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

/*
 * e-shell-view.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-view
 * @short_description: views within the main window
 * @include: shell/e-shell-view.h
 **/

#include "e-shell-view.h"

#include <string.h>
#include <glib/gi18n.h>

#include "e-util/e-binding.h"
#include "e-util/e-extensible.h"
#include "e-util/e-file-utils.h"
#include "e-util/e-plugin-ui.h"
#include "e-util/e-ui-manager.h"
#include "e-util/e-util-private.h"
#include "e-util/e-util.h"
#include "filter/e-rule-context.h"

#include "e-shell-searchbar.h"
#include "e-shell-window-actions.h"

#define E_SHELL_VIEW_GET_PRIVATE(obj) \
    (G_TYPE_INSTANCE_GET_PRIVATE \
    ((obj), E_TYPE_SHELL_VIEW, EShellViewPrivate))

#define SIMPLE_SEARCHBAR_WIDTH 300
#define STATE_SAVE_TIMEOUT_SECONDS 3

struct _EShellViewPrivate {

    gpointer shell_window;  /* weak pointer */

    GKeyFile *state_key_file;
    gpointer state_save_activity;  /* weak pointer */
    guint state_save_timeout_id;

    gchar *title;
    gchar *view_id;
    gint page_num;
    guint merge_id;

    GtkAction *action;
    GtkSizeGroup *size_group;
    GtkWidget *shell_content;
    GtkWidget *shell_sidebar;
    GtkWidget *shell_taskbar;
    GtkWidget *searchbar;

    EFilterRule *search_rule;
    guint execute_search_blocked;

    guint update_actions_blocked;
    gboolean update_actions_called;
};

enum {
    PROP_0,
    PROP_ACTION,
    PROP_PAGE_NUM,
    PROP_SEARCHBAR,
    PROP_SEARCH_RULE,
    PROP_SHELL_BACKEND,
    PROP_SHELL_CONTENT,
    PROP_SHELL_SIDEBAR,
    PROP_SHELL_TASKBAR,
    PROP_SHELL_WINDOW,
    PROP_STATE_KEY_FILE,
    PROP_TITLE,
    PROP_VIEW_ID
};

enum {
    TOGGLED,
    CLEAR_SEARCH,
    CUSTOM_SEARCH,
    EXECUTE_SEARCH,
    UPDATE_ACTIONS,
    LAST_SIGNAL
};

static gpointer parent_class;
static gulong signals[LAST_SIGNAL];

static void
shell_view_init_search_context (EShellViewClass *class)
{
    EShellBackend *shell_backend;
    ERuleContext *search_context;
    EFilterRule *rule;
    EFilterPart *part;
    const gchar *data_dir;
    gchar *system_filename;
    gchar *user_filename;

    shell_backend = class->shell_backend;

    /* Sanity check the class fields we need. */
    g_return_if_fail (class->search_rules != NULL);
    g_return_if_fail (E_IS_SHELL_BACKEND (shell_backend));

    /* The basename for built-in searches is specified in the
     * shell view class.  All built-in search rules live in the
     * same directory. */
    system_filename = g_build_filename (
        EVOLUTION_RULEDIR, class->search_rules, NULL);

    /* The filename for custom saved searches is always of
     * the form "$(shell_backend_data_dir)/searches.xml". */
    data_dir = e_shell_backend_get_data_dir (shell_backend);
    user_filename = g_build_filename (data_dir, "searches.xml", NULL);

    /* Create the search context instance.  Subclasses may override
     * the GType so check that it's really an ERuleContext instance. */
    search_context = g_object_new (class->search_context_type, NULL);
    g_return_if_fail (E_IS_RULE_CONTEXT (search_context));
    class->search_context = search_context;

    e_rule_context_add_part_set (
        search_context, "partset", E_TYPE_FILTER_PART,
        e_rule_context_add_part, e_rule_context_next_part);
    e_rule_context_add_rule_set (
        search_context, "ruleset", E_TYPE_FILTER_RULE,
        e_rule_context_add_rule, e_rule_context_next_rule);
    e_rule_context_load (search_context, system_filename, user_filename);

    rule = e_filter_rule_new ();
    part = e_rule_context_next_part (search_context, NULL);
    if (part == NULL)
        g_warning (
            "Could not load %s search: no parts",
            G_OBJECT_CLASS_NAME (class));
    else
        e_filter_rule_add_part (rule, e_filter_part_clone (part));

    g_free (system_filename);
    g_free (user_filename);
}

static void
shell_view_init_view_collection (EShellViewClass *class)
{
    EShellBackend *shell_backend;
    const gchar *base_dir;
    const gchar *backend_name;
    gchar *system_dir;
    gchar *local_dir;

    shell_backend = class->shell_backend;
    g_return_if_fail (E_IS_SHELL_BACKEND (shell_backend));
    backend_name = E_SHELL_BACKEND_GET_CLASS (shell_backend)->name;

    base_dir = EVOLUTION_GALVIEWSDIR;
    system_dir = g_build_filename (base_dir, backend_name, NULL);

    base_dir = e_shell_backend_get_data_dir (shell_backend);
    local_dir = g_build_filename (base_dir, "views", NULL);

    /* The view collection is never destroyed. */
    class->view_collection = gal_view_collection_new ();

    gal_view_collection_set_title (
        class->view_collection, class->label);

    gal_view_collection_set_storage_directories (
        class->view_collection, system_dir, local_dir);

    g_free (system_dir);
    g_free (local_dir);

    /* This is all we can do.  It's up to the subclasses to
     * add the appropriate factories to the view collection. */
}

static void
shell_view_update_view_id (EShellView *shell_view,
                           GalViewInstance *view_instance)
{
    gchar *view_id;

    view_id = gal_view_instance_get_current_view_id (view_instance);
    e_shell_view_set_view_id (shell_view, view_id);
    g_free (view_id);
}

static void
shell_view_load_state (EShellView *shell_view)
{
    EShellBackend *shell_backend;
    GKeyFile *key_file;
    const gchar *config_dir;
    gchar *filename;
    GError *error = NULL;

    shell_backend = e_shell_view_get_shell_backend (shell_view);
    config_dir = e_shell_backend_get_config_dir (shell_backend);
    filename = g_build_filename (config_dir, "state", NULL);

    /* XXX Should do this asynchronously. */
    key_file = shell_view->priv->state_key_file;
    g_key_file_load_from_file (key_file, filename, 0, &error);

    if (error == NULL)
        goto exit;

    if (!g_error_matches (error, G_FILE_ERROR, G_FILE_ERROR_NOENT))
        g_warning ("%s", error->message);

    g_error_free (error);

exit:
    g_free (filename);
}

typedef struct {
    EShellView *shell_view;
    gchar *contents;
} SaveStateData;

static void
shell_view_save_state_done_cb (GFile *file,
                               GAsyncResult *result,
                               SaveStateData *data)
{
    GError *error = NULL;

    e_file_replace_contents_finish (file, result, NULL, &error);

    if (error != NULL) {
        g_warning ("%s", error->message);
        g_error_free (error);
    }

    g_object_unref (data->shell_view);
    g_free (data->contents);
    g_slice_free (SaveStateData, data);
}

static EActivity *
shell_view_save_state (EShellView *shell_view)
{
    EShellBackend *shell_backend;
    SaveStateData *data;
    EActivity *activity;
    GKeyFile *key_file;
    GFile *file;
    const gchar *config_dir;
    gchar *contents;
    gchar *path;

    shell_backend = e_shell_view_get_shell_backend (shell_view);
    config_dir = e_shell_backend_get_config_dir (shell_backend);
    key_file = shell_view->priv->state_key_file;

    contents = g_key_file_to_data (key_file, NULL, NULL);
    g_return_val_if_fail (contents != NULL, NULL);

    path = g_build_filename (config_dir, "state", NULL);
    file = g_file_new_for_path (path);
    g_free (path);

    /* GIO does not copy the contents string, so we need to keep
     * it in memory until saving is complete.  We reference the
     * shell view to keep it from being finalized while saving. */
    data = g_slice_new (SaveStateData);
    data->shell_view = g_object_ref (shell_view);
    data->contents = contents;

    /* The returned activity is a borrowed reference. */
    activity = e_file_replace_contents_async (
        file, contents, strlen (contents), NULL,
        FALSE, G_FILE_CREATE_PRIVATE, (GAsyncReadyCallback)
        shell_view_save_state_done_cb, data);

#if 0  /* FIXME Enable this for 2.31 and mark the string for translation. */
    e_activity_set_primary_text (
        activity, ("Saving user interface state"));
#endif

    e_shell_backend_add_activity (shell_backend, activity);

    g_object_unref (file);

    return activity;
}

static gboolean
shell_view_state_timeout_cb (EShellView *shell_view)
{
    EActivity *activity;

    /* If a save is still in progress, check back later. */
    if (shell_view->priv->state_save_activity != NULL)
        return TRUE;

    activity = shell_view_save_state (shell_view);

    /* Set up a weak pointer that gets set to NULL when the
     * activity finishes.  This will tell us if we're still
     * busy saving state data to disk on the next timeout. */
    shell_view->priv->state_save_activity = activity;
    g_object_add_weak_pointer (
        G_OBJECT (shell_view->priv->state_save_activity),
        &shell_view->priv->state_save_activity);

    shell_view->priv->state_save_timeout_id = 0;

    return FALSE;
}

static void
shell_view_emit_toggled (EShellView *shell_view)
{
    g_signal_emit (shell_view, signals[TOGGLED], 0);
}

static void
shell_view_set_action (EShellView *shell_view,
                       GtkAction *action)
{
    gchar *label;

    g_return_if_fail (shell_view->priv->action == NULL);

    shell_view->priv->action = g_object_ref (action);

    g_object_get (action, "label", &label, NULL);
    e_shell_view_set_title (shell_view, label);
    g_free (label);

    g_signal_connect_swapped (
        action, "toggled",
        G_CALLBACK (shell_view_emit_toggled), shell_view);
}

static void
shell_view_set_shell_window (EShellView *shell_view,
                             EShellWindow *shell_window)
{
    g_return_if_fail (E_IS_SHELL_WINDOW (shell_window));
    g_return_if_fail (shell_view->priv->shell_window == NULL);

    shell_view->priv->shell_window = shell_window;

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

static void
shell_view_set_property (GObject *object,
                         guint property_id,
                         const GValue *value,
                         GParamSpec *pspec)
{
    switch (property_id) {
        case PROP_ACTION:
            shell_view_set_action (
                E_SHELL_VIEW (object),
                g_value_get_object (value));
            return;

        case PROP_PAGE_NUM:
            e_shell_view_set_page_num (
                E_SHELL_VIEW (object),
                g_value_get_int (value));
            return;

        case PROP_SEARCH_RULE:
            e_shell_view_set_search_rule (
                E_SHELL_VIEW (object),
                g_value_get_object (value));
            return;

        case PROP_SHELL_WINDOW:
            shell_view_set_shell_window (
                E_SHELL_VIEW (object),
                g_value_get_object (value));
            return;

        case PROP_TITLE:
            e_shell_view_set_title (
                E_SHELL_VIEW (object),
                g_value_get_string (value));
            return;

        case PROP_VIEW_ID:
            e_shell_view_set_view_id (
                E_SHELL_VIEW (object),
                g_value_get_string (value));
            return;
    }

    G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
}

static void
shell_view_get_property (GObject *object,
                         guint property_id,
                         GValue *value,
                         GParamSpec *pspec)
{
    switch (property_id) {
        case PROP_ACTION:
            g_value_set_object (
                value, e_shell_view_get_action (
                E_SHELL_VIEW (object)));
            return;

        case PROP_PAGE_NUM:
            g_value_set_int (
                value, e_shell_view_get_page_num (
                E_SHELL_VIEW (object)));
            return;

        case PROP_SEARCHBAR:
            g_value_set_object (
                value, e_shell_view_get_searchbar (
                E_SHELL_VIEW (object)));
            return;

        case PROP_SEARCH_RULE:
            g_value_set_object (
                value, e_shell_view_get_search_rule (
                E_SHELL_VIEW (object)));
            return;

        case PROP_SHELL_BACKEND:
            g_value_set_object (
                value, e_shell_view_get_shell_backend (
                E_SHELL_VIEW (object)));

        case PROP_SHELL_CONTENT:
            g_value_set_object (
                value, e_shell_view_get_shell_content (
                E_SHELL_VIEW (object)));
            return;

        case PROP_SHELL_SIDEBAR:
            g_value_set_object (
                value, e_shell_view_get_shell_sidebar (
                E_SHELL_VIEW (object)));
            return;

        case PROP_SHELL_TASKBAR:
            g_value_set_object (
                value, e_shell_view_get_shell_taskbar (
                E_SHELL_VIEW (object)));
            return;

        case PROP_SHELL_WINDOW:
            g_value_set_object (
                value, e_shell_view_get_shell_window (
                E_SHELL_VIEW (object)));
            return;

        case PROP_STATE_KEY_FILE:
            g_value_set_pointer (
                value, e_shell_view_get_state_key_file (
                E_SHELL_VIEW (object)));
            return;

        case PROP_TITLE:
            g_value_set_string (
                value, e_shell_view_get_title (
                E_SHELL_VIEW (object)));
            return;

        case PROP_VIEW_ID:
            g_value_set_string (
                value, e_shell_view_get_view_id (
                E_SHELL_VIEW (object)));
            return;
    }

    G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
}

static void
shell_view_dispose (GObject *object)
{
    EShellViewPrivate *priv;

    priv = E_SHELL_VIEW_GET_PRIVATE (object);

    /* Expedite any pending state saves. */
    if (priv->state_save_timeout_id > 0) {
        g_source_remove (priv->state_save_timeout_id);
        priv->state_save_timeout_id = 0;
        if (priv->state_save_activity == NULL)
            shell_view_save_state (E_SHELL_VIEW (object));
    }

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

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

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

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

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

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

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

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

static void
shell_view_finalize (GObject *object)
{
    EShellViewPrivate *priv;

    priv = E_SHELL_VIEW_GET_PRIVATE (object);

    g_key_file_free (priv->state_key_file);

    g_free (priv->title);
    g_free (priv->view_id);

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

static void
shell_view_constructed (GObject *object)
{
    EShellViewClass *shell_view_class;
    EShellView *shell_view;
    GtkWidget *widget;

    shell_view = E_SHELL_VIEW (object);
    shell_view_class = E_SHELL_VIEW_GET_CLASS (shell_view);

    shell_view_load_state (shell_view);

    /* Invoke factory methods. */

    /* Create the taskbar widget first so the content and
     * sidebar widgets can access it during construction. */
    widget = shell_view_class->new_shell_taskbar (shell_view);
    shell_view->priv->shell_taskbar = g_object_ref_sink (widget);
    gtk_widget_show (widget);

    widget = shell_view_class->new_shell_content (shell_view);
    shell_view->priv->shell_content = g_object_ref_sink (widget);
    gtk_widget_show (widget);

    widget = shell_view_class->new_shell_sidebar (shell_view);
    shell_view->priv->shell_sidebar = g_object_ref_sink (widget);
    gtk_widget_show (widget);

    if (shell_view_class->construct_searchbar != NULL) {
        widget = shell_view_class->construct_searchbar (shell_view);
        shell_view->priv->searchbar = g_object_ref_sink (widget);
    }

    /* Size group should be safe to unreference now. */
    g_object_unref (shell_view->priv->size_group);
    shell_view->priv->size_group = NULL;

    e_extensible_load_extensions (E_EXTENSIBLE (object));
}

static GtkWidget *
shell_view_construct_searchbar (EShellView *shell_view)
{
    EShell *shell;
    EShellWindow *shell_window;
    EShellContent *shell_content;
    EShellSearchbar *shell_searchbar;
    GtkToolItem *item;
    GtkAction *action;
    GtkWidget *main_toolbar;
    GtkWidget *widget;

    shell_content = e_shell_view_get_shell_content (shell_view);
    shell_window = e_shell_view_get_shell_window (shell_view);
    shell = e_shell_window_get_shell (shell_window);

    widget = e_shell_searchbar_new (shell_view);

    /* In normal mode, we hand the searchbar off to EShellContent. */
    if (!e_shell_get_express_mode (shell)) {
        e_shell_content_set_searchbar (shell_content, widget);
        gtk_widget_show (widget);
        return widget;
    }

    /* Express mode is more complicated.  We append a heavily simplified
     * version of it to the main toolbar, but only show it when this shell
     * view is active.  So each view still gets its own searchbar. */

    shell_searchbar = E_SHELL_SEARCHBAR (widget);
    e_shell_searchbar_set_express_mode (shell_searchbar, TRUE);

    /* XXX Hardcoded sizes are evil, but what should the width be
     *     relative to.  Window width?  The other toolbar width? */
    gtk_widget_set_size_request (widget, SIMPLE_SEARCHBAR_WIDTH, -1);

    main_toolbar = e_shell_window_get_managed_widget (
        shell_window, "/search-toolbar");

    item = gtk_tool_item_new ();
    gtk_container_add (GTK_CONTAINER (item), widget);
    gtk_widget_show (GTK_WIDGET (item));

    action = e_shell_view_get_action (shell_view);
    e_binding_new (action, "active", widget, "visible");

    gtk_toolbar_insert (GTK_TOOLBAR (main_toolbar), item, -1);

    return widget;
}

static gchar *
shell_view_get_search_name (EShellView *shell_view)
{
    EShellSearchbar *searchbar;
    EFilterRule *rule;
    const gchar *search_text;

    rule = e_shell_view_get_search_rule (shell_view);
    g_return_val_if_fail (E_IS_FILTER_RULE (rule), NULL);

    searchbar = E_SHELL_SEARCHBAR (shell_view->priv->searchbar);
    search_text = e_shell_searchbar_get_search_text (searchbar);

    if (search_text == NULL || *search_text == '\0')
        search_text = "''";

    return g_strdup_printf ("%s %s", rule->name, search_text);
}

static void
shell_view_toggled (EShellView *shell_view)
{
    EShellViewPrivate *priv = shell_view->priv;
    EShellViewClass *shell_view_class;
    EShellWindow *shell_window;
    GtkUIManager *ui_manager;
    const gchar *basename, *id;
    gboolean view_is_active;

    shell_view_class = E_SHELL_VIEW_GET_CLASS (shell_view);
    shell_window = e_shell_view_get_shell_window (shell_view);
    ui_manager = e_shell_window_get_ui_manager (shell_window);
    view_is_active = e_shell_view_is_active (shell_view);
    basename = shell_view_class->ui_definition;
    id = shell_view_class->ui_manager_id;

    if (view_is_active && priv->merge_id == 0) {
        priv->merge_id = e_ui_manager_add_ui_from_file (
            E_UI_MANAGER (ui_manager), basename);
        e_plugin_ui_enable_manager (ui_manager, id);

    } else if (!view_is_active && priv->merge_id != 0) {
        e_plugin_ui_disable_manager (ui_manager, id);
        gtk_ui_manager_remove_ui (ui_manager, priv->merge_id);
        priv->merge_id = 0;
    }

    gtk_ui_manager_ensure_update (ui_manager);
}

static void
shell_view_clear_search (EShellView *shell_view)
{
    e_shell_view_set_search_rule (shell_view, NULL);
    e_shell_view_execute_search (shell_view);
}

static void
shell_view_custom_search (EShellView *shell_view,
                          EFilterRule *custom_rule)
{
    e_shell_view_set_search_rule (shell_view, custom_rule);
    e_shell_view_execute_search (shell_view);
}

static void
shell_view_update_actions (EShellView *shell_view)
{
    EShellWindow *shell_window;
    EFocusTracker *focus_tracker;

    g_return_if_fail (!shell_view->priv->update_actions_blocked);
    g_return_if_fail (e_shell_view_is_active (shell_view));

    shell_window = e_shell_view_get_shell_window (shell_view);
    focus_tracker = e_shell_window_get_focus_tracker (shell_window);

    e_focus_tracker_update_actions (focus_tracker);
}

static void
shell_view_class_init (EShellViewClass *class)
{
    GObjectClass *object_class;

    parent_class = g_type_class_peek_parent (class);
    g_type_class_add_private (class, sizeof (EShellViewPrivate));

    object_class = G_OBJECT_CLASS (class);
    object_class->set_property = shell_view_set_property;
    object_class->get_property = shell_view_get_property;
    object_class->dispose = shell_view_dispose;
    object_class->finalize = shell_view_finalize;
    object_class->constructed = shell_view_constructed;

    class->search_context_type = E_TYPE_RULE_CONTEXT;

    /* Default Factories */
    class->new_shell_content = e_shell_content_new;
    class->new_shell_sidebar = e_shell_sidebar_new;
    class->new_shell_taskbar = e_shell_taskbar_new;

    class->construct_searchbar = shell_view_construct_searchbar;
    class->get_search_name = shell_view_get_search_name;

    class->toggled = shell_view_toggled;
    class->clear_search = shell_view_clear_search;
    class->custom_search = shell_view_custom_search;
    class->update_actions = shell_view_update_actions;

    /**
     * EShellView:action:
     *
     * The #GtkRadioAction registered with #EShellSwitcher.
     **/
    g_object_class_install_property (
        object_class,
        PROP_ACTION,
        g_param_spec_object (
            "action",
            "Switcher Action",
            "The switcher action for this shell view",
            GTK_TYPE_RADIO_ACTION,
            G_PARAM_READWRITE |
            G_PARAM_CONSTRUCT_ONLY));

    /**
     * EShellView:page-num
     *
     * The #GtkNotebook page number of the shell view.
     **/
    g_object_class_install_property (
        object_class,
        PROP_PAGE_NUM,
        g_param_spec_int (
            "page-num",
            "Page Number",
            "The notebook page number of the shell view",
            -1,
            G_MAXINT,
            -1,
            G_PARAM_READWRITE));

    /**
     * EShellView:search-rule
     *
     * Criteria for the current search results.
     **/
    g_object_class_install_property (
        object_class,
        PROP_SEARCH_RULE,
        g_param_spec_object (
            "search-rule",
            "Search Rule",
            "Criteria for the current search results",
            E_TYPE_FILTER_RULE,
            G_PARAM_READWRITE));

    /**
     * EShellView:shell-backend
     *
     * The #EShellBackend for this shell view.
     **/
    g_object_class_install_property (
        object_class,
        PROP_SHELL_BACKEND,
        g_param_spec_object (
            "shell-backend",
            "Shell Backend",
            "The EShellBackend for this shell view",
            E_TYPE_SHELL_BACKEND,
            G_PARAM_READABLE));

    /**
     * EShellView:shell-content
     *
     * The content widget appears in an #EShellWindow<!-- -->'s
     * right pane.
     **/
    g_object_class_install_property (
        object_class,
        PROP_SHELL_CONTENT,
        g_param_spec_object (
            "shell-content",
            "Shell Content Widget",
            "The content widget appears in "
              "a shell window's right pane",
            E_TYPE_SHELL_CONTENT,
            G_PARAM_READABLE));

    /**
     * EShellView:shell-sidebar
     *
     * The sidebar widget appears in an #EShellWindow<!-- -->'s
     * left pane.
     **/
    g_object_class_install_property (
        object_class,
        PROP_SHELL_SIDEBAR,
        g_param_spec_object (
            "shell-sidebar",
            "Shell Sidebar Widget",
            "The sidebar widget appears in "
              "a shell window's left pane",
            E_TYPE_SHELL_SIDEBAR,
            G_PARAM_READABLE));

    /**
     * EShellView:shell-taskbar
     *
     * The taskbar widget appears at the bottom of an #EShellWindow.
     **/
    g_object_class_install_property (
        object_class,
        PROP_SHELL_TASKBAR,
        g_param_spec_object (
            "shell-taskbar",
            "Shell Taskbar Widget",
            "The taskbar widget appears at "
              "the bottom of a shell window",
            E_TYPE_SHELL_TASKBAR,
            G_PARAM_READABLE));

    /**
     * EShellView:shell-window
     *
     * The #EShellWindow to which the shell view belongs.
     **/
    g_object_class_install_property (
        object_class,
        PROP_SHELL_WINDOW,
        g_param_spec_object (
            "shell-window",
            "Shell Window",
            "The window to which the shell view belongs",
            E_TYPE_SHELL_WINDOW,
            G_PARAM_READWRITE |
            G_PARAM_CONSTRUCT_ONLY));

    /**
     * EShellView:state-key-file
     *
     * The #GKeyFile holding widget state data.
     **/
    g_object_class_install_property (
        object_class,
        PROP_STATE_KEY_FILE,
        g_param_spec_pointer (
            "state-key-file",
            "State Key File",
            "The key file holding widget state data",
            G_PARAM_READABLE));

    /**
     * EShellView:title
     *
     * The title of the shell view.  Also serves as the #EShellWindow
     * title when the shell view is active.
     **/
    g_object_class_install_property (
        object_class,
        PROP_TITLE,
        g_param_spec_string (
            "title",
            "Title",
            "The title of the shell view",
            NULL,
            G_PARAM_READWRITE));

    /**
     * EShellView:view-id
     *
     * The current #GalView ID.
     **/
    g_object_class_install_property (
        object_class,
        PROP_VIEW_ID,
        g_param_spec_string (
            "view-id",
            "Current View ID",
            "The current GAL view ID",
            NULL,
            G_PARAM_READWRITE));

    /**
     * EShellView::toggled
     * @shell_view: the #EShellView which emitted the signal
     *
     * Emitted when @shell_view is activated or deactivated.
     * Use e_shell_view_is_active() to find out which event has
     * occurred.  The shell view being deactivated is always
     * notified before the shell view being activated.
     *
     * By default, #EShellView adds the UI definition file
     * given in the <structfield>ui_definition</structfield>
     * field of #EShellViewClass on activation, and removes the
     * UI definition on deactivation.
     **/
    signals[TOGGLED] = g_signal_new (
        "toggled",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_FIRST,
        G_STRUCT_OFFSET (EShellViewClass, toggled),
        NULL, NULL,
        g_cclosure_marshal_VOID__VOID,
        G_TYPE_NONE, 0);

    /**
     * EShellView::clear-search
     * @shell_view: the #EShellView which emitted the signal
     *
     * Clears the current search.  See e_shell_view_clear_search() for
     * details.
     **/
    signals[CLEAR_SEARCH] = g_signal_new (
        "clear-search",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_LAST,
        G_STRUCT_OFFSET (EShellViewClass, clear_search),
        NULL, NULL,
        g_cclosure_marshal_VOID__VOID,
        G_TYPE_NONE, 0);

    /**
     * EShellView::custom-search
     * @shell_view: the #EShellView which emitted the signal
     * @custom_rule: criteria for the custom search
     *
     * Emitted when an advanced or saved search is about to be executed.
     * See e_shell_view_custom_search() for details.
     **/
    signals[CUSTOM_SEARCH] = g_signal_new (
        "custom-search",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_LAST,
        G_STRUCT_OFFSET (EShellViewClass, custom_search),
        NULL, NULL,
        g_cclosure_marshal_VOID__OBJECT,
        G_TYPE_NONE, 1,
        E_TYPE_FILTER_RULE);

    /**
     * EShellView::execute-search
     * @shell_view: the #EShellView which emitted the signal
     *
     * #EShellView subclasses should override the
     * <structfield>execute_search</structfield> method in
     * #EShellViewClass to execute the current search conditions.
     **/
    signals[EXECUTE_SEARCH] = g_signal_new (
        "execute-search",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_FIRST,
        G_STRUCT_OFFSET (EShellViewClass, execute_search),
        NULL, NULL,
        g_cclosure_marshal_VOID__VOID,
        G_TYPE_NONE, 0);

    /**
     * EShellView::update-actions
     * @shell_view: the #EShellView which emitted the signal
     *
     * #EShellView subclasses should override the
     * <structfield>update_actions</structfield> method in
     * #EShellViewClass to update sensitivities, labels, or any
     * other aspect of the #GtkAction<!-- -->s they have registered.
     *
     * Plugins can also connect to this signal to be notified
     * when to update their own #GtkAction<!-- -->s.
     **/
    signals[UPDATE_ACTIONS] = g_signal_new (
        "update-actions",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_FIRST,
        G_STRUCT_OFFSET (EShellViewClass, update_actions),
        NULL, NULL,
        g_cclosure_marshal_VOID__VOID,
        G_TYPE_NONE, 0);
}

static void
shell_view_init (EShellView *shell_view,
                 EShellViewClass *class)
{
    GtkSizeGroup *size_group;

    if (class->search_context == NULL)
        shell_view_init_search_context (class);

    if (class->view_collection == NULL)
        shell_view_init_view_collection (class);

    size_group = gtk_size_group_new (GTK_SIZE_GROUP_VERTICAL);

    shell_view->priv = E_SHELL_VIEW_GET_PRIVATE (shell_view);
    shell_view->priv->state_key_file = g_key_file_new ();
    shell_view->priv->size_group = size_group;
}

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

    if (G_UNLIKELY (type == 0)) {
        const GTypeInfo type_info = {
            sizeof (EShellViewClass),
            (GBaseInitFunc) NULL,
            (GBaseFinalizeFunc) NULL,
            (GClassInitFunc) shell_view_class_init,
            (GClassFinalizeFunc) NULL,
            NULL,  /* class_data */
            sizeof (EShellView),
            0,     /* n_preallocs */
            (GInstanceInitFunc) shell_view_init,
            NULL   /* value_table */
        };

        const GInterfaceInfo extensible_info = {
            (GInterfaceInitFunc) NULL,
            (GInterfaceFinalizeFunc) NULL,
            NULL   /* interface_data */
        };

        type = g_type_register_static (
            G_TYPE_OBJECT, "EShellView",
            &type_info, G_TYPE_FLAG_ABSTRACT);

        g_type_add_interface_static (
            type, E_TYPE_EXTENSIBLE, &extensible_info);
    }

    return type;
}

/**
 * e_shell_view_get_name:
 * @shell_view: an #EShellView
 *
 * Returns the view name for @shell_view, which is also the name of
 * the corresponding #EShellBackend (see the <structfield>name</structfield>
 * field in #EShellBackendInfo).
 *
 * Returns: the view name for @shell_view
 **/
const gchar *
e_shell_view_get_name (EShellView *shell_view)
{
    GtkAction *action;

    g_return_val_if_fail (E_IS_SHELL_VIEW (shell_view), NULL);

    action = e_shell_view_get_action (shell_view);

    /* Switcher actions have a secret "view-name" data value.
     * This gets set in e_shell_window_create_switcher_actions(). */
    return g_object_get_data (G_OBJECT (action), "view-name");
}

/**
 * e_shell_view_get_action:
 * @shell_view: an #EShellView
 *
 * Returns the switcher action for @shell_view.
 *
 * An #EShellWindow creates a #GtkRadioAction for each registered subclass
 * of #EShellView.  This action gets passed to the #EShellSwitcher, which
 * displays a button that proxies the action.  The icon at the top of the
 * sidebar also proxies the action.  When @shell_view is active, the
 * action's icon becomes the #EShellWindow icon.
 *
 * Returns: the switcher action for @shell_view
 **/
GtkAction *
e_shell_view_get_action (EShellView *shell_view)
{
    g_return_val_if_fail (E_IS_SHELL_VIEW (shell_view), NULL);

    return shell_view->priv->action;
}

/**
 * e_shell_view_get_title:
 * @shell_view: an #EShellView
 *
 * Returns the title for @shell_view.  When @shell_view is active, the
 * shell view's title becomes the #EShellWindow title.
 *
 * Returns: the title for @shell_view
 **/
const gchar *
e_shell_view_get_title (EShellView *shell_view)
{
    g_return_val_if_fail (E_IS_SHELL_VIEW (shell_view), NULL);

    return shell_view->priv->title;
}

/**
 * e_shell_view_set_title:
 * @shell_view: an #EShellView
 * @title: a title for @shell_view
 *
 * Sets the title for @shell_view.  When @shell_view is active, the
 * shell view's title becomes the #EShellWindow title.
 **/
void
e_shell_view_set_title (EShellView *shell_view,
                        const gchar *title)
{
    g_return_if_fail (E_IS_SHELL_VIEW (shell_view));

    if (title == NULL)
        title = E_SHELL_VIEW_GET_CLASS (shell_view)->label;

    if (g_strcmp0 (shell_view->priv->title, title) == 0)
        return;

    g_free (shell_view->priv->title);
    shell_view->priv->title = g_strdup (title);

    g_object_notify (G_OBJECT (shell_view), "title");
}

/**
 * e_shell_view_get_view_id:
 * @shell_view: an #EShellView
 *
 * Returns the ID of the currently selected #GalView.
 *
 * #EShellView subclasses are responsible for keeping this property in
 * sync with their #GalViewInstance.  #EShellView itself just provides
 * a place to store the view ID, and emits a #GObject::notify signal
 * when the property changes.
 *
 * Returns: the ID of the current #GalView
 **/
const gchar *
e_shell_view_get_view_id (EShellView *shell_view)
{
    g_return_val_if_fail (E_IS_SHELL_VIEW (shell_view), NULL);

    return shell_view->priv->view_id;
}

/**
 * e_shell_view_set_view_id:
 * @shell_view: an #EShellView
 * @view_id: a #GalView ID
 *
 * Selects the #GalView whose ID is equal to @view_id.
 *
 * #EShellView subclasses are responsible for keeping this property in
 * sync with their #GalViewInstance.  #EShellView itself just provides
 * a place to store the view ID, and emits a #GObject::notify signal
 * when the property changes.
 **/
void
e_shell_view_set_view_id (EShellView *shell_view,
                          const gchar *view_id)
{
    g_return_if_fail (E_IS_SHELL_VIEW (shell_view));

    if (g_strcmp0 (shell_view->priv->view_id, view_id) == 0)
        return;

    g_free (shell_view->priv->view_id);
    shell_view->priv->view_id = g_strdup (view_id);

    g_object_notify (G_OBJECT (shell_view), "view-id");
}

/**
 * e_shell_view_get_shell_window:
 * @shell_view: an #EShellView
 *
 * Returns the #EShellWindow to which @shell_view belongs.
 *
 * Returns: the #EShellWindow to which @shell_view belongs
 **/
EShellWindow *
e_shell_view_get_shell_window (EShellView *shell_view)
{
    g_return_val_if_fail (E_IS_SHELL_VIEW (shell_view), NULL);

    return E_SHELL_WINDOW (shell_view->priv->shell_window);
}

/**
 * e_shell_view_is_active:
 * @shell_view: an #EShellView
 *
 * Returns %TRUE if @shell_view is active.  That is, if it's currently
 * visible in its #EShellWindow.  An #EShellWindow can only display one
 * shell view at a time.
 *
 * Technically this just checks the #GtkToggleAction:active property of
 * the shell view's switcher action.  See e_shell_view_get_action().
 *
 * Returns: %TRUE if @shell_view is active
 **/
gboolean
e_shell_view_is_active (EShellView *shell_view)
{
    GtkAction *action;

    g_return_val_if_fail (E_IS_SHELL_VIEW (shell_view), FALSE);

    action = e_shell_view_get_action (shell_view);

    return gtk_toggle_action_get_active (GTK_TOGGLE_ACTION (action));
}

/**
 * e_shell_view_get_page_num:
 * @shell_view: an #EShellView
 *
 * This function is only interesting to #EShellWindow.  It returns the
 * #GtkNotebook page number for @shell_view.  The rest of the application
 * should have no need for this.
 *
 * Returns: the notebook page number for @shell_view
 **/
gint
e_shell_view_get_page_num (EShellView *shell_view)
{
    g_return_val_if_fail (E_IS_SHELL_VIEW (shell_view), -1);

    return shell_view->priv->page_num;
}

/**
 * e_shell_view_set_page_num:
 * @shell_view: an #EShellView
 * @page_num: a notebook page number
 *
 * This function is only interesting to #EShellWindow.  It sets the
 * #GtkNotebook page number for @shell_view.  The rest of the application
 * must never call this because it could mess up shell view switching.
 **/
void
e_shell_view_set_page_num (EShellView *shell_view,
                           gint page_num)
{
    g_return_if_fail (E_IS_SHELL_VIEW (shell_view));

    shell_view->priv->page_num = page_num;

    g_object_notify (G_OBJECT (shell_view), "page-num");
}

/**
 * e_shell_view_get_search_name:
 * @shell_view: an #EShellView
 *
 * Returns a newly-allocated string containing a suitable name for the
 * current search criteria.  This is used as the suggested name in the
 * Save Search dialog.  Free the returned string with g_free().
 *
 * Returns: a name for the current search criteria
 **/
gchar *
e_shell_view_get_search_name (EShellView *shell_view)
{
    EShellViewClass *class;

    g_return_val_if_fail (E_IS_SHELL_VIEW (shell_view), NULL);

    class = E_SHELL_VIEW_GET_CLASS (shell_view);
    g_return_val_if_fail (class->get_search_name != NULL, NULL);

    return class->get_search_name (shell_view);
}

/**
 * e_shell_view_get_search_rule:
 * @shell_view: an #EShellView
 *
 * Returns the search criteria used to generate the current search results.
 *
 * Returns: the current search criteria
 **/
EFilterRule *
e_shell_view_get_search_rule (EShellView *shell_view)
{
    g_return_val_if_fail (E_IS_SHELL_VIEW (shell_view), NULL);

    return shell_view->priv->search_rule;
}

/**
 * e_shell_view_get_searchbar:
 * @shell_view: an #EShellView
 *
 * Returns the searchbar widget for @shell_view.
 **/
GtkWidget *
e_shell_view_get_searchbar (EShellView *shell_view)
{
    g_return_val_if_fail (E_IS_SHELL_VIEW (shell_view), NULL);

    return shell_view->priv->searchbar;
}

/**
 * e_shell_view_set_search_rule:
 * @shell_view: an #EShellView
 * @search_rule: an #EFilterRule
 *
 * Sets the search criteria used to generate the current search results.
 * Note that this will not trigger a search.  e_shell_view_execute_search()
 * must be called explicitly.
 **/
void
e_shell_view_set_search_rule (EShellView *shell_view,
                              EFilterRule *search_rule)
{
    g_return_if_fail (E_IS_SHELL_VIEW (shell_view));

    if (search_rule != NULL) {
        g_return_if_fail (E_IS_FILTER_RULE (search_rule));
        g_object_ref (search_rule);
    }

    if (shell_view->priv->search_rule != NULL)
        g_object_unref (shell_view->priv->search_rule);

    shell_view->priv->search_rule = search_rule;

    g_object_notify (G_OBJECT (shell_view), "search-rule");
}

/**
 * e_shell_view_get_search_query:
 * @shell_view: an #EShellView
 *
 * Converts the #EShellView:search-rule property to a newly-allocated
 * S-expression string.  If the #EShellView:search-rule property is %NULL
 * the function returns %NULL.
 *
 * Returns: an S-expression string, or %NULL
 **/
gchar *
e_shell_view_get_search_query (EShellView *shell_view)
{
    EFilterRule *rule;
    GString *string;

    g_return_val_if_fail (E_IS_SHELL_VIEW (shell_view), NULL);

    rule = e_shell_view_get_search_rule (shell_view);
    if (rule == NULL)
        return NULL;

    string = g_string_sized_new (1024);
    e_filter_rule_build_code (rule, string);

    return g_string_free (string, FALSE);
}

/**
 * e_shell_view_get_size_group:
 * @shell_view: an #EShellView
 *
 * Returns a #GtkSizeGroup that #EShellContent and #EShellSidebar use
 * to keep the search bar and sidebar banner vertically aligned.  The
 * rest of the application should have no need for this.
 *
 * Note, this is only available during #EShellView construction.
 *
 * Returns: a #GtkSizeGroup for internal use
 **/
GtkSizeGroup *
e_shell_view_get_size_group (EShellView *shell_view)
{
    g_return_val_if_fail (E_IS_SHELL_VIEW (shell_view), NULL);

    return shell_view->priv->size_group;
}

/**
 * e_shell_view_get_shell_backend:
 * @shell_view: an #EShellView
 *
 * Returns the corresponding #EShellBackend for @shell_view.
 *
 * Returns: the corresponding #EShellBackend for @shell_view
 **/
EShellBackend *
e_shell_view_get_shell_backend (EShellView *shell_view)
{
    EShellViewClass *class;

    g_return_val_if_fail (E_IS_SHELL_VIEW (shell_view), NULL);

    class = E_SHELL_VIEW_GET_CLASS (shell_view);
    g_return_val_if_fail (class->shell_backend != NULL, NULL);

    return class->shell_backend;
}

/**
 * e_shell_view_get_shell_content:
 * @shell_view: an #EShellView
 *
 * Returns the #EShellContent instance for @shell_view.
 *
 * By default, #EShellView creates a plain #EShellContent during
 * initialization.  But #EShellView subclasses can override the
 * <structfield>new_shell_content</structfield> factory method
 * in #EShellViewClass to create a custom #EShellContent.
 *
 * Returns: the #EShellContent instance for @shell_view
 **/
EShellContent *
e_shell_view_get_shell_content (EShellView *shell_view)
{
    g_return_val_if_fail (E_IS_SHELL_VIEW (shell_view), NULL);

    return E_SHELL_CONTENT (shell_view->priv->shell_content);
}

/**
 * e_shell_view_get_shell_sidebar:
 * @shell_view: an #EShellView
 *
 * Returns the #EShellSidebar instance for @shell_view.
 *
 * By default, #EShellView creates a plain #EShellSidebar during
 * initialization.  But #EShellView subclasses can override the
 * <structfield>new_shell_sidebar</structfield> factory method
 * in #EShellViewClass to create a custom #EShellSidebar.
 *
 * Returns: the #EShellSidebar instance for @shell_view
 **/
EShellSidebar *
e_shell_view_get_shell_sidebar (EShellView *shell_view)
{
    g_return_val_if_fail (E_IS_SHELL_VIEW (shell_view), NULL);

    return E_SHELL_SIDEBAR (shell_view->priv->shell_sidebar);
}

/**
 * e_shell_view_get_shell_taskbar:
 * @shell_view: an #EShellView
 *
 * Returns the #EShellTaskbar instance for @shell_view.
 *
 * By default, #EShellView creates a plain #EShellTaskbar during
 * initialization.  But #EShellView subclasses can override the
 * <structfield>new_shell_taskbar</structfield> factory method
 * in #EShellViewClass to create a custom #EShellTaskbar.
 *
 * Returns: the #EShellTaskbar instance for @shell_view
 **/
EShellTaskbar *
e_shell_view_get_shell_taskbar (EShellView *shell_view)
{
    g_return_val_if_fail (E_IS_SHELL_VIEW (shell_view), NULL);

    return E_SHELL_TASKBAR (shell_view->priv->shell_taskbar);
}

/**
 * e_shell_view_get_state_key_file:
 * @shell_view: an #EShellView
 *
 * Returns the #GKeyFile holding widget state data for @shell_view.
 *
 * Returns: the #GKeyFile for @shell_view
 **/
GKeyFile *
e_shell_view_get_state_key_file (EShellView *shell_view)
{
    g_return_val_if_fail (E_IS_SHELL_VIEW (shell_view), NULL);

    return shell_view->priv->state_key_file;
}

/**
 * e_shell_view_set_state_dirty:
 * @shell_view: an #EShellView
 *
 * Marks the widget state data as modified (or "dirty") and schedules it
 * to be saved to disk after a short delay.  The delay caps the frequency
 * of saving to disk.
 **/
void
e_shell_view_set_state_dirty (EShellView *shell_view)
{
    guint source_id;

    g_return_if_fail (E_IS_SHELL_VIEW (shell_view));

    /* If a timeout is already scheduled, do nothing. */
    if (shell_view->priv->state_save_timeout_id > 0)
        return;

    source_id = g_timeout_add_seconds (
        STATE_SAVE_TIMEOUT_SECONDS, (GSourceFunc)
        shell_view_state_timeout_cb, shell_view);

    shell_view->priv->state_save_timeout_id = source_id;
}

/**
 * e_shell_view_clear_search:
 * @shell_view: an #EShellView
 *
 * Emits the #EShellView::clear-search signal.
 *
 * The default method sets the #EShellView:search-rule property to
 * %NULL and then emits the #EShellView::execute-search signal.
 **/
void
e_shell_view_clear_search (EShellView *shell_view)
{
    g_return_if_fail (E_IS_SHELL_VIEW (shell_view));

    g_signal_emit (shell_view, signals[CLEAR_SEARCH], 0);
}

/**
 * e_shell_view_custom_search:
 * @shell_view: an #EShellView
 * @custom_rule: an #EFilterRule
 *
 * Emits the #EShellView::custom-search signal to indicate an advanced
 * or saved search is about to be executed.
 *
 * The default method sets the #EShellView:search-rule property to
 * @custom_rule and then emits the #EShellView::execute-search signal.
 **/
void
e_shell_view_custom_search (EShellView *shell_view,
                            EFilterRule *custom_rule)
{
    g_return_if_fail (E_IS_SHELL_VIEW (shell_view));
    g_return_if_fail (E_IS_FILTER_RULE (custom_rule));

    g_signal_emit (shell_view, signals[CUSTOM_SEARCH], 0, custom_rule);
}

/**
 * e_shell_view_execute_search:
 * @shell_view: an #EShellView
 *
 * Emits the #EShellView::execute-search signal.
 *
 * #EShellView subclasses should implement the
 * <structfield>execute_search</structfield> method in #EShellViewClass
 * to execute a search based on the current search conditions.
 **/
void
e_shell_view_execute_search (EShellView *shell_view)
{
    g_return_if_fail (E_IS_SHELL_VIEW (shell_view));

    if (!shell_view->priv->execute_search_blocked)
        g_signal_emit (shell_view, signals[EXECUTE_SEARCH], 0);
}

/**
 * e_shell_view_block_execute_search:
 * @shell_view: an #EShellView
 *
 * Blocks e_shell_view_execute_search() in a way it does nothing.
 * Pair function for this is e_shell_view_unblock_execute_search().
 **/
void
e_shell_view_block_execute_search (EShellView *shell_view)
{
    g_return_if_fail (E_IS_SHELL_VIEW (shell_view));
    g_return_if_fail (shell_view->priv->execute_search_blocked + 1 != 0);

    shell_view->priv->execute_search_blocked++;
}

/**
 * e_shell_view_unblock_execute_search:
 * @shell_view: an #EShellView
 *
 * Unblocks previously blocked e_shell_view_execute_search() with
 * function e_shell_view_block_execute_search().
 **/
void
e_shell_view_unblock_execute_search (EShellView *shell_view)
{
    g_return_if_fail (E_IS_SHELL_VIEW (shell_view));
    g_return_if_fail (shell_view->priv->execute_search_blocked > 0);

    shell_view->priv->execute_search_blocked--;
}

/**
 * e_shell_view_update_actions:
 * @shell_view: an #EShellView
 *
 * Emits the #EShellView::update-actions signal.
 *
 * #EShellView subclasses should implement the
 * <structfield>update_actions</structfield> method in #EShellViewClass
 * to update the various #GtkAction<!-- -->s based on the current
 * #EShellSidebar and #EShellContent selections.  The
 * #EShellView::update-actions signal is typically emitted just before
 * showing a popup menu or just after the user selects an item in the
 * shell view.
 *
 * Emission can be blocked by e_shell_view_block_update_actions().
 **/
void
e_shell_view_update_actions (EShellView *shell_view)
{
    g_return_if_fail (E_IS_SHELL_VIEW (shell_view));

    if (!e_shell_view_is_active (shell_view))
        return;

    if (shell_view->priv->update_actions_blocked > 0) {
        shell_view->priv->update_actions_called = TRUE;
    } else {
        shell_view->priv->update_actions_called = FALSE;
        g_signal_emit (shell_view, signals[UPDATE_ACTIONS], 0);
    }
}

/**
 * e_shell_view_block_update_actions:
 * @shell_view: an #EShellView
 *
 * Block emission of #EShellView::update-actions signal through
 * e_shell_view_update_actions(). The emission si blocked until
 * e_shell_view_unblock_update_actions() is called same times as
 * this function.
 **/
void
e_shell_view_block_update_actions (EShellView *shell_view)
{
    g_return_if_fail (E_IS_SHELL_VIEW (shell_view));
    g_return_if_fail (shell_view->priv->update_actions_blocked + 1 != 0);

    shell_view->priv->update_actions_blocked++;
    if (shell_view->priv->update_actions_blocked == 1)
        shell_view->priv->update_actions_called = FALSE;
}

/**
 * e_shell_view_unblock_update_actions:
 * @shell_view: an #EShellView
 *
 * Unblock emission of #EShellView::update-actions signal through
 * e_shell_view_update_actions(), previously blocked by function
 * e_shell_view_block_update_actions().
 **/
void
e_shell_view_unblock_update_actions (EShellView *shell_view)
{
    g_return_if_fail (E_IS_SHELL_VIEW (shell_view));
    g_return_if_fail (shell_view->priv->update_actions_blocked > 0);

    shell_view->priv->update_actions_blocked--;
    if (!shell_view->priv->update_actions_blocked && shell_view->priv->update_actions_called) {
        shell_view->priv->update_actions_called = FALSE;
        e_shell_view_update_actions (shell_view);
    }
}

/**
 * e_shell_view_show_popup_menu:
 * @shell_view: an #EShellView
 * @widget_path: path in the UI definition
 * @event: a #GdkEventButton
 *
 * Displays a context-sensitive (or "popup") menu that is described in
 * the UI definition loaded into @shell_view<!-- -->'s user interface
 * manager.  The menu will be shown at the current mouse cursor position.
 *
 * The #EShellView::update-actions signal is emitted just prior to
 * showing the menu to give @shell_view and any plugins that extend
 * @shell_view a chance to update the menu's actions.
 *
 * Returns: the popup menu being displayed
 **/
GtkWidget *
e_shell_view_show_popup_menu (EShellView *shell_view,
                              const gchar *widget_path,
                              GdkEventButton *event)
{
    EShellWindow *shell_window;
    GtkWidget *menu;

    g_return_val_if_fail (E_IS_SHELL_VIEW (shell_view), NULL);

    e_shell_view_update_actions (shell_view);

    shell_window = e_shell_view_get_shell_window (shell_view);
    menu = e_shell_window_get_managed_widget (shell_window, widget_path);
    g_return_val_if_fail (GTK_IS_MENU (menu), NULL);

    if (event != NULL)
        gtk_menu_popup (
            GTK_MENU (menu), NULL, NULL, NULL, NULL,
            event->button, event->time);
    else
        gtk_menu_popup (
            GTK_MENU (menu), NULL, NULL, NULL, NULL,
            0, gtk_get_current_event_time ());

    return menu;
}

/**
 * e_shell_view_new_view_instance:
 * @shell_view: an #EShellView
 * @instance_id: a name for the #GalViewInstance
 *
 * Creates a new #GalViewInstance and configures it to keep
 * @shell_view<!-- -->'s #EShellView:view-id property up-to-date.
 *
 * Returns: a new #GalViewInstance
 **/
GalViewInstance *
e_shell_view_new_view_instance (EShellView *shell_view,
                                const gchar *instance_id)
{
    EShellViewClass *class;
    GalViewCollection *view_collection;
    GalViewInstance *view_instance;

    g_return_val_if_fail (E_IS_SHELL_VIEW (shell_view), NULL);

    class = E_SHELL_VIEW_GET_CLASS (shell_view);

    view_collection = class->view_collection;
    view_instance = gal_view_instance_new (view_collection, instance_id);

    g_signal_connect_swapped (
        view_instance, "changed",
        G_CALLBACK (shell_view_update_view_id), shell_view);

    g_signal_connect_swapped (
        view_instance, "loaded",
        G_CALLBACK (shell_view_update_view_id), shell_view);

    return view_instance;
}