/*
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) version 3.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with the program; if not, see <http://www.gnu.org/licenses/>
 *
 *
 * Authors:
 *		Mike Kestner  <mkestner@ximian.com>
 *
 * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
 *
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <gdk/gdkkeysyms.h>

#include "e-combo-cell-editable.h"

struct _EComboCellEditablePriv {
	GtkEntry *entry;
	GtkWidget *popup;
	GtkTreeView *tree_view;
	gboolean cancelled;
	GList *list;
};

#define GRAB_MASK  (GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK)

/* Forward Declarations */
static void	e_combo_cell_editable_interface_init
					(GtkCellEditableIface *interface);

G_DEFINE_TYPE_WITH_CODE (
	EComboCellEditable,
	e_combo_cell_editable,
	GTK_TYPE_EVENT_BOX,
	G_IMPLEMENT_INTERFACE (
		GTK_TYPE_CELL_EDITABLE,
		e_combo_cell_editable_interface_init))

static void
kill_popup (EComboCellEditable *ecce)
{
	gtk_grab_remove (GTK_WIDGET (ecce->priv->tree_view));
	gtk_widget_destroy (ecce->priv->popup);

	gtk_cell_editable_editing_done (GTK_CELL_EDITABLE (ecce));
	gtk_cell_editable_remove_widget (GTK_CELL_EDITABLE (ecce));
}

static gboolean
popup_key_press_cb (GtkWidget *widget,
                    GdkEventKey *event,
                    EComboCellEditable *ecce)
{
	switch (event->keyval) {
	case GDK_KEY_Escape:
		ecce->priv->cancelled = TRUE;
		kill_popup (ecce);
		break;

	case GDK_KEY_Return:
	case GDK_KEY_KP_Enter:
		ecce->priv->cancelled = FALSE;
		kill_popup (ecce);
		break;

	default:
		return FALSE;
	}

	return TRUE;
}

static gboolean
popup_button_press_cb (GtkWidget *widget,
                       GdkEventButton *event,
                       EComboCellEditable *ecce)
{
	GtkAllocation alloc;
	GdkWindow *window;
	gdouble rel_x, rel_y;
	gint win_x, win_y;

	if (event->button != 1)
		return FALSE;

	window = gtk_widget_get_window (widget);
	gdk_window_get_root_origin (window, &win_x, &win_y);
	gtk_widget_get_allocation (ecce->priv->popup, &alloc);

	rel_x = event->x_root - win_x - alloc.x;
	rel_y = event->y_root - win_y - alloc.y;

	if (rel_x > 0 && rel_x < alloc.width && rel_y > 0 && rel_y < alloc.height)
		return FALSE;

	ecce->priv->cancelled = TRUE;
	kill_popup (ecce);

	return FALSE;
}

static gboolean
tree_button_release_cb (GtkWidget *widget,
                        GdkEventButton *event,
                        EComboCellEditable *ecce)
{
	kill_popup (ecce);
	return TRUE;
}

static void
selection_changed_cb (GtkTreeSelection *selection,
                      EComboCellEditable *ecce)
{
	GtkTreeModel *model;
	GtkTreeIter iter;
	gchar *text;

	if (!gtk_tree_selection_get_selected (selection, &model, &iter))
		return;

	gtk_tree_model_get (model, &iter, 0, &text, -1);
	e_combo_cell_editable_set_text (ecce, text);
	g_free (text);
}

static void
build_popup (EComboCellEditable *ecce)
{
	GtkWidget *frame;
	GtkTreeSelection *selection;
	GtkTreeModel *model;
	GtkTreeIter iter;
	GList *l;

	ecce->priv->popup = gtk_window_new (GTK_WINDOW_POPUP);

	g_signal_connect (ecce->priv->popup, "button-press-event", G_CALLBACK (popup_button_press_cb), ecce);
	g_signal_connect (ecce->priv->popup, "key-press-event", G_CALLBACK (popup_key_press_cb), ecce);

	frame = gtk_frame_new (NULL);
	gtk_frame_set_shadow_type (GTK_FRAME (frame), GTK_SHADOW_OUT);
	gtk_widget_show (frame);
	gtk_container_add (GTK_CONTAINER (ecce->priv->popup), frame);
	gtk_window_set_type_hint (GTK_WINDOW (ecce->priv->popup), GDK_WINDOW_TYPE_HINT_COMBO);
	ecce->priv->tree_view = GTK_TREE_VIEW (gtk_tree_view_new ());
	model = GTK_TREE_MODEL (gtk_list_store_new (1, G_TYPE_STRING));

	for (l = ecce->priv->list; l; l = l->next) {
		gtk_list_store_append (GTK_LIST_STORE (model), &iter);
		gtk_list_store_set (GTK_LIST_STORE (model), &iter, 0, l->data, -1);
	}

	gtk_tree_view_set_model (ecce->priv->tree_view, model);
	g_object_unref (model);
	gtk_container_add (GTK_CONTAINER (frame), GTK_WIDGET (ecce->priv->tree_view));

	gtk_tree_view_set_headers_visible (ecce->priv->tree_view, FALSE);

	gtk_tree_view_insert_column_with_attributes (ecce->priv->tree_view, 0, NULL,
						     gtk_cell_renderer_text_new (),
						     "text", 0,
						     NULL);

	g_signal_connect (ecce->priv->tree_view, "button-release-event", G_CALLBACK (tree_button_release_cb), ecce);

	selection = gtk_tree_view_get_selection (ecce->priv->tree_view);
	gtk_tree_selection_set_mode (selection, GTK_SELECTION_BROWSE);
	g_signal_connect (selection, "changed", G_CALLBACK (selection_changed_cb), ecce);

	gtk_widget_show (GTK_WIDGET (ecce->priv->tree_view));
}

static gint
lookup_row (GList *list,
            const gchar *text)
{
	GList *l;
	gint result = 0;

	for (l = list; l; l = l->next, result++)
		if (!g_utf8_collate (text, (gchar *) l->data))
			break;

	return result;
}

static void
set_cursor (GtkTreeView *tree_view,
            gint index)
{
	GtkTreePath *path = gtk_tree_path_new ();
	gtk_tree_path_append_index (path, index);

	gtk_tree_view_set_cursor (tree_view, path, NULL, FALSE);

	gtk_tree_path_free (path);
}

static void
grab_popup (GdkWindow *popup)
{
	gdk_pointer_grab (popup, TRUE, GRAB_MASK, NULL, NULL, gtk_get_current_event_time ());
	gdk_keyboard_grab (popup, TRUE, gtk_get_current_event_time ());
}

static void
position_popup (EComboCellEditable *ecce,
                gint x,
                gint y,
                gint offset)
{
	GtkRequisition req;

	gtk_widget_realize (ecce->priv->popup);
	gtk_widget_get_preferred_size (ecce->priv->popup, &req, NULL);

	if (req.height > gdk_screen_height () - y) {
		y -= (offset + req.height);
		if (y < 0)
			y = 0;
	}

	gtk_window_move (GTK_WINDOW (ecce->priv->popup), x, y);
	gtk_widget_show (ecce->priv->popup);
}

static void
show_popup (EComboCellEditable *ecce)
{
	gint row;
	GtkAllocation  alloc;
	GdkWindow *window;
	gint x, y;

	if (!ecce->priv->list)
		return;

	build_popup (ecce);
	row = lookup_row (ecce->priv->list, e_combo_cell_editable_get_text (ecce));
	set_cursor (ecce->priv->tree_view, row);

	gtk_editable_select_region (GTK_EDITABLE (ecce->priv->entry), 0, 0);

	window = gtk_widget_get_window (GTK_WIDGET (ecce));
	gtk_widget_get_allocation (GTK_WIDGET (ecce), &alloc);
	gdk_window_get_origin (window, &x, &y);

	position_popup (ecce, x, y + alloc.height, alloc.height);

	gtk_grab_add (ecce->priv->popup);
	gtk_widget_grab_focus (GTK_WIDGET (ecce->priv->tree_view));

	window = gtk_widget_get_window (ecce->priv->popup);
	grab_popup (window);
}

static void
button_clicked_cb (GtkButton *btn,
                   EComboCellEditable *ecce)
{
	if (ecce->priv->popup) {
		kill_popup (ecce);
		return;
	}

	show_popup (ecce);
}

static void
entry_activated_cb (GtkEntry *entry,
                    EComboCellEditable *widget)
{
	gtk_cell_editable_editing_done (GTK_CELL_EDITABLE (widget));
	gtk_cell_editable_remove_widget (GTK_CELL_EDITABLE (widget));
}

static gboolean
entry_key_press_event_cb (GtkEntry *entry,
                          GdkEventKey *key_event,
                          EComboCellEditable *ecce)
{
	if (key_event->keyval == GDK_KEY_Escape) {
		ecce->priv->cancelled = TRUE;
		gtk_cell_editable_editing_done (GTK_CELL_EDITABLE (ecce));
		gtk_cell_editable_remove_widget (GTK_CELL_EDITABLE (ecce));
		return TRUE;
	}

	if (key_event->state & GDK_MOD1_MASK
		&& key_event->keyval == GDK_KEY_Down) {
		if (!ecce->priv->popup)
			show_popup (ecce);

		return TRUE;
	}

	return FALSE;
}

static void
ecce_start_editing (GtkCellEditable *cell_editable,
                    GdkEvent *event)
{
	EComboCellEditable *ecce = E_COMBO_CELL_EDITABLE (cell_editable);

	gtk_editable_select_region (GTK_EDITABLE (ecce->priv->entry), 0, -1);
}

static void
e_combo_cell_editable_interface_init (GtkCellEditableIface *interface)
{
	interface->start_editing = ecce_start_editing;
}

static void
ecce_finalize (GObject *object)
{
	EComboCellEditable *ecce = (EComboCellEditable *) object;

	g_free (ecce->priv);

	G_OBJECT_CLASS (e_combo_cell_editable_parent_class)->finalize (object);
}

static void
e_combo_cell_editable_init (EComboCellEditable *ecce)
{
	GtkWidget *entry, *btn, *box;

	box = gtk_hbox_new (FALSE, 0);
	gtk_widget_show (box);
	gtk_container_add (GTK_CONTAINER (ecce), box);

	ecce->priv = g_new0 (EComboCellEditablePriv, 1);

	entry = gtk_entry_new ();
	ecce->priv->entry = GTK_ENTRY (entry);
	gtk_entry_set_has_frame (ecce->priv->entry, FALSE);
	gtk_editable_set_editable (GTK_EDITABLE (ecce->priv->entry), FALSE);
	g_signal_connect (entry, "activate", G_CALLBACK (entry_activated_cb), ecce);
	g_signal_connect (entry, "key_press_event", G_CALLBACK (entry_key_press_event_cb), ecce);
	gtk_widget_show (entry);
	gtk_box_pack_start (GTK_BOX (box), entry, TRUE, TRUE, 0);

	btn = gtk_button_new ();
	gtk_container_add (GTK_CONTAINER (btn), gtk_arrow_new (GTK_ARROW_DOWN, GTK_SHADOW_OUT));
	g_signal_connect (btn, "clicked", (GCallback) button_clicked_cb, ecce);
	gtk_widget_show_all (btn);
	gtk_box_pack_start (GTK_BOX (box), btn, FALSE, TRUE, 0);
}

static void
ecce_grab_focus (GtkWidget *widget)
{
	EComboCellEditable *ecce = E_COMBO_CELL_EDITABLE (widget);

	gtk_widget_grab_focus (GTK_WIDGET (ecce->priv->entry));
}

static void
e_combo_cell_editable_class_init (EComboCellEditableClass *class)
{
	GObjectClass *object_class;
	GtkWidgetClass *widget_class;

	object_class = G_OBJECT_CLASS (class);
	object_class->finalize = ecce_finalize;

	widget_class = GTK_WIDGET_CLASS (class);
	widget_class->grab_focus = ecce_grab_focus;
}

GtkCellEditable *
e_combo_cell_editable_new (void)
{
	return g_object_new (E_TYPE_COMBO_CELL_EDITABLE, NULL);
}

const GList *
e_combo_cell_editable_get_list (EComboCellEditable *ecce)
{
	g_return_val_if_fail (E_COMBO_CELL_EDITABLE (ecce), NULL);

	return ecce->priv->list;
}

void
e_combo_cell_editable_set_list (EComboCellEditable *ecce,
                                GList *list)
{
	g_return_if_fail (E_IS_COMBO_CELL_EDITABLE (ecce));

	ecce->priv->list = list;
}

const gchar *
e_combo_cell_editable_get_text (EComboCellEditable *ecce)
{
	g_return_val_if_fail (E_COMBO_CELL_EDITABLE (ecce), NULL);

	return gtk_entry_get_text (ecce->priv->entry);
}

void
e_combo_cell_editable_set_text (EComboCellEditable *ecce,
                                const gchar *text)
{
	g_return_if_fail (E_IS_COMBO_CELL_EDITABLE (ecce));

	gtk_entry_set_text (ecce->priv->entry, text ? text : "");
}

gboolean
e_combo_cell_editable_cancelled (EComboCellEditable *ecce)
{
	g_return_val_if_fail (E_IS_COMBO_CELL_EDITABLE (ecce), FALSE);

	return ecce->priv->cancelled;
}