slk.c

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#include <curses.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include "mucurses.h"
#include "cursor.h"

/** @file
 *
 * Soft label key functions
 */

#define MIN_SPACE_SIZE 2

#define SLK_MAX_LABEL_LEN 8

#define SLK_MAX_NUM_LABELS 12

#define SLK_MAX_NUM_SPACES 2

struct _softlabel {
        // label string
        char label[SLK_MAX_LABEL_LEN];
        /* Format of soft label 
           0: left justify
           1: centre justify
           2: right justify
         */
        unsigned int fmt;
};

struct _softlabelkeys {
        struct _softlabel fkeys[SLK_MAX_NUM_LABELS];
        attr_t attrs;
        /* Soft label layout format
           0: 3-2-3
           1: 4-4
           2: 4-4-4
           3: 4-4-4 with index line
        */
        unsigned int fmt;
        unsigned int max_label_len;
        unsigned int maj_space_len;
        unsigned int num_labels;
        unsigned int num_spaces;
        unsigned int spaces[SLK_MAX_NUM_SPACES];
        struct cursor_pos saved_cursor;
        attr_t saved_attrs;
        short saved_pair;
};

static struct _softlabelkeys *slks;

/*
  I either need to break the primitives here, or write a collection of
  functions specifically for SLKs that directly access the screen
  functions - since this technically isn't part of stdscr, I think
  this should be ok...
 */

static void _enter_slk ( void ) {
        _store_curs_pos ( stdscr, &slks->saved_cursor );
        wattr_get ( stdscr, &slks->saved_attrs, &slks->saved_pair, NULL );
        LINES++;
        wmove ( stdscr, LINES, 0 );
        wattrset ( stdscr, slks->attrs );
}

static void _leave_slk ( void ) {
        LINES--;
        wattr_set ( stdscr, slks->saved_attrs, slks->saved_pair, NULL );
        _restore_curs_pos ( stdscr, &slks->saved_cursor );
}

static void _print_label ( struct _softlabel sl ) {
        int space_ch;
        char str[SLK_MAX_LABEL_LEN + 1];

        assert ( slks->max_label_len <= SLK_MAX_LABEL_LEN );
        space_ch = ' ';

        // protect against gaps in the soft label keys array
        if ( sl.label == NULL ) {
                memset( str, space_ch, (size_t)(slks->max_label_len) );
        } else {
                /* we need to pad the label with varying amounts of leading
                   pad depending on the format of the label */
                if ( sl.fmt == 1 ) {
                        memset( str, space_ch, 
                                (size_t)(slks->max_label_len 
                                         - strlen(sl.label)) / 2 );
                }
                if ( sl.fmt == 2 ) {
                        memset( str, space_ch,
                                (size_t)(slks->max_label_len 
                                         - strlen(sl.label)) );
                }
                strcat(str,sl.label);
                
                // post-padding
                memset(str+strlen(str), space_ch,
                       (size_t)(slks->max_label_len - strlen(str)) );
        }

        // print the formatted label
        _wputstr ( stdscr, str, NOWRAP, slks->max_label_len );
}

/**
 * Return the attribute used for the soft function keys
 *
 * @ret attrs   the current attributes of the soft function keys
 */
attr_t slk_attr ( void ) {
        return ( slks == NULL ? 0 : slks->attrs );
}

/**
 * Turn off soft function key attributes
 *
 * @v attrs     attribute bit mask
 * @ret rc      return status code
 */
int slk_attroff ( const chtype attrs ) {
        if ( slks == NULL ) 
                return ERR;
        slks->attrs &= ~( attrs & A_ATTRIBUTES );
        return OK;
}

/**
 * Turn on soft function key attributes
 *
 * @v attrs     attribute bit mask
 * @ret rc      return status code
 */
int slk_attron ( const chtype attrs ) {
        if ( slks == NULL )
                return ERR;
        slks->attrs |= ( attrs & A_ATTRIBUTES );
        return OK;
}

/**
 * Set soft function key attributes
 *
 * @v attrs     attribute bit mask
 * @ret rc      return status code
 */
int slk_attrset ( const chtype attrs ) {
        if ( slks == NULL ) 
                return ERR;
        slks->attrs = ( attrs & A_ATTRIBUTES );
        return OK;
}

/**
 * Turn off soft function key attributes
 *
 * @v attrs     attribute bit mask
 * @v *opts     undefined (for future implementation)
 * @ret rc      return status code
 */
int slk_attr_off ( const attr_t attrs, void *opts __unused ) {
        return slk_attroff( attrs );
}

/**
 * Turn on soft function key attributes
 *
 * @v attrs     attribute bit mask
 * @v *opts     undefined (for future implementation)
 * @ret rc      return status code
 */
int slk_attr_on ( attr_t attrs, void *opts __unused ) {
        return slk_attron( attrs );
}

/**
 * Set soft function key attributes
 *
 * @v attrs                     attribute bit mask
 * @v colour_pair_number        colour pair integer
 * @v *opts                     undefined (for future implementation)
 * @ret rc                      return status code
 */
int slk_attr_set ( const attr_t attrs, short colour_pair_number,
                   void *opts __unused ) {
        if ( slks == NULL ) 
                return ERR;

        if ( ( unsigned short )colour_pair_number > COLORS )
                return ERR;

        slks->attrs = ( (unsigned short)colour_pair_number << CPAIR_SHIFT ) |
                ( attrs & A_ATTRIBUTES );
        return OK;
}

/**
 * Clear the soft function key labels from the screen
 *
 * @ret rc      return status code
 */
int slk_clear ( void ) {
        if ( slks == NULL )
                return ERR;

        _enter_slk();
        wclrtoeol ( stdscr );
        _leave_slk();

        return OK;
}

/**
 * Set soft label colour pair
 */
int slk_colour ( short colour_pair_number ) {
        if ( slks == NULL ) 
                return ERR;
        if ( ( unsigned short )colour_pair_number > COLORS )
                return ERR;

        slks->attrs = ( (unsigned short)colour_pair_number << CPAIR_SHIFT )
                | ( slks->attrs & A_ATTRIBUTES );

        return OK;
}

/**
 * Initialise the soft function keys
 *
 * @v fmt       format of keys
 * @ret rc      return status code
 */
int slk_init ( int fmt ) {
        unsigned short nmaj, nmin, nblocks, available_width;

        if ( (unsigned)fmt > 3 ) {
                return ERR;
        }

        /* There seems to be no API call to free this data structure... */
        if ( ! slks )
                slks = calloc(1,sizeof(*slks));
        if ( ! slks )
                return ERR;

        slks->attrs = A_DEFAULT;
        slks->fmt = fmt;
        switch(fmt) {
        case 0:
                nblocks = 8; nmaj = 2; nmin = 5;
                slks->spaces[0] = 2; slks->spaces[1] = 4;
                break;
        case 1:
                nblocks = 8; nmaj = 1; nmin = 6;
                slks->spaces[0] = 3;
                break;
        case 2:
                // same allocations as format 3
        case 3:
                nblocks = 12; nmaj = 2; nmin = 9;
                slks->spaces[0] = 3; slks->spaces[1] = 7;
                break;
        default:
                nblocks = 0; nmaj = 0; nmin = 0;
                break;
        }

        // determine maximum label length and major space size
        available_width = COLS - ( ( MIN_SPACE_SIZE * nmaj ) + nmin );
        slks->max_label_len = available_width / nblocks;
        slks->maj_space_len = MIN_SPACE_SIZE + 
                ( available_width % nblocks ) / nmaj;
        slks->num_spaces = nmaj;
        slks->num_labels = nblocks;

        // strip a line from the screen
        LINES -= 1;

        return OK;
}

/**
 * Return the label for the specified soft key
 *
 * @v labnum    soft key identifier
 * @ret label   return label
 */
char* slk_label ( int labnum ) {
        if ( slks == NULL ) 
                return NULL;

        return slks->fkeys[labnum].label;
}

/**
 * Restore soft function key labels to the screen
 *
 * @ret rc      return status code
 */
int slk_restore ( void ) {
        unsigned int i, j, pos_x,
                *next_space, *last_space;
        chtype space_ch;

        if ( slks == NULL )
                return ERR;

        pos_x = 0;

        _enter_slk();

        space_ch = (chtype)' ' | slks->attrs;
        next_space = &(slks->spaces[0]);
        last_space = &(slks->spaces[slks->num_spaces-1]);

        for ( i = 0; i < slks->num_labels ; i++ ) {
                _print_label( slks->fkeys[i] );
                pos_x += slks->max_label_len;

                if ( i == *next_space ) {
                        for ( j = 0; j < slks->maj_space_len; j++, pos_x++ )
                                _wputch ( stdscr, space_ch, NOWRAP );
                        if ( next_space < last_space )
                                next_space++;
                } else {
                        if ( pos_x < COLS )
                                _wputch ( stdscr, space_ch, NOWRAP );
                        pos_x++;
                }
        }

        _leave_slk();

        return OK;
}

/**
 * Configure specified soft key
 *
 * @v labnum    soft label position to configure
 * @v *label    string to use as soft key label
 * @v fmt       justification format of label
 * @ret rc      return status code
 */
int slk_set ( int labnum, const char *label, int fmt ) {
        if ( slks == NULL ) 
                return ERR;
        if ( (unsigned short)labnum >= slks->num_labels )
                return ERR;
        if ( (unsigned short)fmt >= 3 )
                return ERR;

        strncpy(slks->fkeys[labnum].label, label,
                sizeof(slks->fkeys[labnum].label));
        slks->fkeys[labnum].fmt = fmt;

        return OK;
}