DevDesc-class        package:RGraphicsDevice        R Documentation

_C_l_a_s_s "_D_e_v_D_e_s_c_P_t_r" _r_e_p_r_e_s_e_n_t_i_n_g _a _C-_l_e_v_e_l _G_r_a_p_h_i_c_s _D_e_v_i_c_e

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

     The 'DevDescPtr'  class represents a C-level data structure that
     corresponds to an existing R graphics device. If the device is
     active, R graphics commands will cause the device's graphical
     operators to be called.

     We typically obtain a reference to the graphics device via the
     function 'graphicsDevice'. It is also passed as an argument in
     each call to the R functions that operate as  graphical primitives
     for the R-level graphics device.

     We can query and set the state of the device treating it like a
     list in R. We can then access the individual fields, querying and
     setting their values using the regular R operators '[[' and '\$',
     e.g. 'dev$left' and 'dev$right = 1000'.

_O_b_j_e_c_t_s _f_r_o_m _t_h_e _C_l_a_s_s:

     Objects of class 'DevDescPtr' are created by the R graphics engine
     in C code and via the function 'graphicsDevice'. We do not create
     them ourselves.

     On occassion, it might be useful to convert the reference to the C
     structure to an R structure, i.e. one with the corresponding slots
     and the values as R vectors, etc.  We use  the 'DevDesc' class for
     this and we can convert using the 'as' function, e.g. 'as(dev,
     "DevDesc")'.

_S_l_o_t_s:


     '_l_e_f_t': Object of class '"numeric"'  

     '_r_i_g_h_t': Object of class '"numeric"'  

     '_b_o_t_t_o_m': Object of class '"numeric"'  

     '_t_o_p': Object of class '"numeric"'  

     '_c_l_i_p_L_e_f_t': Object of class '"numeric"'  

     '_c_l_i_p_R_i_g_h_t': Object of class '"numeric"'  

     '_c_l_i_p_B_o_t_t_o_m': Object of class '"numeric"'  

     '_c_l_i_p_T_o_p': Object of class '"numeric"'  

     '_x_C_h_a_r_O_f_f_s_e_t': Object of class '"numeric"'  

     '_y_C_h_a_r_O_f_f_s_e_t': Object of class '"numeric"'  

     '_y_L_i_n_e_B_i_a_s': Object of class '"numeric"'  

     '_i_p_r': Object of class '"numeric"'  

     '_c_r_a': Object of class '"numeric"'  

     '_g_a_m_m_a': Object of class '"numeric"'  

     '_c_a_n_C_l_i_p': Object of class '"Rboolean"'  

     '_c_a_n_C_h_a_n_g_e_G_a_m_m_a': Object of class '"Rboolean"'  

     '_c_a_n_H_A_d_j': Object of class '"integer"'  

     '_s_t_a_r_t_p_s': Object of class '"numeric"'  

     '_s_t_a_r_t_c_o_l': Object of class '"integer"'  

     '_s_t_a_r_t_f_i_l_l': Object of class '"integer"'  

     '_s_t_a_r_t_l_t_y': Object of class '"integer"'  

     '_s_t_a_r_t_f_o_n_t': Object of class '"integer"'  

     '_s_t_a_r_t_g_a_m_m_a': Object of class '"numeric"'  

     '_d_e_v_i_c_e_S_p_e_c_i_f_i_c': Object of class '"raw"'  

     '_d_i_s_p_l_a_y_L_i_s_t_O_n': Object of class '"Rboolean"'  

     '_c_a_n_G_e_n_M_o_u_s_e_D_o_w_n': Object of class '"Rboolean"'  

     '_c_a_n_G_e_n_M_o_u_s_e_M_o_v_e': Object of class '"Rboolean"'  

     '_c_a_n_G_e_n_M_o_u_s_e_U_p': Object of class '"Rboolean"'  

     '_c_a_n_G_e_n_K_e_y_b_d': Object of class '"Rboolean"'  

     '_g_e_t_t_i_n_g_E_v_e_n_t': Object of class '"Rboolean"'  

     '_h_a_s_T_e_x_t_U_T_F_8': Object of class '"Rboolean"'  

     '_w_a_n_t_S_y_m_b_o_l_U_T_F_8': Object of class '"Rboolean"'  

     '_u_s_e_R_o_t_a_t_e_d_T_e_x_t_I_n_C_o_n_t_o_u_r': Object of class '"Rboolean"'  

_E_x_t_e_n_d_s:

     Class '"CStruct-class"', directly.

_M_e_t_h_o_d_s:


     "[[" 'signature(x = "DevDescPtr")': these methods allow one to
          query and set the values of the individual fiels

     "$" 'signature(x = "DevDescPtr")': 

     "[[<-" 'signature(x = "DevDescPtr")': 

     "$<-" 'signature(x = "DevDescPtr")': 

     "_a_s" 'signature(x = "DevDescPtr")': this method allows us to
          convert the C-level reference to an R-level 'DevDesc' object
          using regular coercion, i.e. 'as(dev, "DevDesc")'.        

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

     Duncan Temple Lang

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

     The R Internals Manual, R Development Core Team.

_S_e_e _A_l_s_o:

     'graphicsDevice'

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

     showClass("DevDesc")

