path: root/shell/e-shell-taskbar.c

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

/**
 * SECTION: e-shell-taskbar
 * @short_description: the bottom of the main window
 * @include: shell/e-shell-taskbar.h
 **/

#include "e-shell-taskbar.h"

#include <e-shell-view.h>

#include <e-util/e-extensible.h>
#include <misc/e-activity-proxy.h>

struct _EShellTaskbarPrivate {

    gpointer shell_view;  /* weak pointer */

    /* Keep a reference to the shell backend since
     * we connect to its "activity-added" signal. */
    EShellBackend *shell_backend;

    GtkWidget *label;
    GtkWidget *hbox;

    GHashTable *proxy_table;

    gint fixed_height;
};

enum {
    PROP_0,
    PROP_MESSAGE,
    PROP_SHELL_VIEW
};

G_DEFINE_TYPE_WITH_CODE (
    EShellTaskbar,
    e_shell_taskbar,
    GTK_TYPE_HBOX,
    G_IMPLEMENT_INTERFACE (
        E_TYPE_EXTENSIBLE, NULL))

static void
shell_taskbar_weak_notify_cb (EShellTaskbar *shell_taskbar,
                              GObject *where_the_activity_was)
{
    GtkWidget *proxy;
    GtkContainer *container;
    GHashTable *proxy_table;
    GList *children;

    proxy_table = shell_taskbar->priv->proxy_table;
    proxy = g_hash_table_lookup (proxy_table, where_the_activity_was);
    g_hash_table_remove (proxy_table, where_the_activity_was);
    g_return_if_fail (proxy != NULL);

    container = GTK_CONTAINER (shell_taskbar->priv->hbox);
    gtk_container_remove (container, proxy);

    children = gtk_container_get_children (container);

    if (children == NULL)
        gtk_widget_hide (GTK_WIDGET (container));

    g_list_free (children);
}

static void
shell_taskbar_activity_add (EShellTaskbar *shell_taskbar,
                            EActivity *activity)
{
    GtkBox *box;
    GtkWidget *proxy;
    EActivityState state;
    GHashTable *proxy_table;

    /* Sanity check the activity state. */
    state = e_activity_get_state (activity);
    g_return_if_fail (state == E_ACTIVITY_RUNNING);

    /* Make sure it hasn't already been added. */
    proxy_table = shell_taskbar->priv->proxy_table;
    proxy = g_hash_table_lookup (proxy_table, activity);
    g_return_if_fail (proxy == NULL);

    /* Proxy widgets manage their own visibility.
     * Don't call gtk_widget_show() on it here. */
    proxy = e_activity_proxy_new (activity);
    box = GTK_BOX (shell_taskbar->priv->hbox);
    gtk_box_pack_start (box, proxy, TRUE, TRUE, 0);
    gtk_box_reorder_child (box, proxy, 0);
    gtk_widget_show (GTK_WIDGET (box));

    /* The proxy widget also holds a weak reference to the activity,
     * so the activity should get finalized in the normal course of
     * operation.  When that happens we remove the corresponding
     * proxy widget from the taskbar. */

    g_object_weak_ref (
        G_OBJECT (activity), (GWeakNotify)
        shell_taskbar_weak_notify_cb, shell_taskbar);

    g_hash_table_insert (proxy_table, activity, proxy);
}

static gboolean
shell_taskbar_weak_unref (EActivity *activity,
                          EActivityProxy *proxy,
                          EShellTaskbar *shell_taskbar)
{
    g_object_weak_unref (
        G_OBJECT (activity), (GWeakNotify)
        shell_taskbar_weak_notify_cb, shell_taskbar);

    return TRUE;
}

static void
shell_taskbar_set_shell_view (EShellTaskbar *shell_taskbar,
                              EShellView *shell_view)
{
    g_return_if_fail (shell_taskbar->priv->shell_view == NULL);

    shell_taskbar->priv->shell_view = shell_view;

    g_object_add_weak_pointer (
        G_OBJECT (shell_view),
        &shell_taskbar->priv->shell_view);
}

static void
shell_taskbar_set_property (GObject *object,
                            guint property_id,
                            const GValue *value,
                            GParamSpec *pspec)
{
    switch (property_id) {
        case PROP_MESSAGE:
            e_shell_taskbar_set_message (
                E_SHELL_TASKBAR (object),
                g_value_get_string (value));
            return;

        case PROP_SHELL_VIEW:
            shell_taskbar_set_shell_view (
                E_SHELL_TASKBAR (object),
                g_value_get_object (value));
            return;
    }

    G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
}

static void
shell_taskbar_get_property (GObject *object,
                            guint property_id,
                            GValue *value,
                            GParamSpec *pspec)
{
    switch (property_id) {
        case PROP_MESSAGE:
            g_value_set_string (
                value, e_shell_taskbar_get_message (
                E_SHELL_TASKBAR (object)));
            return;

        case PROP_SHELL_VIEW:
            g_value_set_object (
                value, e_shell_taskbar_get_shell_view (
                E_SHELL_TASKBAR (object)));
            return;
    }

    G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
}

static void
shell_taskbar_dispose (GObject *object)
{
    EShellTaskbarPrivate *priv;

    priv = E_SHELL_TASKBAR (object)->priv;

    g_hash_table_foreach_remove (
        priv->proxy_table, (GHRFunc)
        shell_taskbar_weak_unref, object);

    if (priv->shell_view != NULL) {
        g_object_remove_weak_pointer (
            G_OBJECT (priv->shell_view), &priv->shell_view);
        priv->shell_view = NULL;
    }

    if (priv->shell_backend != NULL) {
        g_signal_handlers_disconnect_matched (
            priv->shell_backend, G_SIGNAL_MATCH_DATA,
            0, 0, NULL, NULL, object);
        g_object_unref (priv->shell_backend);
        priv->shell_backend = NULL;
    }

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

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

    /* Chain up to parent's dispose() method. */
    G_OBJECT_CLASS (e_shell_taskbar_parent_class)->dispose (object);
}

static void
shell_taskbar_finalize (GObject *object)
{
    EShellTaskbarPrivate *priv;

    priv = E_SHELL_TASKBAR (object)->priv;

    g_hash_table_destroy (priv->proxy_table);

    /* Chain up to parent's finalize() method. */
    G_OBJECT_CLASS (e_shell_taskbar_parent_class)->finalize (object);
}

static void
shell_taskbar_constructed (GObject *object)
{
    EShellView *shell_view;
    EShellBackend *shell_backend;
    EShellTaskbar *shell_taskbar;

    shell_taskbar = E_SHELL_TASKBAR (object);
    shell_view = e_shell_taskbar_get_shell_view (shell_taskbar);
    shell_backend = e_shell_view_get_shell_backend (shell_view);

    /* Keep a reference to the shell backend so we can
     * disconnect the signal handler during dispose(). */
    shell_taskbar->priv->shell_backend = g_object_ref (shell_backend);

    g_signal_connect_swapped (
        shell_backend, "activity-added",
        G_CALLBACK (shell_taskbar_activity_add), shell_taskbar);

    /* Do not enlarge window width on new activities. */
    gtk_widget_set_size_request (GTK_WIDGET (shell_taskbar), 0, -1);

    e_extensible_load_extensions (E_EXTENSIBLE (object));

    /* Chain up to parent's constructed() method. */
    G_OBJECT_CLASS (e_shell_taskbar_parent_class)->constructed (object);
}

static void
shell_taskbar_size_allocate (GtkWidget *widget,
                             GtkAllocation *allocation)
{
    EShellTaskbar *shell_taskbar;
    gint fixed_height;

    shell_taskbar = E_SHELL_TASKBAR (widget);

    /* Maximum height allocation sticks. */
    fixed_height = shell_taskbar->priv->fixed_height;
    fixed_height = MAX (fixed_height, allocation->height);
    shell_taskbar->priv->fixed_height = fixed_height;

    /* Chain up to parent's size_allocate() method. */
    GTK_WIDGET_CLASS (e_shell_taskbar_parent_class)->
        size_allocate (widget, allocation);
}

static void
shell_taskbar_get_preferred_height (GtkWidget *widget,
                                    gint *minimum_height,
                                    gint *natural_height)
{
    EShellTaskbar *shell_taskbar;

    shell_taskbar = E_SHELL_TASKBAR (widget);

    if (minimum_height != NULL)
        *minimum_height = shell_taskbar->priv->fixed_height;

    if (natural_height != NULL)
        *natural_height = shell_taskbar->priv->fixed_height;
}

static void
e_shell_taskbar_class_init (EShellTaskbarClass *class)
{
    GObjectClass *object_class;
    GtkWidgetClass *widget_class;

    g_type_class_add_private (class, sizeof (EShellTaskbarPrivate));

    object_class = G_OBJECT_CLASS (class);
    object_class->set_property = shell_taskbar_set_property;
    object_class->get_property = shell_taskbar_get_property;
    object_class->dispose = shell_taskbar_dispose;
    object_class->finalize = shell_taskbar_finalize;
    object_class->constructed = shell_taskbar_constructed;

    widget_class = GTK_WIDGET_CLASS (class);
    widget_class->size_allocate = shell_taskbar_size_allocate;
    widget_class->get_preferred_height = shell_taskbar_get_preferred_height;

    /**
     * EShellTaskbar:message
     *
     * The message to display in the taskbar.
     **/
    g_object_class_install_property (
        object_class,
        PROP_MESSAGE,
        g_param_spec_string (
            "message",
            NULL,
            NULL,
            NULL,
            G_PARAM_READWRITE |
            G_PARAM_CONSTRUCT));

    /**
     * EShellTaskbar:shell-view
     *
     * The #EShellView to which the taskbar widget belongs.
     **/
    g_object_class_install_property (
        object_class,
        PROP_SHELL_VIEW,
        g_param_spec_object (
            "shell-view",
            NULL,
            NULL,
            E_TYPE_SHELL_VIEW,
            G_PARAM_READWRITE |
            G_PARAM_CONSTRUCT_ONLY));
}

static void
e_shell_taskbar_init (EShellTaskbar *shell_taskbar)
{
    GtkWidget *widget;

    shell_taskbar->priv = G_TYPE_INSTANCE_GET_PRIVATE (
        shell_taskbar, E_TYPE_SHELL_TASKBAR, EShellTaskbarPrivate);
    shell_taskbar->priv->proxy_table = g_hash_table_new (NULL, NULL);

    gtk_box_set_spacing (GTK_BOX (shell_taskbar), 12);

    widget = gtk_label_new (NULL);
    gtk_label_set_ellipsize (GTK_LABEL (widget), PANGO_ELLIPSIZE_END);
    gtk_box_pack_start (GTK_BOX (shell_taskbar), widget, TRUE, TRUE, 0);
    gtk_misc_set_alignment (GTK_MISC (widget), 0.0, 0.5);
    shell_taskbar->priv->label = g_object_ref (widget);
    gtk_widget_hide (widget);

    widget = gtk_hbox_new (FALSE, 3);
    gtk_box_pack_start (GTK_BOX (shell_taskbar), widget, TRUE, TRUE, 0);
    shell_taskbar->priv->hbox = g_object_ref (widget);
    gtk_widget_hide (widget);
}

/**
 * e_shell_taskbar_new:
 * @shell_view: an #EShellView
 *
 * Creates a new #EShellTaskbar instance belonging to @shell_view.
 *
 * Returns: a new #EShellTaskbar instance
 **/
GtkWidget *
e_shell_taskbar_new (EShellView *shell_view)
{
    g_return_val_if_fail (E_IS_SHELL_VIEW (shell_view), NULL);

    return g_object_new (
        E_TYPE_SHELL_TASKBAR, "shell-view", shell_view, NULL);
}

/**
 * e_shell_taskbar_get_shell_view:
 * @shell_taskbar: an #EShellTaskbar
 *
 * Returns the #EShellView that was passed to e_shell_taskbar_new().
 *
 * Returns: the #EShellView to which @shell_taskbar belongs
 **/
EShellView *
e_shell_taskbar_get_shell_view (EShellTaskbar *shell_taskbar)
{
    g_return_val_if_fail (E_IS_SHELL_TASKBAR (shell_taskbar), NULL);

    return shell_taskbar->priv->shell_view;
}

/**
 * e_shell_taskbar_get_message:
 * @shell_taskbar: an #EShellTaskbar
 *
 * Returns the message currently shown in the taskbar, or an empty string
 * if no message is shown.  Taskbar messages are used primarily for menu
 * tooltips.
 *
 * Returns: the current taskbar message
 **/
const gchar *
e_shell_taskbar_get_message (EShellTaskbar *shell_taskbar)
{
    GtkWidget *label;

    g_return_val_if_fail (E_IS_SHELL_TASKBAR (shell_taskbar), NULL);

    label = shell_taskbar->priv->label;

    return gtk_label_get_text (GTK_LABEL (label));
}

/**
 * e_shell_taskbar_set_message:
 * @shell_taskbar: an #EShellTaskbar
 * @message: the message to show
 *
 * Shows a message in the taskbar.  If @message is %NULL or an empty string,
 * the taskbar message is cleared.  Taskbar messages are used primarily for
 * menu tooltips.
 **/
void
e_shell_taskbar_set_message (EShellTaskbar *shell_taskbar,
                             const gchar *message)
{
    GtkWidget *label;

    g_return_if_fail (E_IS_SHELL_TASKBAR (shell_taskbar));

    label = shell_taskbar->priv->label;
    gtk_label_set_text (GTK_LABEL (label), message);

    if (message != NULL && *message != '\0')
        gtk_widget_show (label);
    else
        gtk_widget_hide (label);

    g_object_notify (G_OBJECT (shell_taskbar), "message");
}

/**
 * e_shell_taskbar_unset_message:
 * @shell_taskbar: an #EShellTaskbar
 *
 * This is equivalent to passing a %NULL message to
 * e_shell_taskbar_set_message().
 **/
void
e_shell_taskbar_unset_message (EShellTaskbar *shell_taskbar)
{
    g_return_if_fail (E_IS_SHELL_TASKBAR (shell_taskbar));

    e_shell_taskbar_set_message (shell_taskbar, NULL);
}

/**
 * e_shell_taskbar_get_activity_count:
 * @shell_taskbar: an #EShellTaskbar
 *
 * Returns the number of active #EActivity instances being tracked.
 *
 * Returns: the number of #EActivity instances
 **/
guint
e_shell_taskbar_get_activity_count (EShellTaskbar *shell_taskbar)
{
    g_return_val_if_fail (E_IS_SHELL_TASKBAR (shell_taskbar), 0);

    return g_hash_table_size (shell_taskbar->priv->proxy_table);
}