menu, hovering is forgotten until we move the mouse again
            if (it->_hoverMouse && _latestInput == MOUSE) {
                _hoverIndex = i;

                // The latest input is the mouse, which means we have to forget the keyboard hover states
                for (auto &e : _element)
                    e._hoverKey = false;
            }
        }

        if (_latestInput == KEYBOARD) {
            // The latest input is the keyboard, which means we have to forget the mouse hover states
            for (auto &it : _element)
                it._hoverMouse = false;
        }
        return -1;
    }

    //------------------------------------------------------------------------
    // Purpose: Draw the menu
    //------------------------------------------------------------------------
    void draw(const int &XOffset = 0, const int &YOffset = 0) {
        for (auto &it : _element)
            it.draw(XOffset, YOffset);
    }

    //------------------------------------------------------------------------
    // Purpose: Get info about the menu
    //------------------------------------------------------------------------
    void useKeyboard(const bool &val) {
        _useKeyboard = val;
    }

    void clear() {
        _element.clear();
    }

    int hoverIndex() {
        return _hoverIndex;
    }

    //------------------------------------------------------------------------
    // Purpose: Assign traversal paths
    //------------------------------------------------------------------------
    void assignPaths() {
        _path.clear();

        // These variables are used to see if the X and Y values of buttons are the same or not
        // Used to determine the path type of the menu
        bool sameX = true, sameY = true;

        if (!_element.empty()) {
            _path.push_back(0);

            for (uint i = 1; i < _element.size(); i++) {
                _path.push_back(i);

                int prevX = _element[i - 1].x;
                int prevY = _element[i - 1].y;

                if (sameX && _element[i].x != prevX)
                    sameX = false;

                if (sameY && _element[i].y != prevY)
                    sameY = false;
            }
        }

        if (sameX) {
            if (sameY)
                _pathType = PATH_DEFAULT;
            else
                _pathType = PATH_VERTICAL;
        } else if (sameY)
            _pathType = PATH_HORIZONTAL;
        else
            _pathType = PATH_DEFAULT;
    }
};

// A menu with simple buttons
typedef Menu<Button> ButtonMenu;
} // End of namespace ui
} // End of namespace pyrodactyl

} // End of namespace Crab

#endif // CRAB_MENU_H