/*
 *  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.
 *
 */

/* session.c for gretl */

#include "gretl.h"
#include "session.h"
#include "selector.h"
#include "boxplots.h"
#include "ssheet.h"
#include "plotspec.h"
#include "gpt_control.h"
#include "guiprint.h"
#include "model_table.h"
#include "graph_page.h"
#include "textbuf.h"
#include "cmdstack.h"
#include "filelists.h"
#include "dlgutils.h"
#include "fileselect.h"
#include "menustate.h"
#include "lib_private.h"

#include "var.h"
#include "varprint.h"
#include "objstack.h"
#include "system.h"
#include "gretl_xml.h"
#include "gretl_func.h"
#include "modelspec.h"
#include "cmd_private.h"

#include <sys/stat.h>
#include <unistd.h>
#include <dirent.h>
#include <errno.h>

#ifdef _WIN32
# include <windows.h>
# include "gretlwin32.h"
#endif

static void auto_save_gp (windata_t *vwin);

#include "../pixmaps/model.xpm"
#include "../pixmaps/boxplot.xpm"
#include "../pixmaps/gnuplot.xpm"
#include "../pixmaps/xfm_sc.xpm"
#include "../pixmaps/xfm_info.xpm"
#include "../pixmaps/xfm_text.xpm"
#include "../pixmaps/rhohat.xpm"
#include "../pixmaps/summary.xpm"
#include "../pixmaps/model_table.xpm"
#include "../pixmaps/graph_page.xpm"
#include "../pixmaps/matrix.xpm"

#define SESSION_DEBUG 0

#define SHOWNAMELEN 12
#define ICONVIEW_MIN_COLS 4

typedef struct SESSION_ SESSION;
typedef struct SESSION_TEXT_ SESSION_TEXT;
typedef struct SESSION_MODEL_ SESSION_MODEL;
typedef struct SESSION_GRAPH_ SESSION_GRAPH;
typedef struct gui_obj_ gui_obj;

enum {
    SESSION_CHANGED = 1 << 0,
    SESSION_SAVED   = 1 << 1
};

struct SESSION_ {
    char name[MAXLEN];
    char dirname[MAXLEN];
    int status;
    int nmodels;
    int ngraphs;
    int ntexts;
    SESSION_GRAPH **graphs;
    SESSION_MODEL **models;
    SESSION_TEXT **texts;
    char *notes;
};

struct SESSION_TEXT_ {
    char name[MAXSAVENAME];
    char *buf;
};

struct SESSION_MODEL_ {
    char name[MAXSAVENAME];
    void *ptr;
    GretlObjType type;
};

struct SESSION_GRAPH_ {
    char name[MAXSAVENAME];
    char fname[MAXLEN];
    int ID;
    GretlObjType type;
}; 

struct gui_obj_ {
    gchar *name;
    gint sort;
    gpointer data;
    GtkWidget *icon;
    GtkWidget *label;
    gint row, col;
};

struct sample_info {
    int t1;
    int t2;
    char *mask;
    int mode;
};

enum {
    ICON_ADD_BATCH,
    ICON_ADD_SINGLE
} icon_add_modes;

enum {
    SAVEFILE_SESSION,
    SAVEFILE_SCRIPT,
    SAVEFILE_ERROR
} savefile_returns;

static GtkTargetEntry session_drag_targets[] = {
    { "model_pointer", GTK_TARGET_SAME_APP, GRETL_MODEL_POINTER },
    { "text/uri-list", 0, GRETL_FILENAME }
};

static char *global_items[] = {
    N_("Save session"),
    N_("Arrange icons"),
    N_("Close window")
};

static char *model_items[] = {
    N_("Display"),
    N_("Add to model table"),
    N_("Delete")
};

static char *model_table_items[] = {
    N_("Display"),
    N_("Clear"),
    N_("Options"),
    N_("Help")
};

static char *graph_page_items[] = {
    N_("Display"),
    N_("Save as TeX..."),
    N_("Clear"),
    N_("Help")
};

static char *var_items[] = {
    N_("Display"),
    N_("Delete")
};

static char *graph_items[] = {
    N_("Display"),
    N_("Edit plot commands"),
    N_("Delete")
};

static char *dataset_items[] = {
    N_("Edit"),
    N_("Save..."),
    N_("Export as CSV..."),
    N_("Copy as CSV...")
};

static char *info_items[] = {
    N_("View"),
    N_("Edit"),
};

static char *matrix_items[] = {
    N_("View"),
    N_("Edit"),
    N_("Properties"),
    N_("Delete")
};

/* file-scope globals */

SESSION session;            /* hold models, graphs */

static int session_file_open;

static GtkWidget *iconview;
static GtkWidget *icon_table;
static GtkWidget *global_popup;
static GtkWidget *model_popup;
static GtkWidget *model_table_popup;
static GtkWidget *var_popup;
static GtkWidget *graph_popup;
static GtkWidget *graph_page_popup;
static GtkWidget *boxplot_popup;
static GtkWidget *data_popup;
static GtkWidget *info_popup;
static GtkWidget *matrix_popup;
static GtkWidget *save_item;

static GList *icon_list;
static gui_obj *active_object;
static gint iconview_width;
static gint iconview_cols;
static gint in_icon;

/* private functions */
static gui_obj *gui_object_new (gchar *name, int sort);
static gui_obj *session_add_icon (gpointer data, int sort, int mode);
static void session_build_popups (void);
static void global_popup_activated (GtkWidget *widget, gpointer data);
static void object_popup_activated (GtkWidget *widget, gpointer data);
static void data_popup_activated (GtkWidget *widget, gpointer data);
static void info_popup_activated (GtkWidget *widget, gpointer data);
static void matrix_popup_activated (GtkWidget *widget, gpointer data);
static void session_delete_icon (gui_obj *obj);
static void open_gui_graph (gui_obj *obj);
static void open_boxplot (gui_obj *obj);
static gboolean session_view_click (GtkWidget *widget, 
				    GdkEventButton *event,
				    gpointer data);
static int real_delete_model_from_session (SESSION_MODEL *model);
static void rename_session_object (gui_obj *obj, const char *newname);

static int session_graph_count;
static int session_bplot_count;

int session_is_modified (void)
{
    return session.status & SESSION_CHANGED;
}

void mark_session_changed (void)
{
    session.status = SESSION_CHANGED;
    if (save_item != NULL) {
	gtk_widget_set_sensitive(save_item, TRUE);
	flip(mdata->ifac, "/File/Session files/Save session", TRUE);
    }
}

static void mark_session_saved (void)
{
    session.status = SESSION_SAVED;
    if (save_item != NULL) {
	gtk_widget_set_sensitive(save_item, FALSE);
	flip(mdata->ifac, "/File/Session files/Save session", FALSE);
    }
}

/* constructors and destructors for session data-objects */

static void free_session_text (SESSION_TEXT *text)
{
    free(text->buf);
    free(text);
}

static void free_session_model (SESSION_MODEL *mod)
{
    /* note: remove a reference to this model */
#if SESSION_DEBUG
    fprintf(stderr, "free_session_model: unref'ing ptr at %p\n", (void *) mod->ptr);
    fprintf(stderr, " also freeing session_model at %p\n", mod);
#endif
    gretl_object_unref(mod->ptr, mod->type);
    free(mod);
}

static SESSION_MODEL *session_model_new (void *ptr, const char *name, 
					 GretlObjType type)
{
    SESSION_MODEL *mod = mymalloc(sizeof *mod);

    if (mod != NULL) {
	mod->ptr = ptr;
	mod->type = type;
	if (name == NULL) {
	    gretl_object_compose_name(ptr, type);
	    name = gretl_object_get_name(ptr, type);
	} 
	*mod->name = 0;
	strncat(mod->name, name, MAXSAVENAME - 1);

	/* note: take care of adding a refence to model */
	gretl_object_ref(ptr, type);
    }

    return mod;
}

static void free_session_graph (SESSION_GRAPH *graph)
{
    /* no allocated members at present */
    free(graph);
}

static int session_append_text (const char *tname, char *buf)
{
    SESSION_TEXT *text;
    SESSION_TEXT **texts;
    int nt = session.ntexts;

    text = mymalloc(sizeof *text);
    if (text == NULL) {
	return 1;
    }

    text->buf = buf;

    *text->name = '\0';
    if (tname != NULL) {
	strncat(text->name, tname, MAXSAVENAME - 1);
    }

    texts = myrealloc(session.texts, (nt + 1) * sizeof *texts);

    if (texts == NULL) {
	free_session_text(text);
	return 1;
    }

    session.texts = texts;
    session.texts[nt] = text;
    session.ntexts += 1;

    return 0;
}

static int session_append_model (SESSION_MODEL *mod)
{
    SESSION_MODEL **models;
    int nm = session.nmodels;

    models = myrealloc(session.models, (nm + 1) * sizeof *models);
    if (models == NULL) {
	free_session_model(mod);
	return 1;
    }

    session.models = models;
    session.models[nm] = mod;
    session.nmodels += 1;

#if SESSION_DEBUG
    fprintf(stderr, "session_append_model: nmodels now = %d\n",
	    session.nmodels);
#endif

    return 0;
}

static SESSION_GRAPH *
session_append_graph (const char *grname,
		      const char *fname,
		      GretlObjType type)
{
    SESSION_GRAPH *graph;
    SESSION_GRAPH **graphs;
    int ng = session.ngraphs;

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

    *graph->name = '\0';
    if (grname != NULL) {
	strncat(graph->name, grname, MAXSAVENAME - 1);
    }

    *graph->fname = '\0';
    if (fname != NULL) {
	strncat(graph->fname, fname, MAXLEN - 1);
    }	

    graph->type = type;

    graphs = myrealloc(session.graphs, (ng + 1) * sizeof *graphs);

    if (graphs == NULL) {
	free_session_graph(graph);
	return NULL;
    }

    session.graphs = graphs;
    session.graphs[ng] = graph;
    graph->ID = session.ngraphs++;

    if (type == GRETL_OBJ_GRAPH) {
	session_graph_count++;
    } else {
	session_bplot_count++;
    }

    return graph;
}

/* first arg should be a MAXLEN string */

static char *session_file_make_path (char *path, const char *fname)
{
#if SESSION_DEBUG
    fprintf(stderr, "session_file_make_path: fname = '%s'\n", fname);
#endif

    if (g_path_is_absolute(fname)) {
	strcpy(path, fname);
    } else {
	sprintf(path, "%s%c%s", session.dirname, SLASH, fname);
    } 

#if SESSION_DEBUG
    fprintf(stderr, "session_file_make_path: path = '%s'\n", path);
#endif

    return path;
}

#include "session_xml.c"

static void edit_session_notes (void)
{
    static GtkWidget *notes_window;

    if (notes_window == NULL) {
	windata_t *vwin;

	vwin = edit_buffer(&session.notes, 80, 400, 
			   _("gretl: session notes"),
			   EDIT_NOTES);
	notes_window = vwin->dialog;
	g_signal_connect(G_OBJECT(vwin->dialog), "destroy",
			 G_CALLBACK(gtk_widget_destroyed),
			 &notes_window);
    } else {
	gdk_window_show(notes_window->window);
	gdk_window_raise(notes_window->window);
    }
}

int is_session_model (void *p)
{
    int i;

#if SESSION_DEBUG
    fprintf(stderr, "is_session_model: testing %p (nmodels = %d)\n", 
	    p, session.nmodels);
#endif

    for (i=0; i<session.nmodels; i++) {
	if (p == session.models[i]->ptr) {
	    return 1;
	}
    }
    return 0;
}

static SESSION_MODEL *get_session_model_by_name (const char *name)
{
    int i;

    for (i=0; i<session.nmodels; i++) {
	if (!strcmp(name, session.models[i]->name)) {
	    return session.models[i];
	}
    }

    return NULL;
}

static SESSION_GRAPH *get_session_graph_by_name (const char *name)
{
    int i;

    for (i=0; i<session.ngraphs; i++) {
	if (!strcmp(name, session.graphs[i]->name)) {
	    return session.graphs[i];
	}
    }

    return NULL;
}

static SESSION_TEXT *get_session_text_by_name (const char *name)
{
    int i;

    for (i=0; i<session.ntexts; i++) {
	if (!strcmp(name, session.texts[i]->name)) {
	    return session.texts[i];
	}
    }

    return NULL;
}

int real_add_text_to_session (PRN *prn, const char *tname)
{
    SESSION_TEXT *text = get_session_text_by_name(tname);
    char *buf = gretl_print_get_chunk(prn);
    int replace = 0;

    if (buf == NULL) {
	return ADD_OBJECT_FAIL;
    }

    if (text != NULL) {
	free(text->buf);
	text->buf = buf;
	replace = 1;
    } else {
	if (session_append_text(tname, buf)) {
	    return ADD_OBJECT_FAIL;
	}
    }
    
    mark_session_changed();

    if (icon_list != NULL && !replace) {
	session_add_icon(text, GRETL_OBJ_TEXT, ICON_ADD_SINGLE);
    }

    return (replace)? ADD_OBJECT_REPLACE : ADD_OBJECT_OK;
}


static int real_add_model_to_session (void *ptr, const char *name,
				      GretlObjType type)
{
    SESSION_MODEL *mod;

#if SESSION_DEBUG
    fprintf(stderr, "real_add_model_to_session: doing session_model_new\n"
	    " with ptr = %p\n", ptr);
#endif

    mod = session_model_new(ptr, name, type);
    if (mod == NULL || session_append_model(mod)) {
	return 1;
    } 

    if (icon_list != NULL) {
	session_add_icon(mod, type, ICON_ADD_SINGLE);
    }

    return 0;
}

static int 
real_add_graph_to_session (const char *fname, const char *grname,
			   GretlObjType type)
{
    SESSION_GRAPH *graph = get_session_graph_by_name(grname);
    int replace = 0;

    if (graph != NULL) {
	graph->type = type;
	strcpy(graph->fname, fname);	
	replace = 1;
    } else {
	graph = session_append_graph(grname, fname, type);
	if (graph == NULL) {
	    return ADD_OBJECT_FAIL;
	}
    }

    mark_session_changed();

    if (icon_list != NULL && !replace) {
	session_add_icon(graph, type, ICON_ADD_SINGLE);
    }

    return (replace)? ADD_OBJECT_REPLACE : ADD_OBJECT_OK;
}

const char *get_session_dirname (void)
{
    return session.dirname;
}

static int session_dir_ok (void)
{
    int ret = 1;

    if (*session.dirname == '\0') {
	pid_t p = getpid();

	errno = 0;

	sprintf(session.dirname, ".gretl-%d", (int) p); /* added dot! */
	if (chdir(paths.userdir)) {
	    perror("moving to user directory");
	    ret = 0;
	} else if (gretl_mkdir(session.dirname)) {
	    ret = 0;
	}
    }

    return ret;
}

int add_graph_to_session (char *fname, char *fullname)
{
    char shortname[MAXSAVENAME];
    char graphname[MAXSAVENAME];
    int err = 0;

    if (Z == NULL) {
	/* we may be called via the "stats calculator" when
	   there's no dataset yet */
	err = open_nulldata(&Z, datainfo, DATA_NONE, 10, NULL);
	if (err) {
	    gui_errmsg(err);
	    return 1;
	}
	register_data(NULL, NULL, 0);
    }
    
    errno = 0;

    if (!session_dir_ok()) {
	errbox(_("Failed to copy graph file"));
	return 1;
    }

    chdir(paths.userdir);

    sprintf(shortname, "graph.%d", session_graph_count + 1);
    session_file_make_path(fullname, shortname);
    sprintf(graphname, "%s %d", _("Graph"), session_graph_count + 1);

    /* move temporary plot file to permanent */
    if (copyfile(fname, fullname)) {
	return 1;
    } 

    remove(fname);
    strcpy(fname, shortname);

    err = real_add_graph_to_session(shortname, graphname, GRETL_OBJ_GRAPH);
    if (err == ADD_OBJECT_FAIL) {
	err = 1;
    }

    return err;
}

void add_boxplot_to_session (const char *boxtmp)
{
    char fname[MAXSAVENAME];
    char grname[MAXSAVENAME];
    char grpath[MAXLEN];

    errno = 0;

    if (!session_dir_ok()) {
	errbox(_("Failed to copy graph file"));
	return;
    }

    chdir(paths.userdir);

    sprintf(fname, "plot.%d", session_bplot_count + 1);
    session_file_make_path(grpath, fname);
    sprintf(grname, "%s %d", _("Boxplot"), session_bplot_count + 1);

    if (copyfile(boxtmp, grpath)) {
	return;
    } 

    real_add_graph_to_session(fname, grname, GRETL_OBJ_PLOT);
}

int cli_add_graph_to_session (const char *fname, const char *gname,
			      GretlObjType type)
{
    char name[MAXSAVENAME];
    char grpath[MAXLEN];
    
    errno = 0;

    if (!session_dir_ok()) {
	errbox(_("Failed to copy graph file"));
	return ADD_OBJECT_FAIL;
    }

    chdir(paths.userdir);

    strcpy(name, gname);
    space_to_score(name);

    session_file_make_path(grpath, name);
    if (copyfile(fname, grpath)) {
	errbox(_("Failed to copy graph file"));
	return ADD_OBJECT_FAIL;
    } 
    remove(fname);

    return real_add_graph_to_session(name, gname, type);
}

void *get_session_object_by_name (const char *name, GretlObjType *type)
{
    int i;

    for (i=0; i<session.nmodels; i++) {
	if (!strcmp(name, session.models[i]->name)) {
	    *type = session.models[i]->type;
	    return session.models[i]->ptr;
	}
    }

    for (i=0; i<session.ngraphs; i++) {
	if (!strcmp(name, session.graphs[i]->name)) {
	    *type = GRETL_OBJ_GRAPH;
	    return session.graphs[i];
	}
    }

    for (i=0; i<session.ntexts; i++) {
	if (!strcmp(name, session.texts[i]->name)) {
	    *type = GRETL_OBJ_TEXT;
	    return session.texts[i];
	}
    }

    return NULL;
}

static SESSION_MODEL *get_session_model_by_data (const void *ptr)
{
    int i;

    for (i=0; i<session.nmodels; i++) {
	if (ptr == session.models[i]->ptr) {
	    return session.models[i];
	}
    }

    return NULL;
}

int maybe_add_model_to_session (void *ptr, GretlObjType type)
{
    SESSION_MODEL *oldmod;
    const char *name;

    if (get_session_model_by_data(ptr)) {
	/* model already present */
	return 1;
    }

    /* check to see if there's already a (different) model with the
       same name: if so, delete it
    */
    name = gretl_object_get_name(ptr, type);
    oldmod = get_session_model_by_name(name);
    if (oldmod != NULL) {
	real_delete_model_from_session(oldmod);
    }

    return real_add_model_to_session(ptr, name, type);
}

void model_add_as_icon (gpointer p, guint type, GtkWidget *w)
{
    windata_t *vwin = (windata_t *) p;
    void *ptr = vwin->data;
    const char *name;

    if (ptr == NULL) {
	return;
    }

#if SESSION_DEBUG
    fprintf(stderr, "model_add_as_icon: ptr = %p\n", ptr);
#endif

    if (get_session_model_by_data(ptr)) {
	infobox(_("Model is already saved"));
	return;
    }

    name = gretl_object_get_name(ptr, type);

    if (real_add_model_to_session(ptr, name, type)) {
	return;
    }

    mark_session_changed();
}

void model_add_as_icon_and_close (gpointer p, guint type, GtkWidget *w)
{
    windata_t *vwin = (windata_t *) p;

    model_add_as_icon(p, type, w);

    if (!window_is_busy(vwin)) {
	gtk_widget_destroy(gtk_widget_get_toplevel(GTK_WIDGET(vwin->w)));
    } 
}

static void
session_name_from_session_file (char *sname, const char *fname)
{
    const char *p = strrchr(fname, SLASH);
    char *q;

    if (p != NULL) {
	strcpy(sname, p + 1);
    } else {
	strcpy(sname, fname);
    }

    q = strstr(sname, ".gretl");
    if (q != NULL && strlen(q) == 6) {
	*q = '\0';
    }

    fprintf(stderr, "session_name_from_session_file: %s -> %s\n",
	    fname, sname);
}

static int unzip_session_file (const char *fname)
{
    int (*gretl_unzip_file)(const char *, GError **);
    void *handle;
    FILE *fp;
    GError *gerr = NULL;
    int err, ret = SAVEFILE_SESSION;

    fp = gretl_fopen(fname, "r");
    if (fp == NULL) {
	return SAVEFILE_ERROR;
    }
    fclose(fp);

    chdir(paths.userdir);

    gretl_unzip_file = gui_get_plugin_function("gretl_unzip_file", 
					       &handle);
    if (gretl_unzip_file == NULL) {
        return 1;
    }

    err = (*gretl_unzip_file)(fname, &gerr);
    if (gerr != NULL) {
	ret = SAVEFILE_ERROR;
	g_error_free(gerr);
    } else if (err) {
	ret = SAVEFILE_ERROR;
    }

    /* FIXME backward compat: try fallback to old-style session file */

    close_plugin(handle);

    return ret;
}

static void sinfo_init (struct sample_info *sinfo)
{
    sinfo->t1 = 0;
    sinfo->t2 = 0;
    sinfo->mask = NULL;
    sinfo->mode = SUBSAMPLE_NONE;
}

static int set_session_dirname (const char *sname)
{
    char test[MAXLEN];
    FILE *fp;
    int err = 0;

    sprintf(session.dirname, ".%s", sname);
    sprintf(test, "%s%csession.xml", session.dirname, SLASH);
    fp = gretl_fopen(test, "r");

    if (fp != NULL) {
	fclose(fp);
    } else {
	/* try without leading dot */
	strcpy(session.dirname, sname);
	sprintf(test, "%s%csession.xml", session.dirname, SLASH);
	fp = gretl_fopen(test, "r");
	if (fp != NULL) {
	    fclose(fp);
	} else {
	    err = E_FOPEN;
	}
    }

    return err;
}

void do_open_session (void)
{
    struct sample_info sinfo;
    char sname[MAXLEN];
    char fname[MAXLEN];
    FILE *fp;
    int status, err = 0;

    sinfo_init(&sinfo);

    fp = gretl_fopen(tryfile, "r");
    if (fp != NULL) {
	fclose(fp);
    } else {
	errbox(_("Couldn't open %s\n"), tryfile);
	delete_from_filelist(FILE_LIST_SESSION, tryfile);
	delete_from_filelist(FILE_LIST_SCRIPT, tryfile);
	return;
    }

    /* close existing session, if any, and initialize */
    close_session(NULL, &Z, &datainfo);

    strcpy(sessionfile, tryfile);
    fprintf(stderr, I_("\nReading session file %s\n"), sessionfile);

    chdir(paths.userdir);
    status = unzip_session_file(sessionfile);

    if (status == SAVEFILE_ERROR) {
	/* FIXME more explicit error message */
	errbox(_("Couldn't open %s"), sessionfile);
	return;
    } else if (status == SAVEFILE_SCRIPT) {
	strcpy(scriptfile, sessionfile);
	*sessionfile = '\0';
	do_open_script();
	return;
    }

    session_name_from_session_file(sname, sessionfile);
    strcpy(session.name, sname);
    
    err = set_session_dirname(sname);
    if (err) {
	errbox(_("Couldn't open %s"), "session.xml");
	return;
    }

    session_file_make_path(fname, "session.xml");
    err = read_session_xml(fname, &sinfo);

    if (err) {
	/* FIXME more explicit error message */
	errbox(_("Couldn't open %s"), "session.xml");
	return;
    }

    session_file_make_path(paths.datfile, "data.gdt");
    err = gretl_read_gdt(&Z, &datainfo, paths.datfile, &paths, DATA_NONE, 
			 NULL, 1);
    if (err) {
	/* FIXME more explicit error message */
	errbox(_("Couldn't open %s"), "data.gdt");
	return;
    }

    session_file_make_path(fname, "matrices.xml");
    err = maybe_read_matrix_file(fname);

    session_file_make_path(fname, "functions.xml");
    err = maybe_read_functions_file(fname);

    session_file_make_path(fname, "lists.xml");
    err = maybe_read_lists_file(fname);

    if (sinfo.mask != NULL) {
	err = restrict_sample_from_mask(sinfo.mask, sinfo.mode, &Z, &datainfo,
					NULL);
    }

    if (err) {
	errbox(_("Couldn't set sample"));
	return;
    }

    datainfo->t1 = sinfo.t1;
    datainfo->t2 = sinfo.t2;

    register_data(paths.datfile, NULL, 0);

    if (sinfo.mask != NULL) {
	set_sample_label(datainfo);
	free(sinfo.mask);
    }

    mkfilelist(FILE_LIST_SESSION, sessionfile);

    /* sync gui with session */
    session_file_open = 1;
    session_menu_state(TRUE);

    view_session();
    mark_session_saved();
}

int is_session_file (const char *fname)
{
    int (*gretl_is_zipfile)(const char *);
    void *handle;
    int ret;

    gretl_is_zipfile = gui_get_plugin_function("gretl_is_zipfile", &handle);
    if (gretl_is_zipfile == NULL) {
        return 0;
    }   

    ret = (*gretl_is_zipfile)(fname);

    close_plugin(handle);

    return ret;
}

void verify_clear_data (void)
{
    if (dataset_locked()) {
	return;
    }

    if (!expert) {
        if (yes_no_dialog ("gretl",                      
			   _("Clearing the data set will end\n"
			     "your current session.  Continue?"), 
			   0) != GRETL_YES) {
            return;
	}
    }

    close_session(NULL, &Z, &datainfo);
}

#ifndef G_OS_WIN32

static const char *readd (DIR *d)
{
    struct dirent *e = readdir(d);

    return (e == NULL)? NULL : e->d_name;
}

#endif

static void remove_session_dir (void)
{
#ifdef G_OS_WIN32
    char *fullpath = g_strdup_printf("%s%s", paths.userdir,
				     session.dirname);

    chdir(paths.userdir);
    win32_delete_dir(fullpath);
    g_free(fullpath);
#else
    const char *fname;
    DIR *dir;

    chdir(paths.userdir);
    dir = opendir(session.dirname);

    if (dir != NULL) {
	chdir(session.dirname);
	while ((fname = readd(dir)) != NULL) {
	    if (strcmp(fname, ".") && strcmp(fname, "..")) {
		remove(fname);
	    }
	}
	closedir(dir);
	chdir(paths.userdir);
	remove(session.dirname);
    }
#endif
}

void session_init (void)
{
    session.models = NULL;
    session.graphs = NULL;
    session.texts = NULL;
    session.notes = NULL;

    session.status = 0; /* note: neither changed nor saved */
    session.nmodels = 0;
    session.ngraphs = 0;
    session.ntexts = 0;
    *session.name = '\0';
    *session.dirname = '\0';

    winstack_init();
}

void free_session (void)
{
    int i;

    if (session.models) {
	for (i=0; i<session.nmodels; i++) {
	    free_session_model(session.models[i]);
	}
	free(session.models);
	session.models = NULL;
    }

    if (session.graphs) {
	for (i=0; i<session.ngraphs; i++) {
	    free_session_graph(session.graphs[i]);
	}
	free(session.graphs);
	session.graphs = NULL;
    }

    if (session.texts) {
	for (i=0; i<session.ntexts; i++) {
	    free_session_text(session.texts[i]);
	}	
	free(session.texts);
	session.texts = NULL;
    }

    if (session.notes) {
	free(session.notes);
	session.notes = NULL;
    }

    session.nmodels = 0;
    session.ngraphs = 0;
    session.ntexts = 0;

    *session.name = '\0';

    if (*session.dirname != '\0') {
	remove_session_dir();
	*session.dirname = '\0';
    }

#if defined(HAVE_FLITE) || defined(G_OS_WIN32)
    stop_talking();
#endif
}

int highest_numbered_variable_in_session (void)
{
    MODEL *pmod;
    GRETL_VAR *var;
    gretl_equation_system *sys;
    int i, mvm, vmax = 0;

    if (session.models) {
	for (i=0; i<session.nmodels; i++) {
	    if (session.models[i]->type == GRETL_OBJ_EQN) {
		pmod = session.models[i]->ptr;
		if (pmod != NULL) {
		    mvm = highest_numbered_var_in_model(pmod, datainfo);
		    if (mvm > vmax) {
			vmax = mvm;
		    }
		}
	    } else if (session.models[i]->type == GRETL_OBJ_VAR) {
		var = session.models[i]->ptr;
		if (var != NULL) {
		    mvm = gretl_VAR_get_highest_variable(var, datainfo);
		    if (mvm > vmax) {
			vmax = mvm;
		    }
		}		
	    } else if (session.models[i]->type == GRETL_OBJ_SYS) {
		sys = session.models[i]->ptr;
		if (sys != NULL) {
		    mvm = highest_numbered_var_in_system(sys, datainfo);
		    if (mvm > vmax) {
			vmax = mvm;
		    }
		}
	    }
	}
    }

    return vmax;
}

int session_file_is_open (void)
{
    return session_file_open;
}

void gui_clear_dataset (void)
{
    *paths.datfile = 0;

    if (Z != NULL) {
	free_Z(Z, datainfo);
	Z = NULL;
    } 

    clear_datainfo(datainfo, CLEAR_FULL);

    clear_varlist(mdata->listbox);
    clear_sample_label();

    data_status = 0;
    orig_vars = 0;
    main_menubar_state(FALSE);
}

static void 
session_clear_data (double ***pZ, DATAINFO **ppdinfo, int realclean)
{
    gui_restore_sample(pZ, ppdinfo);
    gui_clear_dataset();

    /* clear protected models */
    clear_model(models[0]);
    clear_model(models[1]);
    clear_model(models[2]);

    if (realclean) {
	free_command_stack(); 
    }

    free_modelspec();
    reset_model_count();

    lib_cmd_destroy_context();
}

void close_session (ExecState *s, double ***pZ, DATAINFO **ppdinfo)
{
    int realclean = 1;

    /* if we're running the "command log" to get text output
       (SESSION_EXEC), then don't destroy saved stuff */
    if (s != NULL && (s->flags & SESSION_EXEC)) {
	realclean = 0;
    }

#if SESSION_DEBUG
    fprintf(stderr, "close_session: starting cleanup\n");
#endif
    session_clear_data(pZ, ppdinfo, realclean); 

    if (realclean) {
	free_session();

	clear_model_table(NULL);
	clear_graph_page();

	session_menu_state(FALSE);
	session_file_open = 0;
	*scriptfile = '\0';
	*sessionfile = '\0';

	if (iconview != NULL) {
	    gtk_widget_destroy(iconview);
	}

	session.status = 0;
    }

    winstack_destroy();
    clear_selector();
    edit_dialog_special_get_text(NULL);

    if (realclean) {
	libgretl_session_cleanup();
    }

    session_graph_count = 0;
    session_bplot_count = 0;

    reset_plot_count();
}

static int session_overwrite_check (const char *fname)
{
    int ret = 0;

    if (strcmp(fname, sessionfile)) {
	FILE *fp = gretl_fopen(fname, "r");

	if (fp != NULL) {
	    int resp;

	    fclose(fp);
	    resp = yes_no_dialog("gretl", _("There is already a session file of this name.\n"
					    "OK to overwrite it?"), 0);
	    if (resp == GRETL_NO) {
		ret = 1;
	    }
	}
    } 

    return ret;
}

static void relpath_from_fname (char *path, const char *fname)
{
    const char *p;

    strcpy(path, ".");

    p = (*fname == SLASH)? fname + 1 : fname;
    p = strrchr(p, SLASH);

    if (p != NULL) {
	strcat(path, p + 1);
    } else {
	strcat(path, fname);
    }
}

static int save_session_dataset (void)
{
    char tmpname[MAXLEN];
    const double **dZ = NULL;
    DATAINFO *dinfo = NULL;
    int t1, t2;
    int err = 0;

    /* dump current dataset into session dir */
    if (complex_subsampled()) {
	/* save full version of dataset */
	double ***fullZ = fetch_full_Z();

	dZ = (const double **) *fullZ;
	dinfo = fetch_full_datainfo();
    } else {
	dZ = (const double **) Z;
	dinfo = datainfo;
    }

    t1 = dinfo->t1;
    t2 = dinfo->t2;
    dinfo->t1 = 0;
    dinfo->t2 = dinfo->n - 1;
    session_file_make_path(tmpname, "data.gdt");
    err = gretl_write_gdt(tmpname, NULL, dZ, dinfo, 0, NULL);
    dinfo->t1 = t1;
    dinfo->t2 = t2;
    
    return err;
}

int save_session (char *fname) 
{
    char dirname[MAXLEN];
    void *handle;
    int (*gretl_make_zipfile) (const char *, const char *, GError **);
    int len, err = 0;
    GError *gerr = NULL;

    if (session_overwrite_check(fname)) {
	return 0;
    }

    if (!session_dir_ok()) {
	errbox("Couldn't make session directory");
	return 1;
    }

    /* organize directory and file names */
    relpath_from_fname(dirname, fname);
    len = strlen(fname);
    if (len > 6 && !strncmp(fname + len - 6, ".gretl", 6)) {
	dirname[strlen(dirname) - 6] = '\0';
    } else {
	strcat(fname, ".gretl");
    }

    /* paths below are relative to this */
    chdir(paths.userdir);

    if (strcmp(dirname, session.dirname)) {
	/* rename session directory */
	rename(session.dirname, dirname);
	strcpy(session.dirname, dirname);
    }

    write_session_xml();
    err = save_session_dataset();
    
    if (!err) {
	gretl_make_zipfile = gui_get_plugin_function("gretl_make_zipfile", 
						     &handle);
	if (gretl_make_zipfile == NULL) {
	    return 1;
	}

	/* make zipfile containing session files */
	err = (*gretl_make_zipfile)(fname, dirname, &gerr);
	close_plugin(handle);
    }

    if (!err) {
	mkfilelist(FILE_LIST_SESSION, fname);
	mark_session_saved();
    }

    return err;
}

void save_session_callback (GtkWidget *w, guint code, gpointer data)
{
    if (code == SAVE_AS_IS && session_file_open && sessionfile[0]) {
	save_session(sessionfile);
    } else {
	file_selector(_("Save session"), SAVE_SESSION, FSEL_DATA_NONE, NULL);
    }
}

static char *model_cmd_str (MODEL *pmod)
{
    char *str = NULL;

    if (pmod->ci == MLE || pmod->ci == GMM || pmod->ncoeff > 10 ||
	pmod->list[0] > 10) {
	return NULL;
    }

    str = malloc(MAXLEN);
    if (str == NULL) {
	return NULL;
    }

    sprintf(str, "%s ", gretl_command_word(pmod->ci));

    if (pmod->ci == AR) {
        model_list_to_string(pmod->arinfo->arlist, str);
        strcat(str, "; ");
    }

    model_list_to_string(pmod->list, str); 

    return str;
}

static gchar *graph_str (SESSION_GRAPH *graph)
{
    char tmp[MAXLEN];
    FILE *fp;
    gchar *buf = NULL;

    session_file_make_path(tmp, graph->fname);
    fp = gretl_fopen(tmp, "r");

    if (fp != NULL) {
	char line[128], title[64];
	char xlabel[24], ylabel[24];
	int gottitle = 0;
	int gotxy = 0;

	while (fgets(line, sizeof line, fp)) {
	    if (strstr(line, "# timeseries") || strstr(line, "# frequency") ||
		!strncmp(line, "plot", 4)) {
		break;
	    } else if (sscanf(line, "set title '%63[^']", title) == 1) {
		gottitle = 1;
		break;
	    } else if (sscanf(line, "set xlabel '%23[^']", xlabel) == 1) {
		gotxy++;
	    } else if (sscanf(line, "set ylabel '%23[^']", ylabel) == 1) {
		gotxy++;
	    } 
	}

	if (gottitle) {
	    buf = my_locale_to_utf8(title);
	} else if (gotxy == 2) {
	    char *s = g_strdup_printf("%s %s %s", ylabel, _("versus"), xlabel);

	    if (s != NULL) {
		buf = my_locale_to_utf8(s);
		free(s);
	    }
	}

	fclose(fp);
    }

    return buf;
}

static char *boxplot_str (SESSION_GRAPH *graph)
{
    FILE *fp;
    char *str = NULL;

    fp = gretl_fopen(graph->fname, "r");

    if (fp != NULL) {
	char vname[VNAMELEN], line[48];

	str = malloc(MAXLEN);
	if (str == NULL) {
	    return NULL;
	}
	*str = '\0';

	while (fgets(line, 47, fp) && strlen(str) < MAXLEN-48) {
	    chopstr(line);
	    if (sscanf(line, "%*d varname = %15s", vname) == 1) { 
		strcat(str, strchr(line, '=') + 2);
		strcat(str, " ");
	    }
	}
	fclose(fp);
    }

    return str;
}

static int maybe_raise_object_window (gpointer p)
{
    GtkWidget *w = match_window_by_data(p);
    int ret = 0;

    if (w != NULL) {
	gtk_window_present(GTK_WINDOW(w));
	ret = 1;
    }

    return ret;
}

static int display_session_model (SESSION_MODEL *sm)
{ 
    PRN *prn;
    int err = 0;

    if (maybe_raise_object_window(sm->ptr)) {
	return 0;
    }  

    if (sm->type != GRETL_OBJ_SYS && bufopen(&prn)) {
	return 1;
    }

    if (sm->type == GRETL_OBJ_EQN) {
	MODEL *pmod = (MODEL *) sm->ptr;

	printmodel(pmod, datainfo, OPT_NONE, prn);
	view_model(prn, pmod, 78, 400, sm->name);
    } else if (sm->type == GRETL_OBJ_VAR) {
	GRETL_VAR *var = (GRETL_VAR *) sm->ptr;

	gretl_VAR_print(var, datainfo, OPT_NONE, prn);
	view_buffer(prn, 78, 450, sm->name, var->ci, var);
    } else if (sm->type == GRETL_OBJ_SYS) {
	gretl_equation_system *sys = (gretl_equation_system *) sm->ptr;

	edit_dialog(sm->name, NULL, NULL, do_saved_eqn_system, sys, 
		    SYSTEM, VARCLICK_NONE, NULL); 
    }

    return err;
}

/* callback used in objectsave.c */

void session_model_callback (void *ptr, int action)
{
    SESSION_MODEL *mod = get_session_model_by_data(ptr);

    if (mod == NULL) {
	return;
    }
    
    if (action == OBJ_ACTION_SHOW) {
	display_session_model(mod);
    } else if (action == OBJ_ACTION_FREE) {
#if SESSION_DEBUG
	fprintf(stderr, "session_model_callback: gretl_object_unref at %p\n", 
		(void *) ptr);
#endif
	/* FIXME not sure here: should we trash the icon too */
	gretl_object_unref(ptr, mod->type);
    } 
}	

static void open_boxplot (gui_obj *obj)
{
    SESSION_GRAPH *graph = (SESSION_GRAPH *) obj->data;
    char tmp[MAXLEN];

    session_file_make_path(tmp, graph->fname);
    retrieve_boxplot(tmp);
}

static void open_matrix (gui_obj *obj)
{
    user_matrix *um = (user_matrix *) obj->data;

    edit_user_matrix_by_name(user_matrix_get_name(um));
}

static void open_gui_text (gui_obj *obj)
{ 
    SESSION_TEXT *text = (SESSION_TEXT *) obj->data;
    PRN *prn;

    prn = gretl_print_new_with_buffer(g_strdup(text->buf));

    if (prn != NULL) { 
	view_buffer(prn, 80, 400, obj->name, INFO, NULL);
    }
}

static int real_delete_model_from_session (SESSION_MODEL *model)
{
    int nm = session.nmodels - 1;

    if (nm == 0) {
	free_session_model(session.models[0]);
	free(session.models);
	session.models = NULL;
    } else {
	SESSION_MODEL **mods;
	int i, j = 0;

	for (i=0; i<session.nmodels; i++) {
	    if (session.models[i]->ptr == model->ptr) {
		free_session_model(session.models[i]);
		j = i;
		break;
	    }
	}

	for (i=j; i<nm; i++) {
	    session.models[i] = session.models[i+1];
	}

	mods = myrealloc(session.models, nm * sizeof *mods);
	if (mods != NULL) {
	    session.models = mods;
	}
    }

    session.nmodels = nm;
    mark_session_changed();

    return 0;
}

static int real_delete_text_from_session (SESSION_TEXT *junk)
{
    if (session.ntexts == 1) {
	free_session_text(session.texts[0]);
    } else {
	SESSION_TEXT **pptext;
	int i, j;

	pptext = mymalloc((session.ntexts - 1) * sizeof *pptext);
	if (session.ntexts > 1 && pptext == NULL) {
	    return 1;
	}
	j = 0;
	for (i=0; i<session.ntexts; i++) {
	    if (session.texts[i] != junk) {
		pptext[j++] = session.texts[i];
	    } else {
		free_session_text(session.texts[i]);
	    }
	}
	free(session.texts);
	session.texts = pptext;
    }

    session.ntexts -= 1;
    mark_session_changed();

    return 0;
}

static void remove_session_graph_file (const char *gfname)
{
    char fname[MAXLEN];

    chdir(paths.userdir);
    session_file_make_path(fname, gfname);
    remove(fname);
}

static int real_delete_graph_from_session (SESSION_GRAPH *junk)
{
    int i, j;

    if (session.ngraphs == 1) {
	remove_session_graph_file(session.graphs[0]->fname);
	free(session.graphs[0]);
    } else {
	SESSION_GRAPH **ppgr;

	ppgr = mymalloc((session.ngraphs - 1) * sizeof *ppgr);
	if (session.ngraphs > 1 && ppgr == NULL) {
	    return 1;
	}
	j = 0;
	for (i=0; i<session.ngraphs; i++) {
	    if (session.graphs[i]->ID != junk->ID) { 
		ppgr[j++] = session.graphs[i];
	    } else {
		remove_session_graph_file(session.graphs[i]->fname);
		free(session.graphs[i]);
	    }
	}
	free(session.graphs);
	session.graphs = ppgr;
    }

    session.ngraphs -= 1;
    mark_session_changed();

    return 0;
}

static int delete_session_object (gui_obj *obj)
{
    if (obj->sort == GRETL_OBJ_EQN || obj->sort == GRETL_OBJ_VAR ||
	obj->sort == GRETL_OBJ_SYS) { 
	real_delete_model_from_session(obj->data);
    } else if (obj->sort == GRETL_OBJ_GRAPH || obj->sort == GRETL_OBJ_PLOT) { 
	real_delete_graph_from_session(obj->data);
    } else if (obj->sort == GRETL_OBJ_TEXT) { 
	real_delete_text_from_session(obj->data);
    } else if (obj->sort == GRETL_OBJ_MATRIX) { 
	user_matrix_destroy(obj->data);
    }

    session_delete_icon(obj);

    return 0;
}

static void maybe_delete_session_object (gui_obj *obj)
{
    gpointer p;
    gchar *msg;

    if (obj->sort == GRETL_OBJ_EQN || obj->sort == GRETL_OBJ_SYS || 
	obj->sort == GRETL_OBJ_VAR) {
	SESSION_MODEL *mod = obj->data;

	p = mod->ptr;
    } else {
	p = obj->data;
    }

    if (winstack_match_data(p)) {
	errbox(_("Please close this object's window first"));
	return;
    }    

    msg = g_strdup_printf(_("Really delete %s?"), obj->name);

    if (yes_no_dialog(_("gretl: delete"), msg, 0) == GRETL_YES) {
	delete_session_object(obj);
    }

    g_free(msg);
}

static gui_obj *get_gui_obj_by_data (void *finddata)
{
    GList *mylist = icon_list;
    gui_obj *obj = NULL;

    while (mylist != NULL) {
	obj = (gui_obj *) mylist->data;
	if (obj->data == finddata) {
	    return obj;
	}
	mylist = mylist->next;
    }

    return NULL;
}

int session_matrix_destroy_by_name (const char *name, PRN *prn)
{
    user_matrix *u = get_user_matrix_by_name(name);
    int err;

    if (u == NULL) {
	err = E_UNKVAR;
    } else {
	gui_obj *obj = get_gui_obj_by_data(u);
    
	if (obj != NULL) {
	    session_delete_icon(obj);
	}
	err = user_matrix_destroy(u);
    } 
    
    return err;
}

static void rename_session_graph (SESSION_GRAPH *graph, const char *newname)
{
    int i;

    for (i=0; i<session.ngraphs; i++) {
	if (session.graphs[i]->ID == graph->ID) { 
	    session.graphs[i]->name[0] = '\0';
	    strncat(session.graphs[i]->name, newname, MAXSAVENAME - 1);
	    break;
	}
    }
}

static void rename_session_object (gui_obj *obj, const char *newname)
{
    if (obj->sort == GRETL_OBJ_EQN || obj->sort == GRETL_OBJ_SYS || 
	obj->sort == GRETL_OBJ_VAR) { 
	SESSION_MODEL *sm = obj->data;

	gretl_object_rename(sm->ptr, sm->type, newname);
	sm->name[0] = '\0';
	strncat(sm->name, newname, MAXSAVENAME - 1);
    } else if (obj->sort == GRETL_OBJ_GRAPH || obj->sort == GRETL_OBJ_PLOT) { 
	rename_session_graph(obj->data, newname);
    } else if (obj->sort == GRETL_OBJ_MATRIX) {
	user_matrix_set_name(obj->data, newname);
    }

    free(obj->name);
    obj->name = g_strdup(newname);
}

void delete_text_from_session (void *p)
{
    SESSION_TEXT *text = (SESSION_TEXT *) p;
    gui_obj *obj;

    if (text == NULL) return;

    real_delete_text_from_session(text);

    obj = get_gui_obj_by_data((void *) text);
    if (obj != NULL) {
	session_delete_icon(obj);
    }
}

void display_saved_text (void *p)
{
    SESSION_TEXT *text = (SESSION_TEXT *) p;
    PRN *prn;

    if (text == NULL) return;

    prn = gretl_print_new_with_buffer(g_strdup(text->buf));
    if (prn != NULL) { 
	view_buffer(prn, 80, 400, text->name, INFO, NULL);
    }
}

static void session_view_init (void)
{
    icon_list = NULL;
    icon_table = NULL;
    iconview_width = 0;
    iconview_cols = ICONVIEW_MIN_COLS;
}

static void gui_obj_destroy (gui_obj *obj, gpointer p)
{
    if (obj != NULL) {
#if SESSION_DEBUG
	fprintf(stderr, "freeing obj at %p (%s)\n", (void *) obj, obj->name);
#endif
	if (obj->name != NULL) {
	    g_free(obj->name); 
	}
	g_object_unref(obj->icon);
	g_object_unref(obj->label);
	free(obj);
    }
}

static void session_view_free (GtkWidget *w, gpointer data)
{
    iconview = NULL;

    g_list_foreach(icon_list, (GFunc) gui_obj_destroy, NULL);

    g_list_free(icon_list);
    icon_list = NULL;
}

static void session_delete_icon (gui_obj *obj)
{
    if (obj == NULL) return;

    if (obj->icon && GTK_IS_WIDGET(obj->icon))
	gtk_container_remove(GTK_CONTAINER(icon_table), obj->icon);
    if (obj->label && GTK_IS_WIDGET(obj->label))
	gtk_container_remove(GTK_CONTAINER(icon_table), obj->label);

    icon_list = g_list_first(icon_list);
    icon_list = g_list_remove(icon_list, obj);

    gui_obj_destroy(obj, NULL);

    if (icon_list == NULL) {
	fprintf(stderr, "Bad: icon_list has gone NULL\n");
    }
}

/* apparatus for getting a white background */

static GdkColor *get_white (void)
{
    GdkColormap *cmap;
    GdkColor *white;

    white = mymalloc(sizeof *white);
    if (white == NULL) return NULL;

    cmap = gdk_colormap_get_system();
    gdk_color_parse("white", white);
    gdk_colormap_alloc_color(cmap, white, FALSE, TRUE);

    return white;
}

static void white_bg_style (GtkWidget *widget, gpointer data)
{
    static GdkColor *white;

    if (white == NULL) {
	white = get_white();
    }

    gtk_widget_modify_bg(widget, GTK_STATE_NORMAL, white);
}

static void real_pack_icon (gui_obj *obj, int row, int col)
{
    obj->row = row;
    obj->col = col;

    gtk_table_attach(GTK_TABLE(icon_table), obj->icon,
		     col, col + 1, row, row + 1,
		     GTK_EXPAND, GTK_FILL, 5, 5);

    gtk_widget_show(obj->icon);
    white_bg_style(obj->icon, NULL);

    gtk_table_attach(GTK_TABLE(icon_table), obj->label,
		     col, col + 1, row + 1, row + 2,
		     GTK_EXPAND, GTK_FILL, 5, 5);

    gtk_widget_show(obj->label);
}

static void pack_single_icon (gui_obj *obj)
{
    int row, col;
    gui_obj *last;

    icon_list = g_list_last(icon_list);
    last = icon_list->data;
    row = last->row;
    col = last->col;  

    icon_list = g_list_append(icon_list, obj);

    col++;
    if (col > 0 && (col % iconview_cols == 0)) {
	col = 0;
	row += 2;
	gtk_table_resize(GTK_TABLE(icon_table), 2 * row, iconview_cols);
    } 

    real_pack_icon(obj, row, col);
}

static void batch_pack_icons (void)
{
    GList *mylist = g_list_first(icon_list);
    gui_obj *obj;
    int row = 0, col = 0;

    while (mylist != NULL) {
	obj = (gui_obj *) mylist->data;
	real_pack_icon(obj, row, col);
	col++;
	if (col > 0 && (col % iconview_cols == 0)) {
	    col = 0;
	    row += 2;
	    gtk_table_resize(GTK_TABLE(icon_table), 2 * row, iconview_cols);
	}
	if (mylist->next == NULL) {
	    break;
	} else {
	    mylist = mylist->next;
	}
    }
}

static void add_user_matrix_callback (void)
{
    if (iconview != NULL) {
	int n = n_user_matrices();

	if (n > 0) {
	    session_add_icon(get_user_matrix_by_index(n-1), GRETL_OBJ_MATRIX, 
			     ICON_ADD_SINGLE);
	}
    }
}

static void add_all_icons (void) 
{
    int show_graph_page = check_for_prog(latex);
    int i, n;

    active_object = NULL;

    set_matrix_add_callback(add_user_matrix_callback);

    if (data_status) {
	session_add_icon(NULL, GRETL_OBJ_INFO,   ICON_ADD_BATCH);  /* data info */
	session_add_icon(NULL, GRETL_OBJ_DSET,   ICON_ADD_BATCH);  /* data file */
	session_add_icon(NULL, GRETL_OBJ_NOTES,  ICON_ADD_BATCH);  /* session notes */
	session_add_icon(NULL, GRETL_OBJ_STATS,  ICON_ADD_BATCH);  /* summary stats */
	session_add_icon(NULL, GRETL_OBJ_CORR,   ICON_ADD_BATCH);  /* correlation matrix */
	session_add_icon(NULL, GRETL_OBJ_MODTAB, ICON_ADD_BATCH);  /* model table */
	if (show_graph_page) {
	    session_add_icon(NULL, GRETL_OBJ_GPAGE, ICON_ADD_BATCH); /* graph page */
	}
    }

    for (i=0; i<session.nmodels; i++) {
#if SESSION_DEBUG
	fprintf(stderr, "adding session.models[%d] (type %d) to view\n", i,
		session.models[i]->type);
#endif
	session_add_icon(session.models[i], session.models[i]->type, 
			 ICON_ADD_BATCH);
    }

    for (i=0; i<session.ngraphs; i++) {
#if SESSION_DEBUG
	fprintf(stderr, "adding session.graphs[%d] (type %d) to view\n", i,
		session.graphs[i]->type);
#endif
	session_add_icon(session.graphs[i], session.graphs[i]->type,
			 ICON_ADD_BATCH);
    }

    for (i=0; i<session.ntexts; i++) {
#if SESSION_DEBUG
	fprintf(stderr, "adding session.texts[%d] to view\n", i);
#endif
	session_add_icon(session.texts[i], GRETL_OBJ_TEXT, ICON_ADD_BATCH);
    }

    n = n_user_matrices();
    for (i=0; i<n; i++) {
	session_add_icon(get_user_matrix_by_index(i), GRETL_OBJ_MATRIX, 
			 ICON_ADD_BATCH);
    }

    batch_pack_icons();
}

static void undisplay_icon (gui_obj *obj, gpointer p)
{
    if (obj->icon && GTK_IS_WIDGET(obj->icon))
	gtk_container_remove(GTK_CONTAINER(icon_table), obj->icon);
    if (obj->label && GTK_IS_WIDGET(obj->label))
	gtk_container_remove(GTK_CONTAINER(icon_table), obj->label);
}

static void rearrange_icons (void) 
{
    g_list_foreach(icon_list, (GFunc) undisplay_icon, NULL);

    batch_pack_icons();
}

static gint catch_iconview_key (GtkWidget *w, GdkEventKey *key, 
				gpointer p)
{
    /* 'q' quits, but not if we're editing a label */

    if (key->keyval == GDK_q) { 
	GList *mylist = icon_list;
	gui_obj *obj = NULL;

	while (mylist != NULL) {
	    obj = (gui_obj *) mylist->data;
	    if (gtk_editable_get_editable(GTK_EDITABLE(obj->label))) {
		return FALSE;
	    }
	    mylist = mylist->next;
	}

        gtk_widget_destroy(w);
    }

    return FALSE;
}

static void object_popup_show (gui_obj *obj, GdkEventButton *event)
{
    GtkWidget *w = NULL;

    active_object = obj;

    switch (obj->sort) {
    case GRETL_OBJ_EQN: 
	w = model_popup; 
	break;
    case GRETL_OBJ_MODTAB: 
	w = model_table_popup;
	break;
    case GRETL_OBJ_GPAGE:
	w = graph_page_popup; 
	break;
    case GRETL_OBJ_VAR: 
    case GRETL_OBJ_SYS:
    case GRETL_OBJ_TEXT:
	w = var_popup; 
	break;
    case GRETL_OBJ_GRAPH: 
	w = graph_popup; 
	break;
    case GRETL_OBJ_PLOT: 
	w = boxplot_popup; 
	break;
    case GRETL_OBJ_DSET: 
	w = data_popup; 
	break;
    case GRETL_OBJ_INFO: 
	w = info_popup; 
	break;
    case GRETL_OBJ_MATRIX: 
	w = matrix_popup; 
	break;
    default: 
	break;
    }

    gtk_menu_popup(GTK_MENU(w), NULL, NULL, NULL, NULL,
		   event->button, event->time);
}

static void display_model_table_wrapper (void)
{
    display_model_table(1);
}

static void graph_page_save_wrapper (void)
{
    if (graph_page_get_n_graphs() == 0) {
	errbox(_("The graph page is empty"));
    } else {
	file_selector(_("Save LaTeX file"), SAVE_TEX, FSEL_DATA_NONE, NULL);
    }
}

static gboolean session_view_click (GtkWidget *widget, 
				    GdkEventButton *event,
				    gpointer data)
{
    gui_obj *obj;
    GdkModifierType mods;

    if (event == NULL || (in_icon && data == NULL)) {
	return FALSE;
    }

    if (!in_icon) { 
	/* click on window background */
	gtk_menu_popup(GTK_MENU(global_popup), NULL, NULL, NULL, NULL,
		       event->button, event->time);
	return TRUE;
    }

    obj = (gui_obj *) data;

    if (event->type == GDK_2BUTTON_PRESS) {
	switch (obj->sort) {
	case GRETL_OBJ_EQN:
	case GRETL_OBJ_VAR:
	case GRETL_OBJ_SYS:
	    display_session_model(obj->data); 
	    break;
	case GRETL_OBJ_PLOT:
	    open_boxplot(obj); 
	    break;
	case GRETL_OBJ_GRAPH:
	    open_gui_graph(obj); 
	    break;
	case GRETL_OBJ_TEXT:
	    open_gui_text(obj); 
	    break;
	case GRETL_OBJ_DSET:
	    show_spreadsheet(SHEET_EDIT_DATASET); 
	    break;
	case GRETL_OBJ_MATRIX:
	    open_matrix(obj); 
	    break;
	case GRETL_OBJ_INFO:
	    open_info(NULL, 0, NULL); 
	    break;
	case GRETL_OBJ_NOTES:
	    edit_session_notes(); 
	    break;
	case GRETL_OBJ_MODTAB:
	    display_model_table_wrapper(); 
	    break;
	case GRETL_OBJ_GPAGE:
	    display_graph_page(); 
	    break;
	case GRETL_OBJ_CORR:
	    do_menu_op(NULL, ALL_CORR, NULL); 
	    break;
	case GRETL_OBJ_STATS:
	    do_menu_op(NULL, ALL_SUMMARY, NULL); 
	    break;
	}
	return TRUE;
    }

    gdk_window_get_pointer(widget->window, NULL, NULL, &mods);

    if (mods & GDK_BUTTON3_MASK) {
	if (obj->sort == GRETL_OBJ_EQN  || obj->sort == GRETL_OBJ_GRAPH || 
	    obj->sort == GRETL_OBJ_TEXT || obj->sort == GRETL_OBJ_DSET || 
	    obj->sort == GRETL_OBJ_INFO || obj->sort == GRETL_OBJ_GPAGE ||
	    obj->sort == GRETL_OBJ_PLOT || obj->sort == GRETL_OBJ_MODTAB ||
	    obj->sort == GRETL_OBJ_VAR  || obj->sort == GRETL_OBJ_SYS ||
	    obj->sort == GRETL_OBJ_MATRIX) {
	    object_popup_show(obj, (GdkEventButton *) event);
	}
	return TRUE;
    }

    return FALSE;
}

static void global_popup_activated (GtkWidget *widget, gpointer data)
{
    gchar *item = (gchar *) data;

    if (!strcmp(item, _("Save session"))) {
	if (session_file_open && sessionfile[0]) {
	    if (session.status == SESSION_CHANGED) {
		save_session(sessionfile);
	    } else {
		mark_session_saved();
	    }
	} else {
	    file_selector(_("Save session"), SAVE_SESSION, FSEL_DATA_NONE, NULL);
	}
    } else if (!strcmp(item, _("Arrange icons"))) {
	rearrange_icons();
    } else if (!strcmp(item, _("Close window"))) {
	gtk_widget_destroy(iconview);
    }
}

static void info_popup_activated (GtkWidget *widget, gpointer data)
{
    gchar *item = (gchar *) data;

    if (!strcmp(item, _("View"))) {
	open_info(NULL, 0, NULL);
    } else if (!strcmp(item, _("Edit"))) { 
	edit_header(NULL, 0, NULL);
    }
}

static void matrix_popup_activated (GtkWidget *widget, gpointer data)
{
    gchar *item = (gchar *) data;
    gui_obj *obj = active_object;
    user_matrix *u = (user_matrix *) obj->data;
    const char *name = user_matrix_get_name(u);
    gretl_matrix *m;

    if (!strcmp(item, _("View"))) {
	PRN *prn;

	m = user_matrix_get_matrix(u);
	if (m != NULL && bufopen(&prn) == 0) {
	    gretl_matrix_print_to_prn(m, name, prn);
	    view_buffer(prn, 78, 400, name, PRINT, NULL);
	} 
    } else if (!strcmp(item, _("Edit"))) {
	edit_user_matrix_by_name(name);
    } else if (!strcmp(item, _("Properties"))) {
	m = user_matrix_get_matrix(u);
	view_matrix_properties(m, name);
    } else if (!strcmp(item, _("Delete"))) {
	maybe_delete_session_object(obj);
    }
}

static void data_popup_activated (GtkWidget *widget, gpointer data)
{
    gchar *item = (gchar *) data;

    if (!strcmp(item, _("Edit"))) {
	show_spreadsheet(SHEET_EDIT_DATASET);
    } else if (!strcmp(item, _("Save..."))) {
	file_save(mdata, SAVE_DATA, NULL);
    } else if (!strcmp(item, _("Export as CSV..."))) {
	file_save(mdata, EXPORT_CSV, NULL);
    } else if (!strcmp(item, _("Copy as CSV..."))) {
	csv_to_clipboard();
    }
}

static void object_popup_activated (GtkWidget *widget, gpointer data)
{
    gchar *item = (gchar *) data;
    gui_obj *obj = active_object;

    if (!strcmp(item, _("Display"))) {
	if (obj->sort == GRETL_OBJ_EQN ||
	    obj->sort == GRETL_OBJ_VAR ||
	    obj->sort == GRETL_OBJ_SYS) {
	    display_session_model(obj->data);
	} else if (obj->sort == GRETL_OBJ_TEXT) {
	    open_gui_text(obj);
	} else if (obj->sort == GRETL_OBJ_MODTAB) {
	    display_model_table_wrapper();
	} else if (obj->sort == GRETL_OBJ_GPAGE) {
	    display_graph_page();
	} else if (obj->sort == GRETL_OBJ_GRAPH) {
	    open_gui_graph(obj);
	} else if (obj->sort == GRETL_OBJ_PLOT) {
	    open_boxplot(obj);
	}
    } else if (!strcmp(item, _("Edit plot commands"))) {
	if (obj->sort == GRETL_OBJ_GRAPH || obj->sort == GRETL_OBJ_PLOT) {
	    SESSION_GRAPH *graph = (SESSION_GRAPH *) obj->data;
	    char fullname[MAXLEN];

	    chdir(paths.userdir);
	    session_file_make_path(fullname, graph->fname);
	    remove_png_term_from_plotfile_by_name(fullname);
	    view_file(fullname, 1, 0, 78, 400, 
		      (obj->sort == GRETL_OBJ_GRAPH)? GR_PLOT : GR_BOX);
	}
    } else if (!strcmp(item, _("Delete"))) {
	maybe_delete_session_object(obj);
    } else if (!strcmp(item, _("Add to model table"))) {
	if (obj->sort == GRETL_OBJ_EQN) {
	    SESSION_MODEL *mod = (SESSION_MODEL *) obj->data;

	    add_to_model_table(mod->ptr, MODEL_ADD_FROM_MENU, NULL);
	}
    } else if (!strcmp(item, _("Clear"))) {
	if (obj->sort == GRETL_OBJ_MODTAB) {
	    clear_model_table(NULL);
	} else if (obj->sort == GRETL_OBJ_GPAGE) {
	    clear_graph_page();
	}
    } else if (!strcmp(item, _("Help"))) {
	if (obj->sort == GRETL_OBJ_MODTAB) {
	    context_help(NULL, GINT_TO_POINTER(MODELTAB));
	} else if (obj->sort == GRETL_OBJ_GPAGE) {
	    context_help(NULL, GINT_TO_POINTER(GRAPHPAGE));
	}
    } else if (!strcmp(item, _("Options"))) {
	if (obj->sort == GRETL_OBJ_MODTAB) {
	    model_table_dialog();
	} else {
	    dummy_call();
	}
    } else if (!strcmp(item, _("Save as TeX..."))) {   
	if (obj->sort == GRETL_OBJ_GPAGE) {
	    graph_page_save_wrapper();
	}
    }
}

static gboolean icon_entered (GtkWidget *icon, GdkEventCrossing *event,
			      gui_obj *obj)
{
    gtk_widget_set_state(icon, GTK_STATE_SELECTED);
    in_icon = 1;
    
    return FALSE;
}

static gboolean icon_left (GtkWidget *icon, GdkEventCrossing *event,
			   gui_obj *obj)
{
    gtk_widget_set_state(icon, GTK_STATE_NORMAL);
    in_icon = 0;
    
    return FALSE;
}

static void 
session_data_received (GtkWidget *widget,
		       GdkDragContext *context,
		       gint x,
		       gint y,
		       GtkSelectionData *data,
		       guint info,
		       guint time,
		       gpointer p)
{
    if (info == GRETL_MODEL_POINTER && data != NULL) {
	MODEL **ppmod = (MODEL **) data->data;

	if (ppmod != NULL) {
	    add_to_model_table(*ppmod, MODEL_ADD_BY_DRAG, NULL);
	}
    } else if (info == GRETL_FILENAME && data != NULL) {
	gchar *fname = (gchar *) data->data;

	if (fname != NULL) {
	    graph_page_add_file(fname);
	}
    }
}

static void session_drag_setup (gui_obj *obj)
{
    GtkWidget *w = GTK_WIDGET(obj->icon);
    GtkTargetEntry *targ;
    
    if (obj->sort == GRETL_OBJ_MODTAB) {
	targ = &session_drag_targets[0];
    } else {
	targ = &session_drag_targets[1];
    }

    gtk_drag_dest_set (w,
                       GTK_DEST_DEFAULT_ALL,
                       targ, 1,
                       GDK_ACTION_COPY);

    g_signal_connect (G_OBJECT(w), "drag_data_received",
                      G_CALLBACK(session_data_received),
                      NULL);
}

static void drag_graph (GtkWidget *w, GdkDragContext *context,
			GtkSelectionData *sel, guint info, guint t,
			SESSION_GRAPH *graph)
{
    gtk_selection_data_set(sel, GDK_SELECTION_TYPE_STRING, 8, 
                           (const guchar *) graph->fname, 
			   strlen(graph->fname));
}

static void graph_drag_connect (GtkWidget *w, SESSION_GRAPH *graph)
{
    gtk_drag_source_set(w, GDK_BUTTON1_MASK,
                        &session_drag_targets[1],
                        1, GDK_ACTION_COPY);
    g_signal_connect(G_OBJECT(w), "drag_data_get",
                     G_CALLBACK(drag_graph), graph);
}

static void drag_model (GtkWidget *w, GdkDragContext *context,
			GtkSelectionData *sel, guint info, guint t,
			SESSION_MODEL *mod)
{
    gtk_selection_data_set(sel, GDK_SELECTION_TYPE_STRING, 8, 
                           (const guchar *) &mod->ptr, 
			   sizeof mod->ptr);
}

static void model_drag_connect (GtkWidget *w, SESSION_MODEL *mod)
{
    gtk_drag_source_set(w, GDK_BUTTON1_MASK,
                        &session_drag_targets[0],
                        1, GDK_ACTION_COPY);
    g_signal_connect(G_OBJECT(w), "drag_data_get",
                     G_CALLBACK(drag_model), mod);
}

#define WANT_TOOLTIP(t) (t == GRETL_OBJ_EQN || \
	                 t == GRETL_OBJ_GRAPH || \
                         t == GRETL_OBJ_PLOT)

static gui_obj *session_add_icon (gpointer data, int sort, int mode)
{
    gui_obj *obj;
    gchar *name = NULL;
    user_matrix *um = NULL;
    SESSION_GRAPH *graph = NULL;
    SESSION_MODEL *mod = NULL;
    SESSION_TEXT *text = NULL;
    int icon_named = 0;

    switch (sort) {
    case GRETL_OBJ_EQN:
    case GRETL_OBJ_VAR:
    case GRETL_OBJ_SYS:
	mod = (SESSION_MODEL *) data;
	name = g_strdup(mod->name);
	break;
    case GRETL_OBJ_PLOT:
    case GRETL_OBJ_GRAPH:
	graph = (SESSION_GRAPH *) data;
	name = g_strdup(graph->name);
	break;
    case GRETL_OBJ_TEXT:
	text = (SESSION_TEXT *) data;
	name = g_strdup(text->name);
	break;
    case GRETL_OBJ_DSET:
	name = g_strdup(_("Data set"));
	break;
    case GRETL_OBJ_INFO:
	name = g_strdup(_("Data info"));
	break;
    case GRETL_OBJ_NOTES:
	name = g_strdup(_("Notes"));
	break;
    case GRETL_OBJ_CORR:
	name = g_strdup(_("Correlations"));
	break;
    case GRETL_OBJ_STATS:
	name = g_strdup(_("Summary"));
	break;
    case GRETL_OBJ_MODTAB:
	name = g_strdup(_("Model table"));
	break;
    case GRETL_OBJ_GPAGE:
	name = g_strdup(_("Graph page"));
	break;
    case GRETL_OBJ_MATRIX:
	um = (user_matrix *) data;
	name = g_strdup(user_matrix_get_name(um));
	break;
    default:
	break;
    }

    if (name == NULL) {
	fprintf(stderr, "session_add_icon: got NULL name\n");
	return NULL;
    }

    obj = gui_object_new(name, sort);

    /* full-length object name as tooltip */
    if (strlen(name) > SHOWNAMELEN) {
	gretl_tooltips_add(GTK_WIDGET(obj->icon), name);
	icon_named = 1;
    }

    /* attach specific data items */
    if (sort == GRETL_OBJ_EQN || sort == GRETL_OBJ_VAR || sort == GRETL_OBJ_SYS) {
	obj->data = mod;
    } else if (sort == GRETL_OBJ_GRAPH || sort == GRETL_OBJ_PLOT) {
	obj->data = graph;
    } else if (sort == GRETL_OBJ_MATRIX) {
	obj->data = um;
    }

    /* set up for drag and drop */
    if (sort == GRETL_OBJ_EQN) {
	model_drag_connect(obj->icon, obj->data);
    } else if (sort == GRETL_OBJ_GRAPH) {
	graph_drag_connect(obj->icon, obj->data);
    }

    /* second try at adding a tooltip */
    if (WANT_TOOLTIP(sort) && !icon_named) {
	char *str = NULL;
	    
	if (sort == GRETL_OBJ_EQN) {
	    MODEL *pmod = (MODEL *) mod->ptr;

	    str = model_cmd_str(pmod);
	} else if (sort == GRETL_OBJ_GRAPH) {
	    str = graph_str(graph);
	} else if (sort == GRETL_OBJ_PLOT) {
	    str = boxplot_str(graph);
	}
	if (str != NULL) {
	    gretl_tooltips_add(GTK_WIDGET(obj->icon), str);
	    free(str);
	}
    }

    if      (sort == GRETL_OBJ_TEXT)   obj->data = text;
    else if (sort == GRETL_OBJ_DSET)   obj->data = paths.datfile;
    else if (sort == GRETL_OBJ_MODTAB) obj->data = NULL;

    if (mode == ICON_ADD_SINGLE) {
	pack_single_icon(obj);
    } else if (mode == ICON_ADD_BATCH) {
	icon_list = g_list_append(icon_list, obj);
    }

    return obj;
}

static GtkWidget *create_popup_item (GtkWidget *popup, char *str, 
				     GtkCallback callback)
{
    GtkWidget *item;

    item = gtk_menu_item_new_with_label(str);
    g_signal_connect(G_OBJECT(item), "activate",
		     G_CALLBACK(callback),
		     str);
    gtk_widget_show(item);
    gtk_menu_shell_append(GTK_MENU_SHELL(popup), item);

    if (!strcmp(str, _("Save session"))) {
	save_item = item;
    }

    return item;
}

static void session_build_popups (void)
{
    size_t i;

    if (global_popup == NULL) {
	global_popup = gtk_menu_new();
	for (i=0; i<sizeof global_items / sizeof global_items[0]; i++) {
	    create_popup_item(global_popup, 
			      _(global_items[i]), 
			      global_popup_activated);
	}
    }

    if (model_popup == NULL) {
	model_popup = gtk_menu_new();
	for (i=0; i<sizeof model_items / sizeof model_items[0]; i++) {
	    create_popup_item(model_popup, 
			      _(model_items[i]), 
			      object_popup_activated);
	}
    }

    if (model_table_popup == NULL) {
	model_table_popup = gtk_menu_new();
	for (i=0; i<sizeof model_table_items / sizeof model_table_items[0]; i++) {
	    create_popup_item(model_table_popup, 
			      _(model_table_items[i]), 
			      object_popup_activated);
	}
    }

    if (var_popup == NULL) {
	var_popup = gtk_menu_new();
	for (i=0; i<sizeof var_items / sizeof var_items[0]; i++) {
	    create_popup_item(var_popup, 
			      _(var_items[i]), 
			      object_popup_activated);
	}
    }

    if (graph_popup == NULL) {
	graph_popup = gtk_menu_new();
	for (i=0; i<sizeof graph_items / sizeof graph_items[0]; i++) {
	    create_popup_item(graph_popup, 
			      _(graph_items[i]), 
			      object_popup_activated);
	}
    }

    if (graph_page_popup == NULL) {
	graph_page_popup = gtk_menu_new();
	for (i=0; i<sizeof graph_page_items / sizeof graph_page_items[0]; i++) {
	    create_popup_item(graph_page_popup, 
			      _(graph_page_items[i]), 
			      object_popup_activated);
	}
    }

    if (boxplot_popup == NULL) {
	boxplot_popup = gtk_menu_new();
	for (i=0; i<sizeof graph_items / sizeof graph_items[0]; i++) {
	    if (strstr(graph_items[i], "GUI")) continue;
	    create_popup_item(boxplot_popup, 
			      _(graph_items[i]), 
			      object_popup_activated);
	}
    }

    if (data_popup == NULL) {
	data_popup = gtk_menu_new();
	for (i=0; i<sizeof dataset_items / sizeof dataset_items[0]; i++) {
	    create_popup_item(data_popup, 
			      _(dataset_items[i]), 
			      data_popup_activated);	    
	}
    }

    if (info_popup == NULL) {
	info_popup = gtk_menu_new();
	for (i=0; i<sizeof info_items / sizeof info_items[0]; i++) {
	    create_popup_item(info_popup, 
			      _(info_items[i]), 
			      info_popup_activated);	    
	}
    }

    if (matrix_popup == NULL) {
	matrix_popup = gtk_menu_new();
	for (i=0; i<sizeof matrix_items / sizeof matrix_items[0]; i++) {
	    create_popup_item(matrix_popup, 
			      _(matrix_items[i]), 
			      matrix_popup_activated);	    
	}
    }
}

static gboolean 
iconview_resize_callback (GtkWidget *w, GdkEventConfigure *e, gpointer p)
{
    if (e->width != iconview_width) {
	if (iconview_width > 0) {
	    int cols = e->width / 100;

	    if (cols >= ICONVIEW_MIN_COLS && cols != iconview_cols) {
		iconview_cols = cols;
		rearrange_icons();
	    }
	} 
	iconview_width = e->width;
    }

    return FALSE;
}

static void iconview_connect_signals (GtkWidget *iconview)
{
    g_signal_connect(G_OBJECT(iconview), "destroy",
		     G_CALLBACK(session_view_free), NULL);
    g_signal_connect(G_OBJECT(iconview), "key_press_event",
		     G_CALLBACK(catch_iconview_key), NULL);
    g_signal_connect(G_OBJECT(iconview), "configure-event",
		     G_CALLBACK(iconview_resize_callback), NULL);
}

void view_session (void)
{
    GtkWidget *hbox, *scroller;
    gchar *title;

    if (iconview != NULL) {
	gdk_window_show(iconview->window);
	gdk_window_raise(iconview->window);
	return;
    }

    session_view_init();

    title = g_strdup_printf("gretl: %s", 
			    (session.name[0])? session.name : 
			    _("current session"));
    
    iconview = gtk_window_new(GTK_WINDOW_TOPLEVEL);
    gtk_window_set_title(GTK_WINDOW(iconview), title);
    g_free(title);
    gtk_window_set_default_size(GTK_WINDOW(iconview), 400, 300);
    gtk_container_set_border_width(GTK_CONTAINER(iconview), 0);

    iconview_connect_signals(iconview);

    session_build_popups();

    hbox = gtk_hbox_new(FALSE,0);
    gtk_container_add(GTK_CONTAINER(iconview), hbox);
    gtk_container_set_border_width(GTK_CONTAINER(hbox), 5);

    scroller = gtk_scrolled_window_new(NULL, NULL);
    gtk_container_set_border_width(GTK_CONTAINER(scroller), 0);
    gtk_scrolled_window_set_policy(GTK_SCROLLED_WINDOW(scroller),
				   GTK_POLICY_AUTOMATIC, GTK_POLICY_AUTOMATIC);
    g_signal_connect(G_OBJECT(scroller), "button_press_event",
		     G_CALLBACK(session_view_click), NULL);

    gtk_box_pack_start(GTK_BOX(hbox), scroller, TRUE, TRUE, 0); 

    icon_table = gtk_table_new(2, ICONVIEW_MIN_COLS, FALSE);

    gtk_scrolled_window_add_with_viewport(GTK_SCROLLED_WINDOW(scroller), 
					  icon_table);

    add_all_icons();

    gtk_widget_show(icon_table);
    gtk_widget_show(scroller);
    gtk_widget_show(hbox);
    gtk_widget_show(iconview);

    gtk_container_foreach(GTK_CONTAINER(scroller), 
			 (GtkCallback) white_bg_style, 
			 NULL);

    GTK_WIDGET_SET_FLAGS(icon_table, GTK_CAN_FOCUS);
    gtk_widget_grab_focus(icon_table);
}

/* apparatus for renaming session objects */

static void size_name_entry (GtkWidget *w, const char *name)
{
    PangoLayout *layout;
    PangoRectangle rect;
    PangoFontDescription *pfd;
    int width;
#ifdef USE_GNOME
    GtkSettings *settings;
    gchar *fontname;

    settings = gtk_settings_get_default();
    g_object_get(G_OBJECT(settings), "gtk-font-name", &fontname, NULL);
#endif    

    layout = gtk_entry_get_layout(GTK_ENTRY(w));

#ifdef USE_GNOME
    pfd = pango_font_description_from_string(fontname);
    g_free(fontname);
#else
    pfd = pango_font_description_from_string(get_app_fontname());
#endif

    pango_layout_set_font_description(layout, pfd);
    pango_font_description_free(pfd);

    pango_layout_get_pixel_extents(layout, NULL, &rect);
    width = rect.width;
    width = (width < 10)? width + 3 : 1.1 * width;

    gtk_widget_set_size_request(w, width, -1); 
}

static gboolean object_name_return (GtkWidget *w,
				    GdkEventKey *key,
				    gui_obj *obj)
{
    if (!gtk_editable_get_editable(GTK_EDITABLE(obj->label))) {
	return FALSE;
    }

    if (key->keyval == GDK_Return) {
	const gchar *newname = gtk_entry_get_text(GTK_ENTRY(obj->label));

	gtk_editable_set_position(GTK_EDITABLE(obj->label), 0);
	gtk_entry_set_has_frame(GTK_ENTRY(obj->label), FALSE);
	gtk_editable_set_editable(GTK_EDITABLE(obj->label), FALSE);
	
	if (newname != NULL && *newname != '\0' &&
	    strcmp(newname, obj->name)) {
	    rename_session_object(obj, newname);
	}

	size_name_entry(obj->label, newname);
	gtk_widget_grab_focus(icon_table);

	return TRUE;
    } 

    return FALSE;
}

static gboolean start_rename_object (GtkWidget *w,
				     GdkEventButton *event,
				     gui_obj *obj)
{
    if (gtk_editable_get_editable(GTK_EDITABLE(obj->label))) {
	return FALSE;
    }

    gtk_widget_set_size_request(obj->label, -1, -1);
    gtk_entry_set_width_chars(GTK_ENTRY(obj->label), SHOWNAMELEN);
    gtk_entry_set_has_frame(GTK_ENTRY(obj->label), TRUE); 
    gtk_editable_set_editable(GTK_EDITABLE(obj->label), TRUE);
    gtk_editable_select_region(GTK_EDITABLE(obj->label), 0, -1);
    gtk_editable_set_position(GTK_EDITABLE(obj->label), -1);
    gtk_widget_grab_focus(obj->label);
    
    return TRUE;
}

static void make_short_label_string (char *targ, const char *src)
{
    if (strlen(src) > SHOWNAMELEN) {
	*targ = '\0';
	strncat(targ, src, SHOWNAMELEN - 3);
	strcat(targ, "...");
    } else {
	strcpy(targ, src);
    }
}

static void create_gobj_icon (gui_obj *obj, const char **xpm)
{
    GdkPixbuf *pbuf;
    GtkWidget *image;

    pbuf = gdk_pixbuf_new_from_xpm_data(xpm);

    obj->icon = gtk_event_box_new();
    gtk_widget_set_size_request(obj->icon, 36, 36);

    image = gtk_image_new_from_pixbuf(pbuf);
    g_object_unref(G_OBJECT(pbuf));

    gtk_container_add(GTK_CONTAINER(obj->icon), image);
    gtk_widget_show(image);

    if (obj->sort == GRETL_OBJ_MODTAB || obj->sort == GRETL_OBJ_GPAGE) {
	session_drag_setup(obj);
    }

    if (obj->sort == GRETL_OBJ_EQN || obj->sort == GRETL_OBJ_GRAPH ||
	obj->sort == GRETL_OBJ_VAR || obj->sort == GRETL_OBJ_PLOT || 
	obj->sort == GRETL_OBJ_SYS || obj->sort == GRETL_OBJ_MATRIX) { 
	obj->label = gtk_entry_new();
	gtk_entry_set_text(GTK_ENTRY(obj->label), obj->name);
	gtk_editable_set_editable(GTK_EDITABLE(obj->label), FALSE);
	gtk_entry_set_has_frame(GTK_ENTRY(obj->label), FALSE);
	gtk_entry_set_max_length(GTK_ENTRY(obj->label), MAXSAVENAME);
	size_name_entry(obj->label, obj->name);
	g_signal_connect(G_OBJECT(obj->label), "button-press-event",
			 G_CALLBACK(start_rename_object), obj);
	g_signal_connect(G_OBJECT(obj->label), "key-press-event",
			 G_CALLBACK(object_name_return), obj);
    } else {
	gchar str[SHOWNAMELEN + 1];

	make_short_label_string(str, obj->name);
	obj->label = gtk_label_new(str);
    }

    g_object_ref(obj->icon);
    g_object_ref(obj->label);

    g_signal_connect(G_OBJECT(obj->icon), "button_press_event",
		     G_CALLBACK(session_view_click), obj);
    g_signal_connect(G_OBJECT(obj->icon), "enter_notify_event",
		     G_CALLBACK(icon_entered), obj);
    g_signal_connect(G_OBJECT(obj->icon), "leave_notify_event",
		     G_CALLBACK(icon_left), obj);
}

static gui_obj *gui_object_new (gchar *name, int sort)
{
    gui_obj *obj;
    char **xpm = NULL;

    obj = mymalloc(sizeof *obj);
    obj->name = name; 
    obj->sort = sort;
    obj->data = NULL;

#if SESSION_DEBUG
    fprintf(stderr, "Allocated obj at %p (%s)\n", (void *) obj, obj->name);
#endif

    switch (sort) {
    case GRETL_OBJ_EQN:
    case GRETL_OBJ_VAR:
    case GRETL_OBJ_SYS:     xpm = model_xpm;       break;
    case GRETL_OBJ_PLOT:    xpm = boxplot_xpm;     break;
    case GRETL_OBJ_GRAPH:   xpm = gnuplot_xpm;     break;
    case GRETL_OBJ_DSET:    xpm = dot_sc_xpm;      break;
    case GRETL_OBJ_INFO:    xpm = xfm_info_xpm;    break;
    case GRETL_OBJ_TEXT:
    case GRETL_OBJ_NOTES:   xpm = text_xpm;        break;
    case GRETL_OBJ_CORR:    xpm = rhohat_xpm;      break;
    case GRETL_OBJ_STATS:   xpm = summary_xpm;     break;
    case GRETL_OBJ_MODTAB:  xpm = model_table_xpm; break;
    case GRETL_OBJ_GPAGE:   xpm = graph_page_xpm;  break;
    case GRETL_OBJ_MATRIX:  xpm = matrix_xpm;      break;
    default: break;
    }

    create_gobj_icon(obj, (const char **) xpm);

    return obj;
} 

static void auto_save_gp (windata_t *vwin)
{
    FILE *fp;
    gchar *buf;
# ifdef ENABLE_NLS
    gchar *trbuf;
# endif

    buf = textview_get_text(vwin->w);
    if (buf == NULL) return;

    if ((fp = gretl_fopen(vwin->fname, "w")) == NULL) {
	g_free(buf);
	buf = g_strdup_printf(_("Couldn't write to %s"), vwin->fname);
	errbox(buf); 
	g_free(buf);
	return;
    }

# ifdef ENABLE_NLS
    trbuf = gp_locale_from_utf8(buf);
    if (trbuf != NULL) {
	fputs(trbuf, fp);
	g_free(trbuf);
    } else {
	fputs(buf, fp);
    }
# else
    fputs(buf, fp);
# endif

    g_free(buf); 
    fclose(fp);
}

#ifdef G_OS_WIN32

static char *add_pause_to_plotfile (const char *fname)
{
    FILE *fin, *fout;
    char fline[MAXLEN];
    char *tmpfile = NULL;
    int gotpause = 0;

    fin = gretl_fopen(fname, "r");
    if (fin == NULL) return NULL;

    tmpfile = g_strdup_printf("%showtmp.gp", paths.userdir);

    fout = gretl_fopen(tmpfile, "w");
    if (fout == NULL) {
	fclose(fin);
	g_free(tmpfile);
	return NULL;
    }

    while (fgets(fline, MAXLEN - 1, fin)) {
	fputs(fline, fout);
	if (strstr(fline, "pause -1")) {
	    gotpause = 1;
	}
    }

    if (!gotpause) {
	fputs("pause -1\n", fout);
    }

    fclose(fin);
    fclose(fout);

    return tmpfile;
}

void gp_to_gnuplot (gpointer data, guint i, GtkWidget *w)
{
    windata_t *vwin = (windata_t *) data;
    gchar *tmpfile;
    int err = 0;

    auto_save_gp(vwin);

    tmpfile = add_pause_to_plotfile(vwin->fname);

    if (tmpfile != NULL) {
	gchar *buf = g_strdup_printf("\"%s\" \"%s\"", paths.gnuplot, tmpfile);

	err = (WinExec(buf, SW_SHOWNORMAL) < 32);
	remove(tmpfile); /* is this OK? */
	g_free(tmpfile);
	g_free(buf);
    } else {
	err = 1;
    }

    if (err) {
	errbox(_("gnuplot command failed"));
    }
}

#else /* !G_OS_WIN32 */

void gp_to_gnuplot (gpointer data, guint i, GtkWidget *w)
{
    windata_t *vwin = (windata_t *) data;
    gchar *argv[4];
    gboolean run;

    auto_save_gp(vwin);

    argv[0] = g_strdup(paths.gnuplot);
    argv[1] = g_strdup("-persist");
    argv[2] = g_strdup(vwin->fname);
    argv[3] = NULL;
    
    run = g_spawn_async(NULL, argv, NULL, G_SPAWN_SEARCH_PATH, 
			NULL, NULL, NULL, NULL);

    if (!run) {
	errbox(_("gnuplot command failed"));
    }

    g_free(argv[0]);
    g_free(argv[1]);
    g_free(argv[2]);
}

#endif /* ? G_OS_WIN32 */

void save_plot_commands_callback (GtkWidget *w, gpointer p)
{
    auto_save_gp((windata_t *) p);
}

static void open_gui_graph (gui_obj *obj)
{
    SESSION_GRAPH *graph = (SESSION_GRAPH *) obj->data;
    char tmp[MAXLEN];

    session_file_make_path(tmp, graph->fname);
    display_session_graph_png(tmp);
}

void display_session_graph_by_data (void *p)
{
    SESSION_GRAPH *graph = (SESSION_GRAPH *) p;
    char tmp[MAXLEN];

    session_file_make_path(tmp, graph->fname);
    display_session_graph_png(tmp);
}

static int is_idempotent (const gretl_matrix *m,
			  const gretl_matrix *evals)
{
    if (evals != NULL) {
	int i;

	for (i=0; i<m->rows; i++) {
	    if (evals->val[i] != 0.0 && evals->val[i] != 1.0) {
		return 0;
	    }
	}
    }

    return gretl_matrix_is_idempotent(m);
}

void 
view_matrix_properties (const gretl_matrix *m, const char *name)
{
    const char *xfmt = "%-16s %.8g\n";
    const char *ifmt = "%-12s %3d\n";
    gretl_matrix *A = NULL;
    gretl_matrix *evals = NULL;
    PRN *prn;
    int s, err = 0;

    if (m == NULL || bufopen(&prn)) {
	return;
    }

    pprintf(prn, _("Properties of matrix %s"), (name != NULL)? name : "");
    pputs(prn, "\n\n");

    if (m->rows == 1 && m->cols == 1) {
	pprintf(prn, _("Scalar matrix, value %g\n"), m->val[0]);
	goto done;
    } else if (gretl_is_identity_matrix(m)) {
	pprintf(prn, _("Identity matrix, order %d\n"), m->rows);
	goto done;
    } else if (gretl_is_zero_matrix(m)) {
	pprintf(prn, _("Null matrix, %d x %d\n"), m->rows, m->cols);
	goto done;
    } 

    pprintf(prn, ifmt, _("Rows"), m->rows);
    pprintf(prn, ifmt, _("Columns"), m->cols);
    pprintf(prn, ifmt, _("Rank"), gretl_matrix_rank(m, &err));

    s = gretl_matrix_get_structure(m);

    if (s > 0) {
	pprintf(prn, "%s\n", _("Square"));
    }

    if (s == GRETL_MATRIX_DIAGONAL) {
	pprintf(prn, "%s\n", _("Diagonal"));
    } else if (s == GRETL_MATRIX_LOWER_TRIANGULAR) {
	pprintf(prn, "%s\n", _("Lower triangular"));
    } else if (s == GRETL_MATRIX_UPPER_TRIANGULAR) {
	pprintf(prn, "%s\n", _("Upper triangular"));
    } else if (s == GRETL_MATRIX_SYMMETRIC) {
	pprintf(prn, "%s\n", _("Symmetric"));
	A = gretl_matrix_copy(m);
	if (A != NULL) {
	    err = gretl_matrix_cholesky_decomp(A);
	    if (!err) {
		pprintf(prn, "%s\n", _("Positive definite"));
	    } else {
		pprintf(prn, "%s\n", _("Not positive definite"));
	    }
	    gretl_matrix_copy_values(A, m);
	    evals = gretl_symmetric_matrix_eigenvals(A, 0, &err);
	}
    } 

    if (s > 0 && (s != GRETL_MATRIX_SYMMETRIC || evals == NULL)) {
	A = gretl_matrix_copy(m);
	if (A != NULL) {
	    evals = gretl_general_matrix_eigenvals(A, 0, &err);
	}
    }

    if (s > 0) {
	if (is_idempotent(m, evals)) {
	    pprintf(prn, "%s\n", _("Idempotent"));
	} else {
	    pprintf(prn, "%s\n", _("Not idempotent"));
	}
    }

    pputc(prn, '\n');

    pprintf(prn, xfmt, _("1-norm"), gretl_matrix_one_norm(m));
    pprintf(prn, xfmt, _("Infinity-norm"), gretl_matrix_infinity_norm(m));
	    
    if (m->rows == m->cols) {
	double det;

	pprintf(prn, xfmt, _("Trace"), gretl_matrix_trace(m, &err));
	if (A == NULL) {
	    A = gretl_matrix_copy(m);
	} else {
	    gretl_matrix_copy_values(A, m);
	}
	if (A != NULL) {
	    det = gretl_matrix_determinant(A, &err);
	    if (!err) {
		pprintf(prn, xfmt, _("Determinant"), det);
	    }
	}
    }

    if (evals != NULL) {
	int i;

	pprintf(prn, "\n%s:\n", _("Eigenvalues"));

	for (i=0; i<m->rows; i++) {
	    if (s != GRETL_MATRIX_SYMMETRIC) {
		pprintf(prn, "  (%.8g, %.8g)\n", gretl_matrix_get(evals, i, 0),
			gretl_matrix_get(evals, i, 1));
	    } else {
		pprintf(prn, "  %.8g\n", evals->val[i]);
	    }
	}

	gretl_matrix_free(evals);
    }

    if (A != NULL) {
	gretl_matrix_free(A);
    }

 done:

    view_buffer(prn, 78, 400, name, PRINT, NULL);
}