/**
 * @file llchatentry.h
 * @author Paul Guslisty
 * @brief Text editor widget which is used for user input
 *
 * Features:
 *          Optional line history so previous entries can be recalled by CTRL UP/DOWN
 *          Optional auto-resize behavior on input chat field
 *
 * $LicenseInfo:firstyear=2001&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2012, Linden Research, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License only.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */

#ifndef LLCHATENTRY_H_
#define LLCHATENTRY_H_

#include "lltexteditor.h"

class LLChatEntry : public LLTextEditor
{
public:

    struct Params : public LLInitParam::Block<Params, LLTextEditor::Params>
    {
        Optional<bool>      has_history,
                            is_expandable;

        Optional<int>       expand_lines_count;

        Params();
    };

    virtual ~LLChatEntry();

protected:

    friend class LLUICtrlFactory;
    LLChatEntry(const Params& p);
    /*virtual*/ void    beforeValueChange();
    /*virtual*/ void    onValueChange(S32 start, S32 end);
    /*virtual*/ bool    useLabel() const;

public:

    virtual void    draw();
    virtual void    onCommit();
    /*virtual*/ void    onFocusReceived();
    /*virtual*/ void    onFocusLost();

    void enableSingleLineMode(bool single_line_mode);
    boost::signals2::connection setTextExpandedCallback(const commit_signal_t::slot_type& cb);

private:

    /**
     * Implements auto-resize behavior.
     * When user's typing reaches the right edge of the chat field
     * the chat field expands vertically by one line. The bottom of
     * the chat field remains bottom-justified. The chat field does
     * not expand beyond mExpandLinesCount.
     */
    void    expandText();

    /**
     * Implements line history so previous entries can be recalled by CTRL UP/DOWN
     */
    void    updateHistory();

    bool    handleSpecialKey(const KEY key, const MASK mask);


    // Fired when text height expanded to mExpandLinesCount
    commit_signal_t*            mTextExpandedSignal;

    // line history support:
    typedef std::vector<std::string>    line_history_t;
    line_history_t::iterator            mCurrentHistoryLine;    // currently browsed history line
    line_history_t                      mLineHistory;           // line history storage
    bool                                mHasHistory;            // flag for enabled/disabled line history
    bool                                mIsExpandable;
    bool                                mSingleLineMode;

    S32                                 mExpandLinesCount;
    S32                                 mPrevLinesCount;
    S32                                 mPrevExpandedLineCount;
};

#endif /* LLCHATENTRY_H_ */