Use a Scintilla indicator to store navqueue positions

Fixes geany#1480.

src/editor.h

@@ -70,7 +70,10 @@ typedef enum
 	/** Indicator used to highlight search results in the document. This is a
 	 *  rounded box around the text. */
 	/* start container indicator outside of lexer indicators (0..7), see Scintilla docs */
-	GEANY_INDICATOR_SEARCH = 8
+	GEANY_INDICATOR_SEARCH = 8,
+	/* skip 9 which is used in PR #1470 */
+	/** Hidden indicator used to remember and recall navigation history (navqueue). */
+	GEANY_INDICATOR_NAVIGATION = 10
 }
 GeanyIndicator;
 

src/highlighting.c

@@ -660,6 +660,11 @@ static void styleset_common(ScintillaObject *sci, guint ft_id)
 		invert(common_style_set.styling[GCS_MARKER_SEARCH].background));
 	SSM(sci, SCI_INDICSETALPHA, GEANY_INDICATOR_SEARCH, 60);
 
+	/* The navigation indicator is used to store navqueue positions in a way that doesn't break
+	 * whenever document is changed. We don't actually show it to the user. Although an option
+	 * to draw it as INDIC_POINT might be useful in the future. */
+	SSM(sci, SCI_INDICSETSTYLE, GEANY_INDICATOR_NAVIGATION, INDIC_HIDDEN);
+
 	/* define marker symbols
 	 * 0 -> line marker */
 	SSM(sci, SCI_MARKERDEFINE, 0, SC_MARK_SHORTARROW);

src/keybindings.c

@@ -2031,7 +2031,7 @@ static gboolean cb_func_goto_action(guint key_id)
 			return TRUE;
 		case GEANY_KEYS_GOTO_ADDPOSITION:
 			if (doc->file_name)
-				navqueue_add_position(doc->file_name, sci_get_current_position(doc->editor->sci));
+				navqueue_add_position(doc, sci_get_current_position(doc->editor->sci));
 			return TRUE;
 		case GEANY_KEYS_GOTO_LINE:
 		{

src/navqueue.c

@@ -42,12 +42,15 @@
 /* for the navigation history queue */
 typedef struct
 {
-	const gchar *file;	/* This is the document's filename, in UTF-8 */
-	gint pos;
-} filepos;
+	/* The document's filename, in UTF-8 */
+	const gchar *file;
+	/* A unique ID that is associated with the navigation indicator in Scintilla. */
+	gint id;
+} NavigationAnchor;
 
 static GQueue *navigation_queue;
 static guint nav_queue_pos;
+static gint counter;
 
 static GtkAction *navigation_buttons[2];
 
@@ -57,6 +60,7 @@ void navqueue_init(void)
 {
 	navigation_queue = g_queue_new();
 	nav_queue_pos = 0;
+	counter = 0;
 
 	navigation_buttons[0] = toolbar_get_action_by_name("NavBack");
 	navigation_buttons[1] = toolbar_get_action_by_name("NavFor");
@@ -100,30 +104,59 @@ static void adjust_buttons(void)
 }
 
 
+static void set_id_on_position(GeanyDocument *doc, gint pos, gint id)
+{
+	sci_indicator_set(doc->editor->sci, GEANY_INDICATOR_NAVIGATION);
+	sci_indicator_set_value(doc->editor->sci, id);
+	sci_indicator_fill(doc->editor->sci, pos, 1);
+}
+
+
+static gint get_position_for_id(GeanyDocument *doc, gint id)
+{
+	gint pos = 0, prev;
+
+	do
+	{
+		/* Iterate over all ranges of the navigation indicator in this document. See, e.g.:
+		 * https://groups.google.com/d/msg/scintilla-interest/TpBnulcikUo/ZAq9ol8eutMJ */
+		prev = pos;
+		pos = sci_indicator_end(doc->editor->sci, GEANY_INDICATOR_NAVIGATION, pos + 1);
+		if (sci_indicator_value_at(doc->editor->sci, GEANY_INDICATOR_NAVIGATION, pos) == id)
+			return pos;
+	} while (pos > prev);
+
+	return -1;
+}
+
+
 static gboolean
-queue_pos_matches(guint queue_pos, const gchar *fname, gint pos)
+queue_pos_matches(guint queue_pos, GeanyDocument *doc, gint pos)
 {
 	if (queue_pos < g_queue_get_length(navigation_queue))
 	{
-		filepos *fpos = g_queue_peek_nth(navigation_queue, queue_pos);
+		NavigationAnchor *anchor = g_queue_peek_nth(navigation_queue, queue_pos);
 
-		return (utils_str_equal(fpos->file, fname) && fpos->pos == pos);
+		return utils_str_equal(anchor->file, doc->file_name)
+			&& get_position_for_id(doc, anchor->id) == pos;
 	}
 	return FALSE;
 }
 
 
-void navqueue_add_position(const gchar *utf8_filename, gint pos)
+void navqueue_add_position(GeanyDocument *doc, gint pos)
 {
-	filepos *npos;
+	NavigationAnchor *anchor;
 	guint i;
 
-	if (queue_pos_matches(nav_queue_pos, utf8_filename, pos))
+	if (queue_pos_matches(nav_queue_pos, doc, pos))
 		return;	/* prevent duplicates */
 
-	npos = g_new0(filepos, 1);
-	npos->file = utf8_filename;
-	npos->pos = pos;
+	counter += 1;
+	anchor = g_new0(NavigationAnchor, 1);
+	anchor->file = doc->file_name;
+	anchor->id = counter;
+	set_id_on_position(doc, pos, anchor->id);
 
 	/* if we've jumped to a new position from inside the queue rather than going forward */
 	if (nav_queue_pos > 0)
@@ -134,7 +167,7 @@ void navqueue_add_position(const gchar *utf8_filename, gint pos)
 		}
 		nav_queue_pos = 0;
 	}
-	g_queue_push_head(navigation_queue, npos);
+	g_queue_push_head(navigation_queue, anchor);
 	adjust_buttons();
 }
 
@@ -165,42 +198,47 @@ gboolean navqueue_goto_line(GeanyDocument *old_doc, GeanyDocument *new_doc, gint
 	{
 		gint cur_pos = sci_get_current_position(old_doc->editor->sci);
 
-		navqueue_add_position(old_doc->file_name, cur_pos);
+		navqueue_add_position(old_doc, cur_pos);
 	}
 
 	/* now add new file position */
 	if (new_doc->file_name)
 	{
-		navqueue_add_position(new_doc->file_name, pos);
+		navqueue_add_position(new_doc, pos);
 	}
 
 	return editor_goto_pos(new_doc->editor, pos, TRUE);
 }
 
 
-static gboolean goto_file_pos(const gchar *file, gint pos)
+static gboolean goto_file_id(const gchar *file, gint id)
 {
 	GeanyDocument *doc = document_find_by_filename(file);
+	gint pos;
 
 	if (doc == NULL)
 		return FALSE;
 
+	pos = get_position_for_id(doc, id);
+	if (pos < 0)
+		return FALSE;
+
 	return editor_goto_pos(doc->editor, pos, TRUE);
 }
 
 
 void navqueue_go_back(void)
 {
-	filepos *fprev;
+	NavigationAnchor *prev;
 
 	/* return if theres no place to go back to */
 	if (g_queue_is_empty(navigation_queue) ||
 		nav_queue_pos >= g_queue_get_length(navigation_queue) - 1)
 		return;
 
 	/* jump back */
-	fprev = g_queue_peek_nth(navigation_queue, nav_queue_pos + 1);
-	if (goto_file_pos(fprev->file, fprev->pos))
+	prev = g_queue_peek_nth(navigation_queue, nav_queue_pos + 1);
+	if (goto_file_id(prev->file, prev->id))
 	{
 		nav_queue_pos++;
 	}
@@ -215,15 +253,15 @@ void navqueue_go_back(void)
 
 void navqueue_go_forward(void)
 {
-	filepos *fnext;
+	NavigationAnchor *next;
 
 	if (nav_queue_pos < 1 ||
 		nav_queue_pos >= g_queue_get_length(navigation_queue))
 		return;
 
 	/* jump forward */
-	fnext = g_queue_peek_nth(navigation_queue, nav_queue_pos - 1);
-	if (goto_file_pos(fnext->file, fnext->pos))
+	next = g_queue_peek_nth(navigation_queue, nav_queue_pos - 1);
+	if (goto_file_id(next->file, next->id))
 	{
 		nav_queue_pos--;
 	}
@@ -239,7 +277,7 @@ void navqueue_go_forward(void)
 
 static gint find_by_filename(gconstpointer a, gconstpointer b)
 {
-	if (utils_str_equal(((const filepos*)a)->file, (const gchar*) b))
+	if (utils_str_equal(((const NavigationAnchor*)a)->file, (const gchar*) b))
 		return 0;
 	else
 		return 1;

src/navqueue.h

@@ -44,7 +44,7 @@ void navqueue_init(void);
 
 void navqueue_free(void);
 
-void navqueue_add_position(const gchar *utf8_filename, gint pos);
+void navqueue_add_position(GeanyDocument *doc, gint pos);
 
 void navqueue_remove_file(const gchar *filename);
 

src/sciwrappers.c

@@ -1119,12 +1119,30 @@ void sci_indicator_set(ScintillaObject *sci, gint indic)
 }
 
 
+void sci_indicator_set_value(ScintillaObject *sci, gint value)
+{
+	SSM(sci, SCI_SETINDICATORVALUE, (uptr_t) value, 0);
+}
+
+
 void sci_indicator_fill(ScintillaObject *sci, gint pos, gint len)
 {
 	SSM(sci, SCI_INDICATORFILLRANGE, (uptr_t) pos, len);
 }
 
 
+gint sci_indicator_end(ScintillaObject *sci, gint indic, gint pos)
+{
+	return (gint) SSM(sci, SCI_INDICATOREND, (uptr_t) indic, (uptr_t) pos);
+}
+
+
+gint sci_indicator_value_at(ScintillaObject *sci, gint indic, gint pos)
+{
+	return (gint) SSM(sci, SCI_INDICATORVALUEAT, (uptr_t) indic, (uptr_t) pos);
+}
+
+
 /**
  *  Clears the currently set indicator from a range of text.
  *  Starting at @a pos, @a len characters long.

src/sciwrappers.h

@@ -179,7 +179,10 @@ void				sci_set_readonly			(ScintillaObject *sci, gboolean readonly);
 gint				sci_get_lines_selected		(ScintillaObject *sci);
 gint				sci_get_first_visible_line	(ScintillaObject *sci);
 
+void				sci_indicator_set_value		(ScintillaObject *sci, gint value);
 void				sci_indicator_fill			(ScintillaObject *sci, gint pos, gint len);
+gint				sci_indicator_end			(ScintillaObject *sci, gint indic, gint pos);
+gint				sci_indicator_value_at		(ScintillaObject *sci, gint indic, gint pos);
 
 void				sci_select_all				(ScintillaObject *sci);
 gint				sci_get_line_indent_position(ScintillaObject *sci, gint line);