/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/*
* e-selection-model.c: a Selection Model
*
* Author:
* Christopher James Lahey <clahey@ximian.com>
*
* (C) 2000, 2001 Ximian, Inc.
*/
#include <config.h>
#include <gtk/gtksignal.h>
#include "e-selection-model.h"
#include "gal/util/e-util.h"
#include <gdk/gdkkeysyms.h>
#define ESM_CLASS(e) ((ESelectionModelClass *)((GtkObject *)e)->klass)
#define PARENT_TYPE gtk_object_get_type ()
#define ONES ((guint32) 0xffffffff)
#define BOX(n) ((n) / 32)
#define OFFSET(n) (31 - ((n) % 32))
#define BITMASK(n) ((guint32)(((guint32) 0x1) << OFFSET((n))))
#define BITMASK_LEFT(n) ((((n) % 32) == 0) ? 0 : (ONES << (32 - ((n) % 32))))
#define BITMASK_RIGHT(n) ((guint32)(((guint32) ONES) >> ((n) % 32)))
static GtkObjectClass *e_selection_model_parent_class;
static void esm_select_single_row (ESelectionModel *selection, int row);
enum {
CURSOR_CHANGED,
CURSOR_ACTIVATED,
SELECTION_CHANGED,
LAST_SIGNAL
};
static guint e_selection_model_signals [LAST_SIGNAL] = { 0, };
enum {
ARG_0,
ARG_SORTER,
ARG_CURSOR_ROW,
ARG_CURSOR_COL,
ARG_SELECTION_MODE,
ARG_CURSOR_MODE,
};
void
e_selection_model_insert_row(ESelectionModel *esm, int row)
{
int box;
int i;
if(esm->row_count >= 0) {
/* Add another word if needed. */
if ((esm->row_count & 0x1f) == 0) {
esm->selection = g_renew(gint, esm->selection, (esm->row_count >> 5) + 1);
esm->selection[esm->row_count >> 5] = 0;
}
/* The box is the word that our row is in. */
box = BOX(row);
/* Shift all words to the right of our box right one bit. */
for (i = esm->row_count >> 5; i > box; i--) {
esm->selection[i] = (esm->selection[i] >> 1) | (esm->selection[i - 1] << 31);
}
/* Shift right half of box one bit to the right. */
esm->selection[box] = (esm->selection[box] & BITMASK_LEFT(row)) | ((esm->selection[box] & BITMASK_RIGHT(row)) >> 1);
esm->row_count ++;
}
if (esm->cursor_row >= row)
esm->cursor_row ++;
}
void
e_selection_model_delete_row(ESelectionModel *esm, int row)
{
int box;
int i;
int last;
int selected = FALSE;
if(esm->row_count >= 0) {
guint32 bitmask;
box = row >> 5;
last = esm->row_count >> 5;
/* Build bitmasks for the left and right half of the box */
bitmask = BITMASK_RIGHT(row) >> 1;
selected = e_selection_model_is_row_selected(esm, row);
/* Shift right half of box one bit to the left. */
esm->selection[box] = (esm->selection[box] & BITMASK_LEFT(row))| ((esm->selection[box] & bitmask) << 1);
/* Shift all words to the right of our box left one bit. */
if (box < last) {
esm->selection[box] &= esm->selection[box + 1] >> 31;
for (i = box + 1; i < last; i++) {
esm->selection[i] = (esm->selection[i] << 1) | (esm->selection[i + 1] >> 31);
}
/* this over-runs our memory! */
/*esm->selection[i] = esm->selection[i] << 1; */
}
esm->row_count --;
/* Remove the last word if not needed. */
if ((esm->row_count & 0x1f) == 0) {
esm->selection = g_renew(gint, esm->selection, esm->row_count >> 5);
}
if (selected && esm->mode == GTK_SELECTION_SINGLE) {
esm_select_single_row (esm, row > 0 ? row - 1 : 0);
}
}
if (esm->cursor_row >= row && esm->cursor_row > 0)
esm->cursor_row --;
}
inline static void
add_sorter(ESelectionModel *esm, ESorter *sorter)
{
esm->sorter = sorter;
if (sorter) {
gtk_object_ref(GTK_OBJECT(sorter));
}
}
inline static void
drop_sorter(ESelectionModel *esm)
{
if (esm->sorter) {
gtk_object_unref(GTK_OBJECT(esm->sorter));
}
esm->sorter = NULL;
}
static void
esm_destroy (GtkObject *object)
{
ESelectionModel *esm;
esm = E_SELECTION_MODEL (object);
drop_sorter(esm);
g_free(esm->selection);
}
static void
esm_get_arg (GtkObject *o, GtkArg *arg, guint arg_id)
{
ESelectionModel *esm = E_SELECTION_MODEL (o);
switch (arg_id){
case ARG_SORTER:
GTK_VALUE_OBJECT (*arg) = GTK_OBJECT(esm->sorter);
break;
case ARG_CURSOR_ROW:
GTK_VALUE_INT(*arg) = esm->cursor_row;
break;
case ARG_CURSOR_COL:
GTK_VALUE_INT(*arg) = esm->cursor_col;
break;
case ARG_SELECTION_MODE:
GTK_VALUE_ENUM(*arg) = esm->mode;
break;
case ARG_CURSOR_MODE:
GTK_VALUE_ENUM(*arg) = esm->cursor_mode;
break;
}
}
static void
esm_set_arg (GtkObject *o, GtkArg *arg, guint arg_id)
{
ESelectionModel *esm = E_SELECTION_MODEL (o);
switch (arg_id){
case ARG_SORTER:
drop_sorter(esm);
add_sorter(esm, GTK_VALUE_OBJECT (*arg) ? E_SORTER(GTK_VALUE_OBJECT (*arg)) : NULL);
break;
case ARG_CURSOR_ROW:
e_selection_model_do_something(esm, GTK_VALUE_INT(*arg), esm->cursor_col, 0);
break;
case ARG_CURSOR_COL:
e_selection_model_do_something(esm, esm->cursor_row, GTK_VALUE_INT(*arg), 0);
break;
case ARG_SELECTION_MODE:
esm->mode = GTK_VALUE_ENUM(*arg);
if (esm->mode == GTK_SELECTION_SINGLE) {
e_selection_model_do_something(esm, esm->cursor_row, esm->cursor_col, 0);
}
break;
case ARG_CURSOR_MODE:
esm->cursor_mode = GTK_VALUE_ENUM(*arg);
break;
}
}
static void
e_selection_model_init (ESelectionModel *selection)
{
selection->selection = NULL;
selection->row_count = -1;
selection->selection_start_row = 0;
selection->cursor_row = -1;
selection->cursor_col = -1;
selection->mode = GTK_SELECTION_MULTIPLE;
selection->cursor_mode = E_CURSOR_SIMPLE;
}
static void
e_selection_model_class_init (ESelectionModelClass *klass)
{
GtkObjectClass *object_class;
e_selection_model_parent_class = gtk_type_class (gtk_object_get_type ());
object_class = GTK_OBJECT_CLASS(klass);
object_class->destroy = esm_destroy;
object_class->get_arg = esm_get_arg;
object_class->set_arg = esm_set_arg;
e_selection_model_signals [CURSOR_CHANGED] =
gtk_signal_new ("cursor_changed",
GTK_RUN_LAST,
object_class->type,
GTK_SIGNAL_OFFSET (ESelectionModelClass, cursor_changed),
gtk_marshal_NONE__INT_INT,
GTK_TYPE_NONE, 2, GTK_TYPE_INT, GTK_TYPE_INT);
e_selection_model_signals [CURSOR_ACTIVATED] =
gtk_signal_new ("cursor_activated",
GTK_RUN_LAST,
object_class->type,
GTK_SIGNAL_OFFSET (ESelectionModelClass, cursor_activated),
gtk_marshal_NONE__INT_INT,
GTK_TYPE_NONE, 2, GTK_TYPE_INT, GTK_TYPE_INT);
e_selection_model_signals [SELECTION_CHANGED] =
gtk_signal_new ("selection_changed",
GTK_RUN_LAST,
object_class->type,
GTK_SIGNAL_OFFSET (ESelectionModelClass, selection_changed),
gtk_marshal_NONE__NONE,
GTK_TYPE_NONE, 0);
klass->cursor_changed = NULL;
klass->cursor_activated = NULL;
klass->selection_changed = NULL;
gtk_object_class_add_signals (object_class, e_selection_model_signals, LAST_SIGNAL);
gtk_object_add_arg_type ("ESelectionModel::sorter", GTK_TYPE_OBJECT,
GTK_ARG_READWRITE, ARG_SORTER);
gtk_object_add_arg_type ("ESelectionModel::cursor_row", GTK_TYPE_INT,
GTK_ARG_READWRITE, ARG_CURSOR_ROW);
gtk_object_add_arg_type ("ESelectionModel::cursor_col", GTK_TYPE_INT,
GTK_ARG_READWRITE, ARG_CURSOR_COL);
gtk_object_add_arg_type ("ESelectionModel::selection_mode", GTK_TYPE_ENUM,
GTK_ARG_READWRITE, ARG_SELECTION_MODE);
gtk_object_add_arg_type ("ESelectionModel::cursor_mode", GTK_TYPE_ENUM,
GTK_ARG_READWRITE, ARG_CURSOR_MODE);
}
E_MAKE_TYPE(e_selection_model, "ESelectionModel", ESelectionModel,
e_selection_model_class_init, e_selection_model_init, PARENT_TYPE);
/**
* e_selection_model_is_row_selected
* @selection: #ESelectionModel to check
* @n: The row to check
*
* This routine calculates whether the given row is selected.
*
* Returns: %TRUE if the given row is selected
*/
gboolean
e_selection_model_is_row_selected (ESelectionModel *selection,
gint n)
{
if (selection->row_count < n)
return 0;
else
return (selection->selection[BOX(n)] >> OFFSET(n)) & 0x1;
}
/**
* e_selection_model_foreach
* @selection: #ESelectionModel to traverse
* @callback: The callback function to call back.
* @closure: The closure
*
* This routine calls the given callback function once for each
* selected row, passing closure as the closure.
*/
void
e_selection_model_foreach (ESelectionModel *selection,
EForeachFunc callback,
gpointer closure)
{
int i;
int last = (selection->row_count + 31) / 32;
for (i = 0; i < last; i++) {
if (selection->selection[i]) {
int j;
guint32 value = selection->selection[i];
for (j = 0; j < 32; j++) {
if (value & 0x80000000) {
callback(i * 32 + j, closure);
}
value <<= 1;
}
}
}
}
#define OPERATE(object, i,mask,grow) ((grow) ? (((object)->selection[(i)]) |= ((guint32) ~(mask))) : (((object)->selection[(i)]) &= (mask)))
static void
change_one_row(ESelectionModel *selection, int row, gboolean grow)
{
int i;
i = BOX(row);
OPERATE(selection, i, ~BITMASK(row), grow);
}
static void
change_selection(ESelectionModel *selection, int start, int end, gboolean grow)
{
int i, last;
if (start != end) {
if (selection->sorter && e_sorter_needs_sorting(selection->sorter)) {
for ( i = start; i < end; i++) {
change_one_row(selection, e_sorter_sorted_to_model(selection->sorter, i), grow);
}
} else {
i = BOX(start);
last = BOX(end);
if (i == last) {
OPERATE(selection, i, BITMASK_LEFT(start) | BITMASK_RIGHT(end), grow);
} else {
OPERATE(selection, i, BITMASK_LEFT(start), grow);
if (grow)
for (i ++; i < last; i++)
selection->selection[i] = ONES;
else
for (i ++; i < last; i++)
selection->selection[i] = 0;
OPERATE(selection, i, BITMASK_RIGHT(end), grow);
}
}
}
}
static void
esm_select_single_row (ESelectionModel *selection, int row)
{
int i;
for (i = 0; i < ((selection->row_count + 31) / 32); i++) {
if (!((i == BOX(row) && selection->selection[i] == BITMASK(row)) ||
(i != BOX(row) && selection->selection[i] == 0))) {
g_free(selection->selection);
selection->selection = g_new0(gint, (selection->row_count + 31) / 32);
selection->selection[BOX(row)] = BITMASK(row);
gtk_signal_emit(GTK_OBJECT(selection),
e_selection_model_signals [SELECTION_CHANGED]);
break;
}
}
selection->selection_start_row = row;
}
static void
esm_toggle_single_row (ESelectionModel *selection, int row)
{
if (selection->selection[BOX(row)] & BITMASK(row))
selection->selection[BOX(row)] &= ~BITMASK(row);
else
selection->selection[BOX(row)] |= BITMASK(row);
selection->selection_start_row = row;
gtk_signal_emit(GTK_OBJECT(selection),
e_selection_model_signals [SELECTION_CHANGED]);
}
static void
esm_move_selection_end (ESelectionModel *selection, int row)
{
int old_start;
int old_end;
int new_start;
int new_end;
if (selection->sorter && e_sorter_needs_sorting(selection->sorter)) {
old_start = MIN (e_sorter_model_to_sorted(selection->sorter, selection->selection_start_row),
e_sorter_model_to_sorted(selection->sorter, selection->cursor_row));
old_end = MAX (e_sorter_model_to_sorted(selection->sorter, selection->selection_start_row),
e_sorter_model_to_sorted(selection->sorter, selection->cursor_row)) + 1;
new_start = MIN (e_sorter_model_to_sorted(selection->sorter, selection->selection_start_row),
e_sorter_model_to_sorted(selection->sorter, row));
new_end = MAX (e_sorter_model_to_sorted(selection->sorter, selection->selection_start_row),
e_sorter_model_to_sorted(selection->sorter, row)) + 1;
} else {
old_start = MIN (selection->selection_start_row, selection->cursor_row);
old_end = MAX (selection->selection_start_row, selection->cursor_row) + 1;
new_start = MIN (selection->selection_start_row, row);
new_end = MAX (selection->selection_start_row, row) + 1;
}
/* This wouldn't work nearly so smoothly if one end of the selection weren't held in place. */
if (old_start < new_start)
change_selection(selection, old_start, new_start, FALSE);
if (new_start < old_start)
change_selection(selection, new_start, old_start, TRUE);
if (old_end < new_end)
change_selection(selection, old_end, new_end, TRUE);
if (new_end < old_end)
change_selection(selection, new_end, old_end, FALSE);
gtk_signal_emit(GTK_OBJECT(selection),
e_selection_model_signals [SELECTION_CHANGED]);
}
static void
esm_set_selection_end (ESelectionModel *selection, int row)
{
esm_select_single_row(selection, selection->selection_start_row);
selection->cursor_row = selection->selection_start_row;
esm_move_selection_end(selection, row);
}
/**
* e_selection_model_do_something
* @selection: #ESelectionModel to do something to.
* @row: The row to do something in.
* @col: The col to do something in.
* @state: The state in which to do something.
*
* This routine does whatever is appropriate as if the user clicked
* the mouse in the given row and column.
*/
void
e_selection_model_do_something (ESelectionModel *selection,
guint row,
guint col,
GdkModifierType state)
{
gint shift_p = state & GDK_SHIFT_MASK;
gint ctrl_p = state & GDK_CONTROL_MASK;
if (row == -1 && col != -1)
row = 0;
if (col == -1 && row != -1)
col = 0;
if (selection->row_count < 0) {
selection->row_count = e_selection_model_get_row_count(selection);
if (selection->row_count < 0)
return;
g_free(selection->selection);
selection->selection = g_new0(gint, (selection->row_count + 31) / 32);
}
if (selection->row_count >= 0 && row < selection->row_count) {
switch (selection->mode) {
case GTK_SELECTION_SINGLE:
esm_select_single_row (selection, row);
break;
case GTK_SELECTION_BROWSE:
case GTK_SELECTION_MULTIPLE:
case GTK_SELECTION_EXTENDED:
if (shift_p) {
esm_set_selection_end (selection, row);
} else {
if (ctrl_p) {
esm_toggle_single_row (selection, row);
} else {
esm_select_single_row (selection, row);
}
}
break;
}
if (selection->cursor_row != row ||
selection->cursor_col != col) {
selection->cursor_row = row;
selection->cursor_col = col;
gtk_signal_emit(GTK_OBJECT(selection),
e_selection_model_signals[CURSOR_CHANGED], row, col);
gtk_signal_emit(GTK_OBJECT(selection),
e_selection_model_signals[CURSOR_ACTIVATED], row, col);
}
}
}
/**
* e_selection_model_maybe_do_something
* @selection: #ESelectionModel to do something to.
* @row: The row to do something in.
* @col: The col to do something in.
* @state: The state in which to do something.
*
* If this row is selected, this routine just moves the cursor row and
* column. Otherwise, it does the same thing as
* e_selection_model_do_something(). This is for being used on
* right clicks and other events where if the user hit the selection,
* they don't want it to change.
*/
void
e_selection_model_maybe_do_something (ESelectionModel *selection,
guint row,
guint col,
GdkModifierType state)
{
if (e_selection_model_is_row_selected(selection, row)) {
selection->cursor_row = row;
selection->cursor_col = col;
} else {
e_selection_model_do_something(selection, row, col, state);
}
}
static gint
move_selection (ESelectionModel *selection,
gboolean up,
GdkModifierType state)
{
int row = selection->cursor_row;
int col = selection->cursor_col;
int cursor_activated = TRUE;
gint shift_p = state & GDK_SHIFT_MASK;
gint ctrl_p = state & GDK_CONTROL_MASK;
row = e_sorter_model_to_sorted(selection->sorter, row);
if (up)
row--;
else
row++;
if (row < 0)
row = 0;
if (row >= selection->row_count)
row = selection->row_count - 1;
row = e_sorter_sorted_to_model(selection->sorter, row);
switch (selection->mode) {
case GTK_SELECTION_BROWSE:
if (shift_p) {
esm_set_selection_end (selection, row);
} else if (!ctrl_p) {
esm_select_single_row (selection, row);
} else
cursor_activated = FALSE;
break;
case GTK_SELECTION_SINGLE:
case GTK_SELECTION_MULTIPLE:
case GTK_SELECTION_EXTENDED:
esm_select_single_row (selection, row);
break;
}
if (row != -1) {
selection->cursor_row = row;
gtk_signal_emit(GTK_OBJECT(selection),
e_selection_model_signals[CURSOR_CHANGED], row, col);
if (cursor_activated)
gtk_signal_emit(GTK_OBJECT(selection),
e_selection_model_signals[CURSOR_ACTIVATED], row, col);
}
return TRUE;
}
/**
* e_selection_model_key_press
* @selection: #ESelectionModel to affect.
* @key: The event.
*
* This routine does whatever is appropriate as if the user pressed
* the given key.
*
* Returns: %TRUE if the #ESelectionModel used the key.
*/
gint
e_selection_model_key_press (ESelectionModel *selection,
GdkEventKey *key)
{
switch (key->keyval) {
case GDK_Up:
return move_selection(selection, TRUE, key->state);
break;
case GDK_Down:
return move_selection(selection, FALSE, key->state);
break;
case GDK_space:
case GDK_KP_Space:
if (selection->mode != GTK_SELECTION_SINGLE) {
esm_toggle_single_row (selection, selection->cursor_row);
gtk_signal_emit(GTK_OBJECT(selection),
e_selection_model_signals[CURSOR_ACTIVATED], selection->cursor_row, selection->cursor_col);
return TRUE;
}
break;
case GDK_Return:
case GDK_KP_Enter:
if (selection->mode != GTK_SELECTION_SINGLE) {
esm_select_single_row (selection, selection->cursor_row);
gtk_signal_emit(GTK_OBJECT(selection),
e_selection_model_signals[CURSOR_ACTIVATED], selection->cursor_row, selection->cursor_col);
return TRUE;
}
break;
case GDK_Home:
case GDK_KP_Home:
if (selection->cursor_mode == E_CURSOR_LINE) {
int row = 0;
row = e_sorter_sorted_to_model(selection->sorter, row);
selection->cursor_row = row;
esm_select_single_row (selection, selection->cursor_row);
gtk_signal_emit(GTK_OBJECT(selection),
e_selection_model_signals[CURSOR_CHANGED], selection->cursor_row, selection->cursor_col);
gtk_signal_emit(GTK_OBJECT(selection),
e_selection_model_signals[CURSOR_ACTIVATED], selection->cursor_row, selection->cursor_col);
return TRUE;
}
break;
case GDK_End:
case GDK_KP_End:
if (selection->cursor_mode == E_CURSOR_LINE) {
int row = selection->row_count - 1;
row = e_sorter_sorted_to_model(selection->sorter, row);
selection->cursor_row = row;
esm_select_single_row (selection, selection->cursor_row);
gtk_signal_emit(GTK_OBJECT(selection),
e_selection_model_signals[CURSOR_CHANGED], selection->cursor_row, selection->cursor_col);
gtk_signal_emit(GTK_OBJECT(selection),
e_selection_model_signals[CURSOR_ACTIVATED], selection->cursor_row, selection->cursor_col);
return TRUE;
}
break;
}
return FALSE;
}
/**
* e_selection_model_clear
* @selection: #ESelectionModel to clear
*
* This routine clears the selection to no rows selected.
*/
void
e_selection_model_clear(ESelectionModel *selection)
{
g_free(selection->selection);
selection->selection = NULL;
selection->row_count = -1;
selection->cursor_row = -1;
selection->cursor_col = -1;
gtk_signal_emit(GTK_OBJECT(selection),
e_selection_model_signals [CURSOR_CHANGED], -1, -1);
gtk_signal_emit(GTK_OBJECT(selection),
e_selection_model_signals [SELECTION_CHANGED]);
}
#define PART(x,n) (((x) & (0x01010101 << n)) >> n)
#define SECTION(x, n) (((x) >> (n * 8)) & 0xff)
/**
* e_selection_model_selected_count
* @selection: #ESelectionModel to count
*
* This routine calculates the number of rows selected.
*
* Returns: The number of rows selected in the given model.
*/
gint
e_selection_model_selected_count (ESelectionModel *selection)
{
gint count;
int i;
int last;
if (!selection->selection)
return 0;
count = 0;
last = BOX(selection->row_count - 1);
for (i = 0; i <= last; i++) {
int j;
guint32 thiscount = 0;
for (j = 0; j < 8; j++)
thiscount += PART(selection->selection[i], j);
for (j = 0; j < 4; j++)
count += SECTION(thiscount, j);
}
return count;
}
/**
* e_selection_model_select_all
* @selection: #ESelectionModel to select all
*
* This routine selects all the rows in the given
* #ESelectionModel.
*/
void
e_selection_model_select_all (ESelectionModel *selection)
{
int i;
if (selection->row_count < 0) {
selection->row_count = e_selection_model_get_row_count(selection);
if (selection->row_count < 0)
return;
g_free (selection->selection);
selection->selection = g_new0 (gint, (selection->row_count + 31) / 32);
}
if (!selection->selection)
selection->selection = g_new0 (gint, (selection->row_count + 31) / 32);
for (i = 0; i < (selection->row_count + 31) / 32; i ++) {
selection->selection[i] = ONES;
}
/* need to zero out the bits corresponding to the rows not
selected in the last full 32 bit mask */
if (selection->row_count % 32) {
int unselected_mask = 0;
int num_unselected_in_last_byte = 32 - selection->row_count % 32;
for (i = 0; i < num_unselected_in_last_byte; i ++)
unselected_mask |= 1 << i;
selection->selection[(selection->row_count + 31) / 32 - 1] &= ~unselected_mask;
}
selection->cursor_col = 0;
selection->cursor_row = 0;
selection->selection_start_row = 0;
gtk_signal_emit (GTK_OBJECT (selection),
e_selection_model_signals [CURSOR_CHANGED], 0, 0);
gtk_signal_emit (GTK_OBJECT (selection),
e_selection_model_signals [SELECTION_CHANGED]);
}
/**
* e_selection_model_invert_selection
* @selection: #ESelectionModel to invert
*
* This routine inverts all the rows in the given
* #ESelectionModel.
*/
void
e_selection_model_invert_selection (ESelectionModel *selection)
{
int i;
if (selection->row_count < 0) {
selection->row_count = e_selection_model_get_row_count (selection);
if (selection->row_count < 0)
return;
g_free (selection->selection);
selection->selection = g_new0 (gint, (selection->row_count + 31) / 32);
}
if (!selection->selection)
selection->selection = g_new0 (gint, (selection->row_count + 31) / 32);
for (i = 0; i < (selection->row_count + 31) / 32; i ++) {
selection->selection[i] = ~selection->selection[i];
}
selection->cursor_col = -1;
selection->cursor_row = -1;
selection->selection_start_row = 0;
gtk_signal_emit (GTK_OBJECT (selection),
e_selection_model_signals [CURSOR_CHANGED], -1, -1);
gtk_signal_emit (GTK_OBJECT (selection),
e_selection_model_signals [SELECTION_CHANGED]);
}
int
e_selection_model_get_row_count (ESelectionModel *selection)
{
g_return_val_if_fail(selection != NULL, 0);
g_return_val_if_fail(E_IS_SELECTION_MODEL(selection), 0);
if (ESM_CLASS(selection)->get_row_count)
return ESM_CLASS(selection)->get_row_count (selection);
else
return 0;
}
