only scroll the caret if dot changes

* Fixes scrolling with default ^KMOUSE macro from fnkeys.tes which adjusts
  the scroll position without changing dot.
  The unconditional SCI_SCROLLCARET would effectively prevent scrolling to any position
  that does not contain dot.

2 files changed, 28 insertions, 15 deletions

diff --git a/src/interface-curses/interface.c b/src/interface-curses/interface.c
index fe2b1bb..9480822 100644
--- a/src/interface-curses/interface.c
+++ b/src/interface-curses/interface.c
@@ -1573,13 +1573,6 @@ static void
 teco_interface_refresh(void)
 {
 	/*
-	 * Scintilla has been patched to avoid any automatic scrolling since that
-	 * has been benchmarked to be a very costly operation.
-	 * Instead we do it only once after every keypress.
-	 */
-	teco_interface_ssm(SCI_SCROLLCARET, 0, 0);
-
-	/*
 	 * Info window is updated very often which is very
 	 * costly, especially when using PDC_set_title(),
 	 * so we redraw it here, where the overhead does
@@ -1723,6 +1716,9 @@ teco_interface_event_loop_iter(void)
 			? teco_interface_blocking_getch()
 			: GPOINTER_TO_INT(g_queue_pop_head(teco_interface.input_queue));
 
+	const teco_view_t *last_view = teco_interface_current_view;
+	sptr_t last_pos = teco_interface_ssm(SCI_GETCURRENTPOS, 0, 0);
+
 	switch (key) {
 	case ERR:
 		/* shouldn't really happen */
@@ -1842,6 +1838,14 @@ teco_interface_event_loop_iter(void)
 		}
 	}
 
+	/*
+	 * Scintilla has been patched to avoid any automatic scrolling since that
+	 * has been benchmarked to be a very costly operation.
+	 * Instead we do it only once after every keypress.
+	 */
+	if (teco_interface_current_view != last_view ||
+	    last_pos != teco_interface_ssm(SCI_GETCURRENTPOS, 0, 0))
+		teco_interface_ssm(SCI_SCROLLCARET, 0, 0);
 	teco_interface_refresh();
 }
 
@@ -1857,6 +1861,7 @@ teco_interface_event_loop(GError **error)
 	static const teco_cmdline_t empty_cmdline; // FIXME
 	teco_interface_cmdline_update(&empty_cmdline);
 	teco_interface_msg_clear();
+	teco_interface_ssm(SCI_SCROLLCARET, 0, 0);
 	teco_interface_refresh();
 
 #ifdef EMCURSES
diff --git a/src/interface-gtk/interface.c b/src/interface-gtk/interface.c
index 4619b75..ed9271b 100644
--- a/src/interface-gtk/interface.c
+++ b/src/interface-gtk/interface.c
@@ -924,13 +924,6 @@ teco_interface_refresh(gboolean current_view_changed)
 		                  teco_interface.current_view_widget);
 		gtk_widget_show(teco_interface.current_view_widget);
 	}
-
-	/*
-	 * Scintilla has been patched to avoid any automatic scrolling since that
-	 * has been benchmarked to be a very costly operation.
-	 * Instead we do it only once after every keypress.
-	 */
-	teco_interface_ssm(SCI_SCROLLCARET, 0, 0);
 }
 
 static void
@@ -1342,10 +1335,14 @@ static void
 teco_interface_size_allocate_cb(GtkWidget *widget,
                                 GdkRectangle *allocation, gpointer user_data)
 {
+	static gboolean scrolled = FALSE;
+
 	/*
 	 * This especially ensures that the caret is visible after startup.
 	 */
-	teco_interface_ssm(SCI_SCROLLCARET, 0, 0);
+	if (G_UNLIKELY(!scrolled))
+		teco_interface_ssm(SCI_SCROLLCARET, 0, 0);
+	scrolled = TRUE;
 }
 
 static gboolean
@@ -1410,7 +1407,9 @@ teco_interface_input_cb(GtkWidget *widget, GdkEvent *event, gpointer user_data)
 		 * the Curses UI.
 		 */
 		gdk_window_freeze_updates(top_window);
+
 		const teco_view_t *last_view = teco_interface_current_view;
+		sptr_t last_pos = teco_interface_ssm(SCI_GETCURRENTPOS, 0, 0);
 
 		teco_interrupted = FALSE;
 		switch (event->type) {
@@ -1432,6 +1431,15 @@ teco_interface_input_cb(GtkWidget *widget, GdkEvent *event, gpointer user_data)
 		teco_interrupted = FALSE;
 
 		teco_interface_refresh(teco_interface_current_view != last_view);
+		/*
+		 * Scintilla has been patched to avoid any automatic scrolling since that
+		 * has been benchmarked to be a very costly operation.
+		 * Instead we do it only once after every keypress.
+		 */
+		if (teco_interface_current_view != last_view ||
+		    last_pos != teco_interface_ssm(SCI_GETCURRENTPOS, 0, 0))
+			teco_interface_ssm(SCI_SCROLLCARET, 0, 0);
+
 		gdk_window_thaw_updates(top_window);
 
 		if (g_error_matches(error, TECO_ERROR, TECO_ERROR_QUIT)) {