source: mainline/uspace/lib/fmtutil/fmtutil.c@ a35b458

/*
 * Copyright (c) 2011 Martin Sucha
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <io/console.h>
#include <errno.h>
#include <fmtutil.h>
#include <stdlib.h>
#include <str.h>

typedef struct {
        align_mode_t alignment;
        bool newline_always;
        size_t width;
} printmode_t;

errno_t print_wrapped_console(const char *str, align_mode_t alignment)
{
        console_ctrl_t *console = console_init(stdin, stdout);
        if (console == NULL) {
                printf("%s", str);
                return EOK;
        }
        sysarg_t con_rows, con_cols, con_col, con_row;
        errno_t rc = console_get_size(console, &con_cols, &con_rows);
        if (rc != EOK) {
                return rc;
        }
        rc = console_get_pos(console, &con_col, &con_row);
        if (rc != EOK) {
                return rc;
        }
        if (con_col != 0) {
                printf("\n");
        }
        return print_wrapped(str, con_cols, alignment);
}

/** Line consumer that prints the lines aligned according to spec
 *
 **/
static errno_t print_line(wchar_t *wstr, size_t chars, bool last, void *data)
{
        printmode_t *pm = (printmode_t *) data;
        wchar_t old_char = wstr[chars];
        wstr[chars] = 0;
        errno_t rc = print_aligned_w(wstr, pm->width, last, pm->alignment);
        wstr[chars] = old_char;
        return rc;
}

errno_t print_wrapped(const char *str, size_t width, align_mode_t mode)
{
        printmode_t pm;
        pm.alignment = mode;
        pm.newline_always = false;
        pm.width = width;
        wchar_t *wstr = str_to_awstr(str);
        if (wstr == NULL) {
                return ENOMEM;
        }
        errno_t rc = wrap(wstr, width, print_line, &pm);
        free(wstr);
        return rc;
}

errno_t print_aligned_w(const wchar_t *wstr, size_t width, bool last,
    align_mode_t mode)
{
        size_t i;
        size_t len = wstr_length(wstr);
        if (mode == ALIGN_LEFT || (mode == ALIGN_JUSTIFY && last)) {
                for (i = 0; i < width; i++) {
                        if (i < len)
                                putchar(wstr[i]);
                        else
                                putchar(' ');
                }
        }
        else if (mode == ALIGN_RIGHT) {
                for (i = 0; i < width; i++) {
                        if (i < width - len)
                                putchar(' ');
                        else
                                putchar(wstr[i- (width - len)]);
                }
        }
        else if (mode == ALIGN_CENTER) {
                size_t padding = (width - len) / 2;
                for (i = 0; i < width; i++) {
                        if ((i < padding) || ((i - padding) >= len))
                                putchar(' ');
                        else
                                putchar(wstr[i-padding]);
                }
        }
        else if (mode == ALIGN_JUSTIFY) {
                size_t words = 0;
                size_t word_chars = 0;
                bool space = true;
                for (i = 0; i < len; i++) {
                        if (space && wstr[i] != ' ') {
                                words++;
                        }
                        space = wstr[i] == ' ';
                        if (!space) word_chars++;
                }
                size_t done_words = 0;
                size_t done_chars = 0;
                if (words == 0)
                        goto skip_words;
                size_t excess_spaces = width - word_chars - (words-1);
                space = true;
                i = 0;
                size_t j;
                while (i < len) {
                        /* Find a word */
                        while (i < len && wstr[i] == ' ') i++;
                        if (i == len) break;
                        if (done_words) {
                                size_t spaces = 1 + (((done_words *
                                    excess_spaces) / (words - 1)) -
                                    (((done_words - 1) * excess_spaces) /
                                    (words - 1)));
                                for (j = 0; j < spaces; j++) {
                                        putchar(' ');
                                }
                                done_chars += spaces;
                        }
                        while (i < len && wstr[i] != ' ') {
                                putchar(wstr[i++]);
                                done_chars++;
                        }
                        done_words++;
                }
skip_words:
                while (done_chars < width) {
                        putchar(' ');
                        done_chars++;
                }
        }
        else {
                return EINVAL;
        }

        return EOK;
}
errno_t print_aligned(const char *str, size_t width, bool last, align_mode_t mode)
{
        wchar_t *wstr = str_to_awstr(str);
        if (wstr == NULL) {
                return ENOMEM;
        }
        errno_t rc = print_aligned_w(wstr, width, last, mode);
        free(wstr);
        return rc;
}

errno_t wrap(wchar_t *wstr, size_t width, line_consumer_fn consumer, void *data)
{
        size_t word_start = 0;
        size_t last_word_end = 0;
        size_t line_start = 0;
        size_t line_len = 0;
        size_t pos = 0;

        /*
         * Invariants:
         *  * line_len = last_word_end - line_start
         *  * line_start <= last_word_end <= word_start <= pos
         */

        while (wstr[pos] != 0) {
                /* Skip spaces and process newlines */
                while (wstr[pos] == ' ' || wstr[pos] == '\n') {
                        if (wstr[pos] == '\n') {
                                consumer(wstr + line_start, line_len, true,
                                    data);
                                last_word_end = line_start = pos + 1;
                                line_len = 0;
                        }
                        pos++;
                }
                word_start = pos;
                /* Find end of word */
                while (wstr[pos] != 0 && wstr[pos] != ' ' &&
                    wstr[pos] != '\n')
                        pos++;
                bool last = wstr[pos] == 0;
                /* Check if the line still fits width */
                if (pos - line_start > width) {
                        if (line_len > 0)
                                consumer(wstr + line_start, line_len, last,
                                    data);
                        line_start = last_word_end = word_start;
                        line_len = 0;
                }
                /* Check if we need to force wrap of long word*/
                if (pos - word_start > width) {
                        consumer(wstr + word_start, width, last, data);
                        pos = line_start = last_word_end = word_start + width;
                        line_len = 0;
                }
                last_word_end = pos;
                line_len = last_word_end - line_start;
        }
        /* Here we have less than width chars starting from line_start.
         * Moreover, the last portion does not contain spaces or newlines
         */
        if (pos - line_start > 0)
                consumer(wstr + line_start, pos - line_start, true, data);

        return EOK;
}