From 0b38a0663d028e1c141ced1bfdc20222ed412f51 Mon Sep 17 00:00:00 2001 From: Matthias Clasen Date: Mon, 6 Jul 2020 16:53:54 -0400 Subject: [PATCH] inspector: Add dom-like navigation controls MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Maintain a stack of objects, and add ˂˅˄˃ buttons that navigate this stack, as well as the widget tree and list models. --- gtk/inspector/controllers.c | 11 +- gtk/inspector/list-data.c | 13 +- gtk/inspector/misc-info.c | 29 +-- gtk/inspector/misc-info.ui | 2 +- gtk/inspector/prop-list.c | 8 +- gtk/inspector/window.c | 401 +++++++++++++++++++++++++++++++++++- gtk/inspector/window.h | 32 ++- gtk/inspector/window.ui | 51 +++++ 8 files changed, 511 insertions(+), 36 deletions(-) diff --git a/gtk/inspector/controllers.c b/gtk/inspector/controllers.c index 0eae1caafd..d140ac6b82 100644 --- a/gtk/inspector/controllers.c +++ b/gtk/inspector/controllers.c @@ -37,6 +37,7 @@ #include "gtkstack.h" #include "gtkstylecontext.h" #include "gtkwidgetprivate.h" +#include "window.h" struct _GtkInspectorControllers { @@ -66,10 +67,14 @@ row_activated (GtkListBox *box, GtkListBoxRow *row, GtkInspectorControllers *self) { + GtkInspectorWindow *iw; GObject *controller; - + + iw = GTK_INSPECTOR_WINDOW (gtk_widget_get_ancestor (GTK_WIDGET (self), GTK_TYPE_INSPECTOR_WINDOW)); + controller = G_OBJECT (g_object_get_data (G_OBJECT (row), "controller")); - gtk_inspector_object_tree_select_object (self->object_tree, controller); + + gtk_inspector_window_push_object (iw, controller, CHILD_KIND_CONTROLLER, 0); } static void @@ -130,7 +135,7 @@ create_controller_widget (gpointer item, const char *phases[5]; row = gtk_list_box_row_new (); - gtk_list_box_row_set_activatable (GTK_LIST_BOX_ROW (row), FALSE); + gtk_list_box_row_set_activatable (GTK_LIST_BOX_ROW (row), TRUE); box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 40); gtk_list_box_row_set_child (GTK_LIST_BOX_ROW (row), box); gtk_widget_set_margin_start (box, 10); diff --git a/gtk/inspector/list-data.c b/gtk/inspector/list-data.c index bfa0b7f9a1..f3b8ed5c42 100644 --- a/gtk/inspector/list-data.c +++ b/gtk/inspector/list-data.c @@ -31,6 +31,7 @@ #include "gtknoselection.h" #include "gtksignallistitemfactory.h" #include "gtklistitem.h" +#include "window.h" struct _GtkInspectorListData @@ -167,13 +168,15 @@ static void object_properties (GtkWidget *button, GtkListItem *item) { - GtkInspectorListData *sl; - gpointer obj; + GtkInspectorWindow *iw; + GObject *obj; + guint pos; + + iw = GTK_INSPECTOR_WINDOW (gtk_widget_get_ancestor (button, GTK_TYPE_INSPECTOR_WINDOW)); - sl = GTK_INSPECTOR_LIST_DATA (gtk_widget_get_ancestor (button, GTK_TYPE_INSPECTOR_LIST_DATA)); obj = gtk_list_item_get_item (item); - g_object_set_data (G_OBJECT (sl->object_tree), "next-tab", (gpointer)"properties"); - gtk_inspector_object_tree_activate_object (sl->object_tree, obj); + pos = gtk_list_item_get_position (item); + gtk_inspector_window_push_object (iw, obj, CHILD_KIND_LISTITEM, pos); } static void diff --git a/gtk/inspector/misc-info.c b/gtk/inspector/misc-info.c index efd9e602bf..e7194be6a1 100644 --- a/gtk/inspector/misc-info.c +++ b/gtk/inspector/misc-info.c @@ -179,53 +179,56 @@ disconnect_each_other (gpointer still_alive, g_object_weak_unref (still_alive, disconnect_each_other, for_science); } -static void -show_object (GtkInspectorMiscInfo *sl, - GObject *object, - const gchar *tab) -{ - g_object_set_data_full (G_OBJECT (sl->priv->object_tree), "next-tab", g_strdup (tab), g_free); - gtk_inspector_object_tree_activate_object (sl->priv->object_tree, object); -} - static void show_mnemonic_label (GtkWidget *button, GtkInspectorMiscInfo *sl) { + GtkInspectorWindow *iw; GtkWidget *widget; + iw = GTK_INSPECTOR_WINDOW (gtk_widget_get_ancestor (GTK_WIDGET (sl), GTK_TYPE_INSPECTOR_WINDOW)); + widget = g_object_get_data (G_OBJECT (button), "mnemonic-label"); if (widget) - show_object (sl, G_OBJECT (widget), "properties"); + gtk_inspector_window_push_object (iw, G_OBJECT (widget), CHILD_KIND_OTHER, 0); } static void show_surface (GtkWidget *button, GtkInspectorMiscInfo *sl) { + GtkInspectorWindow *iw; GObject *surface; + iw = GTK_INSPECTOR_WINDOW (gtk_widget_get_ancestor (GTK_WIDGET (sl), GTK_TYPE_INSPECTOR_WINDOW)); + surface = (GObject *)gtk_native_get_surface (GTK_NATIVE (sl->priv->object)); if (surface) - show_object (sl, G_OBJECT (surface), "properties"); + gtk_inspector_window_push_object (iw, surface, CHILD_KIND_OTHER, 0); } static void show_renderer (GtkWidget *button, GtkInspectorMiscInfo *sl) { + GtkInspectorWindow *iw; GObject *renderer; + iw = GTK_INSPECTOR_WINDOW (gtk_widget_get_ancestor (GTK_WIDGET (sl), GTK_TYPE_INSPECTOR_WINDOW)); + renderer = (GObject *)gtk_native_get_renderer (GTK_NATIVE (sl->priv->object)); if (renderer) - show_object (sl, G_OBJECT (renderer), "properties"); + gtk_inspector_window_push_object (iw, renderer, CHILD_KIND_OTHER, 0); } static void show_frame_clock (GtkWidget *button, GtkInspectorMiscInfo *sl) { + GtkInspectorWindow *iw; GObject *clock; + iw = GTK_INSPECTOR_WINDOW (gtk_widget_get_ancestor (GTK_WIDGET (sl), GTK_TYPE_INSPECTOR_WINDOW)); + clock = (GObject *)gtk_widget_get_frame_clock (GTK_WIDGET (sl->priv->object)); if (clock) - show_object (sl, G_OBJECT (clock), "properties"); + gtk_inspector_window_push_object (iw, clock, CHILD_KIND_OTHER, 0); } static void diff --git a/gtk/inspector/misc-info.ui b/gtk/inspector/misc-info.ui index 9761503e23..e19d381eb3 100644 --- a/gtk/inspector/misc-info.ui +++ b/gtk/inspector/misc-info.ui @@ -353,7 +353,7 @@ end baseline Properties - + diff --git a/gtk/inspector/prop-list.c b/gtk/inspector/prop-list.c index 915dccf916..1ac46fcdf5 100644 --- a/gtk/inspector/prop-list.c +++ b/gtk/inspector/prop-list.c @@ -45,6 +45,7 @@ #include "gtkgestureclick.h" #include "gtkstylecontext.h" #include "prop-holder.h" +#include "window.h" enum { @@ -201,9 +202,10 @@ show_object (GtkInspectorPropEditor *editor, const gchar *tab, GtkInspectorPropList *pl) { - g_object_set_data_full (G_OBJECT (pl->priv->object_tree), "next-tab", g_strdup (tab), g_free); - gtk_inspector_object_tree_select_object (pl->priv->object_tree, object); - gtk_inspector_object_tree_activate_object (pl->priv->object_tree, object); + GtkInspectorWindow *iw; + + iw = GTK_INSPECTOR_WINDOW (gtk_widget_get_ancestor (GTK_WIDGET (pl), GTK_TYPE_INSPECTOR_WINDOW)); + gtk_inspector_window_push_object (iw, object, CHILD_KIND_PROPERTY, 0); } diff --git a/gtk/inspector/window.c b/gtk/inspector/window.c index a69daa30e6..b2142de98c 100644 --- a/gtk/inspector/window.c +++ b/gtk/inspector/window.c @@ -120,14 +120,10 @@ on_object_activated (GtkInspectorObjectTree *wt, GObject *selected, GtkInspectorWindow *iw) { - const gchar *tab; - - if (!set_selected_object (iw, selected)) - return; - - tab = g_object_get_data (G_OBJECT (wt), "next-tab"); - if (tab) - gtk_stack_set_visible_child_name (GTK_STACK (iw->object_details), tab); + if (GTK_IS_WIDGET (selected)) + gtk_inspector_window_set_object (iw, selected, CHILD_KIND_WIDGET, 0); + else + gtk_inspector_window_set_object (iw, selected, CHILD_KIND_OTHER, 0); gtk_stack_set_visible_child_name (GTK_STACK (iw->object_stack), "object-details"); gtk_stack_set_visible_child_name (GTK_STACK (iw->object_buttons), "details"); @@ -180,8 +176,7 @@ open_object_details (GtkWidget *button, GtkInspectorWindow *iw) selected = gtk_inspector_object_tree_get_selected (GTK_INSPECTOR_OBJECT_TREE (iw->object_tree)); - if (!set_selected_object (iw, selected)) - return; + gtk_inspector_window_set_object (iw, selected, CHILD_KIND_WIDGET, 0); gtk_stack_set_visible_child_name (GTK_STACK (iw->object_stack), "object-details"); gtk_stack_set_visible_child_name (GTK_STACK (iw->object_buttons), "details"); @@ -206,12 +201,21 @@ translate_visible_child_name (GBinding *binding, return TRUE; } +typedef struct +{ + GObject *object; + ChildKind kind; + guint position; +} ChildData; + static void gtk_inspector_window_init (GtkInspectorWindow *iw) { GIOExtensionPoint *extension_point; GList *l, *extensions; + iw->objects = g_array_new (FALSE, FALSE, sizeof (ChildData)); + gtk_widget_init_template (GTK_WIDGET (iw)); g_object_bind_property_full (iw->object_details, "visible-child-name", @@ -299,6 +303,7 @@ gtk_inspector_window_dispose (GObject *object) g_object_set_data (G_OBJECT (iw->inspected_display), "-gtk-inspector", NULL); g_clear_object (&iw->flash_overlay); + g_clear_pointer (&iw->objects, g_array_unref); G_OBJECT_CLASS (gtk_inspector_window_parent_class)->dispose (object); } @@ -327,6 +332,201 @@ toggle_sidebar (GtkWidget *button, } } +static void +go_up_cb (GtkWidget *button, + GtkInspectorWindow *iw) +{ + if (iw->objects->len > 1) + { + gtk_inspector_window_pop_object (iw); + return; + } + else if (iw->objects->len > 0) + { + ChildData *data = &g_array_index (iw->objects, ChildData, 0); + GtkWidget *widget = (GtkWidget *)data->object; + if (GTK_IS_WIDGET (widget) && gtk_widget_get_parent (widget)) + { + GObject *obj = G_OBJECT (gtk_widget_get_parent (widget)); + gtk_inspector_window_replace_object (iw, obj, CHILD_KIND_WIDGET, 0); + return; + } + } + + gtk_widget_error_bell (GTK_WIDGET (iw)); +} + +static void +go_down_cb (GtkWidget *button, + GtkInspectorWindow *iw) +{ + ChildData *data; + GObject *object; + + if (iw->objects->len < 1) + { + gtk_widget_error_bell (GTK_WIDGET (iw)); + return; + } + + data = &g_array_index (iw->objects, ChildData, iw->objects->len - 1); + object = data->object; + + if (GTK_IS_WIDGET (object)) + { + GtkWidget *child = gtk_widget_get_first_child (GTK_WIDGET (object)); + + if (child) + { + gtk_inspector_window_push_object (iw, G_OBJECT (child), CHILD_KIND_WIDGET, 0); + return; + } + } + else if (G_IS_LIST_MODEL (object)) + { + GObject *item = g_list_model_get_item (G_LIST_MODEL (object), 0); + if (item) + { + gtk_inspector_window_push_object (iw, item, CHILD_KIND_LISTITEM, 0); + g_object_unref (item); + return; + } + } + + gtk_widget_error_bell (GTK_WIDGET (iw)); +} + +static void +go_previous_cb (GtkWidget *button, + GtkInspectorWindow *iw) +{ + ChildData *data; + GObject *object; + GObject *parent; + + if (iw->objects->len < 1) + { + gtk_widget_error_bell (GTK_WIDGET (iw)); + return; + } + + if (iw->objects->len > 1) + { + data = &g_array_index (iw->objects, ChildData, iw->objects->len - 2); + parent = data->object; + } + else + parent = NULL; + + data = &g_array_index (iw->objects, ChildData, iw->objects->len - 1); + object = data->object; + + switch (data->kind) + { + case CHILD_KIND_WIDGET: + { + GtkWidget *sibling = gtk_widget_get_prev_sibling (GTK_WIDGET (object)); + if (sibling) + { + gtk_inspector_window_replace_object (iw, (GObject*)sibling, CHILD_KIND_WIDGET, 0); + return; + } + } + break; + + case CHILD_KIND_LISTITEM: + { + GObject *item; + + if (parent && data->position > 0) + item = g_list_model_get_item (G_LIST_MODEL (parent), data->position - 1); + else + item = NULL; + + if (item) + { + gtk_inspector_window_replace_object (iw, item, CHILD_KIND_LISTITEM, data->position - 1); + g_object_unref (item); + return; + } + } + break; + + case CHILD_KIND_CONTROLLER: + case CHILD_KIND_PROPERTY: + case CHILD_KIND_OTHER: + default: ; + } + + gtk_widget_error_bell (GTK_WIDGET (iw)); +} + +static void +go_next_cb (GtkWidget *button, + GtkInspectorWindow *iw) +{ + ChildData *data; + GObject *object; + GObject *parent; + + if (iw->objects->len < 1) + { + gtk_widget_error_bell (GTK_WIDGET (iw)); + return; + } + + if (iw->objects->len > 1) + { + data = &g_array_index (iw->objects, ChildData, iw->objects->len - 2); + parent = data->object; + } + else + parent = NULL; + + data = &g_array_index (iw->objects, ChildData, iw->objects->len - 1); + object = data->object; + + switch (data->kind) + { + case CHILD_KIND_WIDGET: + { + GtkWidget *sibling = gtk_widget_get_next_sibling (GTK_WIDGET (object)); + if (sibling) + { + gtk_inspector_window_replace_object (iw, (GObject*)sibling, CHILD_KIND_WIDGET, 0); + return; + } + } + break; + + case CHILD_KIND_LISTITEM: + { + GObject *item; + + if (parent && + data->position + 1 < g_list_model_get_n_items (G_LIST_MODEL (parent))) + item = g_list_model_get_item (G_LIST_MODEL (parent), data->position + 1); + else + item = NULL; + + if (item) + { + gtk_inspector_window_replace_object (iw, item, CHILD_KIND_LISTITEM, data->position + 1); + g_object_unref (item); + return; + } + } + break; + + case CHILD_KIND_CONTROLLER: + case CHILD_KIND_PROPERTY: + case CHILD_KIND_OTHER: + default: ; + } + + gtk_widget_error_bell (GTK_WIDGET (iw)); +} + static void gtk_inspector_window_realize (GtkWidget *widget) { @@ -461,6 +661,12 @@ gtk_inspector_window_class_init (GtkInspectorWindowClass *klass) gtk_widget_class_bind_template_child (widget_class, GtkInspectorWindow, general); gtk_widget_class_bind_template_child (widget_class, GtkInspectorWindow, logs); + gtk_widget_class_bind_template_child (widget_class, GtkInspectorWindow, go_up_button); + gtk_widget_class_bind_template_child (widget_class, GtkInspectorWindow, go_down_button); + gtk_widget_class_bind_template_child (widget_class, GtkInspectorWindow, go_previous_button); + gtk_widget_class_bind_template_child (widget_class, GtkInspectorWindow, list_position_label); + gtk_widget_class_bind_template_child (widget_class, GtkInspectorWindow, go_next_button); + gtk_widget_class_bind_template_callback (widget_class, gtk_inspector_on_inspect); gtk_widget_class_bind_template_callback (widget_class, on_object_activated); gtk_widget_class_bind_template_callback (widget_class, on_object_selected); @@ -469,6 +675,10 @@ gtk_inspector_window_class_init (GtkInspectorWindowClass *klass) gtk_widget_class_bind_template_callback (widget_class, object_details_changed); gtk_widget_class_bind_template_callback (widget_class, notify_node); gtk_widget_class_bind_template_callback (widget_class, toggle_sidebar); + gtk_widget_class_bind_template_callback (widget_class, go_previous_cb); + gtk_widget_class_bind_template_callback (widget_class, go_up_cb); + gtk_widget_class_bind_template_callback (widget_class, go_down_cb); + gtk_widget_class_bind_template_callback (widget_class, go_next_cb); } static GdkDisplay * @@ -669,5 +879,176 @@ gtk_inspector_window_get_inspected_display (GtkInspectorWindow *iw) return iw->inspected_display; } +static void +update_go_button (GtkWidget *button, + gboolean enabled, + const char *tooltip) +{ + gtk_widget_set_sensitive (button, enabled); + gtk_widget_set_tooltip_text (button, tooltip); +} + +static void +update_go_buttons (GtkInspectorWindow *iw) +{ + GObject *parent; + GObject *object; + ChildKind kind; + guint position; + + if (iw->objects->len > 1) + { + ChildData *data = &g_array_index (iw->objects, ChildData, iw->objects->len - 2); + parent = data->object; + } + else + { + parent = NULL; + } + + if (iw->objects->len > 0) + { + ChildData *data = &g_array_index (iw->objects, ChildData, iw->objects->len - 1); + object = data->object; + kind = data->kind; + position = data->position; + } + else + { + object = NULL; + kind = CHILD_KIND_OTHER; + } + + if (parent) + { + char *text; + text = g_strdup_printf ("Go to %s", G_OBJECT_TYPE_NAME (parent)); + update_go_button (iw->go_up_button, TRUE, text); + g_free (text); + } + else + { + update_go_button (iw->go_up_button, GTK_IS_WIDGET (object) && !GTK_IS_ROOT (object), "Parent widget"); + } + + switch (kind) + { + case CHILD_KIND_WIDGET: + update_go_button (iw->go_down_button, gtk_widget_get_first_child (GTK_WIDGET (object)) != NULL, "First child"); + update_go_button (iw->go_previous_button, gtk_widget_get_prev_sibling (GTK_WIDGET (object)) != NULL, "Previous sibling"); + update_go_button (iw->go_next_button, gtk_widget_get_next_sibling (GTK_WIDGET (object)) != NULL, "Next sibling"); + gtk_widget_hide (iw->list_position_label); + break; + case CHILD_KIND_LISTITEM: + update_go_button (iw->go_down_button, FALSE, NULL); + update_go_button (iw->go_previous_button, position > 0, "Previous list item"); + update_go_button (iw->go_next_button, position + 1 < g_list_model_get_n_items (G_LIST_MODEL (parent)), "Next list item"); + { + char *text = g_strdup_printf ("%u", position); + gtk_label_set_label (GTK_LABEL (iw->list_position_label), text); + g_free (text); + gtk_widget_show (iw->list_position_label); + } + break; + case CHILD_KIND_PROPERTY: + case CHILD_KIND_CONTROLLER: + case CHILD_KIND_OTHER: + update_go_button (iw->go_down_button, FALSE, NULL); + update_go_button (iw->go_previous_button, FALSE, NULL); + update_go_button (iw->go_next_button, FALSE, NULL); + gtk_widget_hide (iw->list_position_label); + break; + default: + g_assert_not_reached (); + break; + } +} + +static void +show_object_details (GtkInspectorWindow *iw, + GObject *object, + const char *tab) +{ + set_selected_object (iw, object); + + if (tab) + gtk_stack_set_visible_child_name (GTK_STACK (iw->object_details), tab); + if (!gtk_stack_get_visible_child_name (GTK_STACK (iw->object_details))) + gtk_stack_set_visible_child_name (GTK_STACK (iw->object_details), "properties"); + + gtk_stack_set_visible_child_name (GTK_STACK (iw->object_stack), "object-details"); + gtk_stack_set_visible_child_name (GTK_STACK (iw->object_buttons), "details"); +} + +void +gtk_inspector_window_push_object (GtkInspectorWindow *iw, + GObject *object, + ChildKind kind, + guint position) +{ + ChildData data; + + data.kind = kind; + data.object = object; + data.position = position; + g_array_append_val (iw->objects, data); + show_object_details (iw, object, "properties"); + update_go_buttons (iw); +} + +void +gtk_inspector_window_pop_object (GtkInspectorWindow *iw) +{ + ChildData *data; + const char *tabs[] = { + "properties", + "controllers", + "properties", + "list-data", + "misc", + }; + const char *tab; + + if (iw->objects->len < 2) + { + gtk_widget_error_bell (GTK_WIDGET (iw)); + return; + } + + data = &g_array_index (iw->objects, ChildData, iw->objects->len - 1); + tab = tabs[data->kind]; + g_array_remove_index (iw->objects, iw->objects->len - 1); + data = &g_array_index (iw->objects, ChildData, iw->objects->len - 1); + show_object_details (iw, data->object, tab); + update_go_buttons (iw); +} + +void +gtk_inspector_window_replace_object (GtkInspectorWindow *iw, + GObject *object, + ChildKind kind, + guint position) +{ + ChildData *data; + + data = &g_array_index (iw->objects, ChildData, iw->objects->len - 1); + g_assert (data->kind == kind); + data->object = object; + data->position = position; + show_object_details (iw, object, NULL); + update_go_buttons (iw); +} + +void +gtk_inspector_window_set_object (GtkInspectorWindow *iw, + GObject *object, + ChildKind kind, + guint position) +{ + g_array_set_size (iw->objects, 0); + gtk_inspector_window_push_object (iw, object, kind, position); + update_go_buttons (iw); +} + // vim: set et sw=2 ts=2: diff --git a/gtk/inspector/window.h b/gtk/inspector/window.h index d96c495755..928c1c5289 100644 --- a/gtk/inspector/window.h +++ b/gtk/inspector/window.h @@ -78,6 +78,12 @@ typedef struct GtkWidget *general; GtkWidget *logs; + GtkWidget *go_up_button; + GtkWidget *go_down_button; + GtkWidget *go_previous_button; + GtkWidget *list_position_label; + GtkWidget *go_next_button; + GList *extra_pages; GdkSeat *grab_seat; @@ -86,6 +92,8 @@ typedef struct gint flash_count; gint flash_cnx; + GArray *objects; + GList *overlays; GdkDisplay *inspected_display; @@ -117,6 +125,29 @@ void gtk_inspector_window_remove_overlay void gtk_inspector_window_select_widget_under_pointer (GtkInspectorWindow *iw); GdkDisplay * gtk_inspector_window_get_inspected_display (GtkInspectorWindow *iw); +typedef enum +{ + CHILD_KIND_WIDGET, + CHILD_KIND_CONTROLLER, + CHILD_KIND_PROPERTY, + CHILD_KIND_LISTITEM, + CHILD_KIND_OTHER +} ChildKind; + +void gtk_inspector_window_push_object (GtkInspectorWindow *iw, + GObject *object, + ChildKind kind, + guint position); +void gtk_inspector_window_pop_object (GtkInspectorWindow *iw); +void gtk_inspector_window_set_object (GtkInspectorWindow *iw, + GObject *object, + ChildKind kind, + guint position); +void gtk_inspector_window_replace_object (GtkInspectorWindow *iw, + GObject *object, + ChildKind kind, + guint position); + gboolean gtk_inspector_is_recording (GtkWidget *widget); GskRenderNode * gtk_inspector_prepare_render (GtkWidget *widget, GskRenderer *renderer, @@ -124,7 +155,6 @@ GskRenderNode * gtk_inspector_prepare_render const cairo_region_t *region, GskRenderNode *node); gboolean gtk_inspector_handle_event (GdkEvent *event); - G_END_DECLS diff --git a/gtk/inspector/window.ui b/gtk/inspector/window.ui index 60a20b2573..2baeecda33 100644 --- a/gtk/inspector/window.ui +++ b/gtk/inspector/window.ui @@ -339,6 +339,57 @@ + + + 6 + 6 + + + go-up-symbolic + Previous object + 0 + center + center + + + + + + go-down-symbolic + Child object + 0 + center + center + + + + + + go-previous-symbolic + Previous sibling + 0 + center + center + + + + + + List Position + + + + + go-next-symbolic + Next sibling + 0 + center + center + + + + +