/**
 * @file llscrollcontainer.h
 * @brief LLScrollContainer class header file.
 *
 * $LicenseInfo:firstyear=2001&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010, 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 LL_LLSCROLLCONTAINER_H
#define LL_LLSCROLLCONTAINER_H

#include "lluictrl.h"
#ifndef LL_V4COLOR_H
#include "v4color.h"
#endif
#include "llcoord.h"
#include "llscrollbar.h"


class LLViewBorder;
class LLUICtrlFactory;

/*****************************************************************************
 *
 * A decorator view class meant to encapsulate a clipped region which is
 * scrollable. It automatically takes care of pixel perfect scrolling
 * and cliipping, as well as turning the scrollbars on or off based on
 * the width and height of the view you're scrolling.
 *
 *****************************************************************************/

struct ScrollContainerRegistry : public LLChildRegistry<ScrollContainerRegistry>
{
    LLSINGLETON_EMPTY_CTOR(ScrollContainerRegistry);
};

class LLScrollContainer : public LLUICtrl
{
public:
    // Note: vertical comes before horizontal because vertical
    // scrollbars have priority for mouse and keyboard events.

    struct Params : public LLInitParam::Block<Params, LLUICtrl::Params>
    {
        Optional<bool>      is_opaque,
                            reserve_scroll_corner,
                            border_visible,
                            hide_scrollbar,
                            ignore_arrow_keys;
        Optional<F32>       min_auto_scroll_rate,
                            max_auto_scroll_rate;
        Optional<U32>       max_auto_scroll_zone;
        Optional<LLUIColor> bg_color;
        Optional<LLScrollbar::callback_t> scroll_callback;
        Optional<S32>       size;

        Params();
    };

    // my valid children are stored in this registry
    typedef ScrollContainerRegistry child_registry_t;

protected:
    LLScrollContainer(const Params&);
    friend class LLUICtrlFactory;
public:
    virtual ~LLScrollContainer( void );

    virtual void    setValue(const LLSD& value) { mInnerRect.setValue(value); }

    void            setBorderVisible( bool b );

    void            scrollToShowRect( const LLRect& rect, const LLRect& constraint);
    void            scrollToShowRect( const LLRect& rect) { scrollToShowRect(rect, LLRect(0, mInnerRect.getHeight(), mInnerRect.getWidth(), 0)); }

    void            setReserveScrollCorner( bool b ) { mReserveScrollCorner = b; }
    LLRect          getVisibleContentRect();
    LLRect          getContentWindowRect();
    virtual const LLRect    getScrolledViewRect() const { return mScrolledView ? mScrolledView->getRect() : LLRect::null; }
    void            pageUp(S32 overlap = 0);
    void            pageDown(S32 overlap = 0);
    void            goToTop();
    void            goToBottom();
    bool            isAtTop() const { return mScrollbar[VERTICAL]->isAtBeginning(); }
    bool            isAtBottom() const { return mScrollbar[VERTICAL]->isAtEnd(); }
    S32             getDocPosVertical() const { return mScrollbar[VERTICAL]->getDocPos(); }
    S32             getDocPosHorizontal() const { return mScrollbar[HORIZONTAL]->getDocPos(); }
    S32             getBorderWidth() const;

    // LLView functionality
    virtual void    reshape(S32 width, S32 height, bool called_from_parent = true);
    virtual bool    handleKeyHere(KEY key, MASK mask);
    virtual bool    handleUnicodeCharHere(llwchar uni_char);
    virtual bool    handleScrollWheel( S32 x, S32 y, S32 clicks );
    virtual bool    handleScrollHWheel( S32 x, S32 y, S32 clicks );
    virtual bool    handleDragAndDrop(S32 x, S32 y, MASK mask, bool drop,
                                   EDragAndDropType cargo_type,
                                   void* cargo_data,
                                   EAcceptance* accept,
                                   std::string& tooltip_msg);

    virtual void    draw();
    virtual bool    addChild(LLView* view, S32 tab_group = 0);

    bool canAutoScroll(S32 x, S32 y);
    bool autoScroll(S32 x, S32 y);

    S32 getSize() const { return mSize; }
    void setSize(S32 thickness);

protected:
    LLView*     mScrolledView;

private:
    // internal scrollbar handlers
    virtual void scrollHorizontal( S32 new_pos );
    virtual void scrollVertical( S32 new_pos );
    void updateScroll();
    bool autoScroll(S32 x, S32 y, bool do_scroll);
    void calcVisibleSize( S32 *visible_width, S32 *visible_height, bool* show_h_scrollbar, bool* show_v_scrollbar ) const;

    LLScrollbar* mScrollbar[ORIENTATION_COUNT];
    S32         mSize;
    bool        mIsOpaque;
    LLUIColor   mBackgroundColor;
    LLRect      mInnerRect;
    LLViewBorder* mBorder;
    bool        mReserveScrollCorner;
    bool        mAutoScrolling;
    F32         mAutoScrollRate;
    F32         mMinAutoScrollRate;
    F32         mMaxAutoScrollRate;
    U32         mMaxAutoScrollZone;
    bool        mHideScrollbar;
    bool        mIgnoreArrowKeys;
};


#endif // LL_LLSCROLLCONTAINER_H