pango-Text-Processing         package:RGtk2         R Documentation

_R_e_n_d_e_r_i_n_g

_D_e_s_c_r_i_p_t_i_o_n:

     Functions to run the rendering pipeline

_M_e_t_h_o_d_s _a_n_d _F_u_n_c_t_i_o_n_s:

     'pangoItemize(context, text, start.index, length, attrs,
     cached.iter = NULL)'
      'pangoItemizeWithBaseDir(context, base.dir, text, start.index,
     length, attrs, cached.iter = NULL)'
      'pangoItemCopy(item)'
      'pangoItemNew()'
      'pangoItemSplit(orig, split.index, split.offset)'
      'pangoReorderItems(logical.items)'
      'pangoContextSetFontMap(object, font.map)'
      'pangoContextGetFontMap(object)'
      'pangoContextGetFontDescription(object)'
      'pangoContextSetFontDescription(object, desc)'
      'pangoContextGetLanguage(object)'
      'pangoContextSetLanguage(object, language)'
      'pangoContextGetBaseDir(object)'
      'pangoContextSetBaseDir(object, direction)'
      'pangoContextGetBaseGravity(object)'
      'pangoContextSetBaseGravity(object, gravity)'
      'pangoContextGetGravity(object)'
      'pangoContextGetGravityHint(object)'
      'pangoContextSetGravityHint(object, hint)'
      'pangoContextGetMatrix(object)'
      'pangoContextSetMatrix(object, matrix)'
      'pangoContextLoadFont(object, desc)'
      'pangoContextLoadFontset(object, desc, language)'
      'pangoContextGetMetrics(object, desc, language = NULL)'
      'pangoContextListFamilies(object)'
      'pangoGetMirrorChar(ch)'
      'pangoUnicharDirection(ch)'
      'pangoFindBaseDir(text, length = -1)'
      'pangoBreak(text, analysis)'
      'pangoGetLogAttrs(text, level, language)'
      'pangoFindParagraphBoundary(text, length = -1)'
      'pangoShape(text, analysis, glyphs)'

_H_i_e_r_a_r_c_h_y:

     GObject
        +----PangoContext 

_D_e_t_a_i_l_e_d _D_e_s_c_r_i_p_t_i_o_n:

     The Pango rendering pipeline takes a string of Unicode characters
     and converts it into glyphs. The functions described in this
     section accomplish various steps of this process.

_S_t_r_u_c_t_u_r_e_s:


     '_P_a_n_g_o_C_o_n_t_e_x_t' The 'PangoContext' structure stores global
          information used to control the itemization process. 


     '_P_a_n_g_o_I_t_e_m' The 'PangoItem' structure stores information about a
          segment of text. It contains the following fields:

          '_o_f_f_s_e_t' [integer] the offset of the segment from the
               beginning of the string in bytes.

          '_l_e_n_g_t_h' [integer] the length of the segment in bytes.

          '_n_u_m_C_h_a_r_s' [integer] the length of the segment in characters.

          '_a_n_a_l_y_s_i_s' ['PangoAnalysis'] the properties of the segment.


     '_P_a_n_g_o_A_n_a_l_y_s_i_s' The 'PangoAnalysis' structure stores information
          about the properties of a segment of text. It has the
          following fields:

          '_f_o_n_t' ['PangoFont'] the engine for doing
               rendering-system-dependent processing.

          '_l_e_v_e_l' [raw] the engine for doing
               rendering-system-independent processing.

          '_l_a_n_g_u_a_g_e' ['PangoLanguage'] the font for this segment.

          '_e_x_t_r_a_A_t_t_r_s' [list] the bidirectional level for this segment.


     '_P_a_n_g_o_L_o_g_A_t_t_r' The 'PangoLogAttr' structure stores information
          about the attributes of a single character.

          '_i_s_L_i_n_e_B_r_e_a_k' [numeric] if set, can break line in front of
               character

          '_i_s_M_a_n_d_a_t_o_r_y_B_r_e_a_k' [numeric] if set, must break line in front
               of character

          '_i_s_C_h_a_r_B_r_e_a_k' [numeric] if set, can break here when doing
               character wrapping

          '_i_s_W_h_i_t_e' [numeric] is whitespace character

          '_i_s_C_u_r_s_o_r_P_o_s_i_t_i_o_n' [numeric] if set, cursor can appear in
               front of character. i.e. this is a grapheme boundary, or
               the first character in the text.

          '_i_s_W_o_r_d_S_t_a_r_t' [numeric] is first character in a word

          '_i_s_W_o_r_d_E_n_d' [numeric] is first non-word char after a word
               Note that in degenerate cases, you could have both
               'is.word.start' and 'is.word.end' set for some
               character.

          '_i_s_S_e_n_t_e_n_c_e_B_o_u_n_d_a_r_y' [numeric] is a sentence boundary. There
               are two ways to divide sentences. The first assigns all
               inter-sentence whitespace/control/format chars to some
               sentence, so all chars are in some sentence;
               'is.sentence.boundary' denotes the boundaries there. The
               second way doesn't assign between-sentence spaces, etc.
               to any sentence, so
               'is.sentence.start'/'is.sentence.end' mark the
               boundaries of those sentences.

          '_i_s_S_e_n_t_e_n_c_e_S_t_a_r_t' [numeric] is first character in a sentence

          '_i_s_S_e_n_t_e_n_c_e_E_n_d' [numeric] is first char after a sentence.
               Note that in degenerate cases, you could have both
               'is.sentence.start' and 'is.sentence.end' set for some
               character. (e.g. no space after a period, so the next
               sentence starts right away)

          '_b_a_c_k_s_p_a_c_e_D_e_l_e_t_e_s_C_h_a_r_a_c_t_e_r' [numeric] if set, backspace
               deletes one character rather than the entire grapheme
               cluster. This field is only meaningful on grapheme
               boundaries (where 'is.cursor.position' is set).  In some
               languages, the full grapheme (e.g.  letter + diacritics)
               is considered a unit, while in others, each decomposed
               character in the grapheme is a unit. In the default
               implementation of 'pangoBreak', this bit is set on all
               grapheme boundaries except those following Latin,
               Cyrillic or Greek base characters.


_E_n_u_m_s _a_n_d _F_l_a_g_s:


     '_P_a_n_g_o_D_i_r_e_c_t_i_o_n' The 'PangoDirection' type represents a direction
          in the Unicode bidirectional algorithm; not every value in
          this enumeration makes sense for every usage of
          'PangoDirection'; for example, the return value of
          'pangoUnicharDirection' and 'pangoFindBaseDir' cannot be
          'PANGO_DIRECTION_WEAK_LTR' or 'PANGO_DIRECTION_WEAK_RTL',
          since every character is either neutral or has a strong
          direction; on the other hand 'PANGO_DIRECTION_NEUTRAL'
          doesn't make sense to pass to 'pangoItemizeWithBaseDir'.

          The 'PANGO_DIRECTION_TTB_LTR', 'PANGO_DIRECTION_TTB_RTL'
          values come from an earlier interpretation of this
          enumeration as the writing direction of a block of text and
          are no longer used; See 'PangoGravity' for how vertical text
          is handled in Pango.  

          '_l_t_r' A strong left-to-right direction

          '_r_t_l' A strong right-to-left direction

          '_t_t_b-_l_t_r' Deprecated value; treated the same as
               'PANGO_DIRECTION_RTL'.

          '_t_t_b-_r_t_l' Deprecated value; treated the same as
               'PANGO_DIRECTION_LTR'


_A_u_t_h_o_r(_s):

     Derived by RGtkGen from GTK+ documentation

_R_e_f_e_r_e_n_c_e_s:

     <URL:
     http://developer.gnome.org/doc/API/2.0/pango/pango-Text-Processing.html>

