gedit                package:gWidgets                R Documentation

_C_o_n_s_t_r_u_c_t_o_r_s _f_o_r _w_i_d_g_e_t_s _t_o _h_a_n_d_l_e _t_e_x_t _i_n_p_u_t

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

     The gedit widget is used to enter single lines of text. The gtext
     widget creates a text buffer for handling multiple lines of text.

_U_s_a_g_e:

     gedit(text = "", width = 25, coerce.with = NULL, handler = NULL, action = NULL, container = NULL, ..., toolkit = guiToolkit())

     gtext (text = NULL, width = NULL, height = 300, font.attr = NULL, 
         wrap = TRUE, handler = NULL, action = NULL, container = NULL, 
         ..., toolkit = guiToolkit()) 

_A_r_g_u_m_e_n_t_s:

    text: Initial text in widget

   width: Width of widget. For gedit, this means the number of
          characters. For gtext the pixel widget

  height: Height of gtext widget in pixels

font.attr: Optional specification of font attributes

    wrap: For gtext, are long lines wrapped?

coerce.with: For gedit, when the value is retrieved this function is
          applied to the result. (The stored value is always a
          character, this can be used to make it numerc, to quote it,
          ...

 handler: Handler called when text is changed. For gedit, this means
          the enter key is pressed.

  action: Passed to handler

container: Optional container to attach widget to

     ...: ignored

 toolkit: Which GUI toolkit to use

_D_e_t_a_i_l_s:

     The 'gedit' widget has the following methods:

     The 'svalue' method retrieves the value. If a function is given to
     the argument 'coerce.with' it is applied before the value is
     returned. This can be used to coerce the text value (always of
     class character) to a numeric, or to a date, or to be quoted, ...

     The 'svalue<-' method is used to set the value.

     The '"["' and '"[<-"' methods refer to the widgets "type-ahead"
     values. A familiar usage is when a url is typed into a web
     browser, matches appear from a users history that could possibly
     complete the typed url.

     The 'gtext' widget has the following methods.

     The 'svalue' method returns the text held in the buffer. If
     'drop=TRUE', then only the text in the buffer selected by the
     mouse is returned.

     The 'svalue<-' method replaces the text in the buffer with the new
     text.

     New text is added with the 'add' method. The basic usage is
     'add(obj,text)' where "text" could be a single line or a vector of
     text, or a gwidget (although some, like gedit,  are kind of
     flaky). Extra arguments include 'do.newline' a logical indicating
     if a new line after the last line should be added (default is
     'TRUE'); 'font.attr' to specify any font attributes; 'where'
     indicating where to add the text (either 'end'  or 'beginning').

     The font can be changed. The 'font.attr' argument to the
     constructon and to 'add' specifies fonts using a namedcharacter
     vector. For instance 'c(style="normal",
     weights="bold",sizes="medium")'. The command 'obj[['tags']]' will
     produce a list containing all the available attributes. 

     The 'font<-' method is used to change the font of the currently
     selected text. It too takes a named character vector specifying
     the font attributes.

     The 'dispose' method clears the text in the buffer.

_E_x_a_m_p_l_e_s:

     ## Not run: 
             gedit("type here", container=TRUE)
             
             ## change handler
             obj = gedit(container=TRUE)
             addhandlerchanged(obj, handler=function(h,...) 
               cat("You typed", svalue(h$obj),"\n"))

              ## coerce to numeric
              obj = gedit("7", container=TRUE, coerce.with=as.numeric)
              svalue(obj)

             ## gtext example
             obj = gtext("First line", container=TRUE)
             add(obj,"second line", font.attr=c(family="monospace"))
             add(obj,"third line", font.attr=c(foreground.colors="red"))
     ## End(Not run)

