CInput.h

Go to the documentation of this file.

/* Copyright (C) 2013 Wildfire Games.
 * This file is part of 0 A.D.
 *
 * 0 A.D. 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.
 *
 * 0 A.D. 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 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
 */

/*
GUI Object - Input [box]

--Overview--

    GUI Object representing a text field you can edit.

--More info--

    Check GUI.h

*/

#ifndef INCLUDED_CINPUT
#define INCLUDED_CINPUT

//--------------------------------------------------------
//  Includes / Compiler directives
//--------------------------------------------------------
#include "GUI.h"

// TODO Gee: Remove
class IGUIScrollBar;

//--------------------------------------------------------
//  Macros
//--------------------------------------------------------

//--------------------------------------------------------
//  Types
//--------------------------------------------------------

//--------------------------------------------------------
//  Declarations
//--------------------------------------------------------

/**
 * Text field where you can input and edit the text.
 *
 * It doesn't use IGUITextOwner, because we don't need
 * any other features than word-wrapping, and we need to be
 * able to rapidly change the string.
 *
 * @see IGUIObject
 */
class CInput : public IGUIScrollBarOwner
{
    GUI_OBJECT(CInput)

protected: // forwards
    struct SRow;

public:
    CInput();
    virtual ~CInput();

    /**
     * @see IGUIObject#ResetStates()
     */
    virtual void ResetStates() { IGUIScrollBarOwner::ResetStates(); }

    // Check where the mouse is hovering, and get the appropriate text position.
    //  return is the text-position index.
    // const in philosophy, but I need to retrieve the caption in a non-const way.
    int GetMouseHoveringTextPosition();

    // Same as above, but only on one row in X, and a given value, not the mouse's
    //  wanted is filled with x if the row didn't extend as far as we 
    int GetXTextPosition(const std::list<SRow>::iterator &c, const float &x, float &wanted);

protected:
    /**
     * @see IGUIObject#HandleMessage()
     */
    virtual void HandleMessage(SGUIMessage &Message);

    /**
     * Handle events manually to catch keyboard inputting.
     */
    virtual InReaction ManuallyHandleEvent(const SDL_Event_* ev);

    /**
     * Handle hotkey events (called by ManuallyHandleEvent)
     */
    virtual InReaction ManuallyHandleHotkeyEvent(const SDL_Event_* ev);

    /**
     * @see IGUIObject#UpdateCachedSize()
     */
    virtual void UpdateCachedSize();

    /**
     * Draws the Text
     */
    virtual void Draw();

    // Calculate m_CharacterPosition
    //  the main task for this function is to perfom word-wrapping
    // You input from which character it has been changed, because
    //  if we add a character to the very last end, we don't want
    //  process everything all over again! Also notice you can
    //  specify a 'to' also, it will only be used though if a '\n'
    //  appears, because then the word-wrapping won't change after
    //  that.
    void UpdateText(int from=0, int to_before=-1, int to_after=-1);

    // Delete the current selection. Also places the pointer at the
    //  crack between the two segments kept.
    void DeleteCurSelection();

    // Is text selected? It can be denote two ways, m_iBufferPos_Tail
    //  being -1 or the same as m_iBufferPos. This makes for clearer
    //  code.
    bool SelectingText() const;

    // Get area of where text can be drawn.
    float GetTextAreaWidth();

    // Called every time the auto-scrolling should be checked.
    void UpdateAutoScroll();

protected:
    // Cursor position 
    //  (the second one is for selection of larger areas, -1 if not used)
    // A note on 'Tail', it was first called 'To', and the natural order
    //  of X and X_To was X then X_To. Now Tail is called so, because it
    //  can be placed both before and after, but the important things is
    //  that m_iBufferPos is ALWAYS where the edit pointer is. Yes, there
    //  is an edit pointer even though you select a larger area. For instance
    //  if you want to resize the selection with Shift+Left/Right, there
    //  are always two ways a selection can look. Check any OS GUI and you'll
    //  see.
    int m_iBufferPos,
        m_iBufferPos_Tail;

    // the outer vector is lines, and the inner is X positions
    //  in a row. So that we can determine where characters are
    //  placed. It's important because we need to know where the
    //  pointer should be placed when the input control is pressed.
    struct SRow
    {
        int                 m_ListStart;    // Where does the Row starts
        std::vector<float>  m_ListOfX;      // List of X values for each character.
    };

    // List of rows, list because I use a lot of iterators, and change
    //  its size continuously, it's easier and safer if I know the
    //  iterators never gets invalidated.
    // For one-liners, only one row is used.
    std::list< SRow > m_CharacterPositions;

    // *** Things for a multi-lined input control *** //

    // This is when you change row with up/down, and the row you jump
    //  to doesn't have anything at that X position, then it will
    //  keep the WantedX position in mind when switching to the next
    //  row. It will keep on being used until it reach a row which meets
    //  the requirements.
    //  0.0f means not in use.
    float m_WantedX;

    // If we are in the process of selecting a larger selection of text
    //  using the mouse click (hold) and drag, this is true.
    bool m_SelectingText;

    // *** Things for one-line input control *** //
    float m_HorizontalScroll;

    // Used to store the previous time for flashing the cursor.
    double m_PrevTime;

    // Cursor blink rate in seconds, if greater than 0.0.
    double m_CursorBlinkRate;

    // If the cursor should be drawn or not.
    bool m_CursorVisState;
};

#endif