llscrollcontainer.cpp

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//*****************************************************************************
//
// A view 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.
//
//*****************************************************************************

#include "linden_common.h"

#include "llgl.h"

#include "llscrollcontainer.h"
#include "llscrollbar.h"
#include "llui.h"
#include "llkeyboard.h"
#include "llviewborder.h"
#include "llfocusmgr.h"
#include "llframetimer.h"
#include "lluictrlfactory.h"
#include "llfontgl.h"

#include "llglheaders.h"


static const S32 HORIZONTAL_MULTIPLE = 8;
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;


// Default constructor
LLScrollableContainerView::LLScrollableContainerView( const LLString& name,
                                                                                                          const LLRect& rect,
                                                                                                          LLView* scrolled_view,
                                                                                                          BOOL is_opaque,
                                                                                                          const LLColor4& bg_color ) :
        LLUICtrl( name, rect, FALSE, NULL, NULL ),
        mScrolledView( scrolled_view ),
        mIsOpaque( is_opaque ),
        mBackgroundColor( bg_color ),
        mReserveScrollCorner( FALSE ),
        mAutoScrolling( FALSE ),
        mAutoScrollRate( 0.f )
{
        if( mScrolledView )
        {
                addChild( mScrolledView );
        }

        init();
}

// LLUICtrl constructor
LLScrollableContainerView::LLScrollableContainerView( const LLString& name, const LLRect& rect,
                                                           LLUICtrl* scrolled_ctrl, BOOL is_opaque,
                                                           const LLColor4& bg_color) :
        LLUICtrl( name, rect, FALSE, NULL, NULL ),
        mScrolledView( scrolled_ctrl ),
        mIsOpaque( is_opaque ),
        mBackgroundColor( bg_color ),
        mReserveScrollCorner( FALSE ),
        mAutoScrolling( FALSE ),
        mAutoScrollRate( 0.f )
{
        if( scrolled_ctrl )
        {
                addChild( scrolled_ctrl );
        }

        init();
}

void LLScrollableContainerView::init()
{
        LLRect border_rect( 0, mRect.getHeight(), mRect.getWidth(), 0 );
        mBorder = new LLViewBorder( "scroll border", border_rect, LLViewBorder::BEVEL_IN );
        addChild( mBorder );

        mInnerRect.set( 0, mRect.getHeight(), mRect.getWidth(), 0 );
        mInnerRect.stretch( -mBorder->getBorderWidth()  );

        LLRect vertical_scroll_rect = mInnerRect;
        vertical_scroll_rect.mLeft = vertical_scroll_rect.mRight - SCROLLBAR_SIZE;
        mScrollbar[VERTICAL] = new LLScrollbar( "scrollable vertical",
                                                                                        vertical_scroll_rect,
                                                                                        LLScrollbar::VERTICAL,
                                                                                        mInnerRect.getHeight(), 
                                                                                        0,
                                                                                        mInnerRect.getHeight(),
                                                                                        NULL, this,
                                                                                        VERTICAL_MULTIPLE);
        addChild( mScrollbar[VERTICAL] );
        mScrollbar[VERTICAL]->setVisible( FALSE );
        mScrollbar[VERTICAL]->setFollowsRight();
        mScrollbar[VERTICAL]->setFollowsTop();
        mScrollbar[VERTICAL]->setFollowsBottom();
        
        LLRect horizontal_scroll_rect = mInnerRect;
        horizontal_scroll_rect.mTop = horizontal_scroll_rect.mBottom + SCROLLBAR_SIZE;
        mScrollbar[HORIZONTAL] = new LLScrollbar( "scrollable horizontal",
                                                                                          horizontal_scroll_rect,
                                                                                          LLScrollbar::HORIZONTAL,
                                                                                          mInnerRect.getWidth(),
                                                                                          0,
                                                                                          mInnerRect.getWidth(),
                                                                                          NULL, this,
                                                                                          HORIZONTAL_MULTIPLE);
        addChild( mScrollbar[HORIZONTAL] );
        mScrollbar[HORIZONTAL]->setVisible( FALSE );
        mScrollbar[HORIZONTAL]->setFollowsLeft();
        mScrollbar[HORIZONTAL]->setFollowsRight();

        setTabStop(FALSE);
}

// Destroys the object
LLScrollableContainerView::~LLScrollableContainerView( void )
{
        // mScrolledView and mScrollbar are child views, so the LLView
        // destructor takes care of memory deallocation.
        for( S32 i = 0; i < SCROLLBAR_COUNT; i++ )
        {
                mScrollbar[i] = NULL;
        }
        mScrolledView = NULL;
}

/*
// scrollbar handlers
void LLScrollableContainerView::horizontalChange( S32 new_pos,
                                                                                                  LLScrollbar* sb,
                                                                                                  void* user_data )
{
        LLScrollableContainerView* cont = reinterpret_cast<LLScrollableContainerView*>(user_data);
//      cont->scrollHorizontal( new_pos );
}


void LLScrollableContainerView::verticalChange( S32 new_pos, LLScrollbar* sb,
                                                                                                void* user_data )
{
        LLScrollableContainerView* cont = reinterpret_cast<LLScrollableContainerView*>(user_data);
//      cont->scrollVertical( new_pos );
}
*/

// internal scrollbar handlers
// virtual
void LLScrollableContainerView::scrollHorizontal( S32 new_pos )
{
        //llinfos << "LLScrollableContainerView::scrollHorizontal()" << llendl;
        if( mScrolledView )
        {
                LLRect doc_rect = mScrolledView->getRect();
                S32 old_pos = -(doc_rect.mLeft - mInnerRect.mLeft);
                mScrolledView->translate( -(new_pos - old_pos), 0 );
        }
}

// virtual
void LLScrollableContainerView::scrollVertical( S32 new_pos )
{
        // llinfos << "LLScrollableContainerView::scrollVertical() " << new_pos << llendl;
        if( mScrolledView )
        {
                LLRect doc_rect = mScrolledView->getRect();
                S32 old_pos = doc_rect.mTop - mInnerRect.mTop;
                mScrolledView->translate( 0, new_pos - old_pos );
        }
}

// LLView functionality
void LLScrollableContainerView::reshape(S32 width, S32 height,
                                                                                BOOL called_from_parent)
{
        LLUICtrl::reshape( width, height, called_from_parent );

        mInnerRect.set( 0, mRect.getHeight(), mRect.getWidth(), 0 );
        mInnerRect.stretch( -mBorder->getBorderWidth() );

        if (mScrolledView)
        {
                const LLRect& scrolled_rect = mScrolledView->getRect();

                S32 visible_width = 0;
                S32 visible_height = 0;
                BOOL show_v_scrollbar = FALSE;
                BOOL show_h_scrollbar = FALSE;
                calcVisibleSize( scrolled_rect, &visible_width, &visible_height, &show_h_scrollbar, &show_v_scrollbar );

                mScrollbar[VERTICAL]->setDocSize( scrolled_rect.getHeight() );
                mScrollbar[VERTICAL]->setPageSize( visible_height );

                mScrollbar[HORIZONTAL]->setDocSize( scrolled_rect.getWidth() );
                mScrollbar[HORIZONTAL]->setPageSize( visible_width );
        }
}

BOOL LLScrollableContainerView::handleKey( KEY key, MASK mask, BOOL called_from_parent )
{
        if( getVisible() && mEnabled )
        {
                if( called_from_parent )
                {
                        // Downward traversal

                        // Don't pass keys to scrollbars on downward.

                        // Handle 'child' view.
                        if( mScrolledView && mScrolledView->handleKey(key, mask, TRUE) )
                        {
                                return TRUE;
                        }
                }
                else
                {
                        // Upward traversal
                        
                        for( S32 i = 0; i < SCROLLBAR_COUNT; i++ )
                        {
                                // Note: the scrollbar _is_ actually being called from it's parent.  Here
                                // we're delgating LLScrollableContainerView's upward traversal to the scrollbars
                                if( mScrollbar[i]->handleKey(key, mask, TRUE) )
                                {
                                        return TRUE;
                                }
                        }

                        if (getParent()) 
                        {
                                return getParent()->handleKey( key, mask, FALSE );
                        }
                }
        }

        return FALSE;
}

BOOL LLScrollableContainerView::handleScrollWheel( S32 x, S32 y, S32 clicks )
{
        if( mEnabled )
        {
                for( S32 i = 0; i < SCROLLBAR_COUNT; i++ )
                {
                        // Note: tries vertical and then horizontal

                        // Pretend the mouse is over the scrollbar
                        if( mScrollbar[i]->handleScrollWheel( 0, 0, clicks ) )
                        {
                                return TRUE;
                        }
                }
        }

        // Opaque
        return TRUE;
}
BOOL LLScrollableContainerView::needsToScroll(S32 x, S32 y, LLScrollableContainerView::SCROLL_ORIENTATION axis)
{
        if(mScrollbar[axis]->getVisible())
        {
                LLRect inner_rect_local( 0, mInnerRect.getHeight(), mInnerRect.getWidth(), 0 );
                const S32 AUTOSCROLL_SIZE = 10;
                if(mScrollbar[axis]->getVisible())
                {
                        inner_rect_local.mRight -= SCROLLBAR_SIZE;
                        inner_rect_local.mTop += AUTOSCROLL_SIZE;
                        inner_rect_local.mBottom = inner_rect_local.mTop - AUTOSCROLL_SIZE;
                }
                if( inner_rect_local.pointInRect( x, y ) && (mScrollbar[axis]->getDocPos() > 0) )
                {
                        return TRUE;
                }

        }
        return FALSE;
}
BOOL LLScrollableContainerView::handleDragAndDrop(S32 x, S32 y, MASK mask,
                                                                                                  BOOL drop,
                                                                                                  EDragAndDropType cargo_type,
                                                                                                  void* cargo_data,
                                                                                                  EAcceptance* accept,
                                                                                                  LLString& tooltip_msg)
{
        // Scroll folder view if needed.  Never accepts a drag or drop.
        *accept = ACCEPT_NO;
        BOOL handled = FALSE;
        if( mScrollbar[HORIZONTAL]->getVisible() || mScrollbar[VERTICAL]->getVisible() )
        {
                const S32 AUTOSCROLL_SIZE = 10;
                S32 auto_scroll_speed = llround(mAutoScrollRate * LLFrameTimer::getFrameDeltaTimeF32());
                
                LLRect inner_rect_local( 0, mInnerRect.getHeight(), mInnerRect.getWidth(), 0 );
                if(     mScrollbar[HORIZONTAL]->getVisible() )
                {
                        inner_rect_local.mBottom += SCROLLBAR_SIZE;
                }
                if(     mScrollbar[VERTICAL]->getVisible() )
                {
                        inner_rect_local.mRight -= SCROLLBAR_SIZE;
                }

                if(     mScrollbar[HORIZONTAL]->getVisible() )
                {
                        LLRect left_scroll_rect = inner_rect_local;
                        left_scroll_rect.mRight = AUTOSCROLL_SIZE;
                        if( left_scroll_rect.pointInRect( x, y ) && (mScrollbar[HORIZONTAL]->getDocPos() > 0) )
                        {
                                mScrollbar[HORIZONTAL]->setDocPos( mScrollbar[HORIZONTAL]->getDocPos() - auto_scroll_speed );
                                mAutoScrolling = TRUE;
                                handled = TRUE;
                        }

                        LLRect right_scroll_rect = inner_rect_local;
                        right_scroll_rect.mLeft = inner_rect_local.mRight - AUTOSCROLL_SIZE;
                        if( right_scroll_rect.pointInRect( x, y ) && (mScrollbar[HORIZONTAL]->getDocPos() < mScrollbar[HORIZONTAL]->getDocPosMax()) )
                        {
                                mScrollbar[HORIZONTAL]->setDocPos( mScrollbar[HORIZONTAL]->getDocPos() + auto_scroll_speed );
                                mAutoScrolling = TRUE;
                                handled = TRUE;
                        }
                }
                if(     mScrollbar[VERTICAL]->getVisible() )
                {
                        LLRect bottom_scroll_rect = inner_rect_local;
                        bottom_scroll_rect.mTop = AUTOSCROLL_SIZE + bottom_scroll_rect.mBottom;
                        if( bottom_scroll_rect.pointInRect( x, y ) && (mScrollbar[VERTICAL]->getDocPos() < mScrollbar[VERTICAL]->getDocPosMax()) )
                        {
                                mScrollbar[VERTICAL]->setDocPos( mScrollbar[VERTICAL]->getDocPos() + auto_scroll_speed );
                                mAutoScrolling = TRUE;
                                handled = TRUE;
                        }

                        LLRect top_scroll_rect = inner_rect_local;
                        top_scroll_rect.mBottom = inner_rect_local.mTop - AUTOSCROLL_SIZE;
                        if( top_scroll_rect.pointInRect( x, y ) && (mScrollbar[VERTICAL]->getDocPos() > 0) )
                        {
                                mScrollbar[VERTICAL]->setDocPos( mScrollbar[VERTICAL]->getDocPos() - auto_scroll_speed );
                                mAutoScrolling = TRUE;
                                handled = TRUE;
                        }
                }
        }

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

        return TRUE;
}


BOOL LLScrollableContainerView::handleToolTip(S32 x, S32 y, LLString& msg, LLRect* sticky_rect)
{
        if( getVisible() && pointInView(x,y) )
        {
                S32 local_x, local_y;
                for( S32 i = 0; i < SCROLLBAR_COUNT; i++ )
                {
                        local_x = x - mScrollbar[i]->getRect().mLeft;
                        local_y = y - mScrollbar[i]->getRect().mBottom;
                        if( mScrollbar[i]->handleToolTip(local_x, local_y, msg, sticky_rect) )
                        {
                                return TRUE;
                        }
                }
                // Handle 'child' view.
                if( mScrolledView )
                {
                        local_x = x - mScrolledView->getRect().mLeft;
                        local_y = y - mScrolledView->getRect().mBottom;
                        if( mScrolledView->handleToolTip(local_x, local_y, msg, sticky_rect) )
                        {
                                return TRUE;
                        }
                }

                // Opaque
                return TRUE;
        }
        return FALSE;
}

void LLScrollableContainerView::calcVisibleSize( S32 *visible_width, S32 *visible_height, BOOL* show_h_scrollbar, BOOL* show_v_scrollbar )
{
        const LLRect& rect = mScrolledView->getRect();
        calcVisibleSize(rect, visible_width, visible_height, show_h_scrollbar, show_v_scrollbar);
}

void LLScrollableContainerView::calcVisibleSize( const LLRect& doc_rect, S32 *visible_width, S32 *visible_height, BOOL* show_h_scrollbar, BOOL* show_v_scrollbar )
{
        S32 doc_width = doc_rect.getWidth();
        S32 doc_height = doc_rect.getHeight();

        *visible_width = mRect.getWidth() - 2 * mBorder->getBorderWidth();
        *visible_height = mRect.getHeight() - 2 * mBorder->getBorderWidth();
        
        *show_v_scrollbar = FALSE;
        if( *visible_height < doc_height )
        {
                *show_v_scrollbar = TRUE;
                *visible_width -= SCROLLBAR_SIZE;
        }

        *show_h_scrollbar = FALSE;
        if( *visible_width < doc_width )
        {
                *show_h_scrollbar = TRUE;
                *visible_height -= SCROLLBAR_SIZE;

                // Must retest now that visible_height has changed
                if( !*show_v_scrollbar && (*visible_height < doc_height) )
                {
                        *show_v_scrollbar = TRUE;
                        *visible_width -= SCROLLBAR_SIZE;
                }
        }
}

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

        if( getVisible() )
        {
                // auto-focus when scrollbar active
                // this allows us to capture user intent (i.e. stop automatically scrolling the view/etc)
                if (!gFocusMgr.childHasKeyboardFocus(this) && 
                        (mScrollbar[VERTICAL]->hasMouseCapture() || mScrollbar[HORIZONTAL]->hasMouseCapture()))
                {
                        focusFirstItem();
                }

                // Draw background
                if( mIsOpaque )
                {
                        LLGLSNoTexture no_texture;
                        glColor4fv( mBackgroundColor.mV );
                        gl_rect_2d( mInnerRect );
                }
                
                // Draw mScrolledViews and update scroll bars.
                // get a scissor region ready, and draw the scrolling view. The
                // scissor region ensures that we don't draw outside of the bounds
                // of the rectangle.
                if( mScrolledView )
                {
                        updateScroll();

                        // Draw the scrolled area.
                        {
                                S32 visible_width = 0;
                                S32 visible_height = 0;
                                BOOL show_v_scrollbar = FALSE;
                                BOOL show_h_scrollbar = FALSE;
                                calcVisibleSize( mScrolledView->getRect(), &visible_width, &visible_height, &show_h_scrollbar, &show_v_scrollbar );

                                LLLocalClipRect clip(LLRect(mInnerRect.mLeft, 
                                                mInnerRect.mBottom + (show_h_scrollbar ? SCROLLBAR_SIZE : 0) + visible_height,
                                                visible_width,
                                                mInnerRect.mBottom + (show_h_scrollbar ? SCROLLBAR_SIZE : 0)
                                                ));
                                drawChild(mScrolledView);
                        }
                }

                // Highlight border if a child of this container has keyboard focus
                if( mBorder->getVisible() )
                {
                        mBorder->setKeyboardFocusHighlight( gFocusMgr.childHasKeyboardFocus(this) );
                }

                // Draw all children except mScrolledView
                // Note: scrollbars have been adjusted by above drawing code
                for (child_list_const_reverse_iter_t child_iter = getChildList()->rbegin();
                         child_iter != getChildList()->rend(); ++child_iter)
                {
                        LLView *viewp = *child_iter;
                        if( sDebugRects )
                        {
                                sDepth++;
                        }
                        if( (viewp != mScrolledView) && viewp->getVisible() )
                        {
                                drawChild(viewp);
                        }
                        if( sDebugRects )
                        {
                                sDepth--;
                        }
                }

                if (sDebugRects)
                {
                        drawDebugRect();
                }
        }
}

void LLScrollableContainerView::updateScroll()
{
        LLRect doc_rect = mScrolledView->getRect();
        S32 doc_width = doc_rect.getWidth();
        S32 doc_height = doc_rect.getHeight();
        S32 visible_width = 0;
        S32 visible_height = 0;
        BOOL show_v_scrollbar = FALSE;
        BOOL show_h_scrollbar = FALSE;
        calcVisibleSize( doc_rect, &visible_width, &visible_height, &show_h_scrollbar, &show_v_scrollbar );

        S32 border_width = mBorder->getBorderWidth();
        if( show_v_scrollbar )
        {
                if( doc_rect.mTop < mRect.getHeight() - border_width )
                {
                        mScrolledView->translate( 0, mRect.getHeight() - border_width - doc_rect.mTop );
                }

                scrollVertical( mScrollbar[VERTICAL]->getDocPos() );
                mScrollbar[VERTICAL]->setVisible( TRUE );

                S32 v_scrollbar_height = visible_height;
                if( !show_h_scrollbar && mReserveScrollCorner )
                {
                        v_scrollbar_height -= SCROLLBAR_SIZE;
                }
                mScrollbar[VERTICAL]->reshape( SCROLLBAR_SIZE, v_scrollbar_height, TRUE );

                // Make room for the horizontal scrollbar (or not)
                S32 v_scrollbar_offset = 0;
                if( show_h_scrollbar || mReserveScrollCorner )
                {
                        v_scrollbar_offset = SCROLLBAR_SIZE;
                }
                LLRect r = mScrollbar[VERTICAL]->getRect();
                r.translate( 0, mInnerRect.mBottom - r.mBottom + v_scrollbar_offset );
                mScrollbar[VERTICAL]->setRect( r );
        }
        else
        {
                mScrolledView->translate( 0, mRect.getHeight() - border_width - doc_rect.mTop );

                mScrollbar[VERTICAL]->setVisible( FALSE );
                mScrollbar[VERTICAL]->setDocPos( 0 );
        }
                
        if( show_h_scrollbar )
        {
                if( doc_rect.mLeft > border_width )
                {
                        mScrolledView->translate( border_width - doc_rect.mLeft, 0 );
                        mScrollbar[HORIZONTAL]->setDocPos( 0 );
                }
                else
                {
                        scrollHorizontal( mScrollbar[HORIZONTAL]->getDocPos() );
                }
        
                mScrollbar[HORIZONTAL]->setVisible( TRUE );
                S32 h_scrollbar_width = visible_width;
                if( !show_v_scrollbar && mReserveScrollCorner )
                {
                        h_scrollbar_width -= SCROLLBAR_SIZE;
                }
                mScrollbar[HORIZONTAL]->reshape( h_scrollbar_width, SCROLLBAR_SIZE, TRUE );
        }
        else
        {
                mScrolledView->translate( border_width - doc_rect.mLeft, 0 );
                
                mScrollbar[HORIZONTAL]->setVisible( FALSE );
                mScrollbar[HORIZONTAL]->setDocPos( 0 );
        }

        mScrollbar[HORIZONTAL]->setDocSize( doc_width );
        mScrollbar[HORIZONTAL]->setPageSize( visible_width );

        mScrollbar[VERTICAL]->setDocSize( doc_height );
        mScrollbar[VERTICAL]->setPageSize( visible_height );
}

void LLScrollableContainerView::setBorderVisible(BOOL b)
{
        mBorder->setVisible( b );
}

// Scroll so that as much of rect as possible is showing (where rect is defined in the space of scroller view, not scrolled)
void LLScrollableContainerView::scrollToShowRect(const LLRect& rect, const LLCoordGL& desired_offset)
{
        if (!mScrolledView)
        {
                llwarns << "LLScrollableContainerView::scrollToShowRect with no view!" << llendl;
                return;
        }

        S32 visible_width = 0;
        S32 visible_height = 0;
        BOOL show_v_scrollbar = FALSE;
        BOOL show_h_scrollbar = FALSE;
        const LLRect& scrolled_rect = mScrolledView->getRect();
        calcVisibleSize( scrolled_rect, &visible_width, &visible_height, &show_h_scrollbar, &show_v_scrollbar );

        // can't be so far left that right side of rect goes off screen, or so far right that left side does
        S32 horiz_offset = llclamp(desired_offset.mX, llmin(0, -visible_width + rect.getWidth()), 0);
        // can't be so high that bottom of rect goes off screen, or so low that top does
        S32 vert_offset = llclamp(desired_offset.mY, 0, llmax(0, visible_height - rect.getHeight()));

        // Vertical
        // 1. First make sure the top is visible
        // 2. Then, if possible without hiding the top, make the bottom visible.
        S32 vert_pos = mScrollbar[VERTICAL]->getDocPos();

        // find scrollbar position to get top of rect on screen (scrolling up)
        S32 top_offset = scrolled_rect.mTop - rect.mTop - vert_offset;
        // find scrollbar position to get bottom of rect on screen (scrolling down)
        S32 bottom_offset = vert_offset == 0 ? scrolled_rect.mTop - rect.mBottom - visible_height : top_offset;
        // scroll up far enough to see top or scroll down just enough if item is bigger than visual area
        if( vert_pos >= top_offset || visible_height < rect.getHeight())
        {
                vert_pos = top_offset;
        }
        // else scroll down far enough to see bottom
        else
        if( vert_pos <= bottom_offset )
        {
                vert_pos = bottom_offset;
        }

        mScrollbar[VERTICAL]->setDocSize( scrolled_rect.getHeight() );
        mScrollbar[VERTICAL]->setPageSize( visible_height );
        mScrollbar[VERTICAL]->setDocPos( vert_pos );

        // Horizontal
        // 1. First make sure left side is visible
        // 2. Then, if possible without hiding the left side, make the right side visible.
        S32 horiz_pos = mScrollbar[HORIZONTAL]->getDocPos();
        S32 left_offset = rect.mLeft - scrolled_rect.mLeft + horiz_offset;
        S32 right_offset = horiz_offset == 0 ? rect.mRight - scrolled_rect.mLeft - visible_width : left_offset;

        if( horiz_pos >= left_offset || visible_width < rect.getWidth() )
        {
                horiz_pos = left_offset;
        }
        else if( horiz_pos <= right_offset )
        {
                horiz_pos = right_offset;
        }
        
        mScrollbar[HORIZONTAL]->setDocSize( scrolled_rect.getWidth() );
        mScrollbar[HORIZONTAL]->setPageSize( visible_width );
        mScrollbar[HORIZONTAL]->setDocPos( horiz_pos );

        // propagate scroll to document
        updateScroll();
}

void LLScrollableContainerView::pageUp(S32 overlap)
{
        mScrollbar[VERTICAL]->pageUp(overlap);
}

void LLScrollableContainerView::pageDown(S32 overlap)
{
        mScrollbar[VERTICAL]->pageDown(overlap);
}

void LLScrollableContainerView::goToTop()
{
        mScrollbar[VERTICAL]->setDocPos(0);
}

void LLScrollableContainerView::goToBottom()
{
        mScrollbar[VERTICAL]->setDocPos(mScrollbar[VERTICAL]->getDocSize());
}

S32 LLScrollableContainerView::getBorderWidth()
{
        if (mBorder)
        {
                return mBorder->getBorderWidth();
        }

        return 0;
}

// virtual
LLXMLNodePtr LLScrollableContainerView::getXML(bool save_children) const
{
        LLXMLNodePtr node = LLView::getXML();

        // Attributes

        node->createChild("opaque", TRUE)->setBoolValue(mIsOpaque);

        if (mIsOpaque)
        {
                node->createChild("color", TRUE)->setFloatValue(4, mBackgroundColor.mV);
        }

        // Contents

        LLXMLNodePtr child_node = mScrolledView->getXML();

        node->addChild(child_node);

        return node;
}

LLView* LLScrollableContainerView::fromXML(LLXMLNodePtr node, LLView *parent, LLUICtrlFactory *factory)
{
        LLString name("scroll_container");
        node->getAttributeString("name", name);

        LLRect rect;
        createRect(node, rect, parent, LLRect());
        
        BOOL opaque = FALSE;
        node->getAttributeBOOL("opaque", opaque);

        LLColor4 color(0,0,0,0);
        LLUICtrlFactory::getAttributeColor(node,"color", color);

        // Create the scroll view
        LLScrollableContainerView *ret = new LLScrollableContainerView(name, rect, (LLPanel*)NULL, opaque, color);

        LLPanel* panelp = NULL;

        // Find a child panel to add
        LLXMLNodePtr child;
        for (child = node->getFirstChild(); child.notNull(); child = child->getNextSibling())
        {
                LLView *control = factory->createCtrlWidget(panelp, child);
                if (control && control->isPanel())
                {
                        if (panelp)
                        {
                                llinfos << "Warning! Attempting to put multiple panels into a scrollable container view!" << llendl;
                                delete control;
                        }
                        else
                        {
                                panelp = (LLPanel*)control;
                        }
                }
        }

        if (panelp == NULL)
        {
                panelp = new LLPanel("dummy", LLRect::null, FALSE);
        }

        ret->mScrolledView = panelp;

        return ret;
}

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