src/common/textmeasurecmn.cpp

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        src/common/textmeasurecmn.cpp
   3 // Purpose:     wxTextMeasureBase implementation
   4 // Author:      Manuel Martin
   5 // Created:     2012-10-05
   6 // RCS-ID:      $Id:
   7 // Copyright:   (c) 1997-2012 wxWidgets team
   8 // Licence:     wxWindows licence
   9 ///////////////////////////////////////////////////////////////////////////////
  10
  11 // ============================================================================
  12 // declarations
  13 // ============================================================================
  14
  15 // ----------------------------------------------------------------------------
  16 // headers
  17 // ----------------------------------------------------------------------------
  18
  19 // for compilers that support precompilation, includes "wx.h".
  20 #include "wx/wxprec.h"
  21
  22 #ifndef WX_PRECOMP
  23     #include "wx/dc.h"
  24     #include "wx/window.h"
  25 #endif //WX_PRECOMP
  26
  27 #include "wx/private/textmeasure.h"
  28
  29 // ============================================================================
  30 // wxTextMeasureBase implementation
  31 // ============================================================================
  32
  33 wxTextMeasureBase::wxTextMeasureBase(const wxDC *dc, const wxFont *theFont)
  34     : m_dc(dc),
  35       m_win(NULL),
  36       m_font(theFont)
  37 {
  38     wxASSERT_MSG( dc, wxS("wxTextMeasure needs a valid wxDC") );
  39 }
  40
  41 wxTextMeasureBase::wxTextMeasureBase(const wxWindow *win, const wxFont *theFont)
  42     : m_dc(NULL),
  43       m_win(win),
  44       m_font(theFont)
  45 {
  46     wxASSERT_MSG( win, wxS("wxTextMeasure needs a valid wxWindow") );
  47 }
  48
  49 void wxTextMeasureBase::GetTextExtent(const wxString& string,
  50                                       wxCoord *width,
  51                                       wxCoord *height,
  52                                       wxCoord *descent,
  53                                       wxCoord *externalLeading)
  54 {
  55     // To make the code simpler, make sure that the width and height pointers
  56     // are always valid, even if they point to dummy variables.
  57     int unusedWidth, unusedHeight;
  58     if ( !width )
  59         width = &unusedWidth;
  60     if ( !height )
  61         height = &unusedHeight;
  62
  63     if ( string.empty() )
  64     {
  65         *width =
  66         *height = 0;
  67
  68         return;
  69     }
  70
  71     MeasuringGuard guard(*this);
  72
  73     DoGetTextExtent(string, width, height, descent, externalLeading);
  74 }
  75
  76 void wxTextMeasureBase::GetMultiLineTextExtent(const wxString& text,
  77                                                wxCoord *width,
  78                                                wxCoord *height,
  79                                                wxCoord *heightOneLine)
  80 {
  81     MeasuringGuard guard(*this);
  82
  83     wxCoord widthTextMax = 0, widthLine,
  84             heightTextTotal = 0, heightLineDefault = 0, heightLine = 0;
  85
  86     wxString curLine;
  87     for ( wxString::const_iterator pc = text.begin(); ; ++pc )
  88     {
  89         if ( pc == text.end() || *pc == wxS('\n') )
  90         {
  91             if ( curLine.empty() )
  92             {
  93                 // we can't use GetTextExtent - it will return 0 for both width
  94                 // and height and an empty line should count in height
  95                 // calculation
  96
  97                 // assume that this line has the same height as the previous
  98                 // one
  99                 if ( !heightLineDefault )
 100                     heightLineDefault = heightLine;
 101
 102                 if ( !heightLineDefault )
 103                 {
 104                     // but we don't know it yet - choose something reasonable
 105                     int dummy;
 106                     DoGetTextExtent(wxS("W"), &dummy, &heightLineDefault);
 107                 }
 108
 109                 heightTextTotal += heightLineDefault;
 110             }
 111             else
 112             {
 113                 DoGetTextExtent(curLine, &widthLine, &heightLine);
 114                 if ( widthLine > widthTextMax )
 115                     widthTextMax = widthLine;
 116                 heightTextTotal += heightLine;
 117             }
 118
 119             if ( pc == text.end() )
 120             {
 121                break;
 122             }
 123             else // '\n'
 124             {
 125                curLine.clear();
 126             }
 127         }
 128         else
 129         {
 130             curLine += *pc;
 131         }
 132     }
 133
 134     if ( width )
 135         *width = widthTextMax;
 136     if ( height )
 137         *height = heightTextTotal;
 138     if ( heightOneLine )
 139         *heightOneLine = heightLine;
 140 }
 141
 142 void wxTextMeasureBase::GetLargestStringExtent(const wxVector<wxString>& strings,
 143                                                wxCoord *width,
 144                                                wxCoord *height)
 145 {
 146     MeasuringGuard guard(*this);
 147
 148     wxCoord w, h, widthMax = 0, heightMax = 0;
 149     for ( wxVector<wxString>::const_iterator i = strings.begin();
 150           i != strings.end();
 151           ++i )
 152     {
 153         DoGetTextExtent(*i, &w, &h);
 154
 155         if ( w > widthMax )
 156             widthMax = w;
 157         if ( h > heightMax )
 158             heightMax = h;
 159     }
 160
 161     if ( width )
 162         *width = widthMax;
 163     if ( height )
 164         *height = heightMax;
 165 }
 166
 167 bool wxTextMeasureBase::GetPartialTextExtents(const wxString& text,
 168                                               wxArrayInt& widths,
 169                                               double scaleX)
 170 {
 171     widths.Empty();
 172     if ( text.empty() )
 173         return true;
 174
 175     MeasuringGuard guard(*this);
 176
 177     widths.Add(0, text.length());
 178
 179     return DoGetPartialTextExtents(text, widths, scaleX);
 180 }