TextDisplay.h

00001 /* mbed TextDisplay Library Base Class
00002  * Copyright (c) 2007-2009 sford
00003  * Released under the MIT License: http://mbed.org/license/mit
00004  *
00005  * A common base class for Text displays
00006  * To port a new display, derive from this class and implement
00007  * the constructor (setup the display), character (put a character
00008  * at a location), rows and columns (number of rows/cols) functions.
00009  * Everything else (locate, printf, putc, cls) will come for free
00010  *
00011  * The model is the display will wrap at the right and bottom, so you can
00012  * keep writing and will always get valid characters. The location is 
00013  * maintained internally to the class to make this easy
00014  */
00015 
00016 #ifndef MBED_TEXTDISPLAY_H
00017 #define MBED_TEXTDISPLAY_H
00018 
00019 #include "../screen/LCDSettings.h"
00020 #include "mbed.h"
00021 
00022 class TextDisplay {
00023 public:
00024 
00025   // functions needing implementation in derived implementation class
00026   /** Create a TextDisplay interface
00027      *
00028      * @param name The name used in the path to access the strean through the filesystem
00029      */
00030     TextDisplay(const char *name = NULL);
00031 
00032     /** output a character at the given position
00033      *
00034      * @param column column where charater must be written
00035      * @param  row where character must be written
00036      * @param c the character to be written to the TextDisplay
00037      */
00038     virtual void character(int column, int row, int c) = 0;
00039 
00040     /** return number if rows on TextDisplay
00041      * @result number of rows
00042      */
00043     virtual int rows() = 0;
00044 
00045     /** return number if columns on TextDisplay
00046     * @result number of rows
00047     */
00048     virtual int columns() = 0;
00049     
00050     // Sets external font usage, eg. dispaly.set_font(Arial12x12);
00051     // This uses pixel positioning.
00052     // display.set_font(NULL); returns to internal default font.
00053     void set_font(const unsigned char * f);
00054     
00055     // set position of the next character or string print.
00056     // External font, set pixel x(column),y(row) position.
00057     // internal(default) font, set character column and row position 
00058     virtual void locate(int column, int row);
00059     
00060     // functions that come for free, but can be overwritten
00061 
00062     /** clear screen
00063     */
00064     virtual void cls();
00065     virtual void foreground(uint16_t colour);
00066     virtual void background(uint16_t colour);
00067     // putc (from Stream)
00068     // printf (from Stream)
00069     virtual void printf(const char* format, ...);
00070     
00071 protected:
00072 
00073     virtual int _putc(int value);
00074     virtual int _getc();
00075     
00076     // external font functions
00077     const unsigned char* font;
00078     int externalfont;
00079  
00080     // character location
00081     uint16_t _column;
00082     uint16_t _row;
00083     unsigned int char_x;
00084     unsigned int char_y;
00085 
00086     // colours
00087     uint16_t _foreground;
00088     uint16_t _background;
00089     char *_path;
00090 };
00091 
00092 #endif