path: root/lib/widgets/ephy-spinner.c

/* 
 * Nautilus
 *
 * Copyright (C) 2000 Eazel, Inc.
 * Copyright (C) 2002-2004 Marco Pesenti Gritti
 * Copyright (C) 2004 Christian Persch
 *
 * 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: Andy Hertzfeld <andy@eazel.com>
 *
 * Ephy port by Marco Pesenti Gritti <marco@it.gnome.org>
 * 
 * This is the spinner (for busy feedback) for the location bar
 *
 * $Id$
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "ephy-spinner.h"

#include <gdk-pixbuf/gdk-pixbuf.h>
#include <gtk/gtkicontheme.h>
#include <gtk/gtkiconfactory.h>

#define spinner_DEFAULT_TIMEOUT 100 /* Milliseconds Per Frame */

#define EPHY_SPINNER_GET_PRIVATE(object)(G_TYPE_INSTANCE_GET_PRIVATE ((object), EPHY_TYPE_SPINNER, EphySpinnerDetails))

struct EphySpinnerDetails
{
    GList   *image_list;
    GdkPixbuf *quiescent_pixbuf;
    GtkIconTheme *icon_theme;
    GtkIconSize size;

    int max_frame;
    int delay;
    int current_frame;
    guint   timer_task;
};

static void ephy_spinner_class_init     (EphySpinnerClass *class);
static void ephy_spinner_init           (EphySpinner *spinner);
static void ephy_spinner_load_images        (EphySpinner *spinner);
static void ephy_spinner_unload_images      (EphySpinner *spinner);
static void ephy_spinner_remove_update_callback (EphySpinner *spinner);
static void ephy_spinner_theme_changed      (GtkIconTheme *icon_theme,
                         EphySpinner *spinner);

static GObjectClass *parent_class = NULL;

GType
ephy_spinner_get_type (void)
{
    static GType type = 0;

    if (type == 0)
    {
        static const GTypeInfo our_info =
        {
            sizeof (EphySpinnerClass),
            NULL, /* base_init */
            NULL, /* base_finalize */
            (GClassInitFunc) ephy_spinner_class_init,
            NULL,
            NULL, /* class_data */
            sizeof (EphySpinner),
            0, /* n_preallocs */
            (GInstanceInitFunc) ephy_spinner_init
        };

        type = g_type_register_static (GTK_TYPE_EVENT_BOX,
                           "EphySpinner",
                           &our_info, 0);
    }

    return type;
}

static gboolean
is_throbbing (EphySpinner *spinner)
{
    return spinner->details->timer_task != 0;
}

/* loop through all the images taking their union to compute the width and height of the spinner */
static void
get_spinner_dimensions (EphySpinner *spinner, int *spinner_width, int* spinner_height)
{
    int current_width, current_height;
    int pixbuf_width, pixbuf_height;
    GList *image_list;
    GdkPixbuf *pixbuf;

    if (spinner->details->image_list == NULL)
    {
        ephy_spinner_load_images (spinner);
    }

    current_width = 0;
    current_height = 0;

    if (spinner->details->quiescent_pixbuf != NULL)
    {
        /* start with the quiescent image */
        current_width = gdk_pixbuf_get_width (spinner->details->quiescent_pixbuf);
        current_height = gdk_pixbuf_get_height (spinner->details->quiescent_pixbuf);
    }

    /* loop through all the installed images, taking the union */
    image_list = spinner->details->image_list;
    while (image_list != NULL)
    {
        pixbuf = GDK_PIXBUF (image_list->data);
        pixbuf_width = gdk_pixbuf_get_width (pixbuf);
        pixbuf_height = gdk_pixbuf_get_height (pixbuf);

        if (pixbuf_width > current_width)
        {
            current_width = pixbuf_width;
        }

        if (pixbuf_height > current_height)
        {
            current_height = pixbuf_height;
        }

        image_list = image_list->next;
    }

    /* return the result */
    *spinner_width = current_width;
    *spinner_height = current_height;
}

static void
ephy_spinner_init (EphySpinner *spinner)
{
    GtkWidget *widget = GTK_WIDGET (spinner);

    gtk_widget_set_events (widget,
                   gtk_widget_get_events (widget)
                   | GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK
                   | GDK_ENTER_NOTIFY_MASK | GDK_LEAVE_NOTIFY_MASK);

    spinner->details = EPHY_SPINNER_GET_PRIVATE (spinner);

    spinner->details->delay = spinner_DEFAULT_TIMEOUT;
    /* FIXME: icon theme is per-screen, not global */
    spinner->details->icon_theme = gtk_icon_theme_get_default ();
    g_signal_connect_object (spinner->details->icon_theme,
                 "changed",
                 G_CALLBACK (ephy_spinner_theme_changed),
                 spinner, 0);

    spinner->details->quiescent_pixbuf = NULL;
    spinner->details->image_list = NULL;
    spinner->details->max_frame = 0;
    spinner->details->current_frame = 0;
    spinner->details->timer_task = 0;
    spinner->details->size = GTK_ICON_SIZE_INVALID;
}

/* handler for handling theme changes */
static void
ephy_spinner_theme_changed (GtkIconTheme *icon_theme, EphySpinner *spinner)
{
    gtk_widget_hide (GTK_WIDGET (spinner));
    ephy_spinner_load_images (spinner);
    gtk_widget_show (GTK_WIDGET (spinner));
    gtk_widget_queue_resize ( GTK_WIDGET (spinner));
}

/* here's the routine that selects the image to draw, based on the spinner's state */

static GdkPixbuf *
select_spinner_image (EphySpinner *spinner)
{
    GList *element;

    if (spinner->details->timer_task == 0)
    {
        if (spinner->details->quiescent_pixbuf)
        {
            return g_object_ref (spinner->details->quiescent_pixbuf);
        }
        else
        {
            return NULL;
        }
    }

    if (spinner->details->image_list == NULL)
    {
        return NULL;
    }

    element = g_list_nth (spinner->details->image_list, spinner->details->current_frame);
    g_return_val_if_fail (element != NULL, NULL);

    return g_object_ref (element->data);
}

/* handle expose events */

static int
ephy_spinner_expose (GtkWidget *widget, GdkEventExpose *event)
{
    EphySpinner *spinner = EPHY_SPINNER (widget);
    GdkPixbuf *pixbuf;
    GdkGC *gc;
    int x_offset, y_offset, width, height;
    GdkRectangle pix_area, dest;

    if (!GTK_WIDGET_DRAWABLE (spinner)) return TRUE;

    if (spinner->details->image_list == NULL)
    {
        ephy_spinner_load_images (spinner);
    }

    pixbuf = select_spinner_image (spinner);
    if (pixbuf == NULL)
    {
        return FALSE;
    }

    width = gdk_pixbuf_get_width (pixbuf);
    height = gdk_pixbuf_get_height (pixbuf);

    /* Compute the offsets for the image centered on our allocation */
    x_offset = (widget->allocation.width - width) / 2;
    y_offset = (widget->allocation.height - height) / 2;

    pix_area.x = x_offset + widget->allocation.x;
    pix_area.y = y_offset + widget->allocation.y;
    pix_area.width = width;
    pix_area.height = height;

    if (!gdk_rectangle_intersect (&event->area, &pix_area, &dest))
    {
        g_object_unref (pixbuf);
        return FALSE;
    }

    gc = gdk_gc_new (widget->window);
    gdk_draw_pixbuf (widget->window, gc, pixbuf,
             dest.x - x_offset - widget->allocation.x,
             dest.y - y_offset - widget->allocation.y,
             dest.x, dest.y,
             dest.width, dest.height,
             GDK_RGB_DITHER_MAX, 0, 0);
    g_object_unref (gc);

    g_object_unref (pixbuf);

    return FALSE;
}

/* here's the actual timeout task to bump the frame and schedule a redraw */

static gboolean
bump_spinner_frame (gpointer callback_data)
{
    EphySpinner *spinner;

    spinner = EPHY_SPINNER (callback_data);

    if (!GTK_WIDGET_DRAWABLE (spinner))
    {
        return TRUE;
    }

    spinner->details->current_frame += 1;
    if (spinner->details->current_frame > spinner->details->max_frame - 1)
    {
        spinner->details->current_frame = 0;
    }

    gtk_widget_queue_draw (GTK_WIDGET (spinner));
    return TRUE;
}

/**
 * ephy_spinner_start:
 * @spinner: a #EphySpinner
 *
 * Start the spinner animation.
 **/
void
ephy_spinner_start (EphySpinner *spinner)
{
    if (is_throbbing (spinner))
    {
        return;
    }

    if (spinner->details->timer_task != 0)
    {
        g_source_remove (spinner->details->timer_task);
    }

    /* reset the frame count */
    spinner->details->current_frame = 0;
    spinner->details->timer_task = g_timeout_add (spinner->details->delay,
                              bump_spinner_frame,
                              spinner);
}

static void
ephy_spinner_remove_update_callback (EphySpinner *spinner)
{
    if (spinner->details->timer_task != 0)
    {
        g_source_remove (spinner->details->timer_task);
    }

    spinner->details->timer_task = 0;
}

/**
 * ephy_spinner_stop:
 * @spinner: a #EphySpinner
 *
 * Stop the spinner animation.
 **/
void
ephy_spinner_stop (EphySpinner *spinner)
{
    if (!is_throbbing (spinner))
    {
        return;
    }

    ephy_spinner_remove_update_callback (spinner);
    gtk_widget_queue_draw (GTK_WIDGET (spinner));

}

/* routines to load the images used to draw the spinner */

/* unload all the images, and the list itself */

static void
ephy_spinner_unload_images (EphySpinner *spinner)
{
    if (spinner->details->quiescent_pixbuf != NULL)
    {
        g_object_unref (spinner->details->quiescent_pixbuf);
        spinner->details->quiescent_pixbuf = NULL;
    }

    /* unref all the images in the list, and then let go of the list itself */
    g_list_foreach (spinner->details->image_list, (GFunc) g_object_unref, NULL);
    g_list_free (spinner->details->image_list);
    spinner->details->image_list = NULL;

    spinner->details->current_frame = 0;
}

static GdkPixbuf *
scale_to_real_size (EphySpinner *spinner, GdkPixbuf *pixbuf)
{
    GdkPixbuf *result;
    int sw, sh, pw, ph;

    if (spinner->details->size == GTK_ICON_SIZE_INVALID)
    {
        return g_object_ref (pixbuf);
    }

    if (!gtk_icon_size_lookup (spinner->details->size, &sw, &sh))
    {
        return NULL;
    }

    pw = gdk_pixbuf_get_width (pixbuf);
    ph = gdk_pixbuf_get_height (pixbuf);

    if (pw != sw || ph != sh)
    {
        result = gdk_pixbuf_scale_simple (pixbuf, sw, sh,
                          GDK_INTERP_BILINEAR);
    }
    else
    {
        result = g_object_ref (pixbuf);
    }

    return result;
}

static GdkPixbuf *
extract_frame (EphySpinner *spinner, GdkPixbuf *grid_pixbuf, int x, int y, int size)
{
    GdkPixbuf *pixbuf, *result;

    if (x + size > gdk_pixbuf_get_width (grid_pixbuf) ||
        y + size > gdk_pixbuf_get_height (grid_pixbuf))
    {
        return NULL;
    }

    pixbuf = gdk_pixbuf_new_subpixbuf (grid_pixbuf,
                       x, y,
                       size, size);
    g_return_val_if_fail (pixbuf != NULL, NULL);

    result = scale_to_real_size (spinner, pixbuf);
    g_object_unref (pixbuf);

    return result;
}

/* load all of the images of the spinner sequentially */
static void
ephy_spinner_load_images (EphySpinner *spinner)
{
    int grid_width, grid_height, x, y, size;
    const char *icon;
    GdkPixbuf *icon_pixbuf, *pixbuf;
    GList *image_list;
    GtkIconInfo *icon_info;

    ephy_spinner_unload_images (spinner);

    /* Load the animation */
    icon_info = gtk_icon_theme_lookup_icon (spinner->details->icon_theme,
                        "gnome-spinner", -1, 0);
    if (icon_info == NULL)
    {
        g_warning ("Throbber animation not found");
        return;
    }

    size = gtk_icon_info_get_base_size (icon_info);
    icon = gtk_icon_info_get_filename (icon_info);
    g_return_if_fail (icon != NULL);

    icon_pixbuf = gdk_pixbuf_new_from_file (icon, NULL);
    grid_width = gdk_pixbuf_get_width (icon_pixbuf);
    grid_height = gdk_pixbuf_get_height (icon_pixbuf);

    image_list = NULL;
    for (y = 0; y < grid_height; y += size)
    {
        for (x = 0; x < grid_width ; x += size)
        {
            pixbuf = extract_frame (spinner, icon_pixbuf, x, y, size);

            if (pixbuf)
            {
                image_list = g_list_prepend (image_list, pixbuf);
            }
            else
            {
                g_warning ("Cannot extract frame from the grid");
            }
        }
    }
    spinner->details->image_list = g_list_reverse (image_list);
    spinner->details->max_frame = g_list_length (spinner->details->image_list);

    gtk_icon_info_free (icon_info);
    g_object_unref (icon_pixbuf);

    /* Load the rest icon */
    icon_info = gtk_icon_theme_lookup_icon (spinner->details->icon_theme,
                        "gnome-spinner-rest", -1, 0);
    if (icon_info == NULL)
    {
        g_warning ("Throbber rest icon not found");
        return;
    }

    size = gtk_icon_info_get_base_size (icon_info);
    icon = gtk_icon_info_get_filename (icon_info);
    g_return_if_fail (icon != NULL);

    icon_pixbuf = gdk_pixbuf_new_from_file (icon, NULL);
    spinner->details->quiescent_pixbuf = scale_to_real_size (spinner, icon_pixbuf);

    g_object_unref (icon_pixbuf);
    gtk_icon_info_free (icon_info);
}

/*
 * ephy_spinner_set_size:
 * @spinner: a #EphySpinner
 * @size: the size of type %GtkIconSize
 *
 * Set the size of the spinner. Use %GTK_ICON_SIZE_INVALID to use the
 * native size of the icon.
 **/
void
ephy_spinner_set_size (EphySpinner *spinner, GtkIconSize size)
{
    if (size != spinner->details->size)
    {
        ephy_spinner_unload_images (spinner);

        spinner->details->size = size;

        gtk_widget_queue_resize (GTK_WIDGET (spinner));
    }
}

/* handle setting the size */

static void
ephy_spinner_size_request (GtkWidget *widget, GtkRequisition *requisition)
{
    EphySpinner *spinner = EPHY_SPINNER (widget);
    int width = 0, height = 0;

    if (spinner->details->size == GTK_ICON_SIZE_INVALID)
    {
        get_spinner_dimensions (spinner, &width, &height);
    }
    else
    {
        gtk_icon_size_lookup (spinner->details->size, &width, &height);
    }

    requisition->width = width;
    requisition->height = height;

    /* allocate some extra margin so we don't butt up against toolbar edges */
    if (spinner->details->size != GTK_ICON_SIZE_MENU)
    {
        requisition->width += 4;
        requisition->height += 4;
    }
}

static void
ephy_spinner_finalize (GObject *object)
{
    EphySpinner *spinner = EPHY_SPINNER (object);

    ephy_spinner_remove_update_callback (spinner);
    ephy_spinner_unload_images (spinner);

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

static void
ephy_spinner_class_init (EphySpinnerClass *class)
{
    GObjectClass *object_class;
    GtkWidgetClass *widget_class;

    object_class = G_OBJECT_CLASS (class);
    widget_class = GTK_WIDGET_CLASS (class);

    parent_class = g_type_class_peek_parent (class);

    object_class->finalize = ephy_spinner_finalize;

    widget_class->expose_event = ephy_spinner_expose;
    widget_class->size_request = ephy_spinner_size_request;

    g_type_class_add_private (object_class, sizeof (EphySpinnerDetails));
}

/*
 * ephy_spinner_new:
 *
 * Create a new #EphySpinner. The spinner is a widget
 * that gives the user feedback about network status with
 * an animated image.
 *
 * Return Value: the spinner #GtkWidget
 **/
GtkWidget *
ephy_spinner_new (void)
{
    return GTK_WIDGET (g_object_new (EPHY_TYPE_SPINNER,
                     "visible-window", FALSE,
                     NULL));
}