## Contacts Browser Example Contacts Browser Example — Explanation of how to create a scrolling window listing contacts in alphabetical order. |

## Introduction

This is a fully functional reference application for implementing scrolling contact browsers using the #EBookClientCursor. With the cursor, the following features are possible.

- Display contacts in a configurable sort order

  Sort by any #EContactField which conforms to #G_TYPE_STRING, this can be checked with e_contact_field_type()

- Minimal memory constraints

  Only load into memory the contacts which are currently visible in the list

- Filter search results on the fly

  Set new search expressions generated with #EBookQuery on the fly. Refresh the contact list at the current position without losing the current cursor position.

- Display the the user's alphabet

  Using interesting features from ICU libraries allow us to display the user's alphabet, and implement features such as jumping to a given letter in the user's alphabet.

The actual example code is built into the 'example' subdirectory of the Evolution Data Server sources. In order to run the example, just launch the program and give it a path to a directory full of vcards, bearing the .vcf filename extention.

## Contact Browser

Below is an example of the contact browser code itself, the example program is broken down into a couple of object classes which are also listed below.

    	/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
    /*
     * Copyright (C) 2013 Intel Corporation
     *
     * This library 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.
     *
     * This library 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 this library. If not, see <http://www.gnu.org/licenses/>.
     *
     * Authors: Tristan Van Berkom <tristanvb@openismus.com>
     */

    #include <libebook/libebook.h>

    #include "cursor-example.h"
    #include "cursor-navigator.h"
    #include "cursor-search.h"
    #include "cursor-slot.h"
    #include "cursor-data.h"
    #include "cursor-slot.h"

    #define N_SLOTS         10

    #define INITIAL_TIMEOUT 600
    #define TICK_TIMEOUT    100

    #define d(x)

    typedef enum _TimeoutActivity TimeoutActivity;

    /* GObjectClass */
    static void            cursor_example_dispose                 (GObject            *object);

    /* UI Callbacks */
    static gboolean        cursor_example_up_button_press         (CursorExample      *example,
    							       GdkEvent           *event,
    							       GtkButton          *button);
    static gboolean        cursor_example_up_button_release       (CursorExample      *example,
    							       GdkEvent           *event,
    							       GtkButton          *button);
    static gboolean        cursor_example_down_button_press       (CursorExample      *example,
    							       GdkEvent           *event,
    							       GtkButton          *button);
    static gboolean        cursor_example_down_button_release     (CursorExample      *example,
    							       GdkEvent           *event,
    							       GtkButton          *button);
    static void            cursor_example_navigator_changed       (CursorExample      *example,
    							       CursorNavigator    *navigator);
    static void            cursor_example_sexp_changed            (CursorExample      *example,
    							       GParamSpec         *pspec,
    							       CursorSearch       *search);

    /* EDS Callbacks */
    static void            cursor_example_refresh                 (EBookClientCursor  *cursor,
    							       CursorExample      *example);
    static void            cursor_example_alphabet_changed        (EBookClientCursor  *cursor,
    							       GParamSpec         *pspec,
    							       CursorExample      *example);
    static void            cursor_example_status_changed          (EBookClientCursor  *cursor,
    							       GParamSpec         *spec,
    							       CursorExample      *example);

    /* Utilities */
    static void            cursor_example_load_alphabet           (CursorExample      *example);
    static gboolean        cursor_example_move_cursor             (CursorExample      *example,
    							       EBookCursorOrigin   origin,
    							       gint                count);
    static gboolean        cursor_example_load_page               (CursorExample      *example,
    							       gboolean           *full_results);
    static void            cursor_example_update_status           (CursorExample      *example);
    static void            cursor_example_update_current_index    (CursorExample      *example,
    							       EContact           *contact);
    static void            cursor_example_ensure_timeout          (CursorExample      *example,
    							       TimeoutActivity     activity);
    static void            cursor_example_cancel_timeout          (CursorExample      *example);

    enum _TimeoutActivity {
    	TIMEOUT_NONE = 0,
    	TIMEOUT_UP_INITIAL,
    	TIMEOUT_UP_TICK,
    	TIMEOUT_DOWN_INITIAL,
    	TIMEOUT_DOWN_TICK,
    };

    struct _CursorExamplePrivate {
    	/* Screen widgets */
    	GtkWidget *browse_up_button;
    	GtkWidget *browse_down_button;
    	GtkWidget *progressbar;
    	GtkWidget *alphabet_label;
    	GtkWidget *slots[N_SLOTS];
    	CursorNavigator *navigator;

    	/* EDS Resources */
    	EBookClient          *client;
    	EBookClientCursor    *cursor;

    	/* Manage the automatic scrolling with button pressed */
    	guint                 timeout_id;
    	TimeoutActivity       activity;
    };

    G_DEFINE_TYPE_WITH_PRIVATE (CursorExample, cursor_example, GTK_TYPE_WINDOW);

    /************************************************************************
     *                          GObjectClass                                *
     ************************************************************************/
    static void
    cursor_example_class_init (CursorExampleClass *klass)
    {
    	GObjectClass *object_class;
    	GtkWidgetClass *widget_class;
    	gint i;

    	object_class = G_OBJECT_CLASS (klass);
    	object_class->dispose = cursor_example_dispose;

    	/* Bind to template */
    	widget_class = GTK_WIDGET_CLASS (klass);
    	gtk_widget_class_set_template_from_resource (widget_class, "/org/gnome/evolution/cursor-example/cursor-example.ui");
    	gtk_widget_class_bind_template_child_private (widget_class, CursorExample, navigator);
    	gtk_widget_class_bind_template_child_private (widget_class, CursorExample, browse_up_button);
    	gtk_widget_class_bind_template_child_private (widget_class, CursorExample, browse_down_button);
    	gtk_widget_class_bind_template_child_private (widget_class, CursorExample, alphabet_label);
    	gtk_widget_class_bind_template_child_private (widget_class, CursorExample, progressbar);

    	for (i = 0; i < N_SLOTS; i++) {
    		gchar *name = g_strdup_printf ("contact_slot_%d", i + 1);

    		gtk_widget_class_bind_template_child_full (widget_class, name, FALSE, 0);
    		g_free (name);
    	}

    	gtk_widget_class_bind_template_callback (widget_class, cursor_example_navigator_changed);
    	gtk_widget_class_bind_template_callback (widget_class, cursor_example_up_button_press);
    	gtk_widget_class_bind_template_callback (widget_class, cursor_example_up_button_release);
    	gtk_widget_class_bind_template_callback (widget_class, cursor_example_down_button_press);
    	gtk_widget_class_bind_template_callback (widget_class, cursor_example_down_button_release);
    	gtk_widget_class_bind_template_callback (widget_class, cursor_example_sexp_changed);
    }

    static void
    cursor_example_init (CursorExample *example)
    {
    	CursorExamplePrivate *priv;
    	gint i;

    	example->priv = priv =
    		cursor_example_get_instance_private (example);

    	g_type_ensure (CURSOR_TYPE_NAVIGATOR);
    	g_type_ensure (CURSOR_TYPE_SEARCH);

    	gtk_widget_init_template (GTK_WIDGET (example));

    	for (i = 0; i < N_SLOTS; i++) {

    		gchar *name = g_strdup_printf ("contact_slot_%d", i + 1);
    		priv->slots[i] = (GtkWidget *) gtk_widget_get_template_child (GTK_WIDGET (example),
    									     CURSOR_TYPE_EXAMPLE,
    									     name);
    		g_free (name);
    	}
    }

    static void
    cursor_example_dispose (GObject *object)
    {
    	CursorExample        *example = CURSOR_EXAMPLE (object);
    	CursorExamplePrivate *priv = example->priv;

    	cursor_example_cancel_timeout (example);

    	if (priv->client) {
    		g_object_unref (priv->client);
    		priv->client = NULL;
    	}

    	if (priv->cursor) {
    		g_object_unref (priv->cursor);
    		priv->cursor = NULL;
    	}

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

    /************************************************************************
     *                           UI Callbacks                               *
     ************************************************************************/
    static gboolean
    cursor_example_up_button_press (CursorExample *example,
                                    GdkEvent *event,
                                    GtkButton *button)
    {
    	d (g_print ("Browse up press\n"));

    	/* Move the cursor backwards by 1 and then refresh the page */
    	if (cursor_example_move_cursor (example, E_BOOK_CURSOR_ORIGIN_CURRENT, 0 - 1))
    		cursor_example_load_page (example, NULL);

    	cursor_example_ensure_timeout (example, TIMEOUT_UP_INITIAL);

    	return FALSE;
    }

    static gboolean
    cursor_example_up_button_release (CursorExample *example,
                                      GdkEvent *event,
                                      GtkButton *button)
    {
    	d (g_print ("Browse up release\n"));

    	cursor_example_cancel_timeout (example);

    	return FALSE;
    }

    static gboolean
    cursor_example_down_button_press (CursorExample *example,
                                      GdkEvent *event,
                                      GtkButton *button)
    {
    	d (g_print ("Browse down press\n"));

    	/* Move the cursor forward by 1 and then refresh the page */
    	if (cursor_example_move_cursor (example, E_BOOK_CURSOR_ORIGIN_CURRENT, 1))
    		cursor_example_load_page (example, NULL);

    	cursor_example_ensure_timeout (example, TIMEOUT_DOWN_INITIAL);

    	return FALSE;
    }

    static gboolean
    cursor_example_down_button_release (CursorExample *example,
                                        GdkEvent *event,
                                        GtkButton *button)
    {
    	d (g_print ("Browse down released\n"));

    	cursor_example_cancel_timeout (example);

    	return FALSE;
    }

    static void
    cursor_example_navigator_changed (CursorExample *example,
                                      CursorNavigator *navigator)
    {
    	CursorExamplePrivate *priv = example->priv;
    	GError               *error = NULL;
    	gint                  index;
    	gboolean              full_results = FALSE;

    	index = cursor_navigator_get_index (priv->navigator);

    	d (g_print ("Alphabet index changed to: %d\n", index));

    	/* Move to this index */
    	if (!e_book_client_cursor_set_alphabetic_index_sync (priv->cursor, index, NULL, &error)) {

    		if (g_error_matches (error,
    				     E_CLIENT_ERROR,
    				     E_CLIENT_ERROR_OUT_OF_SYNC)) {

    			/* Just ignore the error.
    			 *
    			 * The addressbook locale has recently changed, very
    			 * soon we will receive an alphabet change notification
    			 * where we will reset the cursor position and reload
    			 * the alphabet.
    			 */
    			d (g_print ("Cursor was temporarily out of sync while setting the alphabetic target\n"));
    		} else
    			g_warning ("Failed to move the cursor: %s", error->message);

    		g_clear_error (&error);
    	}

    	/* And load one page full of results starting with this index */
    	if (!cursor_example_load_page (example, &full_results))
    		return;

    	/* If we hit the end of the results (less than a full page) then load the last page of results */
    	if (!full_results) {
    		if (cursor_example_move_cursor (example,
    						E_BOOK_CURSOR_ORIGIN_END,
    						0 - (N_SLOTS + 1))) {
    			cursor_example_load_page (example, NULL);
    		}
    	}
    }

    static void
    cursor_example_sexp_changed (CursorExample *example,
                                 GParamSpec *pspec,
                                 CursorSearch *search)
    {
    	CursorExamplePrivate *priv = example->priv;
    	gboolean              full_results = FALSE;
    	GError               *error = NULL;
    	const gchar          *sexp;

    	sexp = cursor_search_get_sexp (search);

    	d (g_print ("Search expression changed to: '%s'\n", sexp));

    	/* Set the search expression */
    	if (!e_book_client_cursor_set_sexp_sync (priv->cursor, sexp, NULL, &error)) {
    		g_warning ("Failed to move the cursor: %s", error->message);
    		g_clear_error (&error);
    	}

    	/* And load one page full of results */
    	if (!cursor_example_load_page (example, &full_results))
    		return;

    	/* If we hit the end of the results (less than a full page) then load the last page of results */
    	if (!full_results)
    		if (cursor_example_move_cursor (example,
    						E_BOOK_CURSOR_ORIGIN_END,
    						0 - (N_SLOTS + 1))) {
    			cursor_example_load_page (example, NULL);
    	}
    }

    /************************************************************************
     *                           EDS Callbacks                              *
     ************************************************************************/
    static void
    cursor_example_refresh (EBookClientCursor *cursor,
                            CursorExample *example)
    {
    	d (g_print ("Cursor refreshed\n"));

    	/* Refresh the page */
    	if (cursor_example_load_page (example, NULL))
    		cursor_example_update_status (example);
    }

    static void
    cursor_example_alphabet_changed (EBookClientCursor *cursor,
                                     GParamSpec *spec,
                                     CursorExample *example)
    {
    	d (g_print ("Alphabet Changed\n"));

    	cursor_example_load_alphabet (example);

    	/* Get the first page of contacts in the addressbook */
    	if (cursor_example_move_cursor (example, E_BOOK_CURSOR_ORIGIN_BEGIN, 0))
    		cursor_example_load_page (example, NULL);
    }

    static void
    cursor_example_status_changed (EBookClientCursor *cursor,
                                   GParamSpec *spec,
                                   CursorExample *example)
    {
    	d (g_print ("Status changed\n"));

    	cursor_example_update_status (example);
    }

    /************************************************************************
     *                             Utilities                                *
     ************************************************************************/
    static void
    cursor_example_load_alphabet (CursorExample *example)
    {
    	CursorExamplePrivate *priv = example->priv;
    	const gchar *const   *alphabet;

    	/* Update the alphabet on the navigator */
    	alphabet = e_book_client_cursor_get_alphabet (priv->cursor, NULL, NULL, NULL, NULL);
    	cursor_navigator_set_alphabet (priv->navigator, alphabet);

    	/* Reset navigator to the beginning */
    	g_signal_handlers_block_by_func (priv->navigator, cursor_example_navigator_changed, example);
    	cursor_navigator_set_index (priv->navigator, 0);
    	g_signal_handlers_unblock_by_func (priv->navigator, cursor_example_navigator_changed, example);
    }

    static gboolean
    cursor_example_move_cursor (CursorExample *example,
                                EBookCursorOrigin origin,
                                gint count)
    {
    	CursorExamplePrivate *priv = example->priv;
    	GError               *error = NULL;
    	gint                  n_results;

    	n_results = e_book_client_cursor_step_sync (
    		priv->cursor,
    		E_BOOK_CURSOR_STEP_MOVE,
    		origin,
    		count,
    		NULL, /* Result list */
    		NULL, /* GCancellable */
    		&error);

    	if (n_results < 0) {

    		if (g_error_matches (error,
    				     E_CLIENT_ERROR,
    				     E_CLIENT_ERROR_OUT_OF_SYNC)) {

    			/* The addressbook has very recently been modified,
    			 * very soon we will receive a "refresh" signal and
    			 * automatically reload the current page position.
    			 */
    			d (g_print ("Cursor was temporarily out of sync while moving\n"));

    		} else if (g_error_matches (error,
    					    E_CLIENT_ERROR,
    					    E_CLIENT_ERROR_QUERY_REFUSED)) {

    			d (g_print ("End of list was reached\n"));

    		} else
    			g_warning ("Failed to move the cursor: %s", error->message);

    		g_clear_error (&error);

    	}

    	return n_results >= 0;
    }

    /* Loads a page at the current cursor position, returns
     * FALSE if there was an error.
     */
    static gboolean
    cursor_example_load_page (CursorExample *example,
                              gboolean *full_results)
    {
    	CursorExamplePrivate *priv = example->priv;
    	GError               *error = NULL;
    	GSList               *results = NULL;
    	gint                  n_results;

    	/* Fetch N_SLOTS contacts after the current cursor position,
    	 * without modifying the current cursor position
    	 */
    	n_results = e_book_client_cursor_step_sync (
    		priv->cursor,
    		E_BOOK_CURSOR_STEP_FETCH,
    		E_BOOK_CURSOR_ORIGIN_CURRENT,
    		N_SLOTS,
    		&results,
    		NULL, /* GCancellable */
    		&error);

    	if (n_results < 0) {
    		if (g_error_matches (error,
    				     E_CLIENT_ERROR,
    				     E_CLIENT_ERROR_OUT_OF_SYNC)) {

    			/* The addressbook has very recently been modified,
    			 * very soon we will receive a "refresh" signal and
    			 * automatically reload the current page position.
    			 */
    			d (g_print ("Cursor was temporarily out of sync while loading page\n"));

    		} else if (g_error_matches (error,
    					    E_CLIENT_ERROR,
    					    E_CLIENT_ERROR_QUERY_REFUSED)) {

    			d (g_print ("End of list was reached\n"));

    		} else
    			g_warning ("Failed to move the cursor: %s", error->message);

    		g_clear_error (&error);

    	} else {
    		/* Display the results */
    		EContact             *contact;
    		gint                  i;

    		/* Fill the page with results for the current cursor position
    		 */
    		for (i = 0; i < N_SLOTS; i++) {
    			contact = g_slist_nth_data (results, i);

    			/* For the first contact, give some visual feedback about where we
    			 * are in the list, which alphabet character we're browsing right now.
    			 */
    			if (i == 0 && contact)
    				cursor_example_update_current_index (example, contact);

    			cursor_slot_set_from_contact (CURSOR_SLOT (priv->slots[i]), contact);
    		}
    	}

    	if (full_results)
    		*full_results = (n_results == N_SLOTS);

    	g_slist_free_full (results, (GDestroyNotify) g_object_unref);

    	return n_results >= 0;
    }

    static void
    cursor_example_update_status (CursorExample *example)
    {
    	CursorExamplePrivate *priv = example->priv;
    	gint                  total, position;
    	gchar                *txt;
    	gboolean              up_sensitive;
    	gboolean              down_sensitive;
    	gdouble               fraction;

    	total = e_book_client_cursor_get_total (priv->cursor);
    	position = e_book_client_cursor_get_position (priv->cursor);

    	/* Set the label showing the cursor position and total contacts */
    	txt = g_strdup_printf ("Position %d / Total %d", position, total);
    	gtk_progress_bar_set_text (GTK_PROGRESS_BAR (priv->progressbar), txt);
    	g_free (txt);

    	/* Give visual feedback on how far we are into the contact list */
    	fraction = position * 1.0F / (total - N_SLOTS);
    	gtk_progress_bar_set_fraction (GTK_PROGRESS_BAR (priv->progressbar), fraction);

    	/* Update sensitivity of buttons */
    	if (total <= N_SLOTS) {
    		/* If the amount of contacts is less than the amount of visual slots,
    		 * then we cannot browse up and down
    		 */
    		up_sensitive = FALSE;
    		down_sensitive = FALSE;
    	} else {
    		/* The cursor is always pointing directly before
    		 * the first contact visible in the view, so if the
    		 * cursor is passed the first contact we can rewind.
    		 */
    		up_sensitive = position > 0;

    		/* If more than N_SLOTS contacts remain, then
    		 * we can still scroll down */
    		down_sensitive = position < total - N_SLOTS;
    	}

    	gtk_widget_set_sensitive (priv->browse_up_button, up_sensitive);
    	gtk_widget_set_sensitive (priv->browse_down_button, down_sensitive);
    }

    /* This is called when refreshing the window contents with
     * the first contact shown in the window.
     */
    static void
    cursor_example_update_current_index (CursorExample *example,
                                         EContact *contact)
    {
    	CursorExamplePrivate *priv = example->priv;
    	const gchar *const   *labels;
    	gint                  index;

    	/* Fetch the alphabetic index for this contact */
    	index = e_book_client_cursor_get_contact_alphabetic_index (priv->cursor, contact);

    	/* Refresh the current alphabet index indicator.
    	 *
    	 * The index returned by e_book_client_cursor_get_contact_alphabetic_index() is
    	 * a valid position into the array returned by e_book_client_cursor_get_alphabet().
    	 */
    	labels = e_book_client_cursor_get_alphabet (priv->cursor, NULL, NULL, NULL, NULL);
    	gtk_label_set_text (GTK_LABEL (priv->alphabet_label), labels[index]);

    	/* Update the current scroll position (and avoid reacting to the value change)
    	 */
    	if (contact) {
    		g_signal_handlers_block_by_func (priv->navigator, cursor_example_navigator_changed, example);
    		cursor_navigator_set_index (priv->navigator, index);
    		g_signal_handlers_unblock_by_func (priv->navigator, cursor_example_navigator_changed, example);
    	}
    }

    static gboolean
    cursor_example_timeout (CursorExample *example)
    {
    	CursorExamplePrivate *priv = example->priv;
    	gboolean can_move;

    	switch (priv->activity) {
    	case TIMEOUT_NONE:
    		break;

    	case TIMEOUT_UP_INITIAL:
    	case TIMEOUT_UP_TICK:

    		/* Move the cursor backwards by 1 and then refresh the page */
    		if (cursor_example_move_cursor (example, E_BOOK_CURSOR_ORIGIN_CURRENT, 0 - 1)) {
    			cursor_example_load_page (example, NULL);
    			cursor_example_ensure_timeout (example, TIMEOUT_UP_TICK);
    		} else
    			cursor_example_cancel_timeout (example);

    		break;

    	case TIMEOUT_DOWN_INITIAL:
    	case TIMEOUT_DOWN_TICK:

    		/* Avoid scrolling past the end of the list - N_SLOTS */
    		can_move = (e_book_client_cursor_get_position (priv->cursor) <
    			    e_book_client_cursor_get_total (priv->cursor) - N_SLOTS);

    		/* Move the cursor forwards by 1 and then refresh the page */
    		if (can_move &&
    		    cursor_example_move_cursor (example, E_BOOK_CURSOR_ORIGIN_CURRENT, 1)) {
    			cursor_example_load_page (example, NULL);
    			cursor_example_ensure_timeout (example, TIMEOUT_DOWN_TICK);
    		} else
    			cursor_example_cancel_timeout (example);

    		break;
    	}

    	return FALSE;
    }

    static void
    cursor_example_ensure_timeout (CursorExample *example,
                                   TimeoutActivity activity)
    {
    	CursorExamplePrivate *priv = example->priv;
    	guint                 timeout = 0;

    	cursor_example_cancel_timeout (example);

    	if (activity == TIMEOUT_UP_INITIAL ||
    	    activity == TIMEOUT_DOWN_INITIAL)
    		timeout = INITIAL_TIMEOUT;
    	else
    		timeout = TICK_TIMEOUT;

    	priv->activity = activity;

    	priv->timeout_id =
    		g_timeout_add (
    			timeout,
    			(GSourceFunc) cursor_example_timeout,
    			example);
    }

    static void
    cursor_example_cancel_timeout (CursorExample *example)
    {
    	CursorExamplePrivate *priv = example->priv;

    	if (priv->timeout_id) {
    		g_source_remove (priv->timeout_id);
    		priv->timeout_id = 0;
    	}
    }

    /************************************************************************
     *                                API                                   *
     ************************************************************************/
    GtkWidget *
    cursor_example_new (const gchar *vcard_path)
    {
      CursorExample *example;
      CursorExamplePrivate *priv;

      example = g_object_new (CURSOR_TYPE_EXAMPLE, NULL);
      priv = example->priv;

      priv->client = cursor_load_data (vcard_path, &priv->cursor);

      cursor_example_load_alphabet (example);

      /* Load the first page of results */
      cursor_example_load_page (example, NULL);
      cursor_example_update_status (example);

      g_signal_connect (priv->cursor, "refresh",
    		    G_CALLBACK (cursor_example_refresh), example);
      g_signal_connect (priv->cursor, "notify::alphabet",
    		    G_CALLBACK (cursor_example_alphabet_changed), example);
      g_signal_connect (priv->cursor, "notify::total",
    		    G_CALLBACK (cursor_example_status_changed), example);
      g_signal_connect (priv->cursor, "notify::position",
    		    G_CALLBACK (cursor_example_status_changed), example);

      g_message ("Cursor example started in locale: %s",
    	     e_book_client_get_locale (priv->client));

      return (GtkWidget *) example;
    }

## The alphabetic navigator

This is a simple class which implements a vertical scroller and displays various letters according to the currently active alphabet. The actual interaction with #EBookClientCursor is done in the main contact browser and this class is simply configured with the active alphabet.

    	/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
    /*
     * Copyright (C) 2013 Intel Corporation
     *
     * This library 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.
     *
     * This library 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 this library. If not, see <http://www.gnu.org/licenses/>.
     *
     * Authors: Tristan Van Berkom <tristanvb@openismus.com>
     */

    #include "cursor-navigator.h"

    /* GObjectClass */
    static void            cursor_navigator_constructed     (GObject              *object);
    static void            cursor_navigator_finalize        (GObject              *object);

    /* GtkScaleClass */
    static gchar          *cursor_navigator_format_value    (GtkScale             *scale,
    							 gdouble               value);

    static void            cursor_navigator_changed         (GtkAdjustment        *adj,
    							 GParamSpec           *pspec,
    							 CursorNavigator      *navigator);

    struct _CursorNavigatorPrivate {
    	gchar **alphabet;
    	gint    letters;
    	gint    index;
    };

    enum {
    	INDEX_CHANGED,
    	LAST_SIGNAL
    };

    static guint signals[LAST_SIGNAL];

    enum {
    	PROP_0,
    	PROP_INDEX,
    };

    G_DEFINE_TYPE (CursorNavigator, cursor_navigator, GTK_TYPE_SCALE);

    /************************************************************************
     *                          GObjectClass                                *
     ************************************************************************/
    static void
    cursor_navigator_class_init (CursorNavigatorClass *klass)
    {
    	GObjectClass       *object_class;
    	GtkScaleClass      *scale_class;

    	object_class = G_OBJECT_CLASS (klass);
    	object_class->constructed = cursor_navigator_constructed;
    	object_class->finalize = cursor_navigator_finalize;

    	scale_class = GTK_SCALE_CLASS (klass);
    	scale_class->format_value = cursor_navigator_format_value;

    	signals[INDEX_CHANGED] = g_signal_new (
    		"index-changed",
    		G_OBJECT_CLASS_TYPE (object_class),
    		G_SIGNAL_RUN_LAST,
    		0, NULL, NULL, NULL,
    		G_TYPE_NONE, 0);

    	g_type_class_add_private (object_class, sizeof (CursorNavigatorPrivate));
    }

    static void
    cursor_navigator_init (CursorNavigator *navigator)
    {
    	CursorNavigatorPrivate *priv;

    	navigator->priv = priv =
    		G_TYPE_INSTANCE_GET_PRIVATE (
    			navigator,
    			CURSOR_TYPE_NAVIGATOR,
    			CursorNavigatorPrivate);

    	priv->letters = -1;
    }

    static void
    cursor_navigator_constructed (GObject *object)
    {
    	CursorNavigator        *navigator = CURSOR_NAVIGATOR (object);
    	GtkAdjustment          *adj = NULL;

    	G_OBJECT_CLASS (cursor_navigator_parent_class)->constructed (object);

    	adj = gtk_adjustment_new (0.0F, 0.0F, 1.0F, 1.0F, 1.0F, 0.0F);
    	gtk_range_set_adjustment (GTK_RANGE (navigator), adj);

    	g_signal_connect (
    		adj, "notify::value",
    		G_CALLBACK (cursor_navigator_changed), navigator);
    }

    static void
    cursor_navigator_finalize (GObject *object)
    {
    	CursorNavigator        *navigator = CURSOR_NAVIGATOR (object);
    	CursorNavigatorPrivate *priv = navigator->priv;

    	g_strfreev (priv->alphabet);

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

    /************************************************************************
     *                          GtkScaleClass                               *
     ************************************************************************/
    static gchar *
    cursor_navigator_format_value (GtkScale *scale,
                                   gdouble value)
    {
    	CursorNavigator        *navigator = CURSOR_NAVIGATOR (scale);
    	CursorNavigatorPrivate *priv = navigator->priv;
    	gint                    index;

    	if (priv->letters < 0)
    		return NULL;

    	index = CLAMP ((gint) value, 0, priv->letters - 1);

    	/* Return the letter for the gvoidiven value
    	 */
    	return g_strdup (priv->alphabet[index]);
    }

    static void
    cursor_navigator_changed (GtkAdjustment *adj,
                              GParamSpec *pspec,
                              CursorNavigator *navigator)
    {
    	gint index = gtk_adjustment_get_value (adj);

    	cursor_navigator_set_index (navigator, index);
    }

    /************************************************************************
     *                                API                                   *
     ************************************************************************/
    CursorNavigator *
    cursor_navigator_new (void)
    {
    	return g_object_new (CURSOR_TYPE_NAVIGATOR, NULL);
    }

    static void
    cursor_navigator_update_parameters (CursorNavigator *navigator)
    {
    	CursorNavigatorPrivate *priv = navigator->priv;
    	GtkScale               *scale = GTK_SCALE (navigator);
    	GtkAdjustment          *adj;
    	gint                    i;

    	gtk_scale_clear_marks (scale);
    	for (i = 0; i < priv->letters; i++) {
    		gchar *letter;

    		letter = g_strdup_printf ("<span size=\"x-small\">%s</span>", priv->alphabet[i]);

    		gtk_scale_add_mark (scale, i, GTK_POS_LEFT, letter);
    		g_free (letter);
    	}

    	adj = gtk_range_get_adjustment (GTK_RANGE (navigator));

    	gtk_adjustment_set_upper (adj, priv->letters - 1);
    }

    void
    cursor_navigator_set_alphabet (CursorNavigator *navigator,
                                   const gchar * const *alphabet)
    {
    	CursorNavigatorPrivate *priv;

    	g_return_if_fail (CURSOR_IS_NAVIGATOR (navigator));
    	g_return_if_fail (alphabet == NULL ||
    			  g_strv_length ((gchar **) alphabet) > 0);

    	priv = navigator->priv;

    	g_free (priv->alphabet);
    	if (alphabet) {
    		priv->alphabet = g_strdupv ((gchar **) alphabet);
    		priv->letters = g_strv_length ((gchar **) alphabet);
    	} else {
    		priv->alphabet = NULL;
    		priv->letters = -1;
    	}

    	cursor_navigator_update_parameters (navigator);
    	cursor_navigator_set_index (navigator, 0);
    }

    const gchar * const *
    cursor_navigator_get_alphabet (CursorNavigator *navigator)
    {
    	CursorNavigatorPrivate *priv;

    	g_return_val_if_fail (CURSOR_IS_NAVIGATOR (navigator), NULL);

    	priv = navigator->priv;

    	return (const gchar * const *) priv->alphabet;
    }

    void
    cursor_navigator_set_index (CursorNavigator *navigator,
                                gint index)
    {
    	CursorNavigatorPrivate *priv;
    	GtkAdjustment          *adj;

    	g_return_if_fail (CURSOR_IS_NAVIGATOR (navigator));

    	priv = navigator->priv;
    	adj = gtk_range_get_adjustment (GTK_RANGE (navigator));

    	index = CLAMP (index, 0, priv->letters);

    	if (priv->index != index) {

    		priv->index = index;

    		g_signal_emit (navigator, signals[INDEX_CHANGED], 0);

    		g_signal_handlers_block_by_func (adj, cursor_navigator_changed, navigator);
    		gtk_adjustment_set_value (adj, priv->index);
    		g_signal_handlers_unblock_by_func (adj, cursor_navigator_changed, navigator);
    	}
    }

    gint
    cursor_navigator_get_index (CursorNavigator *navigator)
    {
    	CursorNavigatorPrivate *priv;

    	g_return_val_if_fail (CURSOR_IS_NAVIGATOR (navigator), 0);

    	priv = navigator->priv;

    	return priv->index;
    }

## The search entry

The search entry is placed at the top of the contacts browser, this class simply implements a drop down box choosing the appropriate search expression which should be used to filter the contacts in the browser display window.

    	/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
    /*
     * Copyright (C) 2013 Intel Corporation
     *
     * This library 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.
     *
     * This library 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 this library. If not, see <http://www.gnu.org/licenses/>.
     *
     * Authors: Tristan Van Berkom <tristanvb@openismus.com>
     */

    #include <libebook/libebook.h>

    #include "cursor-search.h"

    /* GObjectClass */
    static void  cursor_search_finalize       (GObject           *object);
    static void  cursor_search_get_property   (GObject           *object,
    					   guint              property_id,
    					   GValue            *value,
    					   GParamSpec        *pspec);

    /* UI Callbacks */
    static void  cursor_search_option_toggled (CursorSearch         *search,
    					   GtkWidget            *item);
    static void  cursor_search_entry_changed  (CursorSearch         *search,
    					   GtkEditable          *entry);
    static void  cursor_search_icon_press     (CursorSearch         *search,
    					   GtkEntryIconPosition  icon_pos,
    					   GdkEvent             *event,
    					   GtkEntry             *entry);

    typedef enum {
    	SEARCH_NAME,
    	SEARCH_PHONE,
    	SEARCH_EMAIL
    } SearchType;

    struct _CursorSearchPrivate {
    	GtkWidget   *popup;
    	GtkWidget   *name_radio;
    	GtkWidget   *phone_radio;
    	GtkWidget   *email_radio;

    	SearchType   type;
    	gchar       *sexp;
    };

    enum {
    	PROP_0,
    	PROP_SEXP,
    };

    G_DEFINE_TYPE_WITH_PRIVATE (CursorSearch, cursor_search, GTK_TYPE_SEARCH_ENTRY);

    /************************************************************************
     *                          GObjectClass                                *
     ************************************************************************/
    static void
    cursor_search_class_init (CursorSearchClass *klass)
    {
    	GObjectClass *object_class;
    	GtkWidgetClass *widget_class;

    	object_class = G_OBJECT_CLASS (klass);
    	object_class->finalize = cursor_search_finalize;
    	object_class->get_property = cursor_search_get_property;

    	g_object_class_install_property (
    		object_class,
    		PROP_SEXP,
    		g_param_spec_string (
    			"sexp",
    			"Search Expression",
    			"The active search expression",
    			NULL,
    			G_PARAM_READABLE |
    			G_PARAM_STATIC_STRINGS));

    	/* Bind to template */
    	widget_class = GTK_WIDGET_CLASS (klass);
    	gtk_widget_class_set_template_from_resource (widget_class, "/org/gnome/evolution/cursor-example/cursor-search.ui");
    	gtk_widget_class_bind_template_child_private (widget_class, CursorSearch, popup);
    	gtk_widget_class_bind_template_child_private (widget_class, CursorSearch, name_radio);
    	gtk_widget_class_bind_template_child_private (widget_class, CursorSearch, phone_radio);
    	gtk_widget_class_bind_template_child_private (widget_class, CursorSearch, email_radio);
    	gtk_widget_class_bind_template_callback (widget_class, cursor_search_option_toggled);
    	gtk_widget_class_bind_template_callback (widget_class, cursor_search_entry_changed);
    	gtk_widget_class_bind_template_callback (widget_class, cursor_search_icon_press);
    }

    static void
    cursor_search_init (CursorSearch *search)
    {
    	search->priv = cursor_search_get_instance_private (search);

    	gtk_widget_init_template (GTK_WIDGET (search));

    	g_object_set (
    		search,
    		"primary-icon-activatable", TRUE,
    		"primary-icon-sensitive", TRUE,
    		NULL);
    }

    static void
    cursor_search_finalize (GObject *object)
    {
    	CursorSearch        *search = CURSOR_SEARCH (object);
    	CursorSearchPrivate *priv = search->priv;

    	g_free (priv->sexp);

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

    static void
    cursor_search_get_property (GObject *object,
                                guint property_id,
                                GValue *value,
                                GParamSpec *pspec)
    {
    	CursorSearch        *search = CURSOR_SEARCH (object);
    	CursorSearchPrivate *priv = search->priv;

    	switch (property_id) {
    	case PROP_SEXP:
    		g_value_set_string (value, priv->sexp);
    		break;

    	default:
    		G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
    		break;

    	}
    }

    /************************************************************************
     *                              UI Callbacks                            *
     ************************************************************************/
    static void
    cursor_search_option_toggled (CursorSearch *search,
                                  GtkWidget *item)
    {
    	CursorSearchPrivate *priv = search->priv;

    	if (gtk_check_menu_item_get_active (GTK_CHECK_MENU_ITEM (item))) {

    		if (item == priv->name_radio)
    			priv->type = SEARCH_NAME;
    		else if (item == priv->phone_radio)
    			priv->type = SEARCH_PHONE;
    		else if (item == priv->email_radio)
    			priv->type = SEARCH_EMAIL;

    		/* Refresh the search */
    		cursor_search_entry_changed (search, NULL);
    	}
    }

    static void
    cursor_search_entry_changed (CursorSearch *search,
                                 GtkEditable *entry)
    {
    	CursorSearchPrivate *priv = search->priv;
    	EBookQuery  *query = NULL;
    	const gchar *text;

    	text = gtk_entry_get_text (GTK_ENTRY (search));

    	if (text && text[0]) {
    		switch (priv->type) {
    		case SEARCH_NAME:
    			query = e_book_query_orv (
    				e_book_query_field_test (E_CONTACT_FAMILY_NAME,
    				E_BOOK_QUERY_CONTAINS,
    				text),
    				e_book_query_field_test (E_CONTACT_GIVEN_NAME,
    				E_BOOK_QUERY_CONTAINS,
    				text),
    				NULL);
    			break;
    		case SEARCH_PHONE:
    			query = e_book_query_field_test (
    				E_CONTACT_TEL,
    				E_BOOK_QUERY_CONTAINS,
    				text);
    			break;
    		case SEARCH_EMAIL:
    			query = e_book_query_field_test (
    				E_CONTACT_EMAIL,
    				E_BOOK_QUERY_CONTAINS,
    				text);
    			break;
    		}
    	}

    	g_free (priv->sexp);

    	if (query) {
    		priv->sexp = e_book_query_to_string (query);
    		e_book_query_unref (query);
    	} else
    		priv->sexp = g_strdup ("");

    	g_object_notify (G_OBJECT (search), "sexp");
    }

    static void
    cursor_search_icon_press (CursorSearch *search,
                              GtkEntryIconPosition icon_pos,
                              GdkEvent *event,
                              GtkEntry *entry)
    {
    	CursorSearchPrivate *priv = search->priv;
    	GdkEventButton *button_event = (GdkEventButton *) event;

    	if (icon_pos == GTK_ENTRY_ICON_PRIMARY)
    		gtk_menu_popup (
    			GTK_MENU (priv->popup),
    				NULL, NULL, NULL, NULL,
    				button_event->button,
    				button_event->time);
    }

    /************************************************************************
     *                                API                                   *
     ************************************************************************/
    GtkWidget *
    cursor_search_new (void)
    {
      return (GtkWidget *) g_object_new (CURSOR_TYPE_SEARCH, NULL);
    }

    const gchar *
    cursor_search_get_sexp (CursorSearch *search)
    {
    	CursorSearchPrivate *priv;

    	g_return_val_if_fail (CURSOR_IS_SEARCH (search), NULL);

    	priv = search->priv;

    	return priv->sexp;
    }

## The contact slot

This is a very simple class who's only purpose is to display contact related data, each entry in the list is a 'slot'

    	/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
    /*
     * Copyright (C) 2013 Intel Corporation
     *
     * This library 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.
     *
     * This library 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 this library. If not, see <http://www.gnu.org/licenses/>.
     *
     * Authors: Tristan Van Berkom <tristanvb@openismus.com>
     */

    #include <libebook/libebook.h>

    #include "cursor-slot.h"

    struct _CursorSlotPrivate {
    	/* Screen widgets */
    	GtkWidget *area;
    	GtkLabel  *name_label;
    	GtkLabel  *emails_label;
    	GtkLabel  *telephones_label;
    };

    G_DEFINE_TYPE_WITH_PRIVATE (CursorSlot, cursor_slot, GTK_TYPE_GRID);

    /************************************************************************
     *                          GObjectClass                                *
     ************************************************************************/
    static void
    cursor_slot_class_init (CursorSlotClass *klass)
    {
    	GtkWidgetClass *widget_class;

    	/* Bind to template */
    	widget_class = GTK_WIDGET_CLASS (klass);
    	gtk_widget_class_set_template_from_resource (widget_class, "/org/gnome/evolution/cursor-example/cursor-slot.ui");
    	gtk_widget_class_bind_template_child_private (widget_class, CursorSlot, area);
    	gtk_widget_class_bind_template_child_private (widget_class, CursorSlot, name_label);
    	gtk_widget_class_bind_template_child_private (widget_class, CursorSlot, emails_label);
    	gtk_widget_class_bind_template_child_private (widget_class, CursorSlot, telephones_label);
    }

    static void
    cursor_slot_init (CursorSlot *slot)
    {
    	slot->priv = cursor_slot_get_instance_private (slot);

    	gtk_widget_init_template (GTK_WIDGET (slot));
    }

    /************************************************************************
     *                                API                                   *
     ************************************************************************/
    GtkWidget *
    cursor_slot_new (EContact *contact)
    {
      CursorSlot *slot;

      slot = g_object_new (CURSOR_TYPE_SLOT, NULL);

      cursor_slot_set_from_contact (slot, contact);

      return (GtkWidget *) slot;
    }

    static gchar *
    make_string_from_list (EContact *contact,
                           EContactField field)
    {
    	GList *values, *l;
    	GString *string;

    	string = g_string_new ("<span size=\"x-small\">");
    	values = e_contact_get (contact, field);

    	for (l = values; l; l = l->next) {
    		gchar *value = (gchar *) l->data;

    		if (l->prev != NULL)
    			g_string_append (string, ", ");

    		g_string_append (string, value);
    	}

    	if (!values)
    		g_string_append (string, " - none - ");

    	e_contact_attr_list_free (values);
    	g_string_append (string, "</span>");

    	return g_string_free (string, FALSE);
    }

    void
    cursor_slot_set_from_contact (CursorSlot *slot,
                                  EContact *contact)
    {
    	CursorSlotPrivate *priv;
    	const gchar *family_name, *given_name;
    	gchar *str;

    	g_return_if_fail (CURSOR_IS_SLOT (slot));
    	g_return_if_fail (contact == NULL || E_IS_CONTACT (contact));

    	priv = slot->priv;

    	if (!contact) {
    		gtk_widget_hide (priv->area);
    		return;
    	}

    	family_name = (const gchar *) e_contact_get_const (contact, E_CONTACT_FAMILY_NAME);
    	given_name = (const gchar *) e_contact_get_const (contact, E_CONTACT_GIVEN_NAME);

    	str = g_strdup_printf ("%s, %s", family_name, given_name);
    	gtk_label_set_text (priv->name_label, str);
    	g_free (str);

    	str = make_string_from_list (contact, E_CONTACT_EMAIL);
    	gtk_label_set_markup (priv->emails_label, str);
    	g_free (str);

    	str = make_string_from_list (contact, E_CONTACT_TEL);
    	gtk_label_set_markup (priv->telephones_label, str);
    	g_free (str);

    	gtk_widget_show (priv->area);
    }

## Creating addressbooks and loading vcards

This is the messy part of the example, here we take care of creating a custom addressbook and populating it with the contacts found in the directory given to the example.

    	/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
    /*
     * Copyright (C) 2013 Intel Corporation
     *
     * This library 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.
     *
     * This library 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 this library. If not, see <http://www.gnu.org/licenses/>.
     *
     * Authors: Tristan Van Berkom <tristanvb@openismus.com>
     */

    #include "cursor-data.h"

    #define CURSOR_DATA_SOURCE_ID "cursor-example-book"

    /* We need to spin the main loop a bit to wait for the ESource
     * to be created. This particular API is admittedly cumbersome,
     * hopefully this will be fixed in a later version so that
     * the ESource can be synchronously created.
     *
     * Just an example so lets just use some global variables here...
     */
    static EBookClient *address_book = NULL;
    static ESource     *address_book_source = NULL;

    static void
    cursor_data_source_added (ESourceRegistry *registry,
                              ESource *source,
                              gpointer data)
    {
    	GError    *error = NULL;
    	GMainLoop *loop = (GMainLoop *) data;

    	if (g_strcmp0 (e_source_get_uid (source), CURSOR_DATA_SOURCE_ID) != 0)
    		return;

    	/* Open the address book */
    	address_book = (EBookClient *) e_book_client_connect_sync (source, 30, NULL, &error);
    	if (!address_book)
    		g_error ("Unable to create the test book: %s", error->message);

    	address_book_source = g_object_ref (source);

    	if (loop)
    		g_main_loop_quit (loop);
    }

    static gboolean
    cursor_data_source_timeout (gpointer user_data)
    {
    	g_error ("Timed out while waiting for ESource creation from the registry");

    	return FALSE;
    }

    /*
     * Helper function to load a contact from a vcard file.
     */
    static EContact *
    contact_from_file (const gchar *vcard_file)
    {
    	EContact *contact;
    	GError *error;
    	gchar *vcard = NULL;

    	if (!g_file_get_contents (vcard_file, &vcard, NULL, &error))
    		g_error ("Failed to load vcard: %s", error->message);

    	contact = e_contact_new_from_vcard (vcard);
    	g_free (vcard);

    	return contact;
    }

    /*
     * Load all the contacts from 'vcard_directory', and add them to 'client'.
     */
    static void
    load_contacts (EBookClient *client,
                   const gchar *vcard_directory)
    {
    	GDir *dir;
    	GError *error = NULL;
    	const gchar *filename;
    	GSList *contacts = NULL;

    	dir = g_dir_open (vcard_directory, 0, &error);
    	if (!dir)
    		g_error ("Failed to open vcard directory '%s': %s", vcard_directory, error->message);

    	while ((filename = g_dir_read_name (dir)) != NULL) {

    		if (g_str_has_suffix (filename, ".vcf")) {
    			gchar *fullpath = g_build_filename (vcard_directory, filename, NULL);
    			EContact *contact;

    			contact = contact_from_file (fullpath);
    			contacts = g_slist_prepend (contacts, contact);

    			g_free (fullpath);
    		}
    	}

    	g_dir_close (dir);

    	if (contacts != NULL) {

    		if (!e_book_client_add_contacts_sync (client, contacts, NULL, NULL, &error)) {

    			/* If they were already added, ignore the error */
    			if (g_error_matches (error, E_BOOK_CLIENT_ERROR,
    					     E_BOOK_CLIENT_ERROR_CONTACT_ID_ALREADY_EXISTS))
    				g_clear_error (&error);
    			else
    				g_error ("Failed to add test contacts: %s", error->message);
    		}
    	}
    }

    /*
     * Create an EBookClient cursor sorted by family name, and then by given name as
     * the secondary sort key.
     */
    static EBookClientCursor *
    get_cursor (EBookClient *book_client)
    {
      EContactField sort_fields[] = { E_CONTACT_FAMILY_NAME, E_CONTACT_GIVEN_NAME };
      EBookCursorSortType sort_types[] = { E_BOOK_CURSOR_SORT_ASCENDING, E_BOOK_CURSOR_SORT_ASCENDING };
      EBookClientCursor *cursor = NULL;
      GError *error = NULL;

      if (!e_book_client_get_cursor_sync (book_client,
    				      NULL,
    				      sort_fields,
    				      sort_types,
    				      2,
    				      &cursor,
    				      NULL,
    				      &error)) {
    	  g_warning ("Unable to create cursor");
    	  g_clear_error (&error);
      }

      return cursor;
    }

    /* Entry point for this file, here we take care of
     * creating the addressbook if it doesnt exist,
     * getting an EBookClient, and creating our EBookClientCursor.
     */
    EBookClient *
    cursor_load_data (const gchar *vcard_path,
                      EBookClientCursor **ret_cursor)
    {
    	ESourceRegistry *registry;
    	ESource *scratch;
    	ESourceBackend *backend = NULL;
    	GMainLoop *loop;
    	GError  *error = NULL;
    	EBookClient *ret_book;

    	g_return_val_if_fail (vcard_path != NULL, NULL);
    	g_return_val_if_fail (ret_cursor != NULL, NULL);

    	g_print ("Cursor loading data from %s\n", vcard_path);

    	loop = g_main_loop_new (NULL, FALSE);

    	registry = e_source_registry_new_sync (NULL, &error);
    	if (!registry)
    		g_error ("Unable to create the registry: %s", error->message);

    	/* Listen to the registry for our added source */
    	g_signal_connect (
    		registry, "source-added",
    		G_CALLBACK (cursor_data_source_added), loop);

    	/* Now create a scratch source for our addressbook */
    	scratch = e_source_new_with_uid (CURSOR_DATA_SOURCE_ID, NULL, &error);

    	/* Ensure the new ESource will be a local addressbook source */
    	backend = e_source_get_extension (scratch, E_SOURCE_EXTENSION_ADDRESS_BOOK);
    	e_source_backend_set_backend_name (backend, "local");

    	/* Now is the right time to use the ESourceBackendSummarySetup to configure
    	 * your newly created addressbook. This configuration should happen on the
    	 * scratch source before calling e_source_registry_commit_source_sync().
    	 */

    	/* Commit the source to the registry */
    	if (!e_source_registry_commit_source_sync (registry, scratch, NULL, &error)) {

    		/* It's possible the source already exists if we already ran the example with this data server */
    		if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_EXISTS)) {
    			/* If so... then just call our callback early */
    			ESource *source = e_source_registry_ref_source (registry, CURSOR_DATA_SOURCE_ID);

    			g_clear_error (&error);
    			g_return_val_if_fail (E_IS_SOURCE (source), NULL);

    			/* Run the callback which creates the addressbook client connection */
    			cursor_data_source_added (registry, source, NULL);
    			g_object_unref (source);
    		} else
    			g_error ("Unable to add new addressbook source to the registry: %s", error->message);
    	}

    	g_object_unref (scratch);

    	/* Give EDS a little time to actually create the ESource remotely and
    	 * also have a copy if it cached locally, wait for the "source-added"
    	 * signal.
    	 */
    	if (address_book == NULL) {
    		g_timeout_add_seconds (20, cursor_data_source_timeout, NULL);
    		g_main_loop_run (loop);

    		/* By now we aborted or we have an addressbook created */
    		g_return_val_if_fail (address_book != NULL, NULL);
    	}

    	/**********************************************************
    	 * Ok, done with creating an addressbook, let's add data  *
    	 **********************************************************/
    	load_contacts (address_book, vcard_path);

    	/* Addressbook should have contacts now, let's create the cursor */
    	*ret_cursor = get_cursor (address_book);

    	/* Cleanup some resources we used to populate the addressbook */
    	g_main_loop_unref (loop);
    	g_object_unref (address_book_source);
    	g_object_unref (registry);

    	/* Give the ref through the return value*/
    	ret_book = address_book;

    	address_book_source = NULL;
    	address_book = NULL;

    	/* Return the addressbook */
    	return ret_book;
    }