text_box.hpp

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/*
   Copyright (C) 2008 - 2016 by Mark de Wever <[email protected]>
   Part of the Battle for Wesnoth Project http://www.wesnoth.org/

   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 2 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.

   See the COPYING file for more details.
*/

#ifndef GUI_WIDGETS_TEXT_BOX_HPP_INCLUDED
#define GUI_WIDGETS_TEXT_BOX_HPP_INCLUDED

#include "gui/widgets/text.hpp"

namespace gui2
{

// ------------ WIDGET -----------{

/**
 * Class for text input history.
 *
 * The history of text items can be stored in the preferences. This class
 * handles that. Every item needs an id by which the history is loaded and
 * saved.
 */
class ttext_history
{
public:
    /**
     * Gets history that matches id.
     *
     * @param id                  The id of the history to look for.
     * @param enabled             The enabled state of the history.
     *
     * @returns                   The history object.
     */
    static ttext_history get_history(const std::string& id, const bool enabled);

    ttext_history() : history_(0), pos_(0), enabled_(false)
    {
    }

    /**
     * Push string into the history.
     *
     * If the string is empty or the same as the last item in the history this
     * function is a nop.
     *
     * @param text                   The text to push in the history.
     */
    void push(const std::string& text);

    /**
     * One step up in the history.
     *
     * Pushes text to the history if at the end.
     *
     * @param text                The text to push in the history.
     *
     * @returns                   The current value of the history.
     */
    std::string up(const std::string& text = "");

    /**
     * One step down in the history.
     *
     * Pushes text to the history if at the end.
     *
     * @param text                The text to push in the history.
     *
     * @returns                   The current value of the history.
     */
    std::string down(const std::string& text = "");

    /**
     * Gets the current history value.
     *
     * @returns                   If enabled return the current history
     *                            position, otherwise an empty string is
     *                            returned.
     */
    std::string get_value() const;

    /***** ***** ***** setters / getters for members ***** ****** *****/

    void set_enabled(bool enabled = true)
    {
        enabled_ = enabled;
    }
    bool get_enabled() const
    {
        return enabled_;
    }

private:
    ttext_history(std::vector<std::string>* history, const bool enabled)
        : history_(history), pos_(history->size()), enabled_(enabled)
    {
    }

    /** The items in the history. */
    std::vector<std::string>* history_;

    /** The current position in the history. */
    unsigned pos_;

    /** Is the history enabled. */
    bool enabled_;
};

/** Class for a single line text area. */
class ttext_box : public ttext_
{
public:
    ttext_box();

    /** Saves the text in the widget to the history. */
    void save_to_history()
    {
        history_.push(get_value());
    }

    /***** ***** ***** setters / getters for members ***** ****** *****/

    void set_history(const std::string& id)
    {
        history_ = ttext_history::get_history(id, true);
    }

    void set_max_input_length(const size_t length)
    {
        max_input_length_ = length;
    }

    void clear()
    {
        set_value("");
    }

protected:
    /***** ***** ***** ***** layout functions ***** ***** ***** *****/

    /** See @ref twidget::place. */
    virtual void place(const tpoint& origin, const tpoint& size) override;

    /***** ***** ***** ***** Inherited ***** ***** ***** *****/

    /** See @ref tcontrol::update_canvas. */
    virtual void update_canvas() override;

    /** Inherited from ttext_. */
    void goto_end_of_line(const bool select = false)
    {
        goto_end_of_data(select);
    }

    /** Inherited from ttext_. */
    void goto_start_of_line(const bool select = false)
    {
        goto_start_of_data(select);
    }

    /** Inherited from ttext_. */
    void delete_char(const bool before_cursor);

    /** Inherited from ttext_. */
    void delete_selection();

    void handle_mouse_selection(tpoint mouse, const bool start_selection);

private:
    /** The history text for this widget. */
    ttext_history history_;

    /** The maximum length of the text input. */
    size_t max_input_length_;

    /**
     * The x offset in the widget where the text starts.
     *
     * This value is needed to translate a location in the widget to a location
     * in the text.
     */
    unsigned text_x_offset_;

    /**
     * The y offset in the widget where the text starts.
     *
     * Needed to determine whether a click is on the text.
     */
    unsigned text_y_offset_;

    /**
     * The height of the text itself.
     *
     * Needed to determine whether a click is on the text.
     */
    unsigned text_height_;

    /** Updates text_x_offset_ and text_y_offset_. */
    void update_offsets();

    /** Is the mouse in dragging mode, this affects selection in mouse move */
    bool dragging_;

    /**
     * Inherited from ttext_.
     *
     * Unmodified                 Unhandled.
     * Control                    Ignored.
     * Shift                      Ignored.
     * Alt                        Ignored.
     */
    void handle_key_up_arrow(SDLMod /*modifier*/, bool& /*handled*/)
    {
    }

    /**
     * Inherited from ttext_.
     *
     * Unmodified                 Unhandled.
     * Control                    Ignored.
     * Shift                      Ignored.
     * Alt                        Ignored.
     */
    void handle_key_down_arrow(SDLMod /*modifier*/, bool& /*handled*/)
    {
    }

    /**
     * Goes one item up in the history.
     *
     * @returns                   True if there's a history, false otherwise.
     */
    bool history_up();

    /**
     * Goes one item down in the history.
     *
     * @returns                   True if there's a history, false otherwise.
     */
    bool history_down();

    /** Inherited from ttext_. */
    void handle_key_default(bool& handled,
                            SDLKey key,
                            SDLMod modifier,
                            const utf8::string& unicode);

    /** Inherited from ttext_. */
    void handle_key_clear_line(SDLMod modifier, bool& handled);

    /** See @ref tcontrol::get_control_type. */
    virtual const std::string& get_control_type() const override;

    /** Inherited from tcontrol. */
    void load_config_extra();

    /***** ***** ***** signal handlers ***** ****** *****/

    void signal_handler_mouse_motion(const event::tevent event,
                                     bool& handled,
                                     const tpoint& coordinate);

    void signal_handler_left_button_down(const event::tevent event,
                                         bool& handled);

    void signal_handler_left_button_up(const event::tevent event,
                                       bool& handled);

    void signal_handler_left_button_double_click(const event::tevent event,
                                                 bool& handled);
};

// }---------- DEFINITION ---------{

struct ttext_box_definition : public tcontrol_definition
{
    explicit ttext_box_definition(const config& cfg);

    struct tresolution : public tresolution_definition_
    {
        explicit tresolution(const config& cfg);

        tformula<unsigned> text_x_offset;
        tformula<unsigned> text_y_offset;
    };
};

// }---------- BUILDER -----------{

namespace implementation
{

struct tbuilder_text_box : public tbuilder_control
{
public:
    explicit tbuilder_text_box(const config& cfg);

    using tbuilder_control::build;

    twidget* build() const;

    std::string history;

    size_t max_input_length;
};

} // namespace implementation

// }------------ END --------------

} // namespace gui2

#endif