tui: add NmtNewtWidget:help-text, display in NmtNewtForm

If a widget defines the :help-text property, display it in the form's
help line when that widget is focused.

NOTE: requires un-upstreamed newt changes!

5 files changed, 97 insertions, 0 deletions

diff --git a/tui/newt/nmt-newt-form.c b/tui/newt/nmt-newt-form.c
index 305a599481..645606858a 100644
--- a/tui/newt/nmt-newt-form.c
+++ b/tui/newt/nmt-newt-form.c
@@ -53,6 +53,7 @@ typedef struct {
 
 	gboolean dirty, escape_exits;
 	NmtNewtWidget *focus;
+	char *help_line;
 #ifdef HAVE_NEWTFORMGETSCROLLPOSITION
 	int scroll_position = 0;
 #endif
@@ -191,6 +192,30 @@ nmt_newt_form_set_content (NmtNewtForm      *form,
 }
 
 static void
+nmt_newt_form_reset_help_line (NmtNewtForm *form)
+{
+	NmtNewtFormPrivate *priv = NMT_NEWT_FORM_GET_PRIVATE (form);
+	const char *help_text;
+
+	newtPopHelpLine ();
+	if (priv->focus) {
+		help_text = nmt_newt_widget_get_help_text (priv->focus);
+		if (help_text)
+			newtPushHelpLine (help_text);
+	}
+}
+
+static void
+focus_help_text_changed (GObject    *object,
+                         GParamSpec *pspec,
+                         gpointer    user_data)
+{
+	NmtNewtForm *form = user_data;
+
+	nmt_newt_form_reset_help_line (form);
+}
+
+static void
 nmt_newt_form_focus_changed (NmtNewtForm   *form,
                              NmtNewtWidget *focus,
                              newtComponent  co)
@@ -199,6 +224,7 @@ nmt_newt_form_focus_changed (NmtNewtForm   *form,
 
 	if (priv->focus != focus) {
 		if (priv->focus) {
+			g_signal_handlers_disconnect_by_func (priv->focus, G_CALLBACK (focus_help_text_changed), form);
 			nmt_newt_widget_focus_out (priv->focus);
 			g_object_unref (priv->focus);
 		}
@@ -208,9 +234,13 @@ nmt_newt_form_focus_changed (NmtNewtForm   *form,
 		if (priv->focus) {
 			g_object_ref (priv->focus);
 			nmt_newt_widget_focus_in (priv->focus);
+			g_signal_connect (priv->focus, "notify::help-text",
+			                  G_CALLBACK (focus_help_text_changed), form);
 		}
 	}
 
+	nmt_newt_form_reset_help_line (form);
+
 	if (priv->form && priv->focus) {
 		if (!co)
 			co = nmt_newt_widget_get_focus_component (priv->focus);
diff --git a/tui/newt/nmt-newt-form.h b/tui/newt/nmt-newt-form.h
index be95eb68ad..a959ef30d5 100644
--- a/tui/newt/nmt-newt-form.h
+++ b/tui/newt/nmt-newt-form.h
@@ -61,6 +61,10 @@ void           nmt_newt_form_quit             (NmtNewtForm         *form);
 void           nmt_newt_form_set_focus        (NmtNewtForm         *form,
                                                NmtNewtWidget       *widget);
 
+void           nmt_newt_form_set_help_line    (NmtNewtForm      *form,
+                                               NmtNewtWidget    *widget,
+                                               const char       *help_line);
+
 G_END_DECLS
 
 #endif /* NMT_NEWT_FORM_H */
diff --git a/tui/newt/nmt-newt-utils.c b/tui/newt/nmt-newt-utils.c
index 9a960d0e33..22d3f2e963 100644
--- a/tui/newt/nmt-newt-utils.c
+++ b/tui/newt/nmt-newt-utils.c
@@ -403,4 +403,7 @@ nmt_newt_get_screen_size (int *screen_width,
                           int *screen_height)
 {
 	newtGetScreenSize (screen_width, screen_height);
+
+	/* Allow room for the help line at the bottom */
+	*screen_height -= 2;
 }
diff --git a/tui/newt/nmt-newt-widget.c b/tui/newt/nmt-newt-widget.c
index 6251c21b93..057d9abd20 100644
--- a/tui/newt/nmt-newt-widget.c
+++ b/tui/newt/nmt-newt-widget.c
@@ -47,6 +47,7 @@ typedef struct {
 	NmtNewtWidget *parent;
 	gboolean visible, realized, valid;
 	gboolean exit_on_activate;
+	char *help_text;
 
 	int pad_left, pad_top, pad_right, pad_bottom;
 } NmtNewtWidgetPrivate;
@@ -57,6 +58,7 @@ enum {
 	PROP_PARENT,
 	PROP_VISIBLE,
 	PROP_VALID,
+	PROP_HELP_TEXT,
 	PROP_EXIT_ON_ACTIVATE,
 
 	LAST_PROP
@@ -87,6 +89,7 @@ nmt_newt_widget_finalize (GObject *object)
 
 	nmt_newt_widget_unrealize (NMT_NEWT_WIDGET (object));
 	g_clear_object (&priv->parent);
+	g_free (priv->help_text);
 
 	G_OBJECT_CLASS (nmt_newt_widget_parent_class)->finalize (object);
 }
@@ -526,6 +529,46 @@ nmt_newt_widget_set_valid (NmtNewtWidget *widget,
 }
 
 /**
+ * nmt_newt_widget_get_help_text:
+ * @widget: an #NmtNewtWidget
+ *
+ * Gets @widget's #NmtNewtWidget:help-text, indicating text to display
+ * in its form's status line (or %NULL to not display anything).
+ *
+ * Returns: @widget's #NmtNewtWidget:help-text.
+ */
+const char *
+nmt_newt_widget_get_help_text (NmtNewtWidget *widget)
+{
+	NmtNewtWidgetPrivate *priv = NMT_NEWT_WIDGET_GET_PRIVATE (widget);
+
+	return priv->help_text;
+}
+
+/**
+ * nmt_newt_widget_set_help_text:
+ * @widget: an #NmtNewtWidget
+ * @help_text: help text to display when @widget is focused
+ *
+ * Sets @widget's #NmtNewtWidget:help-text, indicating text to display
+ * in its form's status line when the widget is focused.
+ */
+void
+nmt_newt_widget_set_help_text (NmtNewtWidget *widget,
+                               const char    *help_text)
+{
+	NmtNewtWidgetPrivate *priv = NMT_NEWT_WIDGET_GET_PRIVATE (widget);
+
+	if (!g_strcmp0 (priv->help_text, help_text))
+		return;
+
+	g_free (priv->help_text);
+	priv->help_text = g_strdup (help_text);
+
+	g_object_notify (G_OBJECT (widget), "help-text");
+}
+
+/**
  * nmt_newt_widget_needs_rebuilds:
  * @widget: an #NmtNewtWidget
  *
@@ -584,6 +627,9 @@ nmt_newt_widget_get_property (GObject    *object,
 	case PROP_VALID:
 		g_value_set_boolean (value, priv->valid);
 		break;
+	case PROP_HELP_TEXT:
+		g_value_set_string (value, priv->help_text);
+		break;
 	case PROP_EXIT_ON_ACTIVATE:
 		g_value_set_boolean (value, priv->exit_on_activate);
 		break;
@@ -678,6 +724,17 @@ nmt_newt_widget_class_init (NmtNewtWidgetClass *widget_class)
 	                                                       G_PARAM_READABLE |
 	                                                       G_PARAM_STATIC_STRINGS));
 	/**
+	 * NmtNewtWidget:help-text:
+	 *
+	 * Text to display in the widget's form's status line when the
+	 * widget is focused.
+	 */
+	g_object_class_install_property (object_class, PROP_HELP_TEXT,
+	                                 g_param_spec_string ("help-text", "", "",
+	                                                      NULL,
+	                                                      G_PARAM_READABLE |
+	                                                      G_PARAM_STATIC_STRINGS));
+	/**
 	 * NmtNewtWidget:exit-on-activate:
 	 *
 	 * If %TRUE, the widget will call nmt_newt_form_quit() on its form
diff --git a/tui/newt/nmt-newt-widget.h b/tui/newt/nmt-newt-widget.h
index 137ed6381d..b5cde6c89b 100644
--- a/tui/newt/nmt-newt-widget.h
+++ b/tui/newt/nmt-newt-widget.h
@@ -110,6 +110,7 @@ void           nmt_newt_widget_set_exit_on_activate (NmtNewtWidget *widget,
                                                      gboolean       exit_on_activate);
 
 gboolean       nmt_newt_widget_get_valid      (NmtNewtWidget *widget);
+const char *   nmt_newt_widget_get_help_text  (NmtNewtWidget *widget);
 
 NmtNewtWidget *nmt_newt_widget_find_component (NmtNewtWidget *widget,
                                                newtComponent  co);
@@ -118,6 +119,8 @@ NmtNewtWidget *nmt_newt_widget_find_component (NmtNewtWidget *widget,
 void           nmt_newt_widget_needs_rebuild  (NmtNewtWidget *widget);
 void           nmt_newt_widget_set_valid      (NmtNewtWidget *widget,
                                                gboolean       valid);
+void           nmt_newt_widget_set_help_text  (NmtNewtWidget *widget,
+                                               const char    *help_text);
 
 G_END_DECLS