labels.c

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/*************************************************************************
 * Copyright (c) 2011 AT&T Intellectual Property 
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors: Details at https://graphviz.org
 *************************************************************************/
 
#include <common/render.h>
#include <common/htmltable.h>
#include <limits.h>
#include <stdbool.h>
#include <stddef.h>
#include <util/agxbuf.h>
#include <util/alloc.h>
#include <util/streq.h>
 
static char *strdup_and_subst_obj0 (char *str, void *obj, int escBackslash);
 
static void storeline(GVC_t *gvc, textlabel_t *lp, char *line,
                      char terminator) {
    pointf size;
    textspan_t *span;
    size_t oldsz = lp->u.txt.nspans + 1;
 
    lp->u.txt.span = gv_recalloc(lp->u.txt.span, oldsz, oldsz + 1,
                                 sizeof(textspan_t));
    span = &lp->u.txt.span[lp->u.txt.nspans];
    span->str = line;
    span->just = terminator;
    if (line && line[0]) {
        textfont_t tf = {0};
        tf.name = lp->fontname;
        tf.size = lp->fontsize;
        span->font = dtinsert(gvc->textfont_dt, &tf);
        size = textspan_size(gvc, span);
    }
    else {
        size.x = 0.0;
        span->size.y = size.y = (int)(lp->fontsize * LINESPACING);
    }
 
    lp->u.txt.nspans++;
    /* width = max line width */
    lp->dimen.x = MAX(lp->dimen.x, size.x);
    /* accumulate height */
    lp->dimen.y += size.y;
}
 
/* compiles <str> into a label <lp> */
void make_simple_label(GVC_t * gvc, textlabel_t * lp)
{
    lp->dimen.x = lp->dimen.y = 0.0;
    if (*lp->text == '\0')
        return;
 
    agxbuf line = {0};
    for (char c, *p = lp->text; (c = *p++);) {
        unsigned char byte = (unsigned char) c;
        /* wingraphviz allows a combination of ascii and big-5. The latter
         * is a two-byte encoding, with the first byte in 0xA1-0xFE, and
         * the second in 0x40-0x7e or 0xa1-0xfe. We assume that the input
         * is well-formed, but check that we don't go past the ending '\0'.
         */
        if (lp->charset == CHAR_BIG5 && 0xA1 <= byte && byte <= 0xFE) {
            agxbputc(&line, c);
            c = *p++;
            agxbputc(&line, c);
            if (!c) /* NB. Protect against unexpected string end here */
                break;
        } else {
            if (c == '\\') {
                switch (*p) {
                case 'n':
                case 'l':
                case 'r':
                    storeline(gvc, lp, agxbdisown(&line), *p);
                    break;
                default:
                    agxbputc(&line, *p);
                }
                if (*p)
                    p++;
                /* tcldot can enter real linend characters */
            } else if (c == '\n') {
                storeline(gvc, lp, agxbdisown(&line), 'n');
            } else {
                agxbputc(&line, c);
            }
        }
    }
 
    if (agxblen(&line) > 0) {
        storeline(gvc, lp, agxbdisown(&line), 'n');
    }
 
    agxbfree(&line);
    lp->space = lp->dimen;
}
 
/* Assume str is freshly allocated for this instance, so it
 * can be freed in free_label.
 */
textlabel_t *make_label(void *obj, char *str, bool is_html, bool is_record,
                        double fontsize, char *fontname, char *fontcolor) {
    textlabel_t *rv = gv_alloc(sizeof(textlabel_t));
    graph_t *g = NULL, *sg = NULL;
    node_t *n = NULL;
    edge_t *e = NULL;
        char *s;
 
    // disregard HTML intent for empty string labels
    is_html &= !streq(str, "");
 
    switch (agobjkind(obj)) {
    case AGRAPH:
        sg = obj;
        g = sg->root;
        break;
    case AGNODE:
        n = obj;
        g = agroot(agraphof(n));
        break;
    case AGEDGE:
        e = obj;
        g = agroot(agraphof(aghead(e)));
        break;
    }
    rv->fontname = fontname;
    rv->fontcolor = fontcolor;
    rv->fontsize = fontsize;
    rv->charset = GD_charset(g);
    if (is_record) {
        rv->text = gv_strdup(str);
        if (is_html) {
            rv->html = true;
        }
    }
    else if (is_html) {
        rv->text = gv_strdup(str);
        rv->html = true;
        if (make_html_label(obj, rv)) {
            switch (agobjkind(obj)) {
            case AGRAPH:
                agerr(AGPREV, "in label of graph %s\n",agnameof(sg));
                break;
            case AGNODE:
                agerr(AGPREV, "in label of node %s\n", agnameof(n));
                break;
            case AGEDGE:
                agerr(AGPREV, "in label of edge %s %s %s\n",
                        agnameof(agtail(e)), agisdirected(g)?"->":"--", agnameof(aghead(e)));
                break;
            }
        }
    }
    else {
        assert(!is_record);
        assert(!is_html);
        /* This call just processes the graph object based escape sequences. The formatting escape
         * sequences (\n, \l, \r) are processed in make_simple_label. That call also replaces \\ with \.
         */
        rv->text = strdup_and_subst_obj0(str, obj, 0);
        switch (rv->charset) {
        case CHAR_LATIN1:
            s = latin1ToUTF8(rv->text);
            break;
        default: /* UTF8 */
            s = htmlEntityUTF8(rv->text, g);
            break;
        }
        free(rv->text);
        rv->text = s;
        make_simple_label(GD_gvc(g), rv);
    }
    return rv;
}
 
/* Free resources related to textspan_t.
 * tl is an array of cnt textspan_t's.
 * It is also assumed that the text stored in the str field
 * is all stored in one large buffer shared by all of the textspan_t,
 * so only the first one needs to free its tlp->str.
 */
void free_textspan(textspan_t *tl, size_t cnt) {
    textspan_t* tlp = tl;
 
    if (!tl) return;
    for (size_t i = 0; i < cnt; i++) {
        free(tlp->str);
        if (tlp->layout && tlp->free_layout)
            tlp->free_layout (tlp->layout);
        tlp++;
    }
    free(tl);
}
 
void free_label(textlabel_t * p)
{
    if (p) {
        free(p->text);
        if (p->html) {
            if (p->u.html) free_html_label(p->u.html, 1);
        } else {
            free_textspan(p->u.txt.span, p->u.txt.nspans);
        }
        free(p);
    }
}
 
void emit_label(GVJ_t * job, emit_state_t emit_state, textlabel_t * lp)
{
    obj_state_t *obj = job->obj;
    pointf p;
    emit_state_t old_emit_state;
 
    old_emit_state = obj->emit_state;
    obj->emit_state = emit_state;
 
    if (lp->html) {
        emit_html_label(job, lp->u.html, lp);
        obj->emit_state = old_emit_state;
        return;
    }
 
    /* make sure that there is something to do */
    if (lp->u.txt.nspans < 1)
        return;
 
    gvrender_begin_label(job, LABEL_PLAIN);
    gvrender_set_pencolor(job, lp->fontcolor);
 
    /* position for first span */
    switch (lp->valign) {
        case 't':
            p.y = lp->pos.y + lp->space.y / 2.0 - lp->fontsize;
            break;
        case 'b':
            p.y = lp->pos.y - lp->space.y / 2.0 + lp->dimen.y - lp->fontsize;
            break;
        case 'c':
        default:        
            p.y = lp->pos.y + lp->dimen.y / 2.0 - lp->fontsize;
            break;
    }
    if (obj->labeledgealigned)
        p.y -= lp->pos.y;
    for (size_t i = 0; i < lp->u.txt.nspans; i++) {
        switch (lp->u.txt.span[i].just) {
        case 'l':
            p.x = lp->pos.x - lp->space.x / 2.0;
            break;
        case 'r':
            p.x = lp->pos.x + lp->space.x / 2.0;
            break;
        default:
        case 'n':
            p.x = lp->pos.x;
            break;
        }
        gvrender_textspan(job, p, &lp->u.txt.span[i]);
 
        /* UL position for next span */
        p.y -= lp->u.txt.span[i].size.y;
    }
 
    gvrender_end_label(job);
    obj->emit_state = old_emit_state;
}
 
/* Replace various escape sequences with the name of the associated
 * graph object. A double backslash \\ can be used to avoid a replacement.
 * If escBackslash is true, convert \\ to \; else leave alone. All other dyads 
 * of the form \. are passed through unchanged.
 */
static char *strdup_and_subst_obj0 (char *str, void *obj, int escBackslash)
{
    char c, *s;
    char *tp_str = "", *hp_str = "";
    char *g_str = "\\G", *n_str = "\\N", *e_str = "\\E",
        *h_str = "\\H", *t_str = "\\T", *l_str = "\\L";
    bool has_hp = false;
    bool has_tp = false;
    int isEdge = 0;
    textlabel_t *tl;
    port pt;
 
    /* prepare substitution strings */
    switch (agobjkind(obj)) {
        case AGRAPH:
            g_str = agnameof(obj);
            tl = GD_label(obj);
            if (tl) {
                l_str = tl->text;
            }
            break;
        case AGNODE:
            g_str = agnameof(agraphof(obj));
            n_str = agnameof(obj);
            tl = ND_label(obj);
            if (tl) {
                l_str = tl->text;
            }
            break;
        case AGEDGE:
            isEdge = 1;
            g_str = agnameof(agroot(agraphof(agtail(((edge_t *)obj)))));
            t_str = agnameof(agtail(((edge_t *)obj)));
            pt = ED_tail_port(obj);
            if ((tp_str = pt.name))
                has_tp = *tp_str != '\0';
            h_str = agnameof(aghead(((edge_t *)obj)));
            pt = ED_head_port(obj);
            if ((hp_str = pt.name))
                has_hp = *hp_str != '\0';
            tl = ED_label(obj);
            if (tl) {
                l_str = tl->text;
            }
            if (agisdirected(agroot(agraphof(agtail(((edge_t*)obj))))))
                e_str = "->";
            else
                e_str = "--";
            break;
    }
 
    /* allocate a dynamic buffer that we will use to construct the result */
    agxbuf buf = {0};
 
    /* assemble new string */
    for (s = str; (c = *s++);) {
        if (c == '\\' && *s != '\0') {
            switch (c = *s++) {
            case 'G':
                agxbput(&buf, g_str);
                break;
            case 'N':
                agxbput(&buf, n_str);
                break;
            case 'E':
                if (isEdge) {
                    agxbput(&buf, t_str);
                    if (has_tp) {
                        agxbprint(&buf, ":%s", tp_str);
                    }
                    agxbprint(&buf, "%s%s", e_str, h_str);
                    if (has_hp) {
                        agxbprint(&buf, ":%s", hp_str);
                    }
                }
                break;
            case 'T':
                agxbput(&buf, t_str);
                break;
            case 'H':
                agxbput(&buf, h_str);
                break;
            case 'L':
                agxbput(&buf, l_str);
                break;
            case '\\':
                if (escBackslash) {
                    agxbputc(&buf, '\\');
                    break; 
                }
                /* Fall through */
            default:  /* leave other escape sequences unmodified, e.g. \n \l \r */
                agxbprint(&buf, "\\%c", c);
                break;
            }
        } else {
            agxbputc(&buf, c);
        }
    }
 
    /* extract the final string with replacements applied */
    return agxbdisown(&buf);
}
 
char *strdup_and_subst_obj(char *str, void *obj)
{
    return strdup_and_subst_obj0 (str, obj, 1);
}