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