/* -*- Mode: C; indent-tabs-mode: t; c-basic-offset: 8; tab-width: 8 -*- */

/*
 * Nautilus
 *
 * Copyright (C) 2002 Sun Microsystems, Inc.
 *
 * Nautilus 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.
 *
 * Nautilus 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., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 * 
 * Author: Dave Camp <dave@ximian.com>
 * XDS support: Benedikt Meurer <benny@xfce.org> (adapted by Amos Brocco <amos.brocco@unifr.ch>)
 */

/* nautilus-tree-view-drag-dest.c: Handles drag and drop for treeviews which 
 *                                 contain a hierarchy of files
 */

#include <config.h>

#include "nautilus-tree-view-drag-dest.h"

#include "nautilus-file-dnd.h"
#include "nautilus-file-changes-queue.h"
#include "nautilus-icon-dnd.h"
#include "nautilus-link.h"

#include <gtk/gtk.h>

#include <stdio.h>
#include <string.h>

#define DEBUG_FLAG NAUTILUS_DEBUG_LIST_VIEW
#include "nautilus-debug.h"

#define AUTO_SCROLL_MARGIN 20

#define HOVER_EXPAND_TIMEOUT 1

struct _NautilusTreeViewDragDestDetails {
	GtkTreeView *tree_view;

	gboolean drop_occurred;

	gboolean have_drag_data;
	guint drag_type;
	GtkSelectionData *drag_data;
	GList *drag_list;

	guint highlight_id;
	guint scroll_id;
	guint expand_id;
	
	char *direct_save_uri;
};

enum {
	GET_ROOT_URI,
	GET_FILE_FOR_PATH,
	MOVE_COPY_ITEMS,
	HANDLE_NETSCAPE_URL,
	HANDLE_URI_LIST,
	HANDLE_TEXT,
	HANDLE_RAW,
	LAST_SIGNAL
};

static guint signals[LAST_SIGNAL];

G_DEFINE_TYPE (NautilusTreeViewDragDest, nautilus_tree_view_drag_dest,
	       G_TYPE_OBJECT);

static const GtkTargetEntry drag_types [] = {
	{ NAUTILUS_ICON_DND_GNOME_ICON_LIST_TYPE, 0, NAUTILUS_ICON_DND_GNOME_ICON_LIST },
	/* prefer "_NETSCAPE_URL" over "text/uri-list" to satisfy web browsers. */
	{ NAUTILUS_ICON_DND_NETSCAPE_URL_TYPE, 0, NAUTILUS_ICON_DND_NETSCAPE_URL },
	{ NAUTILUS_ICON_DND_URI_LIST_TYPE, 0, NAUTILUS_ICON_DND_URI_LIST },
	{ NAUTILUS_ICON_DND_XDNDDIRECTSAVE_TYPE, 0, NAUTILUS_ICON_DND_XDNDDIRECTSAVE }, /* XDS Protocol Type */
	{ NAUTILUS_ICON_DND_RAW_TYPE, 0, NAUTILUS_ICON_DND_RAW }
};


static void
gtk_tree_view_vertical_autoscroll (GtkTreeView *tree_view)
{
	GdkRectangle visible_rect;
	GtkAdjustment *vadjustment;
	GdkDeviceManager *manager;
	GdkDevice *pointer;
	GdkWindow *window;
	int y;
	int offset;
	float value;
	
	window = gtk_tree_view_get_bin_window (tree_view);
	vadjustment = gtk_scrollable_get_vadjustment (GTK_SCROLLABLE (tree_view));

	manager = gdk_display_get_device_manager (gtk_widget_get_display (GTK_WIDGET (tree_view)));
	pointer = gdk_device_manager_get_client_pointer (manager);
	gdk_window_get_device_position (window, pointer,
					NULL, &y, NULL);
	
	y += gtk_adjustment_get_value (vadjustment);

	gtk_tree_view_get_visible_rect (tree_view, &visible_rect);
	
	offset = y - (visible_rect.y + 2 * AUTO_SCROLL_MARGIN);
	if (offset > 0) {
		offset = y - (visible_rect.y + visible_rect.height - 2 * AUTO_SCROLL_MARGIN);
		if (offset < 0) {
			return;
		}
	}

	value = CLAMP (gtk_adjustment_get_value (vadjustment) + offset, 0.0,
		       gtk_adjustment_get_upper (vadjustment) - gtk_adjustment_get_page_size (vadjustment));
	gtk_adjustment_set_value (vadjustment, value);
}

static int
scroll_timeout (gpointer data)
{
	GtkTreeView *tree_view = GTK_TREE_VIEW (data);
	
	gtk_tree_view_vertical_autoscroll (tree_view);

	return TRUE;
}

static void
remove_scroll_timeout (NautilusTreeViewDragDest *dest)
{
	if (dest->details->scroll_id) {
		g_source_remove (dest->details->scroll_id);
		dest->details->scroll_id = 0;
	}
}

static int
expand_timeout (gpointer data)
{
	GtkTreeView *tree_view;
	GtkTreePath *drop_path;
	
	tree_view = GTK_TREE_VIEW (data);
	
	gtk_tree_view_get_drag_dest_row (tree_view, &drop_path, NULL);
	
	if (drop_path) {
		gtk_tree_view_expand_row (tree_view, drop_path, FALSE);
		gtk_tree_path_free (drop_path);
	}

	return FALSE;
}

static void
remove_expand_timeout (NautilusTreeViewDragDest *dest)
{
	if (dest->details->expand_id) {
		g_source_remove (dest->details->expand_id);
		dest->details->expand_id = 0;
	}
}

static gboolean
highlight_draw (GtkWidget *widget,
		cairo_t   *cr,
                gpointer data)
{
	GdkWindow *bin_window;
	int width;
	int height;
	GtkStyleContext *style;

        /* FIXMEchpe: is bin window right here??? */
        bin_window = gtk_tree_view_get_bin_window (GTK_TREE_VIEW (widget));

        width = gdk_window_get_width (bin_window);
        height = gdk_window_get_height (bin_window);

	style = gtk_widget_get_style_context (widget);

	gtk_style_context_save (style);
	gtk_style_context_add_class (style, "treeview-drop-indicator");

        gtk_render_focus (style,
			  cr,
			  0, 0, width, height);

	gtk_style_context_restore (style);

	return FALSE;
}

static void
set_widget_highlight (NautilusTreeViewDragDest *dest, gboolean highlight)
{
	if (!highlight && dest->details->highlight_id) {
		g_signal_handler_disconnect (dest->details->tree_view,
					     dest->details->highlight_id);
		dest->details->highlight_id = 0;
		gtk_widget_queue_draw (GTK_WIDGET (dest->details->tree_view));
	}
	
	if (highlight && !dest->details->highlight_id) {
		dest->details->highlight_id = 
			g_signal_connect_object (dest->details->tree_view,
						 "draw",
						 G_CALLBACK (highlight_draw),
						 dest, 0);
		gtk_widget_queue_draw (GTK_WIDGET (dest->details->tree_view));
	}
}

static void
set_drag_dest_row (NautilusTreeViewDragDest *dest,
		   GtkTreePath *path)
{
	if (path) {
		set_widget_highlight (dest, FALSE);
		gtk_tree_view_set_drag_dest_row
			(dest->details->tree_view,
			 path,
			 GTK_TREE_VIEW_DROP_INTO_OR_BEFORE);
	} else {
		set_widget_highlight (dest, TRUE);
		gtk_tree_view_set_drag_dest_row (dest->details->tree_view, 
						 NULL, 
						 0);
	}
}

static void
clear_drag_dest_row (NautilusTreeViewDragDest *dest)
{
	gtk_tree_view_set_drag_dest_row (dest->details->tree_view, NULL, 0);
	set_widget_highlight (dest, FALSE);
}

static gboolean
get_drag_data (NautilusTreeViewDragDest *dest,
	       GdkDragContext *context, 
	       guint32 time)
{
	GdkAtom target;
	
	target = gtk_drag_dest_find_target (GTK_WIDGET (dest->details->tree_view), 
					    context, 
					    NULL);

	if (target == GDK_NONE) {
		return FALSE;
	}

	if (target == gdk_atom_intern (NAUTILUS_ICON_DND_XDNDDIRECTSAVE_TYPE, FALSE) &&
	    !dest->details->drop_occurred) {
		dest->details->drag_type = NAUTILUS_ICON_DND_XDNDDIRECTSAVE;
		dest->details->have_drag_data = TRUE;
		return TRUE;
	}

	gtk_drag_get_data (GTK_WIDGET (dest->details->tree_view),
			   context, target, time);

	return TRUE;
}

static void
free_drag_data (NautilusTreeViewDragDest *dest)
{
	dest->details->have_drag_data = FALSE;

	if (dest->details->drag_data) {
		gtk_selection_data_free (dest->details->drag_data);
		dest->details->drag_data = NULL;
	}

	if (dest->details->drag_list) {
		nautilus_drag_destroy_selection_list (dest->details->drag_list);
		dest->details->drag_list = NULL;
	}

	g_free (dest->details->direct_save_uri);
	dest->details->direct_save_uri = NULL;
}

static char *
get_root_uri (NautilusTreeViewDragDest *dest)
{
	char *uri;
	
	g_signal_emit (dest, signals[GET_ROOT_URI], 0, &uri);
	
	return uri;
}

static NautilusFile *
file_for_path (NautilusTreeViewDragDest *dest, GtkTreePath *path)
{
	NautilusFile *file;
	char *uri;
	
	if (path) {
		g_signal_emit (dest, signals[GET_FILE_FOR_PATH], 0, path, &file);
	} else {
		uri = get_root_uri (dest);

		file = NULL;
		if (uri != NULL) {
			file = nautilus_file_get_by_uri (uri);
		}
		
		g_free (uri);
	}
	
	return file;
}

static GtkTreePath *
get_drop_path (NautilusTreeViewDragDest *dest,
	       GtkTreePath *path)
{
	NautilusFile *file;
	GtkTreePath *ret;
	
	if (!path || !dest->details->have_drag_data) {
		return NULL;
	}

	ret = gtk_tree_path_copy (path);
	file = file_for_path (dest, ret);

	/* Go up the tree until we find a file that can accept a drop */
	while (file == NULL /* dummy row */ ||
	       !nautilus_drag_can_accept_info (file,
		       			       dest->details->drag_type,
					       dest->details->drag_list)) {
		if (gtk_tree_path_get_depth (ret) == 1) {
			gtk_tree_path_free (ret);
			ret = NULL;
			break;
		} else {
			gtk_tree_path_up (ret);

			nautilus_file_unref (file);
			file = file_for_path (dest, ret);
		}
	}
	nautilus_file_unref (file);
	
	return ret;
}

static char *
get_drop_target_uri_for_path (NautilusTreeViewDragDest *dest,
			      GtkTreePath *path)
{
	NautilusFile *file;
	char *target;

	file = file_for_path (dest, path);
	if (file == NULL) {
		return NULL;
	}
	
	target = nautilus_file_get_drop_target_uri (file);
	nautilus_file_unref (file);
	
	return target;
}

static guint
get_drop_action (NautilusTreeViewDragDest *dest, 
		 GdkDragContext *context,
		 GtkTreePath *path)
{
	char *drop_target;
	int action;
	
	if (!dest->details->have_drag_data ||
	    (dest->details->drag_type == NAUTILUS_ICON_DND_GNOME_ICON_LIST &&
	     dest->details->drag_list == NULL)) {
		return 0;
	}

	switch (dest->details->drag_type) {
	case NAUTILUS_ICON_DND_GNOME_ICON_LIST :
		drop_target = get_drop_target_uri_for_path (dest, path);
		
		if (!drop_target) {
			return 0;
		}

		nautilus_drag_default_drop_action_for_icons
			(context,
			 drop_target,
			 dest->details->drag_list,
			 &action);

		g_free (drop_target);
		
		return action;
		
	case NAUTILUS_ICON_DND_NETSCAPE_URL:
		drop_target = get_drop_target_uri_for_path (dest, path);

		if (drop_target == NULL) {
			return 0;
		}

		action = nautilus_drag_default_drop_action_for_netscape_url (context);

		g_free (drop_target);

		return action;
		
	case NAUTILUS_ICON_DND_URI_LIST :
		drop_target = get_drop_target_uri_for_path (dest, path);

		if (drop_target == NULL) {
			return 0;
		}

		g_free (drop_target);

		return gdk_drag_context_get_suggested_action (context);

	case NAUTILUS_ICON_DND_TEXT:
	case NAUTILUS_ICON_DND_RAW:
	case NAUTILUS_ICON_DND_XDNDDIRECTSAVE:
		return GDK_ACTION_COPY;

	}

	return 0;
}

static gboolean
drag_motion_callback (GtkWidget *widget,
		      GdkDragContext *context,
		      int x,
		      int y,
		      guint32 time,
		      gpointer data)
{
	NautilusTreeViewDragDest *dest;
	GtkTreePath *path;
	GtkTreePath *drop_path, *old_drop_path;
	GtkTreeModel *model;
	GtkTreeIter drop_iter;
	GtkTreeViewDropPosition pos;
	GdkWindow *bin_window;
	guint action;
	gboolean res = TRUE;

	dest = NAUTILUS_TREE_VIEW_DRAG_DEST (data);

	gtk_tree_view_get_dest_row_at_pos (GTK_TREE_VIEW (widget),
					   x, y, &path, &pos);
	

	if (!dest->details->have_drag_data) {
		res = get_drag_data (dest, context, time);
	}

	if (!res) {
		return FALSE;
	}

	drop_path = get_drop_path (dest, path);
	
	action = 0;
	bin_window = gtk_tree_view_get_bin_window (GTK_TREE_VIEW (widget));
	if (bin_window != NULL) {
		int bin_x, bin_y;
		gdk_window_get_position (bin_window, &bin_x, &bin_y);
		if (bin_y <= y) {
			/* ignore drags on the header */
			action = get_drop_action (dest, context, drop_path);
		}
	}

	gtk_tree_view_get_drag_dest_row (GTK_TREE_VIEW (widget), &old_drop_path,
					 NULL);
	
	if (action) {
		set_drag_dest_row (dest, drop_path);
		model = gtk_tree_view_get_model (GTK_TREE_VIEW (widget));
		if (drop_path == NULL || (old_drop_path != NULL &&
		    gtk_tree_path_compare (old_drop_path, drop_path) != 0)) {
			remove_expand_timeout (dest);
		}
		if (dest->details->expand_id == 0 && drop_path != NULL) {
			gtk_tree_model_get_iter (model, &drop_iter, drop_path);
			if (gtk_tree_model_iter_has_child (model, &drop_iter)) {
				dest->details->expand_id = g_timeout_add_seconds (HOVER_EXPAND_TIMEOUT,
									  expand_timeout,
									  dest->details->tree_view);
			}
		}
	} else {
		clear_drag_dest_row (dest);
		remove_expand_timeout (dest);
	}
	
	if (path) {
		gtk_tree_path_free (path);
	}
	
	if (drop_path) {
		gtk_tree_path_free (drop_path);
	}
	
	if (old_drop_path) {
		gtk_tree_path_free (old_drop_path);
	}
	
	if (dest->details->scroll_id == 0) {
		dest->details->scroll_id = 
			g_timeout_add (150, 
				       scroll_timeout, 
				       dest->details->tree_view);
	}

	gdk_drag_status (context, action, time);

	return TRUE;
}

static void
drag_leave_callback (GtkWidget *widget,
		     GdkDragContext *context,
		     guint32 time,
		     gpointer data)
{
	NautilusTreeViewDragDest *dest;

	dest = NAUTILUS_TREE_VIEW_DRAG_DEST (data);

	clear_drag_dest_row (dest);

	free_drag_data (dest);

	remove_scroll_timeout (dest);
	remove_expand_timeout (dest);
}

static char *
get_drop_target_uri_at_pos (NautilusTreeViewDragDest *dest, int x, int y)
{
	char *drop_target;
	GtkTreePath *path;
	GtkTreePath *drop_path;
	GtkTreeViewDropPosition pos;

	gtk_tree_view_get_dest_row_at_pos (dest->details->tree_view, x, y, 
					   &path, &pos);

	drop_path = get_drop_path (dest, path);

	drop_target = get_drop_target_uri_for_path (dest, drop_path);

	if (path != NULL) {
		gtk_tree_path_free (path);
	}

	if (drop_path != NULL) {
		gtk_tree_path_free (drop_path);
	}

	return drop_target;
}

static void
receive_uris (NautilusTreeViewDragDest *dest,
	      GdkDragContext *context,
	      GList *source_uris,
	      int x, int y)
{
	char *drop_target;
	GdkDragAction action, real_action;

	drop_target = get_drop_target_uri_at_pos (dest, x, y);
	g_assert (drop_target != NULL);

	real_action = gdk_drag_context_get_selected_action (context);

	if (real_action == GDK_ACTION_ASK) {
		if (nautilus_drag_selection_includes_special_link (dest->details->drag_list)) {
			/* We only want to move the trash */
			action = GDK_ACTION_MOVE;
		} else {
			action = GDK_ACTION_MOVE | GDK_ACTION_COPY | GDK_ACTION_LINK;
		}
		real_action = nautilus_drag_drop_action_ask
			(GTK_WIDGET (dest->details->tree_view), action);
	}

	/* We only want to copy external uris */
	if (dest->details->drag_type == NAUTILUS_ICON_DND_URI_LIST) {
		action = GDK_ACTION_COPY;
	}

	if (real_action > 0) {
		if (!nautilus_drag_uris_local (drop_target, source_uris)
			|| real_action != GDK_ACTION_MOVE) {
			g_signal_emit (dest, signals[MOVE_COPY_ITEMS], 0,
				       source_uris, 
				       drop_target,
				       real_action,
				       x, y);
		}
	}

	g_free (drop_target);
}

static void
receive_dropped_icons (NautilusTreeViewDragDest *dest,
		       GdkDragContext *context,
		       int x, int y)
{
	GList *source_uris;
	GList *l;

	/* FIXME: ignore local only moves */

	if (!dest->details->drag_list) {
		return;
	}
	
	source_uris = NULL;
	for (l = dest->details->drag_list; l != NULL; l = l->next) {
		source_uris = g_list_prepend (source_uris,
					      ((NautilusDragSelectionItem *)l->data)->uri);
	}

	source_uris = g_list_reverse (source_uris);

	receive_uris (dest, context, source_uris, x, y);
	
	g_list_free (source_uris);
}

static void
receive_dropped_uri_list (NautilusTreeViewDragDest *dest,
			  GdkDragContext *context,
			  int x, int y)
{
	char *drop_target;

	if (!dest->details->drag_data) {
		return;
	}

	drop_target = get_drop_target_uri_at_pos (dest, x, y);
	g_assert (drop_target != NULL);

	g_signal_emit (dest, signals[HANDLE_URI_LIST], 0,
		       (char*) gtk_selection_data_get_data (dest->details->drag_data),
		       drop_target,
		       gdk_drag_context_get_selected_action (context),
		       x, y);

	g_free (drop_target);
}

static void
receive_dropped_text (NautilusTreeViewDragDest *dest,
		      GdkDragContext *context,
		      int x, int y)
{
	char *drop_target;
	guchar *text;

	if (!dest->details->drag_data) {
		return;
	}

	drop_target = get_drop_target_uri_at_pos (dest, x, y);
	g_assert (drop_target != NULL);

	text = gtk_selection_data_get_text (dest->details->drag_data);
	g_signal_emit (dest, signals[HANDLE_TEXT], 0,
		       (char *) text, drop_target,
		       gdk_drag_context_get_selected_action (context),
		       x, y);

	g_free (text);
	g_free (drop_target);
}

static void
receive_dropped_raw (NautilusTreeViewDragDest *dest,
		      const char *raw_data, int length,
		      GdkDragContext *context,
		      int x, int y)
{
	char *drop_target;

	if (!dest->details->drag_data) {
		return;
	}

	drop_target = get_drop_target_uri_at_pos (dest, x, y);
	g_assert (drop_target != NULL);

	g_signal_emit (dest, signals[HANDLE_RAW], 0,
		       raw_data, length, drop_target,
		       dest->details->direct_save_uri,
		       gdk_drag_context_get_selected_action (context),
		       x, y);

	g_free (drop_target);
}

static void
receive_dropped_netscape_url (NautilusTreeViewDragDest *dest,
			      GdkDragContext *context,
			      int x, int y)
{
	char *drop_target;

	if (!dest->details->drag_data) {
		return;
	}

	drop_target = get_drop_target_uri_at_pos (dest, x, y);
	g_assert (drop_target != NULL);

	g_signal_emit (dest, signals[HANDLE_NETSCAPE_URL], 0,
		       (char*) gtk_selection_data_get_data (dest->details->drag_data),
		       drop_target,
		       gdk_drag_context_get_selected_action (context),
		       x, y);

	g_free (drop_target);
}

static gboolean
receive_xds (NautilusTreeViewDragDest *dest,
	     GtkWidget *widget,
	     guint32 time,
	     GdkDragContext *context,
	     int x, int y)
{
	GFile *location;
	const guchar *selection_data;
	gint selection_format;
	gint selection_length;

	selection_data = gtk_selection_data_get_data (dest->details->drag_data);
	selection_format = gtk_selection_data_get_format (dest->details->drag_data);
	selection_length = gtk_selection_data_get_length (dest->details->drag_data);

	if (selection_format == 8 
	    && selection_length == 1 
	    && selection_data[0] == 'F') {
		gtk_drag_get_data (widget, context,
		                  gdk_atom_intern (NAUTILUS_ICON_DND_RAW_TYPE,
		                                  FALSE),
		                  time);
		return FALSE;
	} else if (selection_format == 8 
		   && selection_length == 1 
		   && selection_data[0] == 'S') {
		g_assert (dest->details->direct_save_uri != NULL);
		location = g_file_new_for_uri (dest->details->direct_save_uri);

		nautilus_file_changes_queue_file_added (location);
		nautilus_file_changes_consume_changes (TRUE);

		g_object_unref (location);
	}
	return TRUE;
}


static gboolean
drag_data_received_callback (GtkWidget *widget,
			     GdkDragContext *context,
			     int x,
			     int y,
			     GtkSelectionData *selection_data,
			     guint info,
			     guint32 time,
			     gpointer data)
{
	NautilusTreeViewDragDest *dest;
	const gchar *tmp;
	int length;
	gboolean success, finished;
	
	dest = NAUTILUS_TREE_VIEW_DRAG_DEST (data);

	if (!dest->details->have_drag_data) {
		dest->details->have_drag_data = TRUE;
		dest->details->drag_type = info;
		dest->details->drag_data = 
			gtk_selection_data_copy (selection_data);
		if (info == NAUTILUS_ICON_DND_GNOME_ICON_LIST) {
			dest->details->drag_list = 
				nautilus_drag_build_selection_list (selection_data);
		}
	}

	if (dest->details->drop_occurred) {
		success = FALSE;
		finished = TRUE;
		switch (info) {
		case NAUTILUS_ICON_DND_GNOME_ICON_LIST :
			receive_dropped_icons (dest, context, x, y);
			success = TRUE;
			break;
		case NAUTILUS_ICON_DND_NETSCAPE_URL :
			receive_dropped_netscape_url (dest, context, x, y);
			success = TRUE;
			break;
		case NAUTILUS_ICON_DND_URI_LIST :
			receive_dropped_uri_list (dest, context, x, y);
			success = TRUE;
			break;
		case NAUTILUS_ICON_DND_TEXT:
			receive_dropped_text (dest, context, x, y);
			success = TRUE;
			break;
		case NAUTILUS_ICON_DND_RAW:
			length = gtk_selection_data_get_length (selection_data);
			tmp = (const gchar *) gtk_selection_data_get_data (selection_data);
			receive_dropped_raw (dest, tmp, length, context, x, y);
			success = TRUE;
			break;
		case NAUTILUS_ICON_DND_XDNDDIRECTSAVE:
			finished = receive_xds (dest, widget, time, context, x, y);
			success = TRUE;
			break;
		}

		if (finished) {
			dest->details->drop_occurred = FALSE;
			free_drag_data (dest);
			gtk_drag_finish (context, success, FALSE, time);
		}
	}

	/* appease GtkTreeView by preventing its drag_data_receive
	 * from being called */
	g_signal_stop_emission_by_name (dest->details->tree_view,
					"drag_data_received");

	return TRUE;
}

static char *
get_direct_save_filename (GdkDragContext *context)
{
	guchar *prop_text;
	gint prop_len;

	if (!gdk_property_get (gdk_drag_context_get_source_window (context), gdk_atom_intern (NAUTILUS_ICON_DND_XDNDDIRECTSAVE_TYPE, FALSE),
			       gdk_atom_intern ("text/plain", FALSE), 0, 1024, FALSE, NULL, NULL,
			       &prop_len, &prop_text)) {
		return NULL;
	}

	/* Zero-terminate the string */
	prop_text = g_realloc (prop_text, prop_len + 1);
	prop_text[prop_len] = '\0';

	/* Verify that the file name provided by the source is valid */
	if (*prop_text == '\0' ||
	    strchr ((const gchar *) prop_text, G_DIR_SEPARATOR) != NULL) {
		DEBUG ("Invalid filename provided by XDS drag site");
		g_free (prop_text);
		return NULL;
	}

	return (gchar *) prop_text;
}

static gboolean
set_direct_save_uri (NautilusTreeViewDragDest *dest,
		     GdkDragContext *context,
		     int x, int y)
{
	GFile *base, *child;
	char *drop_uri;
	char *filename, *uri;

	g_assert (dest->details->direct_save_uri == NULL);

	uri = NULL;

	drop_uri = get_drop_target_uri_at_pos (dest, x, y);
	if (drop_uri != NULL) {
		filename = get_direct_save_filename (context);
		if (filename != NULL) {
			/* Resolve relative path */
			base = g_file_new_for_uri (drop_uri);
			child = g_file_get_child (base, filename);
			uri = g_file_get_uri (child);

			g_object_unref (base);
			g_object_unref (child);

			/* Change the property */
			gdk_property_change (gdk_drag_context_get_source_window (context),
					     gdk_atom_intern (NAUTILUS_ICON_DND_XDNDDIRECTSAVE_TYPE, FALSE),
					     gdk_atom_intern ("text/plain", FALSE), 8,
					     GDK_PROP_MODE_REPLACE, (const guchar *) uri,
					     strlen (uri));

			dest->details->direct_save_uri = uri;
		} else {
			DEBUG ("Invalid filename provided by XDS drag site");
		}
	} else {
		DEBUG ("Could not retrieve XDS drop destination");
	}

	return uri != NULL;
}

static gboolean
drag_drop_callback (GtkWidget *widget,
		    GdkDragContext *context,
		    int x, 
		    int y,
		    guint32 time,
		    gpointer data)
{
	NautilusTreeViewDragDest *dest;
	guint info;
	GdkAtom target;

	dest = NAUTILUS_TREE_VIEW_DRAG_DEST (data);
	
	target = gtk_drag_dest_find_target (GTK_WIDGET (dest->details->tree_view), 
					    context, 
					    NULL);
	if (target == GDK_NONE) {
		return FALSE;
	}

	info = dest->details->drag_type;

	if (info == NAUTILUS_ICON_DND_XDNDDIRECTSAVE) {
		/* We need to set this or get_drop_path will fail, and it
		   was unset by drag_leave_callback */
		dest->details->have_drag_data = TRUE;
		if (!set_direct_save_uri (dest, context, x, y)) {
			return FALSE;
		}
		dest->details->have_drag_data = FALSE;
	}

	dest->details->drop_occurred = TRUE;

	get_drag_data (dest, context, time);
	remove_scroll_timeout (dest);
	remove_expand_timeout (dest);
	clear_drag_dest_row (dest);
	
	return TRUE;
}

static void
tree_view_weak_notify (gpointer user_data,
		       GObject *object)
{
	NautilusTreeViewDragDest *dest;

	dest = NAUTILUS_TREE_VIEW_DRAG_DEST (user_data);
	
	remove_scroll_timeout (dest);
	remove_expand_timeout (dest);

	dest->details->tree_view = NULL;
}

static void
nautilus_tree_view_drag_dest_dispose (GObject *object)
{
	NautilusTreeViewDragDest *dest;
	
	dest = NAUTILUS_TREE_VIEW_DRAG_DEST (object);

	if (dest->details->tree_view) {
		g_object_weak_unref (G_OBJECT (dest->details->tree_view),
				     tree_view_weak_notify,
				     dest);
	}
	
	remove_scroll_timeout (dest);
	remove_expand_timeout (dest);

	G_OBJECT_CLASS (nautilus_tree_view_drag_dest_parent_class)->dispose (object);
}

static void
nautilus_tree_view_drag_dest_finalize (GObject *object)
{
	NautilusTreeViewDragDest *dest;
	
	dest = NAUTILUS_TREE_VIEW_DRAG_DEST (object);
	free_drag_data (dest);

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

static void
nautilus_tree_view_drag_dest_init (NautilusTreeViewDragDest *dest)
{
	dest->details = G_TYPE_INSTANCE_GET_PRIVATE (dest, NAUTILUS_TYPE_TREE_VIEW_DRAG_DEST,
						     NautilusTreeViewDragDestDetails);
}

static void
nautilus_tree_view_drag_dest_class_init (NautilusTreeViewDragDestClass *class)
{
	GObjectClass *gobject_class;

	gobject_class = G_OBJECT_CLASS (class);
	
	gobject_class->dispose = nautilus_tree_view_drag_dest_dispose;
	gobject_class->finalize = nautilus_tree_view_drag_dest_finalize;

	g_type_class_add_private (class, sizeof (NautilusTreeViewDragDestDetails));

	signals[GET_ROOT_URI] = 
		g_signal_new ("get_root_uri",
			      G_TYPE_FROM_CLASS (class),
			      G_SIGNAL_RUN_LAST,
			      G_STRUCT_OFFSET (NautilusTreeViewDragDestClass,
					       get_root_uri),
			      NULL, NULL,
			      g_cclosure_marshal_generic,
			      G_TYPE_STRING, 0);
	signals[GET_FILE_FOR_PATH] = 
		g_signal_new ("get_file_for_path",
			      G_TYPE_FROM_CLASS (class),
			      G_SIGNAL_RUN_LAST,
			      G_STRUCT_OFFSET (NautilusTreeViewDragDestClass,
					       get_file_for_path),
			      NULL, NULL,
			      g_cclosure_marshal_generic,
			      NAUTILUS_TYPE_FILE, 1,
			      GTK_TYPE_TREE_PATH);
	signals[MOVE_COPY_ITEMS] =
		g_signal_new ("move_copy_items",
			      G_TYPE_FROM_CLASS (class),
			      G_SIGNAL_RUN_LAST,
			      G_STRUCT_OFFSET (NautilusTreeViewDragDestClass,
					       move_copy_items),
			      NULL, NULL,
			      
			      g_cclosure_marshal_generic,
			      G_TYPE_NONE, 5,
			      G_TYPE_POINTER,
			      G_TYPE_STRING,
			      GDK_TYPE_DRAG_ACTION,
			      G_TYPE_INT,
			      G_TYPE_INT);
	signals[HANDLE_NETSCAPE_URL] =
		g_signal_new ("handle_netscape_url",
			      G_TYPE_FROM_CLASS (class),
			      G_SIGNAL_RUN_LAST,
			      G_STRUCT_OFFSET (NautilusTreeViewDragDestClass, 
					       handle_netscape_url),
			      NULL, NULL,
			      g_cclosure_marshal_generic,
			      G_TYPE_NONE, 5,
			      G_TYPE_STRING,
			      G_TYPE_STRING,
			      GDK_TYPE_DRAG_ACTION,
			      G_TYPE_INT,
			      G_TYPE_INT);
	signals[HANDLE_URI_LIST] =
		g_signal_new ("handle_uri_list",
			      G_TYPE_FROM_CLASS (class),
			      G_SIGNAL_RUN_LAST,
			      G_STRUCT_OFFSET (NautilusTreeViewDragDestClass, 
					       handle_uri_list),
			      NULL, NULL,
			      g_cclosure_marshal_generic,
			      G_TYPE_NONE, 5,
			      G_TYPE_STRING,
			      G_TYPE_STRING,
			      GDK_TYPE_DRAG_ACTION,
			      G_TYPE_INT,
			      G_TYPE_INT);
	signals[HANDLE_TEXT] =
		g_signal_new ("handle_text",
			      G_TYPE_FROM_CLASS (class),
			      G_SIGNAL_RUN_LAST,
			      G_STRUCT_OFFSET (NautilusTreeViewDragDestClass, 
					       handle_text),
			      NULL, NULL,
			      g_cclosure_marshal_generic,
			      G_TYPE_NONE, 5,
			      G_TYPE_STRING,
			      G_TYPE_STRING,
			      GDK_TYPE_DRAG_ACTION,
			      G_TYPE_INT,
			      G_TYPE_INT);
	signals[HANDLE_RAW] =
		g_signal_new ("handle_raw",
			      G_TYPE_FROM_CLASS (class),
			      G_SIGNAL_RUN_LAST,
			      G_STRUCT_OFFSET (NautilusTreeViewDragDestClass,
					       handle_raw),
			      NULL, NULL,
			      g_cclosure_marshal_generic,
			      G_TYPE_NONE, 7,
			      G_TYPE_POINTER,
			      G_TYPE_INT,
			      G_TYPE_STRING,
			      G_TYPE_STRING,
			      GDK_TYPE_DRAG_ACTION,
			      G_TYPE_INT,
			      G_TYPE_INT);
}



NautilusTreeViewDragDest *
nautilus_tree_view_drag_dest_new (GtkTreeView *tree_view)
{
	NautilusTreeViewDragDest *dest;
	GtkTargetList *targets;
	
	dest = g_object_new (NAUTILUS_TYPE_TREE_VIEW_DRAG_DEST, NULL);

	dest->details->tree_view = tree_view;
	g_object_weak_ref (G_OBJECT (dest->details->tree_view),
			   tree_view_weak_notify, dest);
	
	gtk_drag_dest_set (GTK_WIDGET (tree_view),
			   0, drag_types, G_N_ELEMENTS (drag_types),
			   GDK_ACTION_MOVE | GDK_ACTION_COPY | GDK_ACTION_LINK | GDK_ACTION_ASK);

	targets = gtk_drag_dest_get_target_list (GTK_WIDGET (tree_view));
	gtk_target_list_add_text_targets (targets, NAUTILUS_ICON_DND_TEXT);

	g_signal_connect_object (tree_view,
				 "drag_motion",
				 G_CALLBACK (drag_motion_callback),
				 dest, 0);
	g_signal_connect_object (tree_view,
				 "drag_leave",
				 G_CALLBACK (drag_leave_callback),
				 dest, 0);
	g_signal_connect_object (tree_view,
				 "drag_drop",
				 G_CALLBACK (drag_drop_callback),
				 dest, 0);
	g_signal_connect_object (tree_view, 
				 "drag_data_received",
				 G_CALLBACK (drag_data_received_callback),
				 dest, 0);
	
	return dest;
}
