/**
 * @file llaccordionctrl.cpp
 * @brief Accordion panel  implementation
 *
 * $LicenseInfo:firstyear=2009&license=viewerlgpl$
 * 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
 * $/LicenseInfo$
 */
#include "linden_common.h"

#include "llaccordionctrl.h"
#include "llaccordionctrltab.h"

#include "lluictrlfactory.h" // builds floaters from XML

#include "llwindow.h"
#include "llfocusmgr.h"
#include "lllocalcliprect.h"

#include "boost/bind.hpp"

static const S32 BORDER_MARGIN = 2;
static const S32 PARENT_BORDER_MARGIN = 5;
static const S32 VERTICAL_MULTIPLE = 16;
static const F32 MIN_AUTO_SCROLL_RATE = 120.f;
static const F32 MAX_AUTO_SCROLL_RATE = 500.f;
static const F32 AUTO_SCROLL_RATE_ACCEL = 120.f;

// LLAccordionCtrl =================================================================|

static LLDefaultChildRegistry::Register<LLAccordionCtrl>    t2("accordion");

LLAccordionCtrl::LLAccordionCtrl(const Params& params):LLPanel(params)
 , mFitParent(params.fit_parent)
 , mAutoScrolling( false )
 , mAutoScrollRate( 0.f )
 , mSelectedTab( NULL )
 , mTabComparator( NULL )
 , mNoVisibleTabsHelpText(NULL)
 , mNoVisibleTabsOrigString(params.no_visible_tabs_text.initial_value().asString())
 , mSkipScrollToChild(false)
{
    initNoTabsWidget(params.no_matched_tabs_text);

    mSingleExpansion = params.single_expansion;
    if (mFitParent && !mSingleExpansion)
    {
        LL_INFOS() << "fit_parent works best when combined with single_expansion" << LL_ENDL;
    }
}

LLAccordionCtrl::LLAccordionCtrl() : LLPanel()
 , mAutoScrolling( false )
 , mAutoScrollRate( 0.f )
 , mSelectedTab( NULL )
 , mNoVisibleTabsHelpText(NULL)
{
    initNoTabsWidget(LLTextBox::Params());

    mSingleExpansion = false;
    mFitParent = false;
    buildFromFile( "accordion_parent.xml");
}

//---------------------------------------------------------------------------------
void LLAccordionCtrl::draw()
{
    if (mAutoScrolling)
    {
        // add acceleration to autoscroll
        mAutoScrollRate = llmin(mAutoScrollRate + (LLFrameTimer::getFrameDeltaTimeF32() * AUTO_SCROLL_RATE_ACCEL), MAX_AUTO_SCROLL_RATE);
    }
    else
    {
        // reset to minimum for next time
        mAutoScrollRate = MIN_AUTO_SCROLL_RATE;
    }
    // clear this flag to be set on next call to autoScroll
    mAutoScrolling = false;

    LLRect local_rect(0, getRect().getHeight(), getRect().getWidth(), 0);

    LLLocalClipRect clip(local_rect);

    LLPanel::draw();
}

//---------------------------------------------------------------------------------
bool LLAccordionCtrl::postBuild()
{
    static LLUICachedControl<S32> scrollbar_size("UIScrollbarSize", 0);

    LLRect scroll_rect;
    scroll_rect.setOriginAndSize(
        getRect().getWidth() - scrollbar_size,
        1,
        scrollbar_size,
        getRect().getHeight() - 1);

    LLScrollbar::Params sbparams;
    sbparams.name("scrollable vertical");
    sbparams.rect(scroll_rect);
    sbparams.orientation(LLScrollbar::VERTICAL);
    sbparams.doc_size(mInnerRect.getHeight());
    sbparams.doc_pos(0);
    sbparams.page_size(mInnerRect.getHeight());
    sbparams.step_size(VERTICAL_MULTIPLE);
    sbparams.follows.flags(FOLLOWS_RIGHT | FOLLOWS_TOP | FOLLOWS_BOTTOM);
    sbparams.change_callback(boost::bind(&LLAccordionCtrl::onScrollPosChangeCallback, this, _1, _2));

    mScrollbar = LLUICtrlFactory::create<LLScrollbar>(sbparams);
    LLView::addChild(mScrollbar);
    mScrollbar->setVisible(false);
    mScrollbar->setFollowsRight();
    mScrollbar->setFollowsTop();
    mScrollbar->setFollowsBottom();

    //if it was created from xml...
    std::vector<LLUICtrl*> accordion_tabs;
    for (child_list_const_iter_t it = getChildList()->begin();
        getChildList()->end() != it; ++it)
    {
        LLAccordionCtrlTab* accordion_tab = dynamic_cast<LLAccordionCtrlTab*>(*it);
        if (accordion_tab == NULL)
            continue;
        if (std::find(mAccordionTabs.begin(), mAccordionTabs.end(), accordion_tab) == mAccordionTabs.end())
        {
            accordion_tabs.push_back(accordion_tab);
        }
    }

    for (std::vector<LLUICtrl*>::reverse_iterator it = accordion_tabs.rbegin();
        it < accordion_tabs.rend(); ++it)
    {
        addCollapsibleCtrl(*it);
    }

    arrange();

    if (mSingleExpansion)
    {
        if (!mAccordionTabs[0]->getDisplayChildren())
            mAccordionTabs[0]->setDisplayChildren(true);
        for (size_t i = 1; i < mAccordionTabs.size(); ++i)
        {
            if (mAccordionTabs[i]->getDisplayChildren())
                mAccordionTabs[i]->setDisplayChildren(false);
        }
    }

    updateNoTabsHelpTextVisibility();

    return true;
}


//---------------------------------------------------------------------------------
LLAccordionCtrl::~LLAccordionCtrl()
{
  mAccordionTabs.clear();
}

//---------------------------------------------------------------------------------

void LLAccordionCtrl::reshape(S32 width, S32 height, bool called_from_parent)
{
    // adjust our rectangle
    LLRect rcLocal = getRect();
    rcLocal.mRight = rcLocal.mLeft + width;
    rcLocal.mTop = rcLocal.mBottom + height;

    // get textbox a chance to reshape its content
    mNoVisibleTabsHelpText->reshape(width, height, called_from_parent);

    setRect(rcLocal);

    // assume that help text is always fit accordion.
    // necessary text paddings can be set via h_pad and v_pad
    mNoVisibleTabsHelpText->setRect(getLocalRect());

    arrange();
}

//---------------------------------------------------------------------------------
bool LLAccordionCtrl::handleRightMouseDown(S32 x, S32 y, MASK mask)
{
    return LLPanel::handleRightMouseDown(x, y, mask);
}

//---------------------------------------------------------------------------------
void LLAccordionCtrl::shiftAccordionTabs(S16 panel_num, S32 delta)
{
    for (size_t i = panel_num; i < mAccordionTabs.size(); ++i)
    {
        ctrlShiftVertical(mAccordionTabs[i],delta);
    }
}

//---------------------------------------------------------------------------------
void LLAccordionCtrl::onCollapseCtrlCloseOpen(S16 panel_num)
{
    if (mSingleExpansion)
    {
        for (size_t i = 0; i < mAccordionTabs.size(); ++i)
        {
            if (i == panel_num)
                continue;
            if (mAccordionTabs[i]->getDisplayChildren())
                mAccordionTabs[i]->setDisplayChildren(false);
        }

    }
    arrange();
}

void LLAccordionCtrl::show_hide_scrollbar(S32 width, S32 height)
{
    calcRecuiredHeight();
    if (getRecuiredHeight() > height)
        showScrollbar(width, height);
    else
        hideScrollbar(width, height);
}

void LLAccordionCtrl::showScrollbar(S32 width, S32 height)
{
    bool was_visible = mScrollbar->getVisible();

    mScrollbar->setVisible(true);

    static LLUICachedControl<S32> scrollbar_size ("UIScrollbarSize", 0);

    ctrlSetLeftTopAndSize(mScrollbar
        , width - scrollbar_size - PARENT_BORDER_MARGIN / 2
        , height - PARENT_BORDER_MARGIN
        , scrollbar_size
        , height - PARENT_BORDER_MARGIN * 2);

    mScrollbar->setPageSize(height);
    mScrollbar->setDocParams(mInnerRect.getHeight(), mScrollbar->getDocPos());

    if (was_visible)
    {
        S32 scroll_pos = llmin(mScrollbar->getDocPos(), getRecuiredHeight() - height - 1);
        mScrollbar->setDocPos(scroll_pos);
    }
}

void LLAccordionCtrl::hideScrollbar(S32 width, S32 height)
{
    if (!mScrollbar->getVisible())
        return;
    mScrollbar->setVisible(false);

    static LLUICachedControl<S32> scrollbar_size ("UIScrollbarSize", 0);

    S32 panel_width = width - 2*BORDER_MARGIN;

    // Reshape all accordions and shift all draggers
    for (size_t i = 0; i < mAccordionTabs.size(); ++i)
    {
        LLRect panel_rect = mAccordionTabs[i]->getRect();
        ctrlSetLeftTopAndSize(mAccordionTabs[i], panel_rect.mLeft, panel_rect.mTop, panel_width, panel_rect.getHeight());
    }

    mScrollbar->setDocPos(0);

    if (!mAccordionTabs.empty())
    {
        S32 panel_top = height - BORDER_MARGIN; // Top coordinate of the first panel
        S32 diff = panel_top - mAccordionTabs[0]->getRect().mTop;
        shiftAccordionTabs(0, diff);
    }
}

//---------------------------------------------------------------------------------
S32 LLAccordionCtrl::calcRecuiredHeight()
{
    S32 rec_height = 0;

    std::vector<LLAccordionCtrlTab*>::iterator panel;
    for(panel=mAccordionTabs.begin(); panel!=mAccordionTabs.end(); ++panel)
    {
        LLAccordionCtrlTab* accordion_tab = dynamic_cast<LLAccordionCtrlTab*>(*panel);
        if(accordion_tab && accordion_tab->getVisible())
        {
            rec_height += accordion_tab->getRect().getHeight();
        }
    }

    mInnerRect.setLeftTopAndSize(0, rec_height + BORDER_MARGIN * 2, getRect().getWidth(), rec_height + BORDER_MARGIN);

    return mInnerRect.getHeight();
}

//---------------------------------------------------------------------------------
void LLAccordionCtrl::ctrlSetLeftTopAndSize(LLView* panel, S32 left, S32 top, S32 width, S32 height)
{
    if (!panel)
        return;
    LLRect panel_rect = panel->getRect();
    panel_rect.setLeftTopAndSize( left, top, width, height);
    panel->reshape( width, height, 1);
    panel->setRect(panel_rect);
}

void LLAccordionCtrl::ctrlShiftVertical(LLView* panel, S32 delta)
{
    if (!panel)
        return;
    panel->translate(0,delta);
}

//---------------------------------------------------------------------------------

void LLAccordionCtrl::addCollapsibleCtrl(LLView* view)
{
    LLAccordionCtrlTab* accordion_tab = dynamic_cast<LLAccordionCtrlTab*>(view);
    if (!accordion_tab)
        return;
    if (std::find(beginChild(), endChild(), accordion_tab) == endChild())
        addChild(accordion_tab);
    mAccordionTabs.push_back(accordion_tab);

    accordion_tab->setDropDownStateChangedCallback( boost::bind(&LLAccordionCtrl::onCollapseCtrlCloseOpen, this, (S16)(mAccordionTabs.size() - 1)) );
    arrange();
}

void LLAccordionCtrl::removeCollapsibleCtrl(LLView* view)
{
    LLAccordionCtrlTab* accordion_tab = dynamic_cast<LLAccordionCtrlTab*>(view);
    if(!accordion_tab)
        return;

    if(std::find(beginChild(), endChild(), accordion_tab) != endChild())
        removeChild(accordion_tab);

    for (std::vector<LLAccordionCtrlTab*>::iterator iter = mAccordionTabs.begin();
            iter != mAccordionTabs.end(); ++iter)
    {
        if (accordion_tab == (*iter))
        {
            mAccordionTabs.erase(iter);
            break;
        }
    }

    // if removed is selected - reset selection
    if (mSelectedTab == view)
    {
        mSelectedTab = NULL;
    }
}

void LLAccordionCtrl::initNoTabsWidget(const LLTextBox::Params& tb_params)
{
    LLTextBox::Params tp = tb_params;
    tp.rect(getLocalRect());
    mNoMatchedTabsOrigString = tp.initial_value().asString();
    mNoVisibleTabsHelpText = LLUICtrlFactory::create<LLTextBox>(tp, this);
}

void LLAccordionCtrl::updateNoTabsHelpTextVisibility()
{
    bool visible_exists = false;
    std::vector<LLAccordionCtrlTab*>::const_iterator it = mAccordionTabs.begin();
    const std::vector<LLAccordionCtrlTab*>::const_iterator it_end = mAccordionTabs.end();
    while (it < it_end)
    {
        if ((*(it++))->getVisible())
        {
            visible_exists = true;
            break;
        }
    }

    mNoVisibleTabsHelpText->setVisible(!visible_exists);
}

void LLAccordionCtrl::arrangeSingle()
{
    S32 panel_left = BORDER_MARGIN; // Margin from left side of Splitter
    S32 panel_top = getRect().getHeight() - BORDER_MARGIN; // Top coordinate of the first panel
    S32 panel_width = getRect().getWidth() - 4;
    S32 panel_height;

    S32 collapsed_height = 0;

    for (size_t i = 0; i < mAccordionTabs.size(); ++i)
    {
        LLAccordionCtrlTab* accordion_tab = dynamic_cast<LLAccordionCtrlTab*>(mAccordionTabs[i]);

        if (!accordion_tab->getVisible()) // Skip hidden accordion tabs
            continue;
        if (!accordion_tab->isExpanded() )
        {
            collapsed_height+=mAccordionTabs[i]->getRect().getHeight();
        }
    }

    S32 expanded_height = getRect().getHeight() - BORDER_MARGIN - collapsed_height;

    for (size_t i = 0; i < mAccordionTabs.size(); ++i)
    {
        LLAccordionCtrlTab* accordion_tab = dynamic_cast<LLAccordionCtrlTab*>(mAccordionTabs[i]);

        if (!accordion_tab->getVisible()) // Skip hidden accordion tabs
            continue;
        if (!accordion_tab->isExpanded() )
        {
            panel_height = accordion_tab->getRect().getHeight();
        }
        else
        {
            if (mFitParent)
            {
                panel_height = expanded_height;
            }
            else
            {
                if (accordion_tab->getAccordionView())
                {
                    panel_height = accordion_tab->getAccordionView()->getRect().getHeight() +
                        accordion_tab->getHeaderHeight() + BORDER_MARGIN * 2;
                }
                else
                {
                    panel_height = accordion_tab->getRect().getHeight();
                }
            }
        }

        // make sure at least header is shown
        panel_height = llmax(panel_height, accordion_tab->getHeaderHeight());

        ctrlSetLeftTopAndSize(mAccordionTabs[i], panel_left, panel_top, panel_width, panel_height);
        panel_top -= mAccordionTabs[i]->getRect().getHeight();
    }

    show_hide_scrollbar(getRect().getWidth(), getRect().getHeight());
    updateLayout(getRect().getWidth(), getRect().getHeight());
}

void LLAccordionCtrl::arrangeMultiple()
{
    S32 panel_left = BORDER_MARGIN; // Margin from left side of Splitter
    S32 panel_top = getRect().getHeight() - BORDER_MARGIN; // Top coordinate of the first panel
    S32 panel_width = getRect().getWidth() - 4;

    //Calculate params
    for (size_t i = 0; i < mAccordionTabs.size(); i++ )
    {
        LLAccordionCtrlTab* accordion_tab = dynamic_cast<LLAccordionCtrlTab*>(mAccordionTabs[i]);

        if (!accordion_tab->getVisible()) // Skip hidden accordion tabs
            continue;

        if (!accordion_tab->isExpanded() )
        {
            ctrlSetLeftTopAndSize(mAccordionTabs[i], panel_left, panel_top, panel_width, accordion_tab->getRect().getHeight());
            panel_top -= mAccordionTabs[i]->getRect().getHeight();
        }
        else
        {
            S32 panel_height = accordion_tab->getRect().getHeight();

            if (mFitParent)
            {
                // All expanded tabs will have equal height
                panel_height = calcExpandedTabHeight(static_cast<S32>(i), panel_top);
                ctrlSetLeftTopAndSize(accordion_tab, panel_left, panel_top, panel_width, panel_height);

                // Try to make accordion tab fit accordion view height.
                // Accordion View should implement getRequiredRect() and provide valid height
                S32 optimal_height = accordion_tab->getAccordionView()->getRequiredRect().getHeight();
                optimal_height += accordion_tab->getHeaderHeight() + 2 * BORDER_MARGIN;
                if (optimal_height < panel_height)
                {
                    panel_height = optimal_height;
                }

                // minimum tab height is equal to header height
                if (mAccordionTabs[i]->getHeaderHeight() > panel_height)
                {
                    panel_height = mAccordionTabs[i]->getHeaderHeight();
                }
            }

            ctrlSetLeftTopAndSize(mAccordionTabs[i], panel_left, panel_top, panel_width, panel_height);
            panel_top -= panel_height;

        }
    }

    show_hide_scrollbar(getRect().getWidth(), getRect().getHeight());

    updateLayout(getRect().getWidth(), getRect().getHeight());
}


void LLAccordionCtrl::arrange()
{
    updateNoTabsHelpTextVisibility();

    if (mAccordionTabs.empty())
    {
        // Nothing to arrange
        return;
    }

    if (mAccordionTabs.size() == 1)
    {
        S32 panel_top = getRect().getHeight() - BORDER_MARGIN; // Top coordinate of the first panel
        S32 panel_width = getRect().getWidth() - 4;

        LLAccordionCtrlTab* accordion_tab = dynamic_cast<LLAccordionCtrlTab*>(mAccordionTabs[0]);

        LLRect panel_rect = accordion_tab->getRect();

        S32 panel_height = getRect().getHeight() - BORDER_MARGIN * 2;
        if (accordion_tab->getFitParent())
            panel_height = accordion_tab->getRect().getHeight();

        ctrlSetLeftTopAndSize(accordion_tab, panel_rect.mLeft, panel_top, panel_width, panel_height);

        show_hide_scrollbar(getRect().getWidth(), getRect().getHeight());
        return;
    }

    if (mSingleExpansion)
        arrangeSingle();
    else
        arrangeMultiple();
}

//---------------------------------------------------------------------------------

bool LLAccordionCtrl::handleScrollWheel(S32 x, S32 y, S32 clicks)
{
    if (LLPanel::handleScrollWheel(x, y, clicks))
        return true;
    if (mScrollbar->getVisible() && mScrollbar->handleScrollWheel(0, 0, clicks))
        return true;
    return false;
}

bool LLAccordionCtrl::handleKeyHere(KEY key, MASK mask)
{
    if (mScrollbar->getVisible() && mScrollbar->handleKeyHere(key, mask))
        return true;
    return LLPanel::handleKeyHere(key, mask);
}

bool LLAccordionCtrl::handleDragAndDrop(S32 x, S32 y, MASK mask,
                                        bool drop,
                                        EDragAndDropType cargo_type,
                                        void* cargo_data,
                                        EAcceptance* accept,
                                        std::string& tooltip_msg)
{
    // Scroll folder view if needed.  Never accepts a drag or drop.
    *accept = ACCEPT_NO;
    bool handled = autoScroll(x, y);

    if (!handled)
    {
        handled = childrenHandleDragAndDrop(x, y, mask, drop, cargo_type,
                                            cargo_data, accept, tooltip_msg) != NULL;
    }
    return true;
}

bool LLAccordionCtrl::autoScroll(S32 x, S32 y)
{
    static LLUICachedControl<S32> scrollbar_size ("UIScrollbarSize", 0);

    bool scrolling = false;
    if (mScrollbar->getVisible())
    {
        LLRect rect_local(0, getRect().getHeight(), getRect().getWidth() - scrollbar_size, 0);
        LLRect screen_local_extents;

        // clip rect against root view
        screenRectToLocal(getRootView()->getLocalRect(), &screen_local_extents);
        rect_local.intersectWith(screen_local_extents);

        // autoscroll region should take up no more than one third of visible scroller area
        S32 auto_scroll_region_height = llmin(rect_local.getHeight() / 3, 10);
        S32 auto_scroll_speed = ll_round(mAutoScrollRate * LLFrameTimer::getFrameDeltaTimeF32());

        LLRect bottom_scroll_rect = screen_local_extents;
        bottom_scroll_rect.mTop = rect_local.mBottom + auto_scroll_region_height;
        if (bottom_scroll_rect.pointInRect( x, y ) && (mScrollbar->getDocPos() < mScrollbar->getDocPosMax()))
        {
            mScrollbar->setDocPos(mScrollbar->getDocPos() + auto_scroll_speed);
            mAutoScrolling = true;
            scrolling = true;
        }

        LLRect top_scroll_rect = screen_local_extents;
        top_scroll_rect.mBottom = rect_local.mTop - auto_scroll_region_height;
        if (top_scroll_rect.pointInRect(x, y) && (mScrollbar->getDocPos() > 0))
        {
            mScrollbar->setDocPos(mScrollbar->getDocPos() - auto_scroll_speed);
            mAutoScrolling = true;
            scrolling = true;
        }
    }

    return scrolling;
}

void LLAccordionCtrl::updateLayout(S32 width, S32 height)
{
    S32 panel_top = height - BORDER_MARGIN ;
    if (mScrollbar->getVisible())
        panel_top += mScrollbar->getDocPos();

    S32 panel_width = width - BORDER_MARGIN * 2;

    static LLUICachedControl<S32> scrollbar_size ("UIScrollbarSize", 0);
    if (mScrollbar->getVisible())
        panel_width -= scrollbar_size;

    // set sizes for first panels and dragbars
    for (size_t i = 0; i < mAccordionTabs.size(); ++i)
    {
        if (!mAccordionTabs[i]->getVisible())
            continue;
        LLRect panel_rect = mAccordionTabs[i]->getRect();
        ctrlSetLeftTopAndSize(mAccordionTabs[i], panel_rect.mLeft, panel_top, panel_width, panel_rect.getHeight());
        panel_top -= panel_rect.getHeight();
    }
}

void LLAccordionCtrl::onScrollPosChangeCallback(S32, LLScrollbar*)
{
    updateLayout(getRect().getWidth(), getRect().getHeight());
}

// virtual
void LLAccordionCtrl::onUpdateScrollToChild(const LLUICtrl *cntrl)
{
    if (mScrollbar && mScrollbar->getVisible() && !mSkipScrollToChild)
    {
        // same as scrollToShowRect
        LLRect rect;
        cntrl->localRectToOtherView(cntrl->getLocalRect(), &rect, this);

        // Translate to parent coordinatess to check if we are in visible rectangle
        rect.translate(getRect().mLeft, getRect().mBottom);

        if (!getRect().contains(rect))
        {
            // for accordition's scroll, height is in pixels
            // Back to local coords and calculate position for scroller
            S32 bottom = mScrollbar->getDocPos() - rect.mBottom + getRect().mBottom;
            S32 top = mScrollbar->getDocPos() - rect.mTop + getRect().mTop;

            S32 scroll_pos = llclamp(mScrollbar->getDocPos(),
                bottom, // min vertical scroll
                top); // max vertical scroll

            mScrollbar->setDocPos(scroll_pos);
        }
    }

    LLUICtrl::onUpdateScrollToChild(cntrl);
}

void LLAccordionCtrl::onOpen(const LLSD& key)
{
    for (size_t i = 0; i < mAccordionTabs.size(); ++i)
    {
        LLAccordionCtrlTab* accordion_tab = dynamic_cast<LLAccordionCtrlTab*>(mAccordionTabs[i]);
        LLPanel* panel = dynamic_cast<LLPanel*>(accordion_tab->getAccordionView());
        if (panel != NULL)
        {
            panel->onOpen(key);
        }
    }
}

S32 LLAccordionCtrl::notifyParent(const LLSD& info)
{
    if (info.has("action"))
    {
        std::string str_action = info["action"];
        if (str_action == "size_changes")
        {
            //
            arrange();
            return 1;
        }
        if (str_action == "select_next")
        {
            for (size_t i = 0; i < mAccordionTabs.size(); ++i)
            {
                LLAccordionCtrlTab* accordion_tab = dynamic_cast<LLAccordionCtrlTab*>(mAccordionTabs[i]);
                if (accordion_tab->hasFocus())
                {
                    while (++i < mAccordionTabs.size())
                    {
                        if (mAccordionTabs[i]->getVisible())
                            break;
                    }
                    if (i < mAccordionTabs.size())
                    {
                        accordion_tab = dynamic_cast<LLAccordionCtrlTab*>(mAccordionTabs[i]);
                        accordion_tab->notify(LLSD().with("action","select_first"));
                        return 1;
                    }
                    break;
                }
            }
            return 0;
        }
        if (str_action == "select_prev")
        {
            for (size_t i = 0; i < mAccordionTabs.size(); ++i)
            {
                LLAccordionCtrlTab* accordion_tab = dynamic_cast<LLAccordionCtrlTab*>(mAccordionTabs[i]);
                if (accordion_tab->hasFocus() && i > 0)
                {
                    bool prev_visible_tab_found = false;
                    while (i > 0)
                    {
                        if (mAccordionTabs[--i]->getVisible())
                        {
                            prev_visible_tab_found = true;
                            break;
                        }
                    }

                    if (prev_visible_tab_found)
                    {
                        accordion_tab = dynamic_cast<LLAccordionCtrlTab*>(mAccordionTabs[i]);
                        accordion_tab->notify(LLSD().with("action","select_last"));
                        return 1;
                    }
                    break;
                }
            }
            return 0;
        }
        if (str_action == "select_current")
        {
            for (size_t i = 0; i < mAccordionTabs.size(); ++i)
            {
                // Set selection to the currently focused tab.
                if (mAccordionTabs[i]->hasFocus())
                {
                    if (mAccordionTabs[i] != mSelectedTab)
                    {
                        if (mSelectedTab)
                        {
                            mSelectedTab->setSelected(false);
                        }
                        mSelectedTab = mAccordionTabs[i];
                        mSelectedTab->setSelected(true);
                    }

                    return 1;
                }
            }
            return 0;
        }
        if (str_action == "deselect_current")
        {
            // Reset selection to the currently selected tab.
            if (mSelectedTab)
            {
                mSelectedTab->setSelected(false);
                mSelectedTab = NULL;
                return 1;
            }
            return 0;
        }
    }
    else if (info.has("scrollToShowRect"))
    {
        LLRect screen_rc, local_rc;
        screen_rc.setValue(info["scrollToShowRect"]);
        screenRectToLocal(screen_rc, &local_rc);

        // Translate to parent coordinatess to check if we are in visible rectangle
        local_rc.translate(getRect().mLeft, getRect().mBottom);

        if (!getRect().contains (local_rc))
        {
            // Back to local coords and calculate position for scroller
            S32 bottom = mScrollbar->getDocPos() - local_rc.mBottom + getRect().mBottom;
            S32 top = mScrollbar->getDocPos() - local_rc.mTop + getRect().mTop;

            S32 scroll_pos = llclamp(mScrollbar->getDocPos(),
                                     bottom, // min vertical scroll
                                     top); // max vertical scroll

            mScrollbar->setDocPos(scroll_pos);
        }
        return 1;
    }
    else if (info.has("child_visibility_change"))
    {
        bool new_visibility = info["child_visibility_change"];
        if (new_visibility)
        {
            // there is at least one visible tab
            mNoVisibleTabsHelpText->setVisible(false);
        }
        else
        {
            // it could be the latest visible tab, check all of them
            updateNoTabsHelpTextVisibility();
        }
    }
    return LLPanel::notifyParent(info);
}

void LLAccordionCtrl::reset()
{
    if (mScrollbar)
        mScrollbar->setDocPos(0);
}

void LLAccordionCtrl::expandDefaultTab()
{
    if (!mAccordionTabs.empty())
    {
        LLAccordionCtrlTab* tab = mAccordionTabs.front();

        if (!tab->getDisplayChildren())
        {
            tab->setDisplayChildren(true);
        }

        for (size_t i = 1; i < mAccordionTabs.size(); ++i)
        {
            tab = mAccordionTabs[i];

            if (tab->getDisplayChildren())
            {
                tab->setDisplayChildren(false);
            }
        }

        arrange();
    }
}

void LLAccordionCtrl::sort()
{
    if (!mTabComparator)
    {
        LL_WARNS() << "No comparator specified for sorting accordion tabs." << LL_ENDL;
        return;
    }

    std::sort(mAccordionTabs.begin(), mAccordionTabs.end(), LLComparatorAdaptor(*mTabComparator));
    arrange();
}

void LLAccordionCtrl::setFilterSubString(const std::string& filter_string)
{
    LLStringUtil::format_map_t args;
    args["[SEARCH_TERM]"] = LLURI::escape(filter_string);
    std::string text = filter_string.empty() ? mNoVisibleTabsOrigString : mNoMatchedTabsOrigString;
    LLStringUtil::format(text, args);

    mNoVisibleTabsHelpText->setValue(text);
}

const LLAccordionCtrlTab* LLAccordionCtrl::getExpandedTab() const
{
    typedef std::vector<LLAccordionCtrlTab*>::const_iterator tabs_const_iterator;

    const LLAccordionCtrlTab* result = 0;

    for (tabs_const_iterator i = mAccordionTabs.begin(); i != mAccordionTabs.end(); ++i)
    {
        if ((*i)->isExpanded())
        {
            result = *i;
            break;
        }
    }

    return result;
}

S32 LLAccordionCtrl::calcExpandedTabHeight(S32 tab_index /* = 0 */, S32 available_height /* = 0 */)
{
    if (tab_index < 0)
    {
        return available_height;
    }

    S32 collapsed_tabs_height = 0;
    S32 num_expanded = 0;

    for (size_t n = tab_index; n < mAccordionTabs.size(); ++n)
    {
        if (!mAccordionTabs[n]->isExpanded())
        {
            collapsed_tabs_height += mAccordionTabs[n]->getHeaderHeight();
        }
        else
        {
            ++num_expanded;
        }
    }

    if (0 == num_expanded)
    {
        return available_height;
    }

    S32 expanded_tab_height = available_height - collapsed_tabs_height - BORDER_MARGIN; // top BORDER_MARGIN is added in arrange(), here we add bottom BORDER_MARGIN
    expanded_tab_height /= num_expanded;
    return expanded_tab_height;
}

void LLAccordionCtrl::collapseAllTabs()
{
    if (mAccordionTabs.size() > 0)
    {
        for (size_t i = 0; i < mAccordionTabs.size(); ++i)
        {
            LLAccordionCtrlTab *tab = mAccordionTabs[i];

            if (tab->getDisplayChildren())
            {
                tab->setDisplayChildren(false);
            }
        }
        arrange();
    }
}