kernel - Fix races created by a comedy of circumstansces (3)

[dragonfly.git] / contrib / dialog / guage.c

/*
 *  $Id: guage.c,v 1.69 2015/02/26 02:07:12 tom Exp $
 *
 *  guage.c -- implements the gauge dialog
 *
 *  Copyright 2000-2013,2015    Thomas E. Dickey
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU Lesser General Public License, version 2.1
 *  as published by the Free Software Foundation.
 *
 *  This program is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this program; if not, write to
 *      Free Software Foundation, Inc.
 *      51 Franklin St., Fifth Floor
 *      Boston, MA 02110, USA.
 *
 *  An earlier version of this program lists as authors
 *      Marc Ewing, Red Hat Software
 */

#include <dialog.h>

#include <errno.h>

#define MY_LEN (MAX_LEN)/2

#define MIN_HIGH (4)
#define MIN_WIDE (10 + 2 * (2 + MARGIN))

#define isMarker(buf) !strncmp(buf, "XXX", (size_t) 3)

typedef struct _my_obj {
    DIALOG_CALLBACK obj;        /* has to be first in struct */
    struct _my_obj *next;
    WINDOW *text;
    char *title;
    char *prompt;
    char prompt_buf[MY_LEN];
    int percent;
    int height;
    int width;
    char line[MAX_LEN + 1];
} MY_OBJ;

static MY_OBJ *all_objects;

static int
valid(MY_OBJ * obj)
{
    MY_OBJ *list = all_objects;
    int result = 0;

    while (list != 0) {
        if (list == obj) {
            result = 1;
            break;
        }
        list = list->next;
    }
    return result;
}

static void
delink(MY_OBJ * obj)
{
    MY_OBJ *p = all_objects;
    MY_OBJ *q = 0;
    while (p != 0) {
        if (p == obj) {
            if (q != 0) {
                q->next = p->next;
            } else {
                all_objects = p->next;
            }
            break;
        }
        q = p;
        p = p->next;
    }
}

static int
read_data(char *buffer, FILE *fp)
{
    int result;

    if (feof(fp)) {
        result = 0;
    } else if (fgets(buffer, MY_LEN, fp) != 0) {
        DLG_TRACE(("read_data:%s", buffer));
        buffer[MY_LEN] = '\0';
        dlg_trim_string(buffer);
        result = 1;
    } else {
        result = -1;
    }
    return result;
}

static int
decode_percent(char *buffer)
{
    char *tmp = 0;
    long value = strtol(buffer, &tmp, 10);

    if (tmp != 0 && (*tmp == 0 || isspace(UCH(*tmp))) && value >= 0) {
        return TRUE;
    }
    return FALSE;
}

static void
repaint_text(MY_OBJ * obj)
{
    WINDOW *dialog = obj->obj.win;
    int i, x;

    if (dialog != 0) {
        (void) werase(dialog);
        dlg_draw_box2(dialog, 0, 0, obj->height, obj->width, dialog_attr,
                      border_attr, border2_attr);

        dlg_draw_title(dialog, obj->title);

        (void) wattrset(dialog, dialog_attr);
        dlg_draw_helpline(dialog, FALSE);
        dlg_print_autowrap(dialog, obj->prompt, obj->height, obj->width);

        dlg_draw_box2(dialog,
                      obj->height - 4, 2 + MARGIN,
                      2 + MARGIN, obj->width - 2 * (2 + MARGIN),
                      dialog_attr,
                      border_attr,
                      border2_attr);

        /*
         * Clear the area for the progress bar by filling it with spaces
         * in the gauge-attribute, and write the percentage with that
         * attribute.
         */
        (void) wmove(dialog, obj->height - 3, 4);
        (void) wattrset(dialog, gauge_attr);

        for (i = 0; i < (obj->width - 2 * (3 + MARGIN)); i++)
            (void) waddch(dialog, ' ');

        (void) wmove(dialog, obj->height - 3, (obj->width / 2) - 2);
        (void) wprintw(dialog, "%3d%%", obj->percent);

        /*
         * Now draw a bar in reverse, relative to the background.
         * The window attribute was useful for painting the background,
         * but requires some tweaks to reverse it.
         */
        x = (obj->percent * (obj->width - 2 * (3 + MARGIN))) / 100;
        if ((gauge_attr & A_REVERSE) != 0) {
            wattroff(dialog, A_REVERSE);
        } else {
            (void) wattrset(dialog, A_REVERSE);
        }
        (void) wmove(dialog, obj->height - 3, 4);
        for (i = 0; i < x; i++) {
            chtype ch2 = winch(dialog);
            if (gauge_attr & A_REVERSE) {
                ch2 &= ~A_REVERSE;
            }
            (void) waddch(dialog, ch2);
        }

        (void) wrefresh(dialog);
    }
}

static bool
handle_input(DIALOG_CALLBACK * cb)
{
    MY_OBJ *obj = (MY_OBJ *) cb;
    bool result;
    int status;
    char buf[MY_LEN + 1];

    if (dialog_state.pipe_input == 0) {
        status = -1;
        delink(obj);
        dlg_remove_callback(cb);
    } else if ((status = read_data(buf, dialog_state.pipe_input)) > 0) {

        if (isMarker(buf)) {
            /*
             * Historically, next line should be percentage, but one of the
             * worse-written clones of 'dialog' assumes the number is missing.
             * (Gresham's Law applied to software).
             */
            if ((status = read_data(buf, dialog_state.pipe_input)) > 0) {

                obj->prompt_buf[0] = '\0';
                if (decode_percent(buf))
                    obj->percent = atoi(buf);
                else
                    strcpy(obj->prompt_buf, buf);

                /* Rest is message text */
                while ((status = read_data(buf, dialog_state.pipe_input)) > 0
                       && !isMarker(buf)) {
                    if (strlen(obj->prompt_buf) + strlen(buf) <
                        sizeof(obj->prompt_buf) - 1) {
                        strcat(obj->prompt_buf, buf);
                    }
                }

                if (obj->prompt != obj->prompt_buf)
                    free(obj->prompt);
                obj->prompt = obj->prompt_buf;
            }
        } else if (decode_percent(buf)) {
            obj->percent = atoi(buf);
        }
    } else {
        if (feof(dialog_state.pipe_input) ||
            (ferror(dialog_state.pipe_input) && errno != EINTR)) {
            delink(obj);
            dlg_remove_callback(cb);
        }
    }

    if (status > 0) {
        result = TRUE;
        repaint_text(obj);
    } else {
        repaint_text(obj);
        result = FALSE;
    }

    return result;
}

static bool
handle_my_getc(DIALOG_CALLBACK * cb, int ch, int fkey, int *result)
{
    int status = TRUE;

    *result = DLG_EXIT_OK;
    if (cb != 0) {
        if (!fkey && (ch == ERR)) {
            (void) handle_input(cb);
            /* cb might be freed in handle_input */
            status = (valid((MY_OBJ *) cb) && (cb->input != 0));
        }
    } else {
        status = FALSE;
    }
    return status;
}

static void
my_cleanup(DIALOG_CALLBACK * cb)
{
    MY_OBJ *obj = (MY_OBJ *) cb;

    if (valid(obj)) {
        if (obj->prompt != obj->prompt_buf) {
            free(obj->prompt);
            obj->prompt = obj->prompt_buf;
        }
        delink(obj);
    }
}

void
dlg_update_gauge(void *objptr, int percent)
{
    MY_OBJ *obj = (MY_OBJ *) objptr;
    bool save_finish_string = dialog_state.finish_string;

    dialog_state.finish_string = TRUE;
    curs_set(0);
    obj->percent = percent;
    repaint_text(obj);
    dialog_state.finish_string = save_finish_string;
}

/*
 * (Re)Allocates an object and fills it as per the arguments
 */
void *
dlg_reallocate_gauge(void *objptr,
                     const char *title,
                     const char *cprompt,
                     int height,
                     int width,
                     int percent)
{
    char *prompt = dlg_strclone(cprompt);
    MY_OBJ *obj = objptr;
    bool save_finish_string = dialog_state.finish_string;

    dialog_state.finish_string = TRUE;
    dlg_tab_correct_str(prompt);

    if (objptr == 0) {
        /* create a new object */
        obj = dlg_calloc(MY_OBJ, 1);
        assert_ptr(obj, "dialog_gauge");

        dlg_auto_size(title, prompt, &height, &width, MIN_HIGH, MIN_WIDE);
        dlg_print_size(height, width);
        dlg_ctl_size(height, width);

    } else {
        /* reuse an existing object */
        obj = objptr;
        height = obj->height;
        width = obj->width;
    }

    if (obj->obj.win == 0) {
        /* center dialog box on screen */
        int x = dlg_box_x_ordinate(width);
        int y = dlg_box_y_ordinate(height);
        WINDOW *dialog = dlg_new_window(height, width, y, x);
        obj->obj.win = dialog;
    }

    obj->obj.input = dialog_state.pipe_input;
    obj->obj.keep_win = TRUE;
    obj->obj.bg_task = TRUE;
    obj->obj.handle_getc = handle_my_getc;
    obj->obj.handle_input = handle_input;

    if (obj->title == 0 || strcmp(obj->title, title)) {
        dlg_finish_string(obj->title);
        free(obj->title);
        obj->title = dlg_strclone(title);
    }

    dlg_finish_string(obj->prompt);
    free(obj->prompt);

    obj->prompt = prompt;
    obj->percent = percent;
    obj->height = height;
    obj->width = width;

    /* if this was a new object, link it into the list */
    if (objptr == 0) {
        obj->next = all_objects;
        all_objects = obj;
    }

    dialog_state.finish_string = save_finish_string;
    return (void *) obj;
}

void *
dlg_allocate_gauge(const char *title,
                   const char *cprompt,
                   int height,
                   int width,
                   int percent)
{
    return dlg_reallocate_gauge(NULL, title, cprompt, height, width, percent);
}

void
dlg_free_gauge(void *objptr)
{
    MY_OBJ *obj = (MY_OBJ *) objptr;

    curs_set(1);
    if (valid(obj)) {
        delink(obj);
        obj->obj.keep_win = FALSE;
        dlg_remove_callback(&(obj->obj));
    }
}

/*
 * Display a gauge, or progress meter.  Starts at percent% and reads stdin.  If
 * stdin is not XXX, then it is interpreted as a percentage, and the display is
 * updated accordingly.  Otherwise the next line is the percentage, and
 * subsequent lines up to another XXX are used for the new prompt.  Note that
 * the size of the window never changes, so the prompt can not get any larger
 * than the height and width specified.
 */
int
dialog_gauge(const char *title,
             const char *cprompt,
             int height,
             int width,
             int percent)
{
    int fkey;
    int ch, result;
    void *objptr = dlg_allocate_gauge(title, cprompt, height, width, percent);
    MY_OBJ *obj = (MY_OBJ *) objptr;

    dlg_add_callback_ref((DIALOG_CALLBACK **) & obj, my_cleanup);
    dlg_update_gauge(obj, percent);

    dlg_trace_win(obj->obj.win);
    do {
        ch = dlg_getc(obj->obj.win, &fkey);
#ifdef KEY_RESIZE
        if (fkey && ch == KEY_RESIZE) {
            MY_OBJ *oldobj = obj;

            dlg_mouse_free_regions();

            obj = dlg_allocate_gauge(title,
                                     cprompt,
                                     height,
                                     width,
                                     oldobj->percent);

            /* avoid breaking new window in dlg_remove_callback */
            oldobj->obj.caller = 0;
            oldobj->obj.input = 0;
            oldobj->obj.keep_win = FALSE;

            /* remove the old version of the gauge */
            dlg_clear();
            dlg_remove_callback(&(oldobj->obj));
            refresh();

            dlg_add_callback_ref((DIALOG_CALLBACK **) & obj, my_cleanup);
            dlg_update_gauge(obj, obj->percent);
        }
#endif
    }
    while (valid(obj) && handle_my_getc(&(obj->obj), ch, fkey, &result));

    dlg_free_gauge(obj);

    return (DLG_EXIT_OK);
}