[gtksourceview/wip/chergert/gsv-gtk4] snippets: use informative to display snippet chunk tooltip

[Christian Hergert <chergert src gnome org>]

commit aac05993fd6ee417daed195526bbb8f05e65096e
Author: Christian Hergert <chergert redhat com>
Date:   Wed Sep 9 14:36:16 2020 -0700

    snippets: use informative to display snippet chunk tooltip

 gtksourceview/gtksourceview-private.h  |   5 ++
 gtksourceview/gtksourceview-snippets.c | 116 ++++++++++++++++++++++++++++++++-
 2 files changed, 119 insertions(+), 2 deletions(-)
---
diff --git a/gtksourceview/gtksourceview-private.h b/gtksourceview/gtksourceview-private.h
index e87d535c..3f417484 100644
--- a/gtksourceview/gtksourceview-private.h
+++ b/gtksourceview/gtksourceview-private.h
@@ -22,7 +22,10 @@
 #pragma once
 
 #include "gtksourceview.h"
+
+#include "gtksourceinformative-private.h"
 #include "gtksourceassistant-private.h"
+#include "gtksourcesignalgroup-private.h"
 
 G_BEGIN_DECLS
 
@@ -36,6 +39,8 @@ typedef struct _GtkSourceViewSnippets
 {
        GtkSourceView        *view;
        GtkSourceBuffer      *buffer;
+       GtkSourceSignalGroup *snippet_signals;
+       GtkSourceInformative *informative;
        GQueue                queue;
        gulong                buffer_insert_text_handler;
        gulong                buffer_insert_text_after_handler;
diff --git a/gtksourceview/gtksourceview-snippets.c b/gtksourceview/gtksourceview-snippets.c
index 5b85d070..cd676558 100644
--- a/gtksourceview/gtksourceview-snippets.c
+++ b/gtksourceview/gtksourceview-snippets.c
@@ -25,7 +25,7 @@
 #include "gtksourceiter-private.h"
 #include "gtksourcelanguage.h"
 #include "gtksourcesnippet-private.h"
-#include "gtksourcesnippetchunk.h"
+#include "gtksourcesnippetchunk-private.h"
 #include "gtksourcesnippetmanager.h"
 #include "gtksourceview-private.h"
 
@@ -274,6 +274,77 @@ _gtk_source_view_snippets_set_buffer (GtkSourceViewSnippets *snippets,
        }
 }
 
+static void
+gtk_source_view_snippets_update_informative (GtkSourceViewSnippets *snippets)
+{
+       GtkSourceSnippetChunk *chunk;
+       GtkSourceSnippet *snippet;
+       const char *tooltip_text;
+       int position;
+
+       g_assert (snippets != NULL);
+
+       snippet = g_queue_peek_head (&snippets->queue);
+
+       if (snippets->view == NULL || snippet == NULL)
+       {
+               goto hide_informative;
+       }
+
+       position = gtk_source_snippet_get_focus_position (snippet);
+
+       if (position < 0)
+       {
+               goto hide_informative;
+       }
+
+       chunk = snippet->current_chunk;
+
+       if (chunk == NULL)
+       {
+               goto hide_informative;
+       }
+
+       tooltip_text = gtk_source_snippet_chunk_get_tooltip_text (chunk);
+
+       if (tooltip_text == NULL || tooltip_text[0] == 0)
+       {
+               goto hide_informative;
+       }
+
+       _gtk_source_assistant_set_mark (GTK_SOURCE_ASSISTANT (snippets->informative), chunk->begin_mark);
+       gtk_source_informative_set_message (snippets->informative, tooltip_text);
+       gtk_widget_show (GTK_WIDGET (snippets->informative));
+
+       return;
+
+hide_informative:
+       gtk_widget_hide (GTK_WIDGET (snippets->informative));
+}
+
+static void
+gtk_source_view_snippets_notify_position_cb (GtkSourceViewSnippets *snippets,
+                                             GParamSpec            *pspec,
+                                             GtkSourceSnippet      *snippet)
+{
+       g_assert (snippets != NULL);
+       g_assert (GTK_SOURCE_IS_VIEW (snippets->view));
+       g_assert (GTK_SOURCE_IS_SNIPPET (snippet));
+
+       gtk_source_view_snippets_update_informative (snippets);
+}
+
+static void
+gtk_source_view_snippets_bind_cb (GtkSourceSignalGroup  *signals,
+                                  GtkSourceSnippet      *snippet,
+                                  GtkSourceViewSnippets *snippets)
+{
+       g_assert (snippets != NULL);
+       g_assert (GTK_SOURCE_IS_VIEW (snippets->view));
+
+       gtk_source_view_snippets_update_informative (snippets);
+}
+
 void
 _gtk_source_view_snippets_init (GtkSourceViewSnippets *snippets,
                                 GtkSourceView         *view)
@@ -288,17 +359,40 @@ _gtk_source_view_snippets_init (GtkSourceViewSnippets *snippets,
        memset (snippets, 0, sizeof *snippets);
        snippets->view = view;
 
+       snippets->snippet_signals = gtk_source_signal_group_new (GTK_SOURCE_TYPE_SNIPPET);
+
+       g_signal_connect (snippets->snippet_signals,
+                         "bind",
+                         G_CALLBACK (gtk_source_view_snippets_bind_cb),
+                         snippets);
+
+       gtk_source_signal_group_connect_data (snippets->snippet_signals,
+                                             "notify::focus-position",
+                                             G_CALLBACK (gtk_source_view_snippets_notify_position_cb),
+                                             snippets,
+                                             NULL,
+                                             G_CONNECT_SWAPPED | G_CONNECT_AFTER);
+
        if (GTK_SOURCE_IS_BUFFER (buffer))
        {
                _gtk_source_view_snippets_set_buffer (snippets,
                                                      GTK_SOURCE_BUFFER (buffer));
        }
+
+       snippets->informative = g_object_new (GTK_SOURCE_TYPE_INFORMATIVE,
+                                             "position", GTK_POS_TOP,
+                                             "message-type", GTK_MESSAGE_INFO,
+                                             "icon-name", "dialog-information-symbolic",
+                                             NULL);
+       _gtk_source_view_add_assistant (snippets->view,
+                                       GTK_SOURCE_ASSISTANT (snippets->informative));
 }
 
 void
 _gtk_source_view_snippets_shutdown (GtkSourceViewSnippets *snippets)
 {
-       g_return_if_fail (snippets != NULL);
+       g_assert (snippets != NULL);
+       g_assert (snippets->view != NULL);
 
        g_queue_clear_full (&snippets->queue, g_object_unref);
 
@@ -313,6 +407,15 @@ _gtk_source_view_snippets_shutdown (GtkSourceViewSnippets *snippets)
        g_clear_signal_handler (&snippets->buffer_cursor_moved_handler,
                                snippets->buffer);
 
+       _gtk_source_view_remove_assistant (snippets->view,
+                                          GTK_SOURCE_ASSISTANT (snippets->informative));
+
+       if (snippets->snippet_signals != NULL)
+       {
+               gtk_source_signal_group_set_target (snippets->snippet_signals, NULL);
+               g_clear_object (&snippets->snippet_signals);
+       }
+
        snippets->buffer = NULL;
        snippets->view = NULL;
 }
@@ -508,6 +611,10 @@ _gtk_source_view_snippets_push (GtkSourceViewSnippets *snippets,
        {
                _gtk_source_view_snippets_pop (snippets);
        }
+       else
+       {
+               gtk_source_signal_group_set_target (snippets->snippet_signals, snippet);
+       }
 }
 
 void
@@ -545,7 +652,12 @@ _gtk_source_view_snippets_pop (GtkSourceViewSnippets *snippets)
                gtk_source_view_snippets_scroll_to_insert (snippets);
 
                g_object_unref (snippet);
+
+               gtk_widget_hide (GTK_WIDGET (snippets->informative));
        }
+
+       snippet = g_queue_peek_head (&snippets->queue);
+       gtk_source_signal_group_set_target (snippets->snippet_signals, snippet);
 }
 
 void