assistants: add new assistants subsystem

This subsystem is meant to be a base for popup based tooling around a
GtkSourceView. It can be used for the underlying layer of completion,
interactive tooltips, error bubbles, snippet tooltips, and more.

A new completion engine will land first using this subsystem, but will
keep the GtkSourceAssistant type private similar to how GDK does for
internal (but exposed) types.

1 files changed, 171 insertions, 0 deletions

diff --git a/gtksourceview/gtksourceview-assistants.c b/gtksourceview/gtksourceview-assistants.c
new file mode 100644
index 00000000..0422edec
--- /dev/null
+++ b/gtksourceview/gtksourceview-assistants.c
@@ -0,0 +1,171 @@
+/*
+ * This file is part of GtkSourceView
+ *
+ * Copyright 2020 Christian Hergert <chergert@redhat.com>
+ *
+ * GtkSourceView 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 2.1 of the License, or (at your option) any later version.
+ *
+ * GtkSourceView 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 this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#include "config.h"
+
+#include "gtksourceview-private.h"
+
+void
+_gtk_source_view_assistants_init (GtkSourceViewAssistants *assistants,
+                                  GtkSourceView           *view)
+{
+	g_assert (assistants != NULL);
+	g_assert (assistants->view == NULL);
+
+	assistants->view = view;
+	g_queue_init (&assistants->queue);
+}
+
+void
+_gtk_source_view_assistants_shutdown (GtkSourceViewAssistants *assistants)
+{
+	g_assert (assistants != NULL);
+	g_assert (assistants->view != NULL);
+
+	while (assistants->queue.length > 0)
+	{
+		GtkSourceAssistant*assistant = g_queue_peek_head (&assistants->queue);
+		_gtk_source_view_assistants_remove (assistants, assistant);
+	}
+
+	assistants->view = NULL;
+
+	g_assert (assistants->view == NULL);
+	g_assert (g_queue_is_empty (&assistants->queue));
+}
+
+void
+_gtk_source_view_assistants_add (GtkSourceViewAssistants *assistants,
+                                 GtkSourceAssistant      *assistant)
+{
+	g_assert (assistants != NULL);
+	g_assert (assistants->view != NULL);
+
+	if (gtk_widget_get_parent (GTK_WIDGET (assistant)))
+	{
+		g_warning ("Cannot add assistant, it already has a parent");
+		return;
+	}
+
+	g_queue_push_tail (&assistants->queue, g_object_ref_sink (assistant));
+	gtk_widget_set_parent (GTK_WIDGET (assistant), GTK_WIDGET (assistants->view));
+}
+
+void
+_gtk_source_view_assistants_remove (GtkSourceViewAssistants *assistants,
+                                    GtkSourceAssistant      *assistant)
+{
+	GList *link;
+
+	g_assert (assistants != NULL);
+	g_assert (assistants->view != NULL);
+	g_assert (assistants->queue.length > 0);
+
+	link = g_queue_find (&assistants->queue, assistant);
+
+	if (link != NULL)
+	{
+		g_queue_delete_link (&assistants->queue, link);
+		gtk_widget_unparent (GTK_WIDGET (assistant));
+		g_object_unref (assistant);
+	}
+}
+
+void
+_gtk_source_view_assistants_size_allocate (GtkSourceViewAssistants *assistants,
+                                           int                      width,
+                                           int                      height,
+                                           int                      baseline)
+{
+	g_assert (assistants != NULL);
+
+	for (const GList *iter = assistants->queue.head; iter; iter = iter->next)
+	{
+		GtkSourceAssistant *assistant = iter->data;
+		int assistant_width;
+		int assistant_height;
+
+		g_assert (GTK_SOURCE_IS_ASSISTANT (assistant));
+
+		gtk_widget_measure (GTK_WIDGET (assistant),
+		                    GTK_ORIENTATION_HORIZONTAL,
+		                    -1,
+		                    NULL,
+		                    &assistant_width,
+		                    NULL,
+		                    NULL);
+		gtk_widget_measure (GTK_WIDGET (assistant),
+		                    GTK_ORIENTATION_VERTICAL,
+		                    assistant_width,
+		                    NULL,
+		                    &assistant_height,
+		                    NULL,
+		                    NULL);
+
+		gtk_widget_set_size_request (GTK_WIDGET (assistant),
+		                             assistant_width,
+		                             assistant_height);
+
+		gtk_native_check_resize (GTK_NATIVE (assistant));
+	}
+}
+
+static gboolean
+_gtk_source_view_assistants_hide_all (GtkSourceViewAssistants *assistants)
+{
+	gboolean ret = FALSE;
+
+	g_assert (assistants != NULL);
+
+	for (const GList *iter = assistants->queue.head; iter; iter = iter->next)
+	{
+		GtkSourceAssistant *assistant = iter->data;
+
+		g_assert (GTK_SOURCE_IS_ASSISTANT (assistant));
+
+		if (gtk_widget_get_visible (GTK_WIDGET (assistant)))
+		{
+			gtk_popover_popdown (GTK_POPOVER (assistant));
+			ret = TRUE;
+		}
+	}
+
+	return ret;
+}
+
+gboolean
+_gtk_source_view_assistants_handle_key (GtkSourceViewAssistants *assistants,
+                                        guint                    keyval,
+                                        GdkModifierType          state)
+{
+	g_assert (assistants != NULL);
+
+	if (keyval == GDK_KEY_Escape)
+	{
+		if (_gtk_source_view_assistants_hide_all (assistants))
+		{
+			gtk_widget_grab_focus (GTK_WIDGET (assistants->view));
+			return TRUE;
+		}
+	}
+
+	return FALSE;
+}