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gpt_control.c

/*
 *  Copyright (c) by Allin Cottrell
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   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 General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

/* gpt_control.c for gretl -- gnuplot controller */

#include "gretl.h"
#include "gpt_control.h"
#include "session.h"
#include "gpt_dialog.h"

#undef POINTS_DEBUG

#ifdef G_OS_WIN32
# include <windows.h>
# include <io.h>
#endif

#include <gdk-pixbuf/gdk-pixbuf.h>
#include <gdk/gdkkeysyms.h>

#ifdef PNG_COMMENTS
# include <png.h>
#endif

#if !GLIB_CHECK_VERSION(2,0,0)
# define OLD_GTK
#endif

enum {
    PLOT_SAVED          = 1 << 0,
    PLOT_HAS_CONTROLLER = 1 << 1,
    PLOT_ZOOMED         = 1 << 2,
    PLOT_ZOOMING        = 1 << 3,
    PLOT_NO_MARKERS     = 1 << 4,
    PLOT_PNG_COORDS     = 1 << 5,
    PLOT_DONT_ZOOM      = 1 << 6,
    PLOT_DONT_EDIT      = 1 << 7,
    PLOT_DONT_MOUSE     = 1 << 8,
    PLOT_POSITIONING    = 1 << 9
} plot_status_flags;

enum {
    PLOT_TITLE          = 1 << 0,
    PLOT_XLABEL         = 1 << 1,
    PLOT_YLABEL         = 1 << 2,
    PLOT_Y2AXIS         = 1 << 3,
    PLOT_Y2LABEL        = 1 << 4,
    PLOT_MARKERS_UP     = 1 << 5,
} plot_format_flags;

#define plot_is_saved(p)        (p->status & PLOT_SAVED)
#define plot_has_controller(p)  (p->status & PLOT_HAS_CONTROLLER)
#define plot_is_zoomed(p)       (p->status & PLOT_ZOOMED)
#define plot_is_zooming(p)      (p->status & PLOT_ZOOMING)
#define plot_has_no_markers(p)  (p->status & PLOT_NO_MARKERS)
#define plot_has_png_coords(p)  (p->status & PLOT_PNG_COORDS)
#define plot_not_zoomable(p)    (p->status & PLOT_DONT_ZOOM)
#define plot_not_editable(p)    (p->status & PLOT_DONT_EDIT)
#define plot_doing_position(p)  (p->status & PLOT_POSITIONING)

#define plot_has_title(p)        (p->format & PLOT_TITLE)
#define plot_has_xlabel(p)       (p->format & PLOT_XLABEL)
#define plot_has_ylabel(p)       (p->format & PLOT_YLABEL)
#define plot_has_y2axis(p)       (p->format & PLOT_Y2AXIS)
#define plot_has_y2label(p)      (p->format & PLOT_Y2LABEL)
#define plot_has_data_markers(p) (p->format & PLOT_MARKERS_UP)

#define plot_is_range_mean(p)   (p->spec->code == PLOT_RANGE_MEAN)

enum {
    PNG_START,
    PNG_ZOOM,
    PNG_UNZOOM,
    PNG_REDISPLAY
} png_zoom_codes;

struct png_zoom_t {
    double xmin, xmax;
    double ymin, ymax;
    int screen_xmin, screen_ymin;
};

struct png_plot_t {
    GtkWidget *shell;
    GtkWidget *canvas;
    GtkWidget *popup;
    GtkWidget *statusarea;    
    GtkWidget *statusbar;
    GtkWidget *cursor_label;
    GtkWidget *labelpos_entry;
    GdkPixmap *pixmap;
    GdkGC *invert_gc;
    GPT_SPEC *spec;
    double xmin, xmax;
    double ymin, ymax;
    int pixel_xmin, pixel_xmax;
    int pixel_ymin, pixel_ymax;
    int xint, yint;
    int pd;
    int err;
    guint cid;
    struct png_zoom_t *zoom;
    unsigned long status; 
    unsigned char format;
#ifndef OLD_GTK
    char *labeled;
#endif
};

static void render_pngfile (png_plot *plot, int view);
static int zoom_unzoom_png (png_plot *plot, int view);
static void create_selection_gc (png_plot *plot);
static int get_plot_ranges (png_plot *plot);

#ifdef G_OS_WIN32
enum {
    WIN32_TO_CLIPBOARD,
    WIN32_TO_PRINTER
};
#endif /* G_OS_WIN32 */

#ifdef PNG_COMMENTS

enum {
    GRETL_PNG_OK,
    GRETL_PNG_NO_OPEN,
    GRETL_PNG_NOT_PNG,
    GRETL_PNG_NO_COMMENTS,
    GRETL_PNG_BAD_COMMENTS,
    GRETL_PNG_NO_COORDS
};

typedef struct png_bounds_t png_bounds;

struct png_bounds_t {
    int xleft;
    int xright;
    int ybot;
    int ytop;
    double xmin;
    double xmax;
    double ymin;
    double ymax;
};

static int get_png_bounds_info (png_bounds *bounds);

#endif /* PNG_COMMENTS */

#define PLOTSPEC_DETAILS_IN_MEMORY(s)  (s->data != NULL)

static void terminate_plot_positioning (png_plot *plot)
{
    plot->status ^= PLOT_POSITIONING;
    plot->labelpos_entry = NULL;
    gdk_window_set_cursor(plot->canvas->window, NULL);
    gtk_statusbar_pop(GTK_STATUSBAR(plot->statusbar), plot->cid);
    raise_gpt_control_window();
}

void plot_remove_controller (png_plot *plot) 
{
    if (plot_has_controller(plot)) {
      plot->status ^= PLOT_HAS_CONTROLLER;
      if (plot_doing_position(plot)) {
          terminate_plot_positioning(plot);
      }
    }
}

int plot_is_mouseable (const png_plot *plot)
{
    return !(plot->status & PLOT_DONT_MOUSE);
}

void set_plot_has_y2_axis (png_plot *plot, gboolean s)
{
    if (s == TRUE) {
      plot->format |= PLOT_Y2AXIS;
    } else {
      plot->format &= ~PLOT_Y2AXIS;
    }
}

void plot_label_position_click (GtkWidget *w, GPT_SPEC *spec)
{
    png_plot *plot = (png_plot *) spec->ptr;

    if (plot != NULL) {
      GtkWidget *entry;
      GdkCursor* cursor;

      cursor = gdk_cursor_new(GDK_CROSSHAIR);
      gdk_window_set_cursor(plot->canvas->window, cursor);
      gdk_cursor_destroy(cursor);
      entry = g_object_get_data(G_OBJECT(w), "labelpos_entry");
      plot->labelpos_entry = entry;
      plot->status |= PLOT_POSITIONING;
      gtk_statusbar_push(GTK_STATUSBAR(plot->statusbar), plot->cid, 
                     _(" Click to set label position"));
    }
}

static void line_to_file (const char *s, FILE *fp, int l2)
{
#ifdef ENABLE_NLS
    if (l2 == -1) {
      print_as_html(s, fp);
    } else if (l2 == 1) {
      print_as_locale(s, fp);
    } else {
      fputs(s, fp);
    }
#else
    fputs(s, fp);
#endif
}

static FILE *open_gp_file (const char *fname, const char *mode)
{
    FILE *fp = gretl_fopen(fname, mode);

    if (fp == NULL) {
      if (*mode == 'w') {
          sprintf(errtext, _("Couldn't write to %s"), fname);
      } else {
          sprintf(errtext, _("Couldn't open %s"), fname);
      }
        errbox(errtext);
    }

    return fp;
}

static int commented_term_line (const char *s)
{
    return !strncmp(s, "# set term png", 14);
}

static int set_output_line (const char *s)
{
    return !strncmp(s, "set output", 10);
}

static int add_or_remove_png_term (const char *fname, int add, GPT_SPEC *spec)
{
    FILE *fsrc, *ftmp;
    char temp[MAXLEN], fline[MAXLEN];
    char restore_line[MAXLEN] = {0};
    int png_line_saved = 0;
#ifdef ENABLE_NLS
    int l2 = use_latin_2();
#else
    int l2 = 0;
#endif

    sprintf(temp, "%sgpttmp.XXXXXX", paths.userdir);
    if (mktemp(temp) == NULL) return 1;

    ftmp = open_gp_file(temp, "w");
    if (ftmp == NULL) return 1;

    fsrc = open_gp_file(fname, "r");
    if (fsrc == NULL) {
      fclose(ftmp);
      return 1;
    }

    if (add && spec == NULL) {
      /* see if there's a commented out term setting to restore */
      while (fgets(fline, sizeof fline, fsrc)) {
          if (commented_term_line(fline)) {
            strcat(restore_line, fline + 2);
            break;
          }
      }
      rewind(fsrc);
    }

    if (add) {
      int need_term_line = 1;

      if (spec == NULL) {
          /* we're reconstituting a session graph from a 
             saved gnuplot command file */
          if (*restore_line) {
            /* found a saved png term specification */
            fputs(restore_line, ftmp);
            need_term_line = 0;
          }
      }
      if (need_term_line) {
          fprintf(ftmp, "%s\n",
                get_gretl_png_term_line(PLOT_REGULAR));
      }         
      fprintf(ftmp, "set output '%sgretltmp.png'\n", 
            paths.userdir);
    }

    /* now for the body of the plot file */
    while (fgets(fline, sizeof fline, fsrc)) {
      if (add) {
          if (!commented_term_line(fline) && !set_output_line(fline)) {
            line_to_file(fline, ftmp, -l2);
          }
      } else {
          /* we're removing the png term line */
          int printit = 1;

          if (!strncmp(fline, "set term png", 12)) {
            if (!png_line_saved) {
                /* comment it out, for future reference */
                fprintf(ftmp, "# %s", fline);
                png_line_saved = 1;
            } 
            printit = 0;
          }
          else if (commented_term_line(fline)) {
            printit = 0;
          } else if (set_output_line(fline)) {
            printit = 0;
          } else if (spec != NULL && (spec->flags & GPTSPEC_OLS_HIDDEN)
                   && is_auto_ols_string(fline)) {
            printit = 0;
          }
          if (printit) {
            line_to_file(fline, ftmp, l2);
          }
      }
    }

    fclose(fsrc);
    fclose(ftmp);

    remove(fname);
    return rename(temp, fname);
}

static int add_png_term_to_plotfile (const char *fname)
{
    return add_or_remove_png_term(fname, 1, NULL);
}

/* public because called from session.c when saving a graph file */

int remove_png_term_from_plotfile (const char *fname, GPT_SPEC *spec)
{
    return add_or_remove_png_term(fname, 0, spec);
}

void mark_plot_as_saved (GPT_SPEC *spec)
{
    png_plot *plot = (png_plot *) spec->ptr;

    plot->status |= PLOT_SAVED;
}

static int gnuplot_png_init (GPT_SPEC *spec, FILE **fpp)
{
    *fpp = gretl_fopen(spec->fname, "w");

    if (*fpp == NULL) {
      sprintf(errtext, _("Couldn't write to %s"), spec->fname);
      errbox(errtext);
      return 1;
    }

    fprintf(*fpp, "%s\n", get_gretl_png_term_line(spec->code));
    fprintf(*fpp, "set output '%sgretltmp.png'\n", paths.userdir);

    return 0;
}

void display_session_graph_png (char *fname) 
{
    char *myfname = fname;
    gchar *plotcmd;
    int err = 0;

    /* take saved plot source file and make PNG from it, then display
       the PNG */
    if (add_png_term_to_plotfile(myfname)) {
      return;
    }

    plotcmd = g_strdup_printf("\"%s\" \"%s\"", paths.gnuplot, myfname);
#ifdef G_OS_WIN32
    err = winfork(plotcmd, NULL, SW_SHOWMINIMIZED, 0);
#else
    err = gretl_spawn(plotcmd);
#endif
    g_free(plotcmd);

    if (err) {
      errbox(_("Gnuplot error creating graph"));
    } else {
      gnuplot_show_png(myfname, NULL, 1);
    }
}

#ifdef G_OS_WIN32
static void win32_process_graph (GPT_SPEC *spec, int color, int dest);
#endif

void save_this_graph (GPT_SPEC *plot, const char *fname)
{
    FILE *fq;
    PRN *prn;
    char plottmp[MAXLEN], plotline[MAXLEN], termstr[MAXLEN];
    gchar *plotcmd = NULL;
    int cmds, err;

    if (!user_fopen("gptout.tmp", plottmp, &prn)) {
      return;
    }

    fq = gretl_fopen(plot->fname, "r");
    if (fq == NULL) {
      errbox(_("Couldn't access graph info"));
      gretl_print_destroy(prn);
      return;
    }
 
    cmds = get_termstr(plot, termstr);
  
    if (cmds) {
      if (copyfile(plot->fname, fname)) { 
          errbox(_("Failed to copy graph file"));
      }
      return;
    } else {
#ifdef ENABLE_NLS
      pprint_gnuplot_encoding(termstr, prn);
#endif /* ENABLE_NLS */
      pprintf(prn, "set term %s\n", termstr);
      pprintf(prn, "set output '%s'\n", fname);
      while (fgets(plotline, MAXLEN-1, fq)) {
          if (strncmp(plotline, "set term", 8) && 
            strncmp(plotline, "set output", 10))
            pputs(prn, plotline);
      }
    }

    gretl_print_destroy(prn);
    fclose(fq);

    plotcmd = g_strdup_printf("\"%s\" \"%s\"", paths.gnuplot, 
                        plottmp);

#ifdef G_OS_WIN32
    err = winfork(plotcmd, NULL, SW_SHOWMINIMIZED, 0);
#else
    err = gretl_spawn(plotcmd);
#endif /* G_OS_WIN32 */

    remove(plottmp);
    g_free(plotcmd);

    if (err) {
      errbox(_("Gnuplot error creating graph"));
    } else {
      infobox(_("Graph saved"));
    }
}

/* chop trailing comma, if present; return 1 if comma chopped,
   zero otherwise */

static int chop_comma (char *str)
{
    size_t i, n = strlen(str);

    for (i=n-1; i>0; i--) {
      if (isspace((unsigned char) str[i])) {
          continue;
      }
      if (str[i] == ',') {
          str[i] = 0;
          return 1;
      } else {
          break;
      }
    }
            
    return 0;
}

static int get_gpt_marker (const char *line, char *label)
{
    const char *p = strchr(line, '#');
    char format[6];

    if (p != NULL) {
      sprintf(format, "%%%ds", OBSLEN - 1);
      sscanf(p + 1, format, label);
      return 0;
    }

    return 1;
}

static void get_gpt_data (char *line, double *x, double *y)
{
#ifdef ENABLE_NLS
    setlocale(LC_NUMERIC, "C");
#endif

    if (x != NULL) {
      if (sscanf(line, "%lf %lf", x, y) == 2) {
          ; /* we're fine */
      } else {
          if (sscanf(line, "%lf", x) == 1) {
            *y = NADBL;
          } else if (sscanf(line, "%*s %lf", y) == 1) {
            *x = NADBL;
          } else {
            *x = *y = NADBL;
          }
      }
    } else {
      if (sscanf(line, "%*s %lf", y) != 1) {
          *y = NADBL;
      }
    }

#ifdef ENABLE_NLS
    setlocale(LC_NUMERIC, "");
#endif
}

/* ........................................................... */

static int cant_zoom (const char *line)
{
    if (strncmp(line, "# multi", 7) == 0) {
      /* multiple scatterplots */
      return 1;
    }
    if (strncmp(line, "# CUSUM", 7) == 0) {
      /* graph from CUSUM test */
      return 1;
    }
    if (strncmp(line, "# frequ", 7) == 0) {
      /* frequency distribution plot */
      return 1;
    }
    if (strncmp(line, "# sampl", 7) == 0) {
      /* sampling distribution graph (stats calculator) */
      return 1;
    }
    if (strncmp(line, "# corre", 7) == 0) {
      /* correlogram */
      return 1;
    }
    if (strncmp(line, "# perio", 7) == 0) {
      /* periodogram */
      return 1;
    }
    if (strncmp(line, "# range", 7) == 0) {
      /* range-mean plot */
      return 1;
    }
    if (strncmp(line, "# lever", 7) == 0) {
      /* leverage plot */
      return 1;
    }
    if (strstr(line, "no auto-parse")) {
      /* general prohibition on gui plot editing */
      return 1;
    }
    return 0;
}

/* ........................................................... */

static int cant_edit (const char *line)
{
    if (strncmp(line, "# mult", 6) == 0) {
      /* multiple scatterplots (or excessive number of lines) */
      return 1;
    }
    if (strncmp(line, "# CUSUM", 7) == 0) {
      /* graph from CUSUM test */
      return 1;
    }
    if (strncmp(line, "# corre", 7) == 0) {
      /* correlogram */
      return 1;
    }
    if (strncmp(line, "# sampl", 7) == 0) {
      /* sampling distribution graph (stats calculator) */
      return 1;
    }
    if (strncmp(line, "# lever", 7) == 0) {
      /* leverage plot */
      return 1;
    }
    if (strstr(line, "no auto-parse")) {
      /* general prohibition on gui plot editing */
      return 1;
    }
    return 0;
}

/* ........................................................... */

static void plot_label_init (GPT_LABEL *lbl)
{
    lbl->text[0] = '\0';
    lbl->just = GP_JUST_LEFT;
    lbl->pos[0] = NADBL;
    lbl->pos[1] = NADBL;
}

static GPT_SPEC *plotspec_new (void)
{
    GPT_SPEC *spec;
    int i;

    spec = mymalloc(sizeof *spec);
    if (spec == NULL) {
      return NULL;
    }

    spec->lines = mymalloc(MAX_PLOT_LINES * sizeof *spec->lines);

    if (spec->lines == NULL) {
      free(spec);
      return NULL;
    }

    for (i=0; i<MAX_PLOT_LINES; i++) {
      spec->lines[i].varnum = 0;
      spec->lines[i].title[0] = 0;
      spec->lines[i].formula[0] = 0;
      spec->lines[i].style[0] = 0;
      spec->lines[i].scale[0] = 0;
      spec->lines[i].yaxis = 1;
    }

    for (i=0; i<4; i++) {
      spec->titles[i][0] = 0;
      spec->literal[i] = NULL;
    }

    for (i=0; i<MAX_PLOT_LABELS; i++) {
      plot_label_init(&(spec->labels[i]));
    }

    spec->xtics[0] = 0;
    spec->mxtics[0] = 0;
    spec->fname[0] = 0;
    strcpy(spec->keyspec, "left top");

    for (i=0; i<3; i++) {
      spec->range[i][0] = NADBL;
      spec->range[i][1] = NADBL;
    }

    spec->code = PLOT_REGULAR;
    spec->flags = 0;
    spec->fp = NULL;
    spec->data = NULL;
    spec->markers = NULL;
    spec->nmarkers = 0;
    spec->ptr = NULL;
    spec->nlines = 0;
    spec->n_y_series = 0;

    spec->termtype[0] = 0;
    spec->t1 = spec->t2 = 0;

    return spec;
}

/* read a gnuplot source line specifying a text label */

static int parse_label_line (GPT_SPEC *spec, const char *line, int i)
{
    const char *p, *s;
    double x, y;
    int nc, q2 = 0;
    int textread = 0;

    /* set label "this is a label" at 1998.26,937.557 left front */
    /* set label 'foobar' at 1500,350 left */

    if (i >= MAX_PLOT_LABELS) {
      return 1;
    }

    plot_label_init(&(spec->labels[i]));

    /* find first single or double quote */
    p = strchr(line, '\'');
    if (p == NULL) {
      p = strchr(line, '"');
      if (p == NULL) {
          return 1;
      }
      q2 = 1;
    }

    p++;
    s = p;

    /* get the label text */
    while (*s) {
      if (q2) {
          if (*s == '"' && *(s-1) != '\\') {
            textread = 1;
          }
      } else if (*s == '\'') {
          textread = 1;
      }

      if (textread) {
          int len = s - p;

          if (len > PLOT_LABEL_TEXT_LEN) {
            len = PLOT_LABEL_TEXT_LEN;
          }
          strncat(spec->labels[i].text, p, len);
          break;
      }

      s++;
    }

    if (!textread) {
      return 1;
    }

    /* get the position */
    p = strstr(s, "at");
    if (p == NULL) {
      spec->labels[i].text[0] = '\0';
      return 1;
    }

    p += 2;

#ifdef ENABLE_NLS
    setlocale(LC_NUMERIC, "C");
#endif
    nc = sscanf(p, "%lf,%lf", &x, &y);
#ifdef ENABLE_NLS
    setlocale(LC_NUMERIC, "");
#endif

    if (nc != 2) {
      spec->labels[i].text[0] = '\0';
      return 1;
    }

    spec->labels[i].pos[0] = x;
    spec->labels[i].pos[1] = y;

    /* justification */
    if (strstr(p, "right")) {
      spec->labels[i].just = GP_JUST_RIGHT;
    } else if (strstr(p, "center")) {
      spec->labels[i].just = GP_JUST_CENTER;
    } 

    return 0;
}

static int 
read_plotspec_range (const char *obj, const char *s, GPT_SPEC *spec)
{
    double r0, r1;
    int i = 0, err = 0;

    if (!strcmp(obj, "xrange")) {
      i = 0;
    } else if (!strcmp(obj, "yrange")) {
      i = 1;
    } else if (!strcmp(obj, "y2range")) {
      i = 2;
    } else {
      err = 1;
    }

    if (!strcmp(s, "[*:*]")) {
      r0 = r1 = NADBL;
    } else {
#ifdef ENABLE_NLS
      setlocale(LC_NUMERIC, "C");
#endif
      if (!err && sscanf(s, "[%lf:%lf]", &r0, &r1) != 2) {
          err = 1;
      }
#ifdef ENABLE_NLS
      setlocale(LC_NUMERIC, "");
#endif
    }

    if (!err) {
      spec->range[i][0] = r0;
      spec->range[i][1] = r1;
    }

    return err;
}

static int parse_gp_set_line (GPT_SPEC *spec, const char *s, int *labelno)
{
    char variable[16] = {0};
    char value[MAXLEN] = {0};

    if (strstr(s, "encoding") != NULL) {
      return 0;
    }

    if (sscanf(s + 4, "%11s", variable) != 1) {
      errbox(_("Failed to parse gnuplot file"));
      fprintf(stderr, "parse_gp_set_line: bad line '%s'\n", s);
      return 1;
    }

    if (strcmp(variable, "y2tics") == 0) {
      spec->flags |= GPTSPEC_Y2AXIS;
      return 0;
    } else if (strcmp(variable, "border 3") == 0) {
      spec->flags |= GPTSPEC_BORDER_HIDDEN;
      return 0;
    }    

    strcpy(value, s + 4 + strlen(variable));
    top_n_tail(value);

    if (strstr(variable, "range")) {
      if (read_plotspec_range(variable, value, spec)) {
          errbox(_("Failed to parse gnuplot file"));
          fprintf(stderr, "parse_gp_set_line: bad line '%s'\n", s);
          return 1;
      }
    } else if (!strcmp(variable, "title")) {
      strcpy(spec->titles[0], value);
    } else if (!strcmp(variable, "xlabel")) {
      strcpy(spec->titles[1], value);
    } else if (!strcmp(variable, "ylabel")) {
      strcpy(spec->titles[2], value);
    } else if (!strcmp(variable, "y2label")) {
      strcpy(spec->titles[3], value);
    } else if (!strcmp(variable, "key")) {
      strcpy(spec->keyspec, value);
    } else if (!strcmp(variable, "nokey")) {
      strcpy(spec->keyspec, "none");
    } else if (!strcmp(variable, "xtics")) { 
      safecpy(spec->xtics, value, 15);
    } else if (!strcmp(variable, "mxtics")) { 
      safecpy(spec->mxtics, value, 3);
    } else if (!strcmp(variable, "label")) {
      parse_label_line(spec, s, *labelno);
      *labelno += 1;
    }

    return 0;
}

/* allocate markers for identifying particular data points */

static int allocate_plotspec_markers (GPT_SPEC *spec, int plot_n)
{
    int i;

    spec->markers = mymalloc(plot_n * sizeof *spec->markers);
    if (spec->markers == NULL) {
      return 1;
    }

    for (i=0; i<plot_n; i++) {
      spec->markers[i] = malloc(OBSLEN);
      if (spec->markers[i] == NULL) {
          free(spec->markers);
          spec->nmarkers = 0;
          return 1;
      }
      spec->markers[i][0] = 0;
    }

    spec->nmarkers = plot_n;

    return 0;
}

/* determine the number of data points in a plot, and whether
   there are any data-point markers along with the data 
*/

static int get_plot_n (FILE *fp, int *got_markers)
{
    int n = 0, started = -1;
    char line[MAXLEN], label[OBSLEN];
    char *p;

    *got_markers = 0;

    while (fgets(line, MAXLEN - 1, fp)) {
      if (!strncmp(line, "plot", 4)) {
          started = 0;
      }
      if (started == 0 && strchr(line, '\\') == NULL) {
          started = 1;
          continue;
      }
      if (started == 1) {
          if (*got_markers == 0 && (p = strchr(line, '#')) != NULL) {
            if (sscanf(p + 1, "%8s", label) == 1) {
                *got_markers = 1;
            }
          }
          if (*line == 'e') {
            break;
          }
          n++;
      }
    }

    return n;
}

/* Read plotspec struct from gnuplot command file.  This is _not_ a
   general parser for gnuplot files; it is designed specifically for
   files auto-generated by gretl.
*/

static int read_plotspec_from_file (GPT_SPEC *spec)
{
    int i, t, n, plot_n, done, labelno;
    int got_markers = 0;
    char gpline[MAXLEN];
    char *got = NULL, *p = NULL;
    double *tmpy = NULL;
    size_t diff;
    FILE *fp;

    /* check: are we already done? */
    if (PLOTSPEC_DETAILS_IN_MEMORY(spec)) {
      return 0;
    }

    /* open the plot file */
    fp = gretl_fopen(spec->fname, "r");
    if (fp == NULL) {
      errbox(_("Couldn't open graph file"));
      return 1;
    }

    /* get the number of data-points, and check for markers */
    plot_n = get_plot_n(fp, &got_markers);
    if (plot_n == 0) {
      fclose(fp);
      return 1;
    }

    rewind(fp);

    /* get the preamble and "set" lines */
    labelno = 0;
    while ((got = fgets(gpline, MAXLEN - 1, fp))) {
      if (cant_edit(gpline)) {
          goto plot_bailout;
      }
      if (strncmp(gpline, "# timeseries", 12) == 0) {
          spec->flags |= GPTSPEC_TS;
          continue;
      }
      if (strncmp(gpline, "# freq", 6) == 0 ||
          strncmp(gpline, "# peri", 6) == 0) {
          /* special cases */
          if (gpline[2] == 'f') {
            if (strstr(gpline, "normal")) {
                spec->code = PLOT_FREQ_NORMAL;
            } else if (strstr(gpline, "gamma")) {
                spec->code = PLOT_FREQ_GAMMA;
            } else {
                spec->code = PLOT_FREQ_SIMPLE;
            }
          } else {
            spec->code = PLOT_PERIODOGRAM;
          }
          if (spec->code != PLOT_FREQ_SIMPLE) {
            /* grab special plot lines */
            for (i=0; i<4; i++) {
                spec->literal[i] = mymalloc(MAXLEN);
                if (spec->literal[i] == NULL) {
                  return 1;
                }
                if (!fgets(spec->literal[i], MAXLEN - 1, fp)) {
                  errbox(_("Plot file is corrupted"));
                  free(spec->literal[i]);
                  spec->literal[i] = NULL;
                  goto plot_bailout;
                }
                top_n_tail(spec->literal[i]);
            }
          }
          continue;
      }

      if (strncmp(gpline, "# forecast", 10) == 0) {
          spec->code = PLOT_FORECAST;
          continue;
      }

      if (strstr(gpline, "automatic OLS")) {
          spec->flags |= GPTSPEC_AUTO_OLS;
          continue;
      }

      if (strncmp(gpline, "# ", 2) == 0) {
          /* ignore unknown comment lines */
          continue;
      }

      if (strncmp(gpline, "set ", 4)) {
          /* done reading "set" lines */
          break;
      }

      if (parse_gp_set_line(spec, gpline, &labelno)) {
          goto plot_bailout;
      }
    }

    if (got == NULL) {
      goto plot_bailout;
    }

    for (i=0; i<4; i++) {
      if (spec->titles[i][0] != 0) {
          delchar('\'', spec->titles[i]);
      }
    }

    if (spec->keyspec[0] == 0) {
      strcpy(spec->keyspec, "none");
    }

    /* then get the "plot" lines */
    if (strncmp(gpline, "plot ", 4) ||
      (strlen(gpline) < 10 && fgets(gpline, MAXLEN - 1, fp) == NULL)) { 
      errbox(_("Failed to parse gnuplot file"));
      fprintf(stderr, "bad plotfile line: '%s'\n", gpline);
      goto plot_bailout;
    }

    i = 0;
    done = 0;
    while (1) {
      top_n_tail(gpline);

      if (!chop_comma(gpline)) {
          /* line did not end with comma -> no contination of
             the plot command */
          done = 1;
      } 

      /* scale, [yaxis,] style */
      p = strstr(gpline, "using");
      if (p && p[11] == '*') {
            safecpy(spec->lines[i].scale, p + 12, 7);
          charsub(spec->lines[i].scale, ')', '\0');
      } else {
          if (p) { 
            strcpy(spec->lines[i].scale, "1.0");
          } else {
            strcpy(spec->lines[i].scale, "NA");
            p = strstr(gpline, "axes");
            if (p == NULL) {
                p = strstr(gpline, "title");
            }
            if (p != NULL) {
                diff = p - gpline;
                strncpy(spec->lines[i].formula, gpline, diff);
                spec->lines[i].formula[diff - 1] = 0;
            } 
          }
      }

      spec->lines[i].yaxis = 1;
      if (strstr(gpline, "axes x1y2")) {
          spec->lines[i].yaxis = 2;
      }

      p = strstr(gpline, "title");
      if (p != NULL) {
          sscanf(p + 7, "%79[^']'", spec->lines[i].title);
      }

      p = strstr(gpline, " w ");
      if (p != NULL) {
          sscanf(p + 3, "%15[^, ]", spec->lines[i].style);
      } else {
          strcpy(spec->lines[i].style, "points");
      }

      if (done) {
          break;
      }

      i++;

      if ((got = fgets(gpline, MAXLEN - 1, fp)) == NULL) {
          break;
      }
    }

    if (got == NULL) {
      goto plot_bailout;
    }

    spec->nlines = i + 1; /* i is a zero-based index */

    /* free any unused lines */
    if (spec->nlines < MAX_PLOT_LINES) {
      spec->lines = myrealloc(spec->lines, 
                        spec->nlines * sizeof *spec->lines);
    }

    /* finally, get the plot data, and markers if any */
    spec->data = mymalloc(plot_n * (i + 2) * sizeof *spec->data);
    tmpy = mymalloc(plot_n * sizeof *tmpy);
    if (spec->data == NULL || tmpy == NULL) {
      goto plot_bailout;
    }

    if (got_markers) {
      if (allocate_plotspec_markers(spec, plot_n)) {
          free(spec->data);
          spec->data = NULL;
          free(tmpy);
          goto plot_bailout;
      }
    }

    /* Below: read the data from the plot.  There may be more
       than one y series. */
    i = 1;
    t = 0;
    n = 0;
    while (fgets(gpline, MAXLEN - 1, fp)) {
      if (gpline[0] == 'e') {
          n = t;
          t = 0;
          i++;
          continue;
      }
      if (strncmp(gpline, "pause", 5) == 0) {
          break;
      }
      if (i == 1) { 
          /* first set: read both x and y (and label?) */ 
          get_gpt_data(gpline, &(spec->data[t]), &(tmpy[t]));
          if (got_markers) {
            get_gpt_marker(gpline, spec->markers[t]);
          }
      } else {      
          /* any subsequent sets: read y only */ 
          get_gpt_data(gpline, NULL, &(spec->data[i * n + t]));
      }
      t++;
    }

    spec->n_y_series = i - 1;

    /* put "tmpy" in as last data column */
    for (t=0; t<n; t++) {
      spec->data[n + t] = tmpy[t];
    }
    free(tmpy);

    spec->t1 = 0;
    spec->t2 = n - 1;

    /* see if we really have any markers */
    if (spec->markers != NULL && !got_markers) {
      for (i=0; i<plot_n; i++) {
          free(spec->markers[i]);
      }
      free(spec->markers);
      spec->markers = NULL;
      spec->nmarkers = 0;
    }

#if 0
    fprintf(stderr, "spec->markers = %p, spec->nmarkers = %d\n",
          (void *) spec->markers, spec->nmarkers);
#endif

    fclose(fp);
    return 0;

 plot_bailout:

    fclose(fp);
    return 1;
}

/* Size of drawing area */
#define PLOT_PIXEL_WIDTH  640   /* try 576? 608? */
#define PLOT_PIXEL_HEIGHT 480   /* try 432? 456? */

#ifdef USE_GNOME
extern void gnome_print_graph (const char *fname);
#endif

static int get_data_xy (png_plot *plot, int x, int y, 
                  double *data_x, double *data_y)
{
    double xmin, xmax;
    double ymin, ymax;

    if (plot_is_zoomed(plot)) {
      xmin = plot->zoom->xmin;
      xmax = plot->zoom->xmax;
      ymin = plot->zoom->ymin;
      ymax = plot->zoom->ymax;
    } else {
      xmin = plot->xmin;
      xmax = plot->xmax;
      ymin = plot->ymin;
      ymax = plot->ymax;
    }

#ifdef POINTS_DEBUG
    if (plot_doing_position(plot)) {
      fprintf(stderr, "get_data_xy:\n"
            " plot->xmin=%g, plot->xmax=%g, plot->ymin=%g, plot->ymax=%g\n",
            plot->xmin, plot->xmax, plot->ymin, plot->ymax);
    }
#endif

    if (xmin == 0.0 && xmax == 0.0) { /* unknown x range */
      fprintf(stderr, "get_data_xy: unknown x range\n");
      *data_x = NADBL;
    } else {
      *data_x = xmin + ((double) x - plot->pixel_xmin) / 
          (plot->pixel_xmax - plot->pixel_xmin) * (xmax - xmin);
    }

    if (!na(*data_x)) {
      if (ymin == 0.0 && ymax == 0.0) { /* unknown y range */
          fprintf(stderr, "get_data_xy: unknown y range\n");
          *data_y = NADBL;
      } else {
          *data_y = ymax - ((double) y - plot->pixel_ymin) / 
            (plot->pixel_ymax - plot->pixel_ymin) * (ymax - ymin);
      }
    }

    return (!na(*data_x) && !na(*data_y));
}

static void x_to_date (double x, int pd, char *str)
{
    int yr = (int) x;
    double t, frac = 1.0 / pd;
    int subper = (int) ((x - yr + frac) * pd);
    static int decpoint;

    if (decpoint == 0) decpoint = get_local_decpoint();

    t = yr + subper / ((pd < 10)? 10.0 : 100.0);
    sprintf(str, "%.*f", (pd < 10)? 1 : 2, t);
    charsub(str, decpoint, ':');
}

static void create_selection_gc (png_plot *plot)
{
    if (plot->invert_gc == NULL) {
      plot->invert_gc = gdk_gc_new(plot->canvas->window);
      gdk_gc_set_function(plot->invert_gc, GDK_INVERT);
    }
}

static void draw_selection_rectangle (png_plot *plot,
                              int x, int y)
{
    int rx, ry, rw, rh;

    rx = (plot->zoom->screen_xmin < x)? plot->zoom->screen_xmin : x;
    ry = (plot->zoom->screen_ymin < y)? plot->zoom->screen_ymin : y;
    rw = x - plot->zoom->screen_xmin;
    rh = y - plot->zoom->screen_ymin;
    if (rw < 0) rw = -rw;
    if (rh < 0) rh = -rh;    

    /* draw one time to make the rectangle appear */
    gdk_draw_rectangle(plot->pixmap,
                   plot->invert_gc,
                   FALSE,
                   rx, ry, rw, rh);
    /* show the modified pixmap */
    gdk_window_copy_area(plot->canvas->window,
                   plot->canvas->style->fg_gc[GTK_STATE_NORMAL],
                   0, 0,
                   plot->pixmap,
                   0, 0,
                   PLOT_PIXEL_WIDTH, PLOT_PIXEL_HEIGHT);
    /* draw (invert) again to erase the rectangle */
    gdk_draw_rectangle(plot->pixmap,
                   plot->invert_gc,
                   FALSE,
                   rx, ry, rw, rh);
}

#ifdef OLD_GTK

static void
write_label_to_plot (png_plot *plot, const gchar *label,
                 gint x, gint y)
{
    static GdkFont *label_font;

    if (plot->invert_gc == NULL) {
      create_selection_gc(plot);
    }

    if (label_font == NULL) {
      label_font = gdk_font_load("fixed");
    }

    /* draw the label */
    gdk_draw_text (plot->pixmap,
               label_font,
               plot->invert_gc,
               x, y,
               label,
               strlen(label));

    /* show the modified pixmap */
    gdk_window_copy_area(plot->canvas->window,
                   plot->canvas->style->fg_gc[GTK_STATE_NORMAL],
                   0, 0,
                   plot->pixmap,
                   0, 0,
                   PLOT_PIXEL_WIDTH, PLOT_PIXEL_HEIGHT);

    /* draw (invert) again to erase the text */
    gdk_draw_text (plot->pixmap,
               label_font,
               plot->invert_gc,
               x, y,
               label,
               strlen(label));
}

#else

static void
write_label_to_plot (png_plot *plot, const gchar *label,
                 gint x, gint y)
{
    PangoContext *context;
    PangoLayout *pl;

    if (plot->invert_gc == NULL) {
      create_selection_gc(plot);
    }

    context = gtk_widget_get_pango_context(plot->shell);
    pl = pango_layout_new(context);
    pango_layout_set_text(pl, label, -1);

    /* draw the label */
    gdk_draw_layout (plot->pixmap, plot->invert_gc, x, y, pl);

    /* show the modified pixmap */
    gdk_window_copy_area(plot->canvas->window,
                   plot->canvas->style->fg_gc[GTK_STATE_NORMAL],
                   0, 0,
                   plot->pixmap,
                   0, 0,
                   PLOT_PIXEL_WIDTH, PLOT_PIXEL_HEIGHT);

    /* trash the pango layout */
    g_object_unref (G_OBJECT(pl));

    /* record that a label is shown */
    plot->format |= PLOT_MARKERS_UP;
}

#endif /* GTK versions */

#define TOLDIST 0.01

static gint
identify_point (png_plot *plot, int pixel_x, int pixel_y,
            double x, double y) 
{
    double xrange, yrange;
    double xdiff, ydiff;
    double min_xdist, min_ydist;
    int best_match = -1;
    int t, plot_n;
    const double *data_x, *data_y = NULL;

    if (!PLOTSPEC_DETAILS_IN_MEMORY(plot->spec) && !plot->err) {
      plot->err = read_plotspec_from_file(plot->spec);
      if (plot->err) {
          return TRUE;
      }
    }

    /* no markers to show */
    if (plot->spec->markers == NULL) {
      plot->status |= PLOT_NO_MARKERS;    
      return TRUE;
    }

    plot_n = plot->spec->t2 - plot->spec->t1 + 1;

#ifndef OLD_GTK
    /* need array to keep track of which points are labeled */
    if (plot->labeled == NULL) {
      plot->labeled = mymalloc(plot_n);
      if (plot->labeled == NULL) {
          return TRUE;
      }
      memset(plot->labeled, 0, plot_n);
    }
#endif

    if (plot_is_zoomed(plot)) {
      min_xdist = xrange = plot->zoom->xmax - plot->zoom->xmin;
      min_ydist = yrange = plot->zoom->ymax - plot->zoom->ymin;
    } else {
      min_xdist = xrange = plot->xmax - plot->xmin;
      min_ydist = yrange = plot->ymax - plot->ymin;
    }

    data_x = &plot->spec->data[0];
    /* there's an ambiguity here: in case of more than one y series,
       what do we want to use as "data_y"? */
    if (plot_has_y2axis(plot)) {
      /* use first y-var that's on y1 axis */
      int i;

      for (i=0; i<plot->spec->nlines; i++) {
          if (plot->spec->lines[i].yaxis == 1) {
            data_y = &plot->spec->data[(i + 1) * plot_n];
            break;
          }
      }
    } 

    if (data_y == NULL) {
      data_y = &plot->spec->data[plot->spec->n_y_series * plot_n];
    }

    /* try to find the best-matching data point */
    for (t=0; t<plot_n; t++) {
      if (na(data_x[t]) || na(data_y[t])) {
          continue;
      }
      xdiff = fabs(data_x[t] - x);
      ydiff = fabs(data_y[t] - y);
      if (xdiff <= min_xdist && ydiff <= min_ydist) {
          min_xdist = xdiff;
          min_ydist = ydiff;
          best_match = t;
      }
    }

#ifndef OLD_GTK
    /* if the point is already labeled, skip */
    if (plot->labeled[best_match]) {
      return TRUE;
    }
#endif

    /* if the match is good enough, show the label */
    if (best_match >= 0 && min_xdist < TOLDIST * xrange &&
      min_ydist < TOLDIST * yrange) {
      write_label_to_plot(plot, plot->spec->markers[best_match],
                      pixel_x, pixel_y);
#ifndef OLD_GTK
      /* flag the point as labeled already */
      plot->labeled[best_match] = 1;
#endif
    }

    return TRUE;
}

#define MAX_MARKERS_SHOWN 250

static gint
motion_notify_event (GtkWidget *widget, GdkEventMotion *event,
                 png_plot *plot)
{
    int x, y;
    GdkModifierType state;
    gchar label[32], label_y[16];

    if (plot->err) {
      return TRUE;
    }

    if (event->is_hint) {
        gdk_window_get_pointer(event->window, &x, &y, &state);
    } else {
        x = event->x;
        y = event->y;
        state = event->state;
    }

    *label = 0;

    if (x > plot->pixel_xmin && x < plot->pixel_xmax && 
      y > plot->pixel_ymin && y < plot->pixel_ymax) {
      double data_x, data_y;

      get_data_xy(plot, x, y, &data_x, &data_y);
      if (na(data_x)) return TRUE;

      if (!(plot_has_no_markers(plot)) && 
          datainfo->t2 - datainfo->t1 < MAX_MARKERS_SHOWN &&
          !plot_is_zooming(plot) &&
          !na(data_y)) {
          identify_point(plot, x, y, data_x, data_y);
      }

      if (plot->pd == 4 || plot->pd == 12) {
          x_to_date(data_x, plot->pd, label);
      } else {
          sprintf(label, (plot->xint)? "%7.0f" : "%7.4g", data_x);
      }

      if (!na(data_y)) {
          if (plot_has_png_coords(plot)) {
            sprintf(label_y, (plot->yint)? " %-7.0f" : " %-7.4g", data_y);
          } else {
            /* pretty much guessing at y coordinate here */
            sprintf(label_y, (plot->yint)? " %-7.0f" : " %-6.3g", data_y);
          }
          strcat(label, label_y);
      }

      if (plot_is_zooming(plot) && (state & GDK_BUTTON1_MASK)) {
          draw_selection_rectangle(plot, x, y);
      }
    } 

    gtk_label_set_text(GTK_LABEL(plot->cursor_label), label);
  
    return TRUE;
}

static void set_plot_format_flags (png_plot *plot)
{
    plot->format = 0;

    if (!string_is_blank(plot->spec->titles[0])) {
      plot->format |= PLOT_TITLE;
    }
    if (!string_is_blank(plot->spec->titles[1])) {
      plot->format |= PLOT_XLABEL;
    }
    if (!string_is_blank(plot->spec->titles[2])) {
      plot->format |= PLOT_YLABEL;
    }
    if (!string_is_blank(plot->spec->titles[3])) {
      plot->format |= PLOT_Y2LABEL;
    }
    if (plot->spec->flags & GPTSPEC_Y2AXIS) {
      plot->format |= PLOT_Y2AXIS;
    }
}

/* called from png plot popup menu */

static void start_editing_png_plot (png_plot *plot)
{
    /* the spec struct is not yet filled out by reference
       to the gnuplot source file */
    plot->err = read_plotspec_from_file(plot->spec);
    if (plot->err) {
      return;
    }

    if (show_gnuplot_dialog(plot->spec) == 0) { /* OK */
      plot->status |= PLOT_HAS_CONTROLLER;
    }
}

#ifdef HAVE_AUDIO
static void audio_render_plot (png_plot *plot)
{
    void *handle;
    int (*midi_play_graph) (const char *, const char *, const char *);

    if (plot_not_editable(plot)) {
      return;
    }

    midi_play_graph = gui_get_plugin_function("midi_play_graph", 
                                    &handle);
    if (midi_play_graph == NULL) {
        return;
    }

# ifdef G_OS_WIN32
    (*midi_play_graph) (plot->spec->fname, paths.userdir, NULL);
# else
    (*midi_play_graph) (plot->spec->fname, paths.userdir, midiplayer);
# endif

    close_plugin(handle);
}
#endif

static gint color_popup_activated (GtkWidget *w, gpointer data)
{
    gchar *item = (gchar *) data;
    gpointer ptr = g_object_get_data(G_OBJECT(w), "plot");
    png_plot *plot = (png_plot *) ptr;
    gint color = strcmp(item, _("monochrome"));
    GtkWidget *parent = (GTK_MENU(w->parent))->parent_menu_item;
    gchar *parent_item = g_object_get_data(G_OBJECT(parent), "string");

    if (!strcmp(parent_item, _("Save as postscript (EPS)..."))) {
      strcpy(plot->spec->termtype, "postscript");
      if (color) {
          strcat(plot->spec->termtype, " color");
      }
      file_selector(_("Save gnuplot graph"), SAVE_THIS_GRAPH, 
                  plot->spec);
    } else if (!strcmp(parent_item, _("Save as Windows metafile (EMF)..."))) {
      strcpy(plot->spec->termtype, "emf");
      if (color) {
          strcat(plot->spec->termtype, " color");
      }
      file_selector(_("Save gnuplot graph"), SAVE_THIS_GRAPH, 
                  plot->spec);
    } 
#ifdef G_OS_WIN32
    else if (!strcmp(parent_item, _("Copy to clipboard"))) {
      win32_process_graph(plot->spec, color, WIN32_TO_CLIPBOARD);
    } else if (!strcmp(parent_item, _("Print"))) {
      win32_process_graph(plot->spec, color, WIN32_TO_PRINTER);
    }    
#endif   

    return TRUE;
}

static gint plot_popup_activated (GtkWidget *w, gpointer data)
{
    gchar *item = (gchar *) data;
    gpointer ptr = g_object_get_data(G_OBJECT(w), "plot");
    png_plot *plot = (png_plot *) ptr;
    int killplot = 0;

    gtk_widget_destroy(plot->popup);
    plot->popup = NULL;

    if (!strcmp(item, _("Save as PNG..."))) {
      strcpy(plot->spec->termtype, "png");
        file_selector(_("Save gnuplot graph"), SAVE_THIS_GRAPH, plot->spec);
    } else if (!strcmp(item, _("Save to session as icon"))) { 
      add_graph_to_session(plot->spec, GRETL_GNUPLOT_GRAPH, NULL);
    } else if (plot_is_range_mean(plot) && !strcmp(item, _("Help"))) { 
      context_help(NULL, GINT_TO_POINTER(RMPLOT));
    }
#ifndef OLD_GTK
    else if (!strcmp(item, _("Clear data labels"))) { 
      zoom_unzoom_png(plot, PNG_START);
    }
#endif
    else if (!strcmp(item, _("Zoom..."))) { 
      GdkCursor* cursor;

      cursor = gdk_cursor_new(GDK_CROSSHAIR);
      gdk_window_set_cursor(plot->canvas->window, cursor);
      gdk_cursor_destroy(cursor);
      plot->status |= PLOT_ZOOMING;
      gtk_statusbar_push(GTK_STATUSBAR(plot->statusbar), plot->cid, 
                     _(" Drag to define zoom rectangle"));
      create_selection_gc(plot);
    } else if (!strcmp(item, _("Restore full view"))) { 
      zoom_unzoom_png(plot, PNG_UNZOOM);
    }
#ifdef USE_GNOME 
    else if (!strcmp(item, _("Print..."))) { 
      gnome_print_graph(plot->spec->fname);
    }
#endif 
    else if (!strcmp(item, _("Edit"))) { 
      start_editing_png_plot(plot);
    } else if (!strcmp(item, _("Close"))) { 
        killplot = 1;
    } 

    if (killplot) {
      gtk_widget_destroy(plot->shell);
    }

    return TRUE;
}

static void attach_color_popup (GtkWidget *w, png_plot *plot)
{
    GtkWidget *item, *cpopup;
    const char *color_items[] = {
      N_("color"),
      N_("monochrome")
    };
    int i;

    cpopup = gtk_menu_new();

    for (i=0; i<2; i++) {
      item = gtk_menu_item_new_with_label(_(color_items[i]));
      g_signal_connect(G_OBJECT(item), "activate",
                   G_CALLBACK(color_popup_activated),
                   _(color_items[i]));
      g_object_set_data(G_OBJECT(item), "plot", plot);
      gtk_widget_show(item);
      gtk_menu_shell_append(GTK_MENU_SHELL(cpopup), item);
    } 

    gtk_menu_item_set_submenu(GTK_MENU_ITEM(w), cpopup);
}

static void build_plot_menu (png_plot *plot)
{
    GtkWidget *item;    
    const char *regular_items[] = {
#ifdef G_OS_WIN32
      N_("Save as Windows metafile (EMF)..."),
#endif
      N_("Save as PNG..."),
        N_("Save as postscript (EPS)..."),
#ifndef G_OS_WIN32
      N_("Save as Windows metafile (EMF)..."),
#endif
#ifdef G_OS_WIN32
      N_("Copy to clipboard"),
#endif
      N_("Save to session as icon"),
#ifndef OLD_GTK
      N_("Clear data labels"),
#endif
      N_("Zoom..."),
#ifdef USE_GNOME
      N_("Print..."),
#endif
#ifdef G_OS_WIN32
      N_("Print"),
#endif
      N_("Edit"),
      N_("Help"),
        N_("Close"),
        NULL
    };
    const char *zoomed_items[] = {
      N_("Restore full view"),
      N_("Close"),
      NULL
    };
    const char **plot_items;
    int i;

    plot->popup = gtk_menu_new();

    if (plot_is_zoomed(plot)) {
      plot_items = zoomed_items;
    } else {
      plot_items = regular_items;
    }

    i = 0;
    while (plot_items[i]) {
      if (plot_not_zoomable(plot) &&
          !strcmp(plot_items[i], "Zoom...")) {
          i++;
          continue;
      }
      if (!plot_is_range_mean(plot) &&
          !strcmp(plot_items[i], "Help")) {
          i++;
          continue;
      }
      if (plot_is_saved(plot) &&
          !strcmp(plot_items[i], "Save to session as icon")) {
          i++;
          continue;
      }
      if ((plot_has_controller(plot) || plot_not_editable(plot)) &&
          !strcmp(plot_items[i], "Edit")) {
          i++;
          continue;
      }
#ifndef OLD_GTK
      if (!plot_has_data_markers(plot) &&
          !strcmp(plot_items[i], "Clear data labels")) {
          i++;
          continue;
      }
#endif

        item = gtk_menu_item_new_with_label(_(plot_items[i]));
        g_object_set_data(G_OBJECT(item), "plot", plot);
        gtk_widget_show(item);
        gtk_menu_shell_append(GTK_MENU_SHELL(plot->popup), item);

      /* items with color sub-menu */
      if (!strcmp(plot_items[i], "Save as Windows metafile (EMF)...") ||
          !strcmp(plot_items[i], "Save as postscript (EPS)...") ||
          !strcmp(plot_items[i], "Copy to clipboard") ||
          !strcmp(plot_items[i], "Print")) {
          attach_color_popup(item, plot);
          g_object_set_data(G_OBJECT(item), "string", _(plot_items[i]));
      } else {
          g_signal_connect(G_OBJECT(item), "activate",
                       G_CALLBACK(plot_popup_activated),
                       _(plot_items[i]));
      }
        i++;
    }

    g_signal_connect(G_OBJECT(plot->popup), "destroy",
                 G_CALLBACK(gtk_widget_destroyed), 
                 &plot->popup);
}

int redisplay_edited_png (png_plot *plot)
{
    gchar *plotcmd;
    FILE *fp;
    int err = 0;

    /* open file in which to dump plot specification */
    gnuplot_png_init(plot->spec, &fp);
    if (fp == NULL) {
      return 1;
    }

    /* dump the edited plot details to file */
    set_png_output(plot->spec);
    print_plotspec_details(plot->spec, fp);
    fclose(fp);

    /* get gnuplot to create a new PNG graph */
    plotcmd = g_strdup_printf("\"%s\" \"%s\"", paths.gnuplot, 
                        plot->spec->fname);

#ifdef G_OS_WIN32
    err = winfork(plotcmd, NULL, SW_SHOWMINIMIZED, 0);
#else    
    err = gretl_spawn(plotcmd);
#endif

    g_free(plotcmd);

    if (err) {
      errbox(_("Failed to generate PNG file"));
      return 1;
    }

    /* grab (possibly modified) data ranges */
    get_plot_ranges(plot);

    /* put the newly created PNG onto the plot canvas */
    render_pngfile(plot, PNG_REDISPLAY);

    return 0;
}

static int zoom_unzoom_png (png_plot *plot, int view)
{
    int err = 0;
    char zoomname[MAXLEN];
    gchar *plotcmd = NULL;

    if (view == PNG_ZOOM) {
      FILE *fpin, *fpout;
      char line[MAXLEN];

      fpin = gretl_fopen(plot->spec->fname, "r");
      if (fpin == NULL) {
          return 1;
      }

      build_path(paths.userdir, "zoomplot.gp", zoomname, NULL);
      fpout = gretl_fopen(zoomname, "w");
      if (fpout == NULL) {
          fclose(fpin);
          return 1;
      }

      /* write zoomed range into auxiliary gnuplot source file */

#ifdef ENABLE_NLS
      setlocale(LC_NUMERIC, "C");
#endif
      fprintf(fpout, "set xrange [%g:%g]\n", plot->zoom->xmin,
            plot->zoom->xmax);
      fprintf(fpout, "set yrange [%g:%g]\n", plot->zoom->ymin,
            plot->zoom->ymax);
#ifdef ENABLE_NLS
      setlocale(LC_NUMERIC, "");
#endif

      while (fgets(line, MAXLEN-1, fpin)) {
          if (strncmp(line, "set xrange", 10) &&
            strncmp(line, "set yrange", 10))
            fputs(line, fpout);
      }

      fclose(fpout);
      fclose(fpin);

      plotcmd = g_strdup_printf("\"%s\" \"%s\"", paths.gnuplot, 
                          zoomname);
    } else { /* PNG_UNZOOM or PNG_START */
      plotcmd = g_strdup_printf("\"%s\" \"%s\"", paths.gnuplot, 
                          plot->spec->fname);
    }

#ifdef G_OS_WIN32
    err = winfork(plotcmd, NULL, SW_SHOWMINIMIZED, 0);
#else
    err = gretl_spawn(plotcmd);
#endif
    g_free(plotcmd);  

    if (view == PNG_ZOOM) {
      remove(zoomname);
    }

    if (err) {
      errbox(_("Failed to generate PNG file"));
      return 1;
    }

    render_pngfile(plot, view);

    return 0;
}

static gint plot_button_release (GtkWidget *widget, GdkEventButton *event, 
                         png_plot *plot)
{
    if (plot_is_zooming(plot)) {
      double z;

      if (!get_data_xy(plot, event->x, event->y, 
                   &plot->zoom->xmax, &plot->zoom->ymax)) {
          return TRUE;
      }

      /* flip the selected rectangle if required */
      if (plot->zoom->xmin > plot->zoom->xmax) {
          z = plot->zoom->xmax;
          plot->zoom->xmax = plot->zoom->xmin;
          plot->zoom->xmin = z;
      }

      if (plot->zoom->ymin > plot->zoom->ymax) {
          z = plot->zoom->ymax;
          plot->zoom->ymax = plot->zoom->ymin;
          plot->zoom->ymin = z;
      }

      if (plot->zoom->xmin != plot->zoom->xmax &&
          plot->zoom->ymin != plot->zoom->ymax) {
          zoom_unzoom_png(plot, PNG_ZOOM);
      }

      plot->status ^= PLOT_ZOOMING;
      gdk_window_set_cursor(plot->canvas->window, NULL);
      gtk_statusbar_pop(GTK_STATUSBAR(plot->statusbar), plot->cid);
    }

    return TRUE;
}

static gint plot_button_press (GtkWidget *widget, GdkEventButton *event, 
                         png_plot *plot)
{
    if (plot_is_zooming(plot)) {
      /* think about this */
      if (get_data_xy(plot, event->x, event->y, 
                  &plot->zoom->xmin, &plot->zoom->ymin)) {
          plot->zoom->screen_xmin = event->x;
          plot->zoom->screen_ymin = event->y;
      }
      return TRUE;
    }

    if (plot_doing_position(plot)) {
      if (plot->labelpos_entry != NULL) {
          double dx, dy;
          
          if (get_data_xy(plot, event->x, event->y, &dx, &dy)) {
            gchar *posstr;

            posstr = g_strdup_printf("%g %g", dx, dy);
            gtk_entry_set_text(GTK_ENTRY(plot->labelpos_entry), posstr);
            g_free(posstr);
          }
      } 
      terminate_plot_positioning(plot);
      return TRUE;
    }

    if (plot->popup != NULL) {
      gtk_widget_destroy(plot->popup);
      plot->popup = NULL;
    }

    if (!plot->err) {
      build_plot_menu(plot);
      gtk_menu_popup(GTK_MENU(plot->popup), NULL, NULL, NULL, NULL,
                   event->button, event->time);
    }

    return TRUE;
}

static gboolean 
plot_key_handler (GtkWidget *w, GdkEventKey *key, png_plot *plot)
{
    switch (key->keyval) {
    case GDK_q:
    case GDK_Q:
      gtk_widget_destroy(w);
      break;
    case GDK_s:
    case GDK_S:
      add_graph_to_session(plot->spec, GRETL_GNUPLOT_GRAPH, NULL);
      break;
#ifdef G_OS_WIN32
    case GDK_c:
      win32_process_graph(plot->spec, 1, WIN32_TO_CLIPBOARD);
      break;
#endif
#ifdef HAVE_AUDIO
    case GDK_a:
    case GDK_A:
      audio_render_plot(plot);
      break;
#endif
    default:
      break;
    }

    return TRUE;
}

static 
void plot_expose (GtkWidget *widget, GdkEventExpose *event,
              GdkPixmap *dbuf_pixmap)
{
    /* Don't repaint entire window on each exposure */
    gdk_window_set_back_pixmap(widget->window, NULL, FALSE);

    /* Refresh double buffer, then copy the "dirtied" area to
       the on-screen GdkWindow */
    gdk_window_copy_area(widget->window,
                   widget->style->fg_gc[GTK_STATE_NORMAL],
                   event->area.x, event->area.y,
                   dbuf_pixmap,
                   event->area.x, event->area.y,
                   event->area.width, event->area.height);
}

#ifdef OLD_GTK

#include <errno.h>

static int test_file_open (const char *fname)
{
    FILE *fp;
    int err = 0;

    errno = 0;

    fp = fopen(fname, "r");
    if (fp == NULL) {
      char *errstr = strerror(errno);

      sprintf(errtext, _("Couldn't open %s"), fname);
      strcat(errtext, ": ");
      strcat(errtext, errstr);
      errbox(errtext);
      err = 1;
    } else {
      fclose(fp);
    }

    return err;
}
#endif

static void render_pngfile (png_plot *plot, int view)
{
    gint width;
    gint height;
    GdkPixbuf *pbuf;
    char pngname[MAXLEN];
#ifndef OLD_GTK
    GError *error = NULL;
#endif

    build_path(paths.userdir, "gretltmp.png", pngname, NULL);

#ifdef OLD_GTK
    if (test_file_open(pngname)) {
      return;
    }
    pbuf = gdk_pixbuf_new_from_file(pngname);
    if (pbuf == NULL) {
      errbox(_("Failed to create pixbuf from file"));
      remove(pngname);
      return;
    }
#else
    pbuf = gdk_pixbuf_new_from_file(pngname, &error);
    if (pbuf == NULL) {
        errbox(error->message);
        g_error_free(error);
      remove(pngname);
      return;
    }
#endif

    width = gdk_pixbuf_get_width(pbuf);
    height = gdk_pixbuf_get_height(pbuf);

    if (width == 0 || height == 0) {
      errbox(_("Malformed PNG file for graph"));
#ifdef OLD_GTK
      gdk_pixbuf_unref(pbuf);
#else
      g_object_unref(pbuf);
#endif
      remove(pngname);
      return;
    }

#ifndef OLD_GTK
    /* scrap any old record of which points are labeled */
    if (plot->labeled != NULL) {
      free(plot->labeled);
      plot->labeled = NULL;
      plot->format ^= PLOT_MARKERS_UP;
    }
#endif

    gdk_pixbuf_render_to_drawable(pbuf, plot->pixmap, 
                          plot->canvas->style->fg_gc[GTK_STATE_NORMAL],
                          0, 0, 0, 0, width, height,
                          GDK_RGB_DITHER_NONE, 0, 0);

#ifdef OLD_GTK
    gdk_pixbuf_unref(pbuf);
#else
    g_object_unref(pbuf);
#endif
    remove(pngname);
    
    if (view != PNG_START) { 
      /* we're changing the view, so refresh the whole canvas */
      gdk_window_copy_area(plot->canvas->window,
                       plot->canvas->style->fg_gc[GTK_STATE_NORMAL],
                       0, 0,
                       plot->pixmap,
                       0, 0,
                       PLOT_PIXEL_WIDTH, PLOT_PIXEL_HEIGHT);
      if (view == PNG_ZOOM) {
          plot->status |= PLOT_ZOOMED;
      } else if (view == PNG_UNZOOM) {
          plot->status ^= PLOT_ZOOMED;
      }
    }
}

static void destroy_png_plot (GtkWidget *w, png_plot *plot)
{
    /* delete temporary plot source file? */
    if (!plot_is_saved(plot)) {
      remove(plot->spec->fname);
    }

    if (plot_has_controller(plot)) {
      /* if the png plot has a controller, destroy it too */
      plot->spec->ptr = NULL;
      destroy_gpt_control_window();
    } else {
      /* no controller: take responsibility for freeing the
         plot specification */
      free_plotspec(plot->spec);
    }

    /* free allocated elements of png_plot struct */
    if (plot->zoom != NULL) {
      free(plot->zoom);
    }
#ifndef OLD_GTK
    if (plot->labeled != NULL) {
      free(plot->labeled);
    }
#endif
    if (plot->invert_gc != NULL) {
      gdk_gc_destroy(plot->invert_gc);
    }

    free(plot);
}

static void set_approx_pixel_bounds (png_plot *plot, 
                             int max_num_width,
                             int max_num2_width)
{
    if (PLOTSPEC_DETAILS_IN_MEMORY(plot->spec)) {
      set_plot_format_flags(plot);
    }

    if (plot_has_xlabel(plot)) {
      plot->pixel_ymax = PLOT_PIXEL_HEIGHT - 36;
    } else {
      plot->pixel_ymax = PLOT_PIXEL_HEIGHT - 24;
    }

    if (plot_has_title(plot)) {
      plot->pixel_ymin = 36;
    } else {
      plot->pixel_ymin = 14;
    }

    plot->pixel_xmin = 27 + 7 * max_num_width;
    if (plot_has_ylabel(plot)) {
      plot->pixel_xmin += 12;
    }

    plot->pixel_xmax = PLOT_PIXEL_WIDTH - 20; 
    if (plot_has_y2axis(plot)) {
      plot->pixel_xmax -= 7 * (max_num2_width + 1);
    }
    if (plot_has_y2label(plot)) {
      plot->pixel_xmax -= 11;
    }

#ifdef POINTS_DEBUG
    fprintf(stderr, "set_approx_pixel_bounds():\n"
          " xmin=%d xmax=%d ymin=%d ymax=%d\n", 
          plot->pixel_xmin, plot->pixel_xmax,
          plot->pixel_ymin, plot->pixel_ymax);
    fprintf(stderr, "set_approx_pixel_bounds():\n"
          " max_num_width=%d max_num2_width=%d\n", 
          max_num_width, max_num2_width);
#endif
}

/* Attempt to read y-range info from the ascii representation
   of a gnuplot graph (the "dumb" terminal): return 0 on
   success, non-zero on failure.
*/

static int get_dumb_plot_yrange (png_plot *plot)
{
    FILE *fpin, *fpout;
    char line[MAXLEN], dumbgp[MAXLEN], dumbtxt[MAXLEN];
    gchar *plotcmd = NULL;
    int err = 0, x2axis = 0;
    int max_ywidth = 0;
    int max_y2width = 0;

    fpin = gretl_fopen(plot->spec->fname, "r");
    if (fpin == NULL) {
      return 1;
    }

    build_path(paths.userdir, "dumbplot.gp", dumbgp, NULL);
    build_path(paths.userdir, "gptdumb.txt", dumbtxt, NULL);
    fpout = gretl_fopen(dumbgp, "w");
    if (fpout == NULL) {
      fclose(fpin);
      return 1;
    }

    /* switch to the "dumb" (ascii) terminal in gnuplot */
    while (fgets(line, MAXLEN-1, fpin)) {
      if (strstr(line, "set term")) {
          fputs("set term dumb\n", fpout);
      } else if (strstr(line, "set output")) { 
          fprintf(fpout, "set output '%s'\n", dumbtxt);
      } else {
          fputs(line, fpout);
      }
      if (strstr(line, "x2range")) {
          x2axis = 1;
      }
    }

    fclose(fpin);
    fclose(fpout);

    plotcmd = g_strdup_printf("\"%s\" \"%s\"", paths.gnuplot,
                        dumbgp);

#ifdef G_OS_WIN32
    err = winfork(plotcmd, NULL, SW_SHOWMINIMIZED, 0);
#else
    err = gretl_spawn(plotcmd);
#endif
    
    g_free(plotcmd);
    remove(dumbgp);

    if (err) {
#ifdef POINTS_DEBUG
      fputs("get_dumb_plot_yrange(): plot command failed\n", stderr);
#endif
      return 1;
    } else {
      double y[16] = {0};
      int y_numwidth[16] = {0};
      int y2_numwidth[16] = {0};
      char numstr[32];
      int i, j, k, imin;

      fpin = gretl_fopen(dumbtxt, "r");
      if (fpin == NULL) {
          return 1;
      }

      /* read the y-axis min and max from the ascii graph */
#ifdef ENABLE_NLS
      setlocale(LC_NUMERIC, "C");
#endif
      i = j = 0;
      while (i < 16 && fgets(line, MAXLEN-1, fpin)) {
          const char *s = line;
          int nsp = 0;

          while (isspace((unsigned char) *s)) {
              nsp++;
              s++;
            }
          if (nsp > 5) {
            /* not a y-axis number */
            continue; 
          }
          if (sscanf(s, "%lf", &y[i]) == 1) {
#ifdef POINTS_DEBUG
            fprintf(stderr, "from text plot: read y[%d]=%g\n",
                  i, y[i]);
#endif
            sscanf(s, "%31s", numstr);
            y_numwidth[i++] = strlen(numstr);
          }
          if (plot_has_y2axis(plot) && j < 16) {
            double y2;

            s = strrchr(s, ' ');
            if (s != NULL && sscanf(s, "%lf", &y2) == 1) {
                sscanf(s, "%31s", numstr);
                y2_numwidth[j++] = strlen(numstr);
            }
          }
      }
#ifdef ENABLE_NLS
      setlocale(LC_NUMERIC, "");
#endif

      fclose(fpin);
#ifndef POINTS_DEBUG
      remove(dumbtxt);
#endif

      imin = (x2axis)? 1 : 0;

      if (i > (imin + 2) && y[imin] > y[i-1]) {
          plot->ymin = y[i-1];
          plot->ymax = y[imin];
          for (k=imin; k<i-1; k++) {
            if (y_numwidth[k] > max_ywidth) {
                max_ywidth = y_numwidth[k];
            }
          }
      }         

#ifdef POINTS_DEBUG
      fprintf(stderr, "Reading y range from text plot: plot->ymin=%g, "
            "plot->ymax=%g\n", plot->ymin, plot->ymax);
#endif

      if (plot_has_y2axis(plot)) {
          for (k=imin; k<j-2; k++) {
            if (y2_numwidth[k] > max_y2width) {
                max_y2width = y2_numwidth[k];
            }
          }
      }
    }

    if (plot->ymax <= plot->ymin) {
      err = 1;
    }

    if (!err) {
      set_approx_pixel_bounds(plot, max_ywidth, max_y2width);
    }
    
    return err;
}

/* do a partial parse of the gnuplot source file, enough to determine
   the data ranges so we can read back the mouse pointer coordinates
   when the user moves the pointer over the graph 
*/

static int get_plot_ranges (png_plot *plot)
{
    FILE *fp;
    char line[MAXLEN];
    int noedit = 0;
    int got_x = 0, got_y = 0, got_pd = 0;
    int err = 0;
#ifdef PNG_COMMENTS
    png_bounds b;
#endif

    plot->xmin = plot->xmax = 0.0;
    plot->ymin = plot->ymax = 0.0;   
    plot->xint = plot->yint = 0;
    plot->pd = 0;

    fp = gretl_fopen(plot->spec->fname, "r");
    if (fp == NULL) {
      return 1;
    }

#ifdef ENABLE_NLS
    setlocale(LC_NUMERIC, "C");
#endif

    while (fgets(line, MAXLEN-1, fp)) {

      if (cant_edit(line)) {
          plot->status |= PLOT_DONT_EDIT;
          plot->status |= PLOT_DONT_ZOOM;
          noedit = 1;
          break;
      }

      if (strstr(line, "# forecasts with 95")) {
          /* auto-parse can't handle the error bars */
          plot->status |= PLOT_DONT_EDIT;
      } else if (strstr(line, "# range-mean")) {
          plot->spec->code = PLOT_RANGE_MEAN;
      } else if (sscanf(line, "set xrange [%lf:%lf]", 
                    &plot->xmin, &plot->xmax) == 2) { 
          got_x = 1;
      } else if (sscanf(line, "# timeseries %d", &plot->pd) == 1) {
          got_pd = 1;
      }

      if (!PLOTSPEC_DETAILS_IN_MEMORY(plot->spec)) {
          if (!strncmp(line, "set tit", 7)) {
            plot->format |= PLOT_TITLE;
          } else if (!strncmp(line, "set xla", 7)) {
            plot->format |= PLOT_XLABEL;
          } else if (!strncmp(line, "set yla", 7)) {
            plot->format |= PLOT_YLABEL;
          } else if (!strncmp(line, "set y2la", 8)) {
            plot->format |= PLOT_Y2LABEL;
          } else if (!strncmp(line, "set y2ti", 8)) {
            plot->format |= PLOT_Y2AXIS;
          } else if (cant_zoom(line)) {
            plot->status |= PLOT_DONT_ZOOM;
          } 
      }

      if (!strncmp(line, "plot ", 5)) {
          break;
      }
    }

#ifdef ENABLE_NLS
    setlocale(LC_NUMERIC, "");
#endif

    fclose(fp);

    if (noedit) {
      return 1;
    }

#ifdef PNG_COMMENTS
    /* now try getting accurate coordinate info from PNG file */
    if (get_png_bounds_info(&b) == GRETL_PNG_OK) {
      plot->status |= PLOT_PNG_COORDS;
      got_x = got_y = 1;
      plot->pixel_xmin = b.xleft;
      plot->pixel_xmax = b.xright;
      plot->pixel_ymin = PLOT_PIXEL_HEIGHT - b.ytop;
      plot->pixel_ymax = PLOT_PIXEL_HEIGHT - b.ybot;
      plot->xmin = b.xmin;
      plot->xmax = b.xmax;
      plot->ymin = b.ymin;
      plot->ymax = b.ymax;
# ifdef POINTS_DEBUG
      fprintf(stderr, "get_png_bounds_info():\n"
            " xmin=%d xmax=%d ymin=%d ymax=%d\n", 
            plot->pixel_xmin, plot->pixel_xmax,
            plot->pixel_ymin, plot->pixel_ymax);
# endif
    } else {
      fprintf(stderr, "get_png_bounds_info(): failed\n");
    }
#endif /* PNG_COMMENTS */

    /* If got_x = 0 at this point, we didn't an x-range out of
       the gnuplot source file OR the PNG file, so we might as
       well give up.
    */

    if (got_x) {
      /* get the "dumb" coordinates only if we haven't got
         more accurate ones from the PNG file */
      if (!plot_has_png_coords(plot)) { 
          err = get_dumb_plot_yrange(plot);
      }

      if (!err) {
          got_y = 1;
          if ((plot->xmax - plot->xmin) / 
            (plot->pixel_xmax - plot->pixel_xmin) >= 1.0) {
            plot->xint = 1;
          }
          if ((plot->ymax - plot->ymin) / 
            (plot->pixel_ymax - plot->pixel_ymin) >= 1.0) {
            plot->yint = 1;
          }
      }
    }

    if (!got_x || !got_y) {
      plot->status |= (PLOT_DONT_ZOOM | PLOT_DONT_MOUSE);
#ifdef POINTS_DEBUG 
      fputs("get_plot_ranges: setting PLOT_DONT_ZOOM, PLOT_DONT_MOUSE\n", 
            stderr);
#endif
      err = 1;
    }

    return err;
}

static png_plot *png_plot_new (void)
{
    png_plot *plot;

    plot = mymalloc(sizeof *plot);
    if (plot == NULL) {
      return NULL;
    }

    plot->shell = NULL;
    plot->canvas = NULL;
    plot->popup = NULL;
    plot->statusarea = NULL;    
    plot->statusbar = NULL;
    plot->cursor_label = NULL;
    plot->pixmap = NULL;
    plot->invert_gc = NULL;
    plot->spec = NULL;
    plot->xmin = plot->xmax = 0.0;
    plot->ymin = plot->ymax = 0.0;
    plot->xint = plot->yint = 0;
    plot->pd = 0;
    plot->err = 0;
    plot->cid = 0;
    plot->zoom = NULL;
    plot->status = 0;
    plot->format = 0;
#ifndef OLD_GTK
    plot->labeled = NULL;
#endif

    return plot;
}

int gnuplot_show_png (const char *plotfile, GPT_SPEC *spec, int saved)
{
    png_plot *plot;
    int plot_has_xrange = 0;
    int err = 0;

    GtkWidget *vbox;
    GtkWidget *canvas_hbox;
    GtkWidget *label_frame = NULL;
    GtkWidget *status_hbox = NULL;

    plot = png_plot_new();
    if (plot == NULL) {
      return 1;
    }

    if (spec != NULL) {
      plot->spec = spec;
    } else {
      plot->spec = plotspec_new();
      if (plot->spec == NULL) {
          free(plot);
          return 1;
      }
      strcpy(plot->spec->fname, plotfile);
    }

    /* make png plot struct accessible via spec */
    plot->spec->ptr = plot;

    plot->zoom = mymalloc(sizeof *plot->zoom);
    if (plot->zoom == NULL) {
      if (spec == NULL) {
          free_plotspec(plot->spec);
      }
      free(plot);
      return 1;
    }

    if (saved) {
      plot->status |= PLOT_SAVED;
    }

    /* parse this file for x range */
    err = get_plot_ranges(plot);
    if (!err) {
      /* we'd better check that the full plot info is OK */
      err = read_plotspec_from_file(plot->spec);
      if (!err) {
          plot_has_xrange = 1;
      } else {
          plot->err = 1;
      }
    }

#ifdef OLD_GTK
    gtk_widget_push_visual(gdk_rgb_get_visual());
    gtk_widget_push_colormap(gdk_rgb_get_cmap());
    plot->shell = gtk_window_new(GTK_WINDOW_TOPLEVEL);
    gtk_widget_pop_visual();
    gtk_widget_pop_colormap();
#else
    plot->shell = gtk_window_new(GTK_WINDOW_TOPLEVEL);
#endif

    gtk_widget_ref(plot->shell);

    gtk_window_set_title(GTK_WINDOW(plot->shell), _("gretl: gnuplot graph")); 
#ifdef OLD_GTK
    gtk_window_set_policy(GTK_WINDOW(plot->shell), FALSE, FALSE, FALSE);
#else
    gtk_window_set_resizable(GTK_WINDOW(plot->shell), FALSE);
#endif

    vbox = gtk_vbox_new(FALSE, 2);
    gtk_container_add(GTK_CONTAINER(plot->shell), vbox);

    g_signal_connect(G_OBJECT(plot->shell), "destroy",
                 G_CALLBACK(destroy_png_plot), plot);
    g_signal_connect(G_OBJECT(plot->shell), "key_press_event", 
                 G_CALLBACK(plot_key_handler), plot);

    /* box to hold canvas */
    canvas_hbox = gtk_hbox_new(FALSE, 1);
    gtk_box_pack_start(GTK_BOX(vbox), canvas_hbox, TRUE, TRUE, 0);
    gtk_widget_show(canvas_hbox);

    /*  eventbox and hbox for status area  */
    plot->statusarea = gtk_event_box_new();
    gtk_box_pack_start(GTK_BOX(vbox), plot->statusarea, FALSE, FALSE, 0);

    status_hbox = gtk_hbox_new (FALSE, 2);
    gtk_container_add(GTK_CONTAINER(plot->statusarea), status_hbox);
    gtk_widget_show (status_hbox);
    gtk_container_set_resize_mode (GTK_CONTAINER (status_hbox),
                           GTK_RESIZE_QUEUE);

    /* Create drawing-area widget */
    plot->canvas = gtk_drawing_area_new();
#ifdef OLD_GTK
    gtk_drawing_area_size(GTK_DRAWING_AREA(plot->canvas), 
                    PLOT_PIXEL_WIDTH, PLOT_PIXEL_HEIGHT);
#else
    gtk_widget_set_size_request(GTK_WIDGET(plot->canvas), 
                        PLOT_PIXEL_WIDTH, PLOT_PIXEL_HEIGHT);
#endif
    gtk_widget_set_events (plot->canvas, GDK_EXPOSURE_MASK
                           | GDK_LEAVE_NOTIFY_MASK
                           | GDK_BUTTON_PRESS_MASK
                           | GDK_BUTTON_RELEASE_MASK
                           | GDK_POINTER_MOTION_MASK
                           | GDK_POINTER_MOTION_HINT_MASK);

    GTK_WIDGET_SET_FLAGS (plot->canvas, GTK_CAN_FOCUS);

    g_signal_connect(G_OBJECT(plot->canvas), "button_press_event", 
                 G_CALLBACK(plot_button_press), plot);
    g_signal_connect(G_OBJECT(plot->canvas), "button_release_event", 
                 G_CALLBACK(plot_button_release), plot);

    /* create the contents of the status area */
    if (plot_has_xrange) {
      /* cursor label (graph position indicator) */
      label_frame = gtk_frame_new(NULL);
      gtk_frame_set_shadow_type(GTK_FRAME(label_frame), GTK_SHADOW_IN);

      plot->cursor_label = gtk_label_new(" ");
      gtk_container_add(GTK_CONTAINER(label_frame), plot->cursor_label);
      gtk_widget_show(plot->cursor_label);
    }

    /* the statusbar */
    plot->statusbar = gtk_statusbar_new();
#ifdef OLD_GTK
    gtk_widget_set_usize(plot->statusbar, 1, -1);
#else
    gtk_widget_set_size_request(plot->statusbar, 1, -1);
    gtk_statusbar_set_has_resize_grip(GTK_STATUSBAR(plot->statusbar), FALSE);
#endif
    gtk_container_set_resize_mode(GTK_CONTAINER (plot->statusbar),
                          GTK_RESIZE_QUEUE);
    plot->cid = gtk_statusbar_get_context_id (GTK_STATUSBAR (plot->statusbar),
                                    "plot_message");

    if (!plot->err) {
      gtk_statusbar_push(GTK_STATUSBAR (plot->statusbar),
                     plot->cid, _(" Click on graph for pop-up menu"));
    }
    
    if (plot_has_xrange) {
      g_signal_connect(G_OBJECT(plot->canvas), "motion_notify_event",
                   G_CALLBACK(motion_notify_event), plot);
    }

    /* pack the widgets */
    gtk_box_pack_start(GTK_BOX(canvas_hbox), plot->canvas, FALSE, FALSE, 0);

    /* fill the status area */
    if (plot_has_xrange) {
      gtk_box_pack_start(GTK_BOX(status_hbox), label_frame, FALSE, FALSE, 0);
    }

    gtk_box_pack_start(GTK_BOX(status_hbox), plot->statusbar, TRUE, TRUE, 0); 

    /* show stuff */
    gtk_widget_show(plot->canvas);

    if (plot_has_xrange) {
      gtk_widget_show(label_frame);
    }

    gtk_widget_show(plot->statusbar);
    gtk_widget_show(plot->statusarea);

    gtk_widget_realize (plot->canvas);
    gdk_window_set_back_pixmap (plot->canvas->window, NULL, FALSE);

    if (plot_has_xrange) {
      gtk_widget_realize (plot->cursor_label);
#ifdef OLD_GTK
      gtk_widget_set_usize (plot->cursor_label, 140, -1);
#else
      gtk_widget_set_size_request (plot->cursor_label, 140, -1);
#endif
    }

    gtk_widget_show(vbox);
    gtk_widget_show(plot->shell);       

    /* set the focus to the canvas area */
    gtk_widget_grab_focus(plot->canvas);  

    plot->pixmap = gdk_pixmap_new(plot->shell->window, 
                          PLOT_PIXEL_WIDTH, PLOT_PIXEL_HEIGHT, 
                          -1);
    g_signal_connect(G_OBJECT(plot->canvas), "expose_event",
                 G_CALLBACK(plot_expose), plot->pixmap);

    render_pngfile(plot, PNG_START);

    return 0;
}

/* apparatus for getting coordinate info out of PNG files created using
   Allin Cottrell's modified version of gnuplot, which writes such info
   into the PNG comment fields
*/

#ifdef PNG_COMMENTS

static int get_png_plot_bounds (const char *str, png_bounds *bounds)
{
    int ret = GRETL_PNG_OK;

    if (sscanf(str, "xleft=%d xright=%d ybot=%d ytop=%d", 
             &bounds->xleft, &bounds->xright,
             &bounds->ybot, &bounds->ytop) != 4) {
      ret = GRETL_PNG_BAD_COMMENTS;
    } else if (bounds->xleft == 0 && bounds->xright == 0 &&
             bounds->ybot == 0 && bounds->ytop == 0) {
      ret = GRETL_PNG_NO_COORDS;
    } 

    return ret;
}

static int get_png_data_bounds (char *str, png_bounds *bounds)
{
    char *p = str;
    int ret = GRETL_PNG_OK;

    while (*p) {
      if (*p == ',') *p = '.';
      p++;
    }

#ifdef ENABLE_NLS
    setlocale(LC_NUMERIC, "C");
#endif

    if (sscanf(str, "xmin=%lf xmax=%lf ymin=%lf ymax=%lf", 
             &bounds->xmin, &bounds->xmax,
             &bounds->ymin, &bounds->ymax) != 4) {
      ret = GRETL_PNG_BAD_COMMENTS;
    } else if (bounds->xmin == 0.0 && bounds->xmax == 0.0 &&
             bounds->ymin == 0.0 && bounds->ymax == 0.0) {
      ret = GRETL_PNG_NO_COORDS;
    } 

#ifdef ENABLE_NLS
    setlocale(LC_NUMERIC, "");
#endif

    return ret;
}

#define PNG_CHECK_BYTES 4

static int get_png_bounds_info (png_bounds *bounds)
{
    FILE *fp;
    char header[PNG_CHECK_BYTES];
    char pngname[MAXLEN];
    png_structp png_ptr;
    png_infop info_ptr;
    png_text *text_ptr = NULL;
    int i, num_text;
    volatile int ret = GRETL_PNG_OK;

    build_path(paths.userdir, "gretltmp.png", pngname, NULL); 

    fp = gretl_fopen(pngname, "rb");
    if (fp == NULL) {
      return GRETL_PNG_NO_OPEN;
    }

    fread(header, 1, PNG_CHECK_BYTES, fp);

    if (png_sig_cmp(header, 0, PNG_CHECK_BYTES)) {
      fclose(fp);
      sprintf(errtext, "Bad PNG header: Got bytes %x %x %x %x", 
            header[0],header[1],header[2],header[3]);
      errbox(errtext);
      return GRETL_PNG_NOT_PNG;
    }

    png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, 
                             NULL, NULL, NULL);
    if (png_ptr == NULL) {
      fclose(fp);
      return GRETL_PNG_NO_OPEN;
    }

    info_ptr = png_create_info_struct(png_ptr);
    if (info_ptr == NULL) {
        png_destroy_read_struct(&png_ptr, (png_infopp) NULL, 
                        (png_infopp) NULL);
      fclose(fp);
        return GRETL_PNG_NO_OPEN;
    }

    if (setjmp(png_ptr->jmpbuf)) {
        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
        fclose(fp);
        return GRETL_PNG_NO_OPEN;
    }

    png_init_io(png_ptr, fp);

    png_set_sig_bytes(png_ptr, PNG_CHECK_BYTES);
    png_read_info(png_ptr, info_ptr);

    num_text = png_get_text(png_ptr, info_ptr, &text_ptr, &num_text);

    if (num_text > 1) {
      int plot_ret = -1, data_ret = -1;

      for (i=1; i<num_text; i++) {
          if (!strcmp(text_ptr[i].key, "plot bounds")) {
            plot_ret = get_png_plot_bounds(text_ptr[i].text, bounds);
          }
          if (!strcmp(text_ptr[i].key, "data bounds")) {
            data_ret = get_png_data_bounds(text_ptr[i].text, bounds);
          }
      }
      if (plot_ret == GRETL_PNG_NO_COORDS && data_ret == GRETL_PNG_NO_COORDS) {
          /* comments were present and correct, but all zero */
          ret = GRETL_PNG_NO_COORDS;
      }
      else if (plot_ret != GRETL_PNG_OK || data_ret != GRETL_PNG_OK) {
          /* one or both set of coordinates bad or missing */
          if (plot_ret >= 0 || data_ret >= 0) {
            ret = GRETL_PNG_BAD_COMMENTS;
          } else {
            ret = GRETL_PNG_NO_COMMENTS;
          }
      }
    } else {
      /* no coordinates comments present */
      ret = GRETL_PNG_NO_COMMENTS;
    }

    png_destroy_read_struct(&png_ptr, &info_ptr, NULL);

    fclose(fp);
    
    return ret;
}

#endif /* PNG_COMMENTS */

#ifdef G_OS_WIN32

/* win32: copy plot to clipboard by generating an EMF file (enhanced
   metafile), reading it into a buffer, and putting it on the
   clipboard.

   Weirdness: when an emf is put on the clipboard as below, Word 2000
   behaves thus: a straight "Paste" puts in a version of the graph
   with squashed up numbers on the axes and no legend text; but a
   "Paste special" (where one accepts the default of pasting it as an
   enhanced metafile) puts in an accurate version with correct text.
   Go figure.  (This is on win98)
*/

#include <gdk/gdkwin32.h>
#include "guiprint.h"

static int emf_to_clip (char *emfname)
{
    HWND mainw;
    HENHMETAFILE hemf, hemfclip;
    HANDLE htest;

    mainw = GDK_WINDOW_HWND(mdata->w->window);
    if (mainw == NULL) {
      errbox("Got NULL HWND");
      return 1;
    } 

    if (!OpenClipboard(mainw)) {
      errbox(_("Cannot open the clipboard"));
      return 1;
    }

    EmptyClipboard();

    hemf = GetEnhMetaFile(emfname);
    if (hemf == NULL) {
      errbox("Couldn't get handle to graphic metafile");
      return 1;
    }

    hemfclip = CopyEnhMetaFile(hemf, NULL);
    if (hemfclip == NULL) {
      errbox("Couldn't copy graphic metafile");
      return 1;
    }    

    htest = SetClipboardData(CF_ENHMETAFILE, hemfclip);
    if (htest == NULL) {
      errbox("Failed to put data on clipboard");
      return 1;
    }       

    CloseClipboard();

    DeleteEnhMetaFile(hemf);

    return 0;
}

static void win32_process_graph (GPT_SPEC *spec, int color, int dest)
{
    FILE *fq;
    PRN *prn;
    char plottmp[MAXLEN], plotline[MAXLEN];
    gchar *plotcmd = NULL;
    gchar *emfname = NULL;
    int err;

    /* create temporary file to hold the special gnuplot commands */
    if (!user_fopen("gptout.tmp", plottmp, &prn)) return;

    /* open the gnuplot source file for the graph */
    fq = gretl_fopen(spec->fname, "r");
    if (fq == NULL) {
      errbox(_("Couldn't access graph info"));
      gretl_print_destroy(prn);
      return;
    }

    /* generate gnuplot source file to make emf */
    pprintf(prn, "%s\n", get_gretl_emf_term_line(spec->code, color));
    emfname = g_strdup_printf("%sgpttmp.emf", paths.userdir);
    pprintf(prn, "set output '%s'\n", emfname);
    pprintf(prn, "set size 0.8,0.8\n");
    while (fgets(plotline, MAXLEN-1, fq)) {
      if (strncmp(plotline, "set term", 8) && 
          strncmp(plotline, "set output", 10))
          pprintf(prn, "%s", plotline);
    }

    gretl_print_destroy(prn);
    fclose(fq);

    /* get gnuplot to create the emf file */
    plotcmd = g_strdup_printf("\"%s\" \"%s\"", paths.gnuplot, 
                        plottmp);
    err = winfork(plotcmd, NULL, SW_SHOWMINIMIZED, 0);
    g_free(plotcmd);
    remove(plottmp);
    
    if (err) {
        errbox(_("Gnuplot error creating graph"));
    } else if (dest == WIN32_TO_CLIPBOARD) {
      err = emf_to_clip(emfname);
      if (!err) {
          infobox(_("To paste, use Edit/Paste special.../Enhanced metafile"));
      }
    } else if (dest == WIN32_TO_PRINTER) {
      err = winprint_graph(emfname);
    }

    remove(emfname);
    g_free(emfname);
}

#endif /* G_OS_WIN32 */


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