]> git.saurik.com Git - wxWidgets.git/blobdiff - src/html/htmlcell.cpp
Added windowing and scrolling logic to generic
[wxWidgets.git] / src / html / htmlcell.cpp
index 665db26ff2504aa094bdd955f9519e9f2fe86343..114097e2fae2d7d956f740a2fd333766bb1c6f3b 100644 (file)
@@ -4,13 +4,9 @@
 // Author:      Vaclav Slavik
 // RCS-ID:      $Id$
 // Copyright:   (c) 1999 Vaclav Slavik
-// Licence:     wxWindows Licence
+// Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 
-#ifdef __GNUG__
-#pragma implementation "htmlcell.h"
-#endif
-
 #include "wx/wxprec.h"
 
 #include "wx/defs.h"
@@ -31,6 +27,7 @@
 #include "wx/html/htmlwin.h"
 #include "wx/settings.h"
 #include "wx/module.h"
+#include "wx/dynarray.h"
 
 #include <stdlib.h>
 
@@ -61,20 +58,22 @@ void wxHtmlSelection::Set(const wxHtmlCell *fromCell, const wxHtmlCell *toCell)
     wxPoint p2 = toCell ? toCell->GetAbsPos() : wxDefaultPosition;
     if ( toCell )
     {
-        p2.x += toCell->GetWidth()-1;
-        p2.y += toCell->GetHeight()-1;
+        p2.x += toCell->GetWidth();
+        p2.y += toCell->GetHeight();
     }
     Set(p1, fromCell, p2, toCell);
 }
 
-wxColour wxDefaultHtmlRenderingStyle::GetSelectedTextColour(
-                                        const wxColour& clr)
+wxColour
+wxDefaultHtmlRenderingStyle::
+GetSelectedTextColour(const wxColour& WXUNUSED(clr))
 {
     return wxSystemSettings::GetColour(wxSYS_COLOUR_HIGHLIGHTTEXT);
 }
 
-wxColour wxDefaultHtmlRenderingStyle::GetSelectedTextBgColour(
-                                        const wxColour& WXUNUSED(clr))
+wxColour
+wxDefaultHtmlRenderingStyle::
+GetSelectedTextBgColour(const wxColour& WXUNUSED(clr))
 {
     return wxSystemSettings::GetColour(wxSYS_COLOUR_HIGHLIGHT);
 }
@@ -84,12 +83,16 @@ wxColour wxDefaultHtmlRenderingStyle::GetSelectedTextBgColour(
 // wxHtmlCell
 //-----------------------------------------------------------------------------
 
+IMPLEMENT_ABSTRACT_CLASS(wxHtmlCell, wxObject)
+
 wxHtmlCell::wxHtmlCell() : wxObject()
 {
     m_Next = NULL;
     m_Parent = NULL;
     m_Width = m_Height = m_Descent = 0;
-    m_CanLiveOnPagebreak = TRUE;
+    m_ScriptMode = wxHTML_SCRIPT_NORMAL;        // <sub> or <sup> mode
+    m_ScriptBaseline = 0;                       // <sub> or <sup> baseline
+    m_CanLiveOnPagebreak = true;
     m_Link = NULL;
 }
 
@@ -98,6 +101,21 @@ wxHtmlCell::~wxHtmlCell()
     delete m_Link;
 }
 
+// Update the descent value when whe are in a <sub> or <sup>.
+// prevbase is the parent base
+void wxHtmlCell::SetScriptMode(wxHtmlScriptMode mode, long previousBase)
+{
+    m_ScriptMode = mode;
+
+    if (mode == wxHTML_SCRIPT_SUP)
+        m_ScriptBaseline = previousBase - (m_Height + 1) / 2;
+    else if (mode == wxHTML_SCRIPT_SUB)
+        m_ScriptBaseline = previousBase + (m_Height + 1) / 6;
+    else
+        m_ScriptBaseline = 0;
+
+    m_Descent += m_ScriptBaseline;
+}
 
 void wxHtmlCell::OnMouseClick(wxWindow *parent, int x, int y,
                               const wxMouseEvent& event)
@@ -134,10 +152,10 @@ bool wxHtmlCell::AdjustPagebreak(int *pagebreak, int* WXUNUSED(known_pagebreaks)
                 m_PosY < *pagebreak && m_PosY + m_Height > *pagebreak)
     {
         *pagebreak = m_PosY;
-        return TRUE;
+        return true;
     }
 
-    return FALSE;
+    return false;
 }
 
 
@@ -158,16 +176,6 @@ void wxHtmlCell::Layout(int WXUNUSED(w))
 
 
 
-void wxHtmlCell::GetHorizontalConstraints(int *left, int *right) const
-{
-    if (left)
-        *left = m_PosX;
-    if (right)
-        *right = m_PosX + m_Width;
-}
-
-
-
 const wxHtmlCell* wxHtmlCell::Find(int WXUNUSED(condition), const void* WXUNUSED(param)) const
 {
     return NULL;
@@ -184,10 +192,10 @@ wxHtmlCell *wxHtmlCell::FindCellByPos(wxCoord x, wxCoord y,
     else
     {
         if ((flags & wxHTML_FIND_NEAREST_AFTER) &&
-                (y < 0 || (y == 0 && x <= 0)))
+                (y < 0 || (y < 0+m_Height && x < 0+m_Width)))
             return wxConstCast(this, wxHtmlCell);
         else if ((flags & wxHTML_FIND_NEAREST_BEFORE) &&
-                (y > m_Height-1 || (y == m_Height-1 && x >= m_Width)))
+                (y >= 0+m_Height || (y >= 0 && x >= 0)))
             return wxConstCast(this, wxHtmlCell);
         else
             return NULL;
@@ -259,32 +267,57 @@ bool wxHtmlCell::IsBefore(wxHtmlCell *cell) const
 // wxHtmlWordCell
 //-----------------------------------------------------------------------------
 
-wxHtmlWordCell::wxHtmlWordCell(const wxString& word, wxDC& dc) : wxHtmlCell()
+IMPLEMENT_ABSTRACT_CLASS(wxHtmlWordCell, wxHtmlCell)
+
+wxHtmlWordCell::wxHtmlWordCell(const wxString& word, const wxDC& dc) : wxHtmlCell()
 {
     m_Word = word;
     dc.GetTextExtent(m_Word, &m_Width, &m_Height, &m_Descent);
-    SetCanLiveOnPagebreak(FALSE);
+    SetCanLiveOnPagebreak(false);
+    m_allowLinebreak = true;
 }
 
+void wxHtmlWordCell::SetPreviousWord(wxHtmlWordCell *cell)
+{
+    if ( cell && m_Parent == cell->m_Parent &&
+         !wxIsspace(cell->m_Word.Last()) && !wxIsspace(m_Word[0u]) )
+    {
+        m_allowLinebreak = false;
+    }
+}
 
 // Splits m_Word into up to three parts according to selection, returns
 // substring before, in and after selection and the points (in relative coords)
 // where s2 and s3 start:
-void wxHtmlWordCell::Split(wxDC& dc,
+void wxHtmlWordCell::Split(const wxDC& dc,
                            const wxPoint& selFrom, const wxPoint& selTo,
                            unsigned& pos1, unsigned& pos2) const
 {
     wxPoint pt1 = (selFrom == wxDefaultPosition) ?
                    wxDefaultPosition : selFrom - GetAbsPos();
     wxPoint pt2 = (selTo == wxDefaultPosition) ?
-                   wxPoint(m_Width, -1) : selTo - GetAbsPos();
+                   wxPoint(m_Width, wxDefaultCoord) : selTo - GetAbsPos();
 
-    wxCoord charW, charH;
     unsigned len = m_Word.length();
     unsigned i = 0;
     pos1 = 0;
 
+    // adjust for cases when the start/end position is completely
+    // outside the cell:
+    if ( pt1.y < 0 )
+        pt1.x = 0;
+    if ( pt2.y >= m_Height )
+        pt2.x = m_Width;
+
     // before selection:
+#ifdef __WXMAC__
+    // implementation using PartialExtents to support fractional widths
+    wxArrayInt widths ;
+    dc.GetPartialTextExtents(m_Word,widths) ;
+    while( i < len && pt1.x >= widths[i] )
+        i++ ;
+#else // __WXMAC__
+    wxCoord charW, charH;
     while ( pt1.x > 0 && i < len )
     {
         dc.GetTextExtent(m_Word[i], &charW, &charH);
@@ -295,9 +328,14 @@ void wxHtmlWordCell::Split(wxDC& dc,
             i++;
         }
     }
+#endif // __WXMAC__/!__WXMAC__
 
     // in selection:
     unsigned j = i;
+#ifdef __WXMAC__
+    while( j < len && pt2.x >= widths[j] )
+        j++ ;
+#else // __WXMAC__
     pos2 = pos1;
     pt2.x -= pos2;
     while ( pt2.x > 0 && j < len )
@@ -310,12 +348,13 @@ void wxHtmlWordCell::Split(wxDC& dc,
             j++;
         }
     }
+#endif // __WXMAC__/!__WXMAC__
 
     pos1 = i;
     pos2 = j;
 }
 
-void wxHtmlWordCell::SetSelectionPrivPos(wxDC& dc, wxHtmlSelection *s) const
+void wxHtmlWordCell::SetSelectionPrivPos(const wxDC& dc, wxHtmlSelection *s) const
 {
     unsigned p1, p2;
 
@@ -349,12 +388,15 @@ static void SwitchSelState(wxDC& dc, wxHtmlRenderingInfo& info,
         dc.SetBackgroundMode(wxSOLID);
         dc.SetTextForeground(info.GetStyle().GetSelectedTextColour(fg));
         dc.SetTextBackground(info.GetStyle().GetSelectedTextBgColour(bg));
+        dc.SetBackground(wxBrush(info.GetStyle().GetSelectedTextBgColour(bg),
+                                 wxSOLID));
     }
     else
     {
         dc.SetBackgroundMode(wxTRANSPARENT);
         dc.SetTextForeground(fg);
         dc.SetTextBackground(bg);
+        dc.SetBackground(wxBrush(bg, wxSOLID));
     }
 }
 
@@ -364,9 +406,12 @@ void wxHtmlWordCell::Draw(wxDC& dc, int x, int y,
                           wxHtmlRenderingInfo& info)
 {
 #if 0 // useful for debugging
-    dc.DrawRectangle(x+m_PosX,y+m_PosY,m_Width,m_Height);
+    dc.SetPen(*wxBLACK_PEN);
+    dc.DrawRectangle(x+m_PosX,y+m_PosY,m_Width /* VZ: +1? */ ,m_Height);
 #endif
 
+    bool drawSelectionAfterCell = false;
+
     if ( info.GetState().GetSelectionState() == wxHTML_SEL_CHANGING )
     {
         // Selection changing, we must draw the word piecewise:
@@ -414,22 +459,49 @@ void wxHtmlWordCell::Draw(wxDC& dc, int x, int y,
             txt = m_Word.Mid(part2);
             dc.DrawText(txt, ofs + x + m_PosX, y + m_PosY);
         }
+        else
+            drawSelectionAfterCell = true;
     }
     else
     {
+        wxHtmlSelectionState selstate = info.GetState().GetSelectionState();
         // Not changing selection state, draw the word in single mode:
-
-        if ( info.GetState().GetSelectionState() != wxHTML_SEL_OUT &&
+        if ( selstate != wxHTML_SEL_OUT &&
              dc.GetBackgroundMode() != wxSOLID )
         {
             SwitchSelState(dc, info, true);
         }
-        else if ( info.GetState().GetSelectionState() == wxHTML_SEL_OUT &&
+        else if ( selstate == wxHTML_SEL_OUT &&
                   dc.GetBackgroundMode() == wxSOLID )
         {
             SwitchSelState(dc, info, false);
         }
         dc.DrawText(m_Word, x + m_PosX, y + m_PosY);
+        drawSelectionAfterCell = (selstate != wxHTML_SEL_OUT);
+    }
+
+    // NB: If the text is justified then there is usually some free space
+    //     between adjacent cells and drawing the selection only onto cells
+    //     would result in ugly unselected spaces. The code below detects
+    //     this special case and renders the selection *outside* the sell,
+    //     too.
+    if ( m_Parent->GetAlignHor() == wxHTML_ALIGN_JUSTIFY &&
+         drawSelectionAfterCell )
+    {
+        wxHtmlCell *nextCell = m_Next;
+        while ( nextCell && nextCell->IsFormattingCell() )
+            nextCell = nextCell->GetNext();
+        if ( nextCell )
+        {
+            int nextX = nextCell->GetPosX();
+            if ( m_PosX + m_Width < nextX )
+            {
+                dc.SetBrush(dc.GetBackground());
+                dc.SetPen(*wxTRANSPARENT_PEN);
+                dc.DrawRectangle(x + m_PosX + m_Width, y + m_PosY,
+                                 nextX - m_PosX - m_Width, m_Height);
+            }
+        }
     }
 }
 
@@ -477,18 +549,20 @@ wxCursor wxHtmlWordCell::GetCursor() const
 // wxHtmlContainerCell
 //-----------------------------------------------------------------------------
 
+IMPLEMENT_ABSTRACT_CLASS(wxHtmlContainerCell, wxHtmlCell)
 
 wxHtmlContainerCell::wxHtmlContainerCell(wxHtmlContainerCell *parent) : wxHtmlCell()
 {
     m_Cells = m_LastCell = NULL;
     m_Parent = parent;
+    m_MaxTotalWidth = 0;
     if (m_Parent) m_Parent->InsertCell(this);
     m_AlignHor = wxHTML_ALIGN_LEFT;
     m_AlignVer = wxHTML_ALIGN_BOTTOM;
     m_IndentLeft = m_IndentRight = m_IndentTop = m_IndentBottom = 0;
     m_WidthFloat = 100; m_WidthFloatUnits = wxHTML_UNITS_PERCENT;
-    m_UseBkColour = FALSE;
-    m_UseBorder = FALSE;
+    m_UseBkColour = false;
+    m_UseBorder = false;
     m_MinHeight = 0;
     m_MinHeightAlign = wxHTML_ALIGN_TOP;
     m_LastLayout = -1;
@@ -533,7 +607,7 @@ int wxHtmlContainerCell::GetIndent(int ind) const
 
 int wxHtmlContainerCell::GetIndentUnits(int ind) const
 {
-    bool p = FALSE;
+    bool p = false;
     if (ind & wxHTML_INDENT_LEFT) p = m_IndentLeft < 0;
     else if (ind & wxHTML_INDENT_RIGHT) p = m_IndentRight < 0;
     else if (ind & wxHTML_INDENT_TOP) p = m_IndentTop < 0;
@@ -552,13 +626,13 @@ bool wxHtmlContainerCell::AdjustPagebreak(int *pagebreak, int* known_pagebreaks,
     else
     {
         wxHtmlCell *c = GetFirstChild();
-        bool rt = FALSE;
+        bool rt = false;
         int pbrk = *pagebreak - m_PosY;
 
         while (c)
         {
             if (c->AdjustPagebreak(&pbrk, known_pagebreaks, number_of_pages))
-                rt = TRUE;
+                rt = true;
             c = c->GetNext();
         }
         if (rt)
@@ -589,13 +663,14 @@ void wxHtmlContainerCell::Layout(int w)
        return;
     }
 
-    wxHtmlCell *cell = m_Cells, *line = m_Cells;
+    wxHtmlCell *nextCell;
     long xpos = 0, ypos = m_IndentTop;
     int xdelta = 0, ybasicpos = 0, ydiff;
-    int s_width, s_indent;
+    int s_width, nextWordWidth, s_indent;
     int ysizeup = 0, ysizedown = 0;
     int MaxLineWidth = 0;
-    int xcnt = 0;
+    int curLineWidth = 0;
+    m_MaxTotalWidth = 0;
 
 
     /*
@@ -634,6 +709,8 @@ void wxHtmlContainerCell::Layout(int w)
     s_width = m_Width - s_indent - ((m_IndentRight < 0) ? (-m_IndentRight * m_Width / 100) : m_IndentRight);
 
     // my own layouting:
+    wxHtmlCell *cell = m_Cells,
+               *line = m_Cells;
     while (cell != NULL)
     {
         switch (m_AlignVer)
@@ -647,13 +724,40 @@ void wxHtmlContainerCell::Layout(int w)
         if (cell->GetDescent() + ydiff > ysizedown) ysizedown = cell->GetDescent() + ydiff;
         if (ybasicpos + cell->GetDescent() < -ysizeup) ysizeup = - (ybasicpos + cell->GetDescent());
 
+        // layout nonbreakable run of cells:
         cell->SetPos(xpos, ybasicpos + cell->GetDescent());
         xpos += cell->GetWidth();
+        if (!cell->IsTerminalCell())
+        {
+            // Container cell indicates new line
+            if (curLineWidth > m_MaxTotalWidth)
+                m_MaxTotalWidth = curLineWidth;
+
+            if (wxMax(cell->GetWidth(), cell->GetMaxTotalWidth()) > m_MaxTotalWidth)
+                m_MaxTotalWidth = cell->GetMaxTotalWidth();
+            curLineWidth = 0;
+        }
+        else
+            // Normal cell, add maximum cell width to line width
+            curLineWidth += cell->GetMaxTotalWidth();
+
         cell = cell->GetNext();
-        xcnt++;
 
-        // force new line if occured:
-        if ((cell == NULL) || (xpos + cell->GetWidth() > s_width))
+        // compute length of the next word that would be added:
+        nextWordWidth = 0;
+        if (cell)
+        {
+            nextCell = cell;
+            do
+            {
+                nextWordWidth += nextCell->GetWidth();
+                nextCell = nextCell->GetNext();
+            } while (nextCell && !nextCell->IsLinebreakAllowed());
+        }
+
+        // force new line if occurred:
+        if ((cell == NULL) ||
+            (xpos + nextWordWidth > s_width && cell->IsLinebreakAllowed()))
         {
             if (xpos > MaxLineWidth) MaxLineWidth = xpos;
             if (ysizeup < 0) ysizeup = 0;
@@ -676,30 +780,88 @@ void wxHtmlContainerCell::Layout(int w)
             ypos += ysizeup;
 
             if (m_AlignHor != wxHTML_ALIGN_JUSTIFY || cell == NULL)
+            {
                 while (line != cell)
                 {
                     line->SetPos(line->GetPosX() + xdelta,
                                    ypos + line->GetPosY());
                     line = line->GetNext();
                 }
-            else
+            }
+            else // align == justify
             {
-                int counter = 0;
-                int step = (s_width - xpos);
-                if (step < 0) step = 0;
-                xcnt--;
-                if (xcnt > 0) while (line != cell)
+                // we have to distribute the extra horz space between the cells
+                // on this line
+
+                // an added complication is that some cells have fixed size and
+                // shouldn't get any increment (it so happens that these cells
+                // also don't allow line break on them which provides with an
+                // easy way to test for this) -- and neither should the cells
+                // adjacent to them as this could result in a visible space
+                // between two cells separated by, e.g. font change, cell which
+                // is wrong
+
+                int step = s_width - xpos;
+                if ( step > 0 )
                 {
-                    line->SetPos(line->GetPosX() + s_indent +
-                                   (counter++ * step / xcnt),
-                                   ypos + line->GetPosY());
-                    line = line->GetNext();
+                    // first count the cells which will get extra space
+                    int total = 0;
+
+                    const wxHtmlCell *c;
+                    if ( line != cell )
+                    {
+                        for ( c = line->GetNext(); c != cell; c = c->GetNext() )
+                        {
+                            if ( c->IsLinebreakAllowed() )
+                            {
+                                total++;
+                            }
+                        }
+                    }
+
+                    // and now extra space to those cells which merit it
+                    if ( total )
+                    {
+                        // first cell on line is not moved:
+                        line->SetPos(line->GetPosX() + s_indent,
+                                     line->GetPosY() + ypos);
+
+                        line = line->GetNext();
+                        for ( int n = 0; line != cell; line = line->GetNext() )
+                        {
+                            if ( line->IsLinebreakAllowed() )
+                            {
+                                // offset the next cell relative to this one
+                                // thus increasing our size
+                                n++;
+                            }
+
+                            line->SetPos(line->GetPosX() + s_indent +
+                                           ((n * step) / total),
+                                           line->GetPosY() + ypos);
+                        }
+                    }
+                    else
+                    {
+                        // this will cause the code to enter "else branch" below:
+                        step = 0;
+                    }
+                }
+                // else branch:
+                if ( step <= 0 ) // no extra space to distribute
+                {
+                    // just set the indent properly
+                    while (line != cell)
+                    {
+                        line->SetPos(line->GetPosX() + s_indent,
+                                     line->GetPosY() + ypos);
+                        line = line->GetNext();
+                    }
                 }
-                xcnt++;
             }
 
             ypos += ysizedown;
-            xpos = xcnt = 0;
+            xpos = 0;
             ysizeup = ysizedown = 0;
             line = cell;
         }
@@ -724,6 +886,10 @@ void wxHtmlContainerCell::Layout(int w)
         m_Height = m_MinHeight;
     }
 
+    if (curLineWidth > m_MaxTotalWidth)
+        m_MaxTotalWidth = curLineWidth;
+
+    m_MaxTotalWidth += s_indent + ((m_IndentRight < 0) ? (-m_IndentRight * m_Width / 100) : m_IndentRight);
     MaxLineWidth += s_indent + ((m_IndentRight < 0) ? (-m_IndentRight * m_Width / 100) : m_IndentRight);
     if (m_Width < MaxLineWidth) m_Width = MaxLineWidth;
 
@@ -758,52 +924,64 @@ void wxHtmlContainerCell::UpdateRenderingStatePost(wxHtmlRenderingInfo& info,
 void wxHtmlContainerCell::Draw(wxDC& dc, int x, int y, int view_y1, int view_y2,
                                wxHtmlRenderingInfo& info)
 {
-    // container visible, draw it:
-    if ((y + m_PosY <= view_y2) && (y + m_PosY + m_Height > view_y1))
+#if 0 // useful for debugging
+    dc.SetPen(*wxRED_PEN);
+    dc.DrawRectangle(x+m_PosX,y+m_PosY,m_Width,m_Height);
+#endif
+
+    int xlocal = x + m_PosX;
+    int ylocal = y + m_PosY;
+
+    if (m_UseBkColour)
     {
-        if (m_UseBkColour)
-        {
-            wxBrush myb = wxBrush(m_BkColour, wxSOLID);
+        wxBrush myb = wxBrush(m_BkColour, wxSOLID);
 
-            int real_y1 = mMax(y + m_PosY, view_y1);
-            int real_y2 = mMin(y + m_PosY + m_Height - 1, view_y2);
+        int real_y1 = mMax(ylocal, view_y1);
+        int real_y2 = mMin(ylocal + m_Height - 1, view_y2);
 
-            dc.SetBrush(myb);
-            dc.SetPen(*wxTRANSPARENT_PEN);
-            dc.DrawRectangle(x + m_PosX, real_y1, m_Width, real_y2 - real_y1 + 1);
-        }
+        dc.SetBrush(myb);
+        dc.SetPen(*wxTRANSPARENT_PEN);
+        dc.DrawRectangle(xlocal, real_y1, m_Width, real_y2 - real_y1 + 1);
+    }
 
-        if (m_UseBorder)
-        {
-            wxPen mypen1(m_BorderColour1, 1, wxSOLID);
-            wxPen mypen2(m_BorderColour2, 1, wxSOLID);
-
-            dc.SetPen(mypen1);
-            dc.DrawLine(x + m_PosX, y + m_PosY, x + m_PosX, y + m_PosY + m_Height - 1);
-            dc.DrawLine(x + m_PosX, y + m_PosY, x + m_PosX + m_Width, y + m_PosY);
-            dc.SetPen(mypen2);
-            dc.DrawLine(x + m_PosX + m_Width - 1, y + m_PosY, x + m_PosX +  m_Width - 1, y + m_PosY + m_Height - 1);
-            dc.DrawLine(x + m_PosX, y + m_PosY + m_Height - 1, x + m_PosX + m_Width, y + m_PosY + m_Height - 1);
-        }
+    if (m_UseBorder)
+    {
+        wxPen mypen1(m_BorderColour1, 1, wxSOLID);
+        wxPen mypen2(m_BorderColour2, 1, wxSOLID);
+
+        dc.SetPen(mypen1);
+        dc.DrawLine(xlocal, ylocal, xlocal, ylocal + m_Height - 1);
+        dc.DrawLine(xlocal, ylocal, xlocal + m_Width, ylocal);
+        dc.SetPen(mypen2);
+        dc.DrawLine(xlocal + m_Width - 1, ylocal, xlocal +  m_Width - 1, ylocal + m_Height - 1);
+        dc.DrawLine(xlocal, ylocal + m_Height - 1, xlocal + m_Width, ylocal + m_Height - 1);
+    }
 
-        if (m_Cells)
+    if (m_Cells)
+    {
+        // draw container's contents:
+        for (wxHtmlCell *cell = m_Cells; cell; cell = cell->GetNext())
         {
-            // draw container's contents:
-            for (wxHtmlCell *cell = m_Cells; cell; cell = cell->GetNext())
+
+            // optimize drawing: don't render off-screen content:
+            if ((ylocal + cell->GetPosY() <= view_y2) &&
+                (ylocal + cell->GetPosY() + cell->GetHeight() > view_y1))
             {
+                // the cell is visible, draw it:
                 UpdateRenderingStatePre(info, cell);
                 cell->Draw(dc,
-                           x + m_PosX, y + m_PosY, view_y1, view_y2,
+                           xlocal, ylocal, view_y1, view_y2,
                            info);
                 UpdateRenderingStatePost(info, cell);
             }
+            else
+            {
+                // the cell is off-screen, proceed with font+color+etc.
+                // changes only:
+                cell->DrawInvisible(dc, xlocal, ylocal, info);
+            }
         }
     }
-    // container invisible, just proceed font+color changing:
-    else
-    {
-        DrawInvisible(dc, x, y, info);
-    }
 }
 
 
@@ -907,11 +1085,9 @@ const wxHtmlCell* wxHtmlContainerCell::Find(int condition, const void* param) co
 {
     if (m_Cells)
     {
-        const wxHtmlCell *r = NULL;
-
         for (wxHtmlCell *cell = m_Cells; cell; cell = cell->GetNext())
         {
-            r = cell->Find(condition, param);
+            const wxHtmlCell *r = cell->Find(condition, param);
             if (r) return r;
         }
     }
@@ -939,14 +1115,16 @@ wxHtmlCell *wxHtmlContainerCell::FindCellByPos(wxCoord x, wxCoord y,
     else if ( flags & wxHTML_FIND_NEAREST_AFTER )
     {
         wxHtmlCell *c;
-        int y2;
         for ( const wxHtmlCell *cell = m_Cells; cell; cell = cell->GetNext() )
         {
-            y2 = cell->GetPosY() + cell->GetHeight() - 1;
-            if (y2 < y || (y2 == y && cell->GetPosX()+cell->GetWidth()-1 < x))
+            if ( cell->IsFormattingCell() )
                 continue;
-            c = cell->FindCellByPos(x - cell->GetPosX(), y - cell->GetPosY(),
-                                    flags);
+            int cellY = cell->GetPosY();
+            if (!( y < cellY || (y < cellY + cell->GetHeight() &&
+                                 x < cell->GetPosX() + cell->GetWidth()) ))
+                continue;
+
+            c = cell->FindCellByPos(x - cell->GetPosX(), y - cellY, flags);
             if (c) return c;
         }
     }
@@ -955,11 +1133,13 @@ wxHtmlCell *wxHtmlContainerCell::FindCellByPos(wxCoord x, wxCoord y,
         wxHtmlCell *c2, *c = NULL;
         for ( const wxHtmlCell *cell = m_Cells; cell; cell = cell->GetNext() )
         {
-            if (cell->GetPosY() > y ||
-                    (cell->GetPosY() == y && cell->GetPosX() > x))
+            if ( cell->IsFormattingCell() )
+                continue;
+            int cellY = cell->GetPosY();
+            if (!( cellY + cell->GetHeight() <= y ||
+                   (y >= cellY && x >= cell->GetPosX()) ))
                 break;
-            c2 = cell->FindCellByPos(x - cell->GetPosX(), y - cell->GetPosY(),
-                                     flags);
+            c2 = cell->FindCellByPos(x - cell->GetPosX(), y - cellY, flags);
             if (c2)
                 c = c2;
         }
@@ -979,30 +1159,6 @@ void wxHtmlContainerCell::OnMouseClick(wxWindow *parent, int x, int y, const wxM
 
 
 
-void wxHtmlContainerCell::GetHorizontalConstraints(int *left, int *right) const
-{
-    int cleft = m_PosX + m_Width, cright = m_PosX; // worst case
-    int l, r;
-
-    for (wxHtmlCell *cell = m_Cells; cell; cell = cell->GetNext())
-    {
-        cell->GetHorizontalConstraints(&l, &r);
-        if (l < cleft)
-            cleft = l;
-        if (r > cright)
-            cright = r;
-    }
-
-    cleft -= (m_IndentLeft < 0) ? (-m_IndentLeft * m_Width / 100) : m_IndentLeft;
-    cright += (m_IndentRight < 0) ? (-m_IndentRight * m_Width / 100) : m_IndentRight;
-
-    if (left)
-        *left = cleft;
-    if (right)
-        *right = cright;
-}
-
-
 wxHtmlCell *wxHtmlContainerCell::GetFirstTerminal() const
 {
     if ( m_Cells )
@@ -1027,9 +1183,14 @@ wxHtmlCell *wxHtmlContainerCell::GetLastTerminal() const
         if ( c )
             return c;
 
+        wxHtmlCell *ctmp;
         wxHtmlCell *c2 = NULL;
         for (c = m_Cells; c; c = c->GetNext())
-            c2 = c->GetLastTerminal();
+        {
+            ctmp = c->GetLastTerminal();
+            if ( ctmp )
+                c2 = ctmp;
+        }
         return c2;
     }
     else
@@ -1037,12 +1198,93 @@ wxHtmlCell *wxHtmlContainerCell::GetLastTerminal() const
 }
 
 
+static bool IsEmptyContainer(wxHtmlContainerCell *cell)
+{
+    for ( wxHtmlCell *c = cell->GetFirstChild(); c; c = c->GetNext() )
+    {
+        if ( !c->IsTerminalCell() || !c->IsFormattingCell() )
+            return false;
+    }
+    return true;
+}
+
+void wxHtmlContainerCell::RemoveExtraSpacing(bool top, bool bottom)
+{
+    if ( top )
+        SetIndent(0, wxHTML_INDENT_TOP);
+    if ( bottom )
+        SetIndent(0, wxHTML_INDENT_BOTTOM);
+
+    if ( m_Cells )
+    {
+        wxHtmlCell *c;
+        wxHtmlContainerCell *cont;
+        if ( top )
+        {
+            for ( c = m_Cells; c; c = c->GetNext() )
+            {
+                if ( c->IsTerminalCell() )
+                {
+                    if ( !c->IsFormattingCell() )
+                        break;
+                }
+                else
+                {
+                    cont = (wxHtmlContainerCell*)c;
+                    if ( IsEmptyContainer(cont) )
+                    {
+                        cont->SetIndent(0, wxHTML_INDENT_VERTICAL);
+                    }
+                    else
+                    {
+                        cont->RemoveExtraSpacing(true, false);
+                        break;
+                    }
+                }
+            }
+        }
+
+        if ( bottom )
+        {
+            wxArrayPtrVoid arr;
+            for ( c = m_Cells; c; c = c->GetNext() )
+                arr.Add((void*)c);
+
+            for ( int i = arr.GetCount() - 1; i >= 0; i--)
+            {
+                c = (wxHtmlCell*)arr[i];
+                if ( c->IsTerminalCell() )
+                {
+                    if ( !c->IsFormattingCell() )
+                        break;
+                }
+                else
+                {
+                    cont = (wxHtmlContainerCell*)c;
+                    if ( IsEmptyContainer(cont) )
+                    {
+                        cont->SetIndent(0, wxHTML_INDENT_VERTICAL);
+                    }
+                    else
+                    {
+                        cont->RemoveExtraSpacing(false, true);
+                        break;
+                    }
+                }
+            }
+        }
+    }
+}
+
+
 
 
 // --------------------------------------------------------------------------
 // wxHtmlColourCell
 // --------------------------------------------------------------------------
 
+IMPLEMENT_ABSTRACT_CLASS(wxHtmlColourCell, wxHtmlCell)
+
 void wxHtmlColourCell::Draw(wxDC& dc,
                             int x, int y,
                             int WXUNUSED(view_y1), int WXUNUSED(view_y2),
@@ -1069,11 +1311,16 @@ void wxHtmlColourCell::DrawInvisible(wxDC& dc,
     {
         state.SetBgColour(m_Colour);
         if (state.GetSelectionState() != wxHTML_SEL_IN)
+        {
             dc.SetTextBackground(m_Colour);
+            dc.SetBackground(wxBrush(m_Colour, wxSOLID));
+        }
         else
-            dc.SetTextBackground(
-                    info.GetStyle().GetSelectedTextBgColour(m_Colour));
-        dc.SetBackground(wxBrush(m_Colour, wxSOLID));
+        {
+            wxColour c = info.GetStyle().GetSelectedTextBgColour(m_Colour);
+            dc.SetTextBackground(c);
+            dc.SetBackground(wxBrush(c, wxSOLID));
+        }
     }
 }
 
@@ -1084,6 +1331,8 @@ void wxHtmlColourCell::DrawInvisible(wxDC& dc,
 // wxHtmlFontCell
 // ---------------------------------------------------------------------------
 
+IMPLEMENT_ABSTRACT_CLASS(wxHtmlFontCell, wxHtmlCell)
+
 void wxHtmlFontCell::Draw(wxDC& dc,
                           int WXUNUSED(x), int WXUNUSED(y),
                           int WXUNUSED(view_y1), int WXUNUSED(view_y2),
@@ -1109,6 +1358,8 @@ void wxHtmlFontCell::DrawInvisible(wxDC& dc, int WXUNUSED(x), int WXUNUSED(y),
 // wxHtmlWidgetCell
 // ---------------------------------------------------------------------------
 
+IMPLEMENT_ABSTRACT_CLASS(wxHtmlWidgetCell, wxHtmlCell)
+
 wxHtmlWidgetCell::wxHtmlWidgetCell(wxWindow *wnd, int w)
 {
     int sx, sy;