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pdf::text::CText Class Reference

the text segment class More...

#include <Text.hh>

Collaboration diagram for pdf::text::CText:

[legend]List of all members.

Public Methods

• CText (const std::string &line, const CState &state, const CPosition &position=CNullPos())
• CText (const std::string &line, const CState &state, double offset_x, double offset_y)
• CText (const CText &text)
• ~CText ()
• const std::string & Line () const
• const CState & State () const
• std::ostream & Write (std::ostream &os, const CState &prev) const
• void Move (const CPosition &new_pos)
• double Width () const

Static Private Methods

• const std::string EscapeString (const std::string &str)

Private Attributes

• std::string m_line
• CState m_state
• std::auto_ptr< CPosition > m_position

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Detailed Description

the text segment class

this class represent a text segment. a text segment is a string with the same formatting. the formatting data is stored in a CState object. in addition to string and formatting, it also store the position of the text string in the page. the position is given as offset from the last text segment, i.e. the coordinate is relative.

primary use of this class is to construct it and add it to the CPage class by CPage::DrawText().

example:

    text::CText text( "I am a line", text::CState( ) ) ;
    page.DrawText( text ) ;

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Constructor & Destructor Documentation

pdf::text::CText::CText (  const std::string &    line, const CState &    state, const CPosition &    position = CNullPos( ) )

construct a text segment given the text string, state and position. the "position" is specified as a reference of the CPosition class. it can be a CNullPos, which means this segment is right after the previous text segment; or it can be a COffsetPos, which specified the X-Y offset from the start of the last text segment; or it can be a CAbsolutePos, which specified the absolute coordinate of the text segment. Parameters: line  the text string state  the formatting of this string position  the position of the string. See also: Move( ) : m_line( line ), m_state( state ), m_position( position.Dup( ) ) { }

pdf::text::CText::CText (  const std::string &    line, const CState &    state, double    offset_x, double    offset_y )

construct a text segment. unlike the other constructor, the offset can be specified. Parameters: line  the text string state  the formatting of this string x_offset  the horizonal offset from the previous text segment in the page. i.e. relative. y_offset  relative vertical offset Note: specifying an offset of (0,0) is different from no offset. since the offset is relative to the starting point of the previous text segment. setting an offset of (0,0) will make two segments overlap. See also: Move( ) : m_line( line ), m_state( state ), m_position( new COffsetPos( offset_x, offset_y ) ) { }

pdf::text::CText::CText (  const CText &    text )

copy constructor is needed because I used auto_ptr internally. : m_line( text.m_line ), m_state( text.m_state ), m_position( text.m_position->Dup( ) ) { }

pdf::text::CText::~CText (    )

destructor does nothing. the auto_ptr will clean up the m_position pointer. { }

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Member Function Documentation

std::ostream & pdf::text::CText::Write (  std::ostream &    os, const CState &    prev )  const

For internal use only. write the text segment to the PDF file. it is called by CPage::Write(). library clients should not call this directly. the "prev" text state will be passed to CState::Write(). Parameters: os  the I/O stream of the PDF file prev  text state { assert( m_position.get( ) != 0 ) ; // write the position of the text m_position->Write( os, m_state.Leading( ) ) ; // write the formatting m_state.Write( os, prev ) ; // write the string enclosed by brackets return os << '(' << EscapeString( m_line ) << ") Tj\n" ; }

void pdf::text::CText::Move (  const CPosition &    new_pos )

this function changes the text position. see the constructor for the meaning of the CPosition class. See also: CText( ) { m_position.reset( new_pos.Dup( ) ) ; }

double pdf::text::CText::Width (    )  const

calculate the width of the text line, including all transformation. the unit is default user space, i.e. 1/72 inches. Note: currently the width is not calculated by the matrix formula from the PDF spec. the formula is in this implementation, the matrix is igored for now. {fs} & 0 \\ 0 & T_{rise} & 1 \end{bmatrix} \times T_m \times CTM \f] in this implementation, the \f$T_m\f$ matrix is igored for now. */ double CText::Width( ) const { double result = 0.0f ; // use iterator is faster than array index typedef std::string::const_iterator iterator ; for ( iterator i = m_line.begin() ; i != m_line.end() ; ++i ) { assert( m_state.Font( ) != 0 ) ; // character width in glyph space double char_width = m_state.Font( )->GlyphWidth( *i ) ; // transform to user space

const std::string pdf::text::CText::EscapeString (  const std::string &    str )  [static, private]

convert the escape chars. it will put escape characters into the string and return it. { using namespace std ; string escape_chars = "()\\" ; string result ; result.reserve( str.size( ) + 1 ) ; // use iterator is faster than array index for ( string::const_iterator i = str.begin( ) ; i != str.end( ) ; ++i ) { if ( escape_chars.find( *i ) != string::npos ) result.push_back( '\\' ) ; result.push_back( *i ) ; } return result ; }

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Member Data Documentation

std::string pdf::text::CText::m_line [private]

the content of the text segment

CState pdf::text::CText::m_state [private]

the formatting of the text segment

std::auto_ptr<CPosition> pdf::text::CText::m_position [private]

position of the text segment

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The documentation for this class was generated from the following files:

• Text.hh
• Text.cc

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