[Nano-devel] [PATCH 1/2] scrolling: add a function and a key binding to center the cursor line

[Benno Schulenberg]

From: Benno Schulenberg <address@hidden>

---
 doc/nano.texi |  3 +++
 doc/nanorc.5  |  3 +++
 src/global.c  | 15 +++++++++++++--
 src/move.c    |  7 +++++++
 src/proto.h   |  1 +
 5 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/doc/nano.texi b/doc/nano.texi
index 04dc5756..999f6e9b 100644
--- a/doc/nano.texi
+++ b/doc/nano.texi
@@ -1193,6 +1193,9 @@ Scrolls up one line of text from the current position.
 @item scrolldown
 Scrolls down one line of text from the current position.
 
address@hidden center
+Scrolls the line with the cursor to the middle of the screen.
+
 @item prevword
 Moves the cursor to the beginning of the previous word.
 
diff --git a/doc/nanorc.5 b/doc/nanorc.5
index 0e6198aa..a85d2d07 100644
--- a/doc/nanorc.5
+++ b/doc/nanorc.5
@@ -548,6 +548,9 @@ Scrolls up one line of text from the current position.
 .B scrolldown
 Scrolls down one line of text from the current position.
 .TP
+.B center
+Scrolls the line with the cursor to the middle of the screen.
+.TP
 .B prevword
 Moves the cursor to the beginning of the previous word.
 .TP
diff --git a/src/global.c b/src/global.c
index 2d4d04f0..b86014c5 100644
--- a/src/global.c
+++ b/src/global.c
@@ -580,6 +580,8 @@ void shortcut_init(void)
                N_("Scroll up one line without scrolling the cursor");
        const char *scrolldown_gist =
                N_("Scroll down one line without scrolling the cursor");
+       const char *center_gist =
+               N_("Center the line where the cursor is");
 #endif
 #ifdef ENABLE_MULTIBUFFER
        const char *prevfile_gist = N_("Switch to the previous file buffer");
@@ -978,6 +980,9 @@ void shortcut_init(void)
        add_to_funcs(do_savefile, MMAIN,
                N_("Save"), WITHORSANS(savefile_gist), BLANKAFTER, NOVIEW);
 
+       add_to_funcs(do_center, MMAIN,
+               N_("Center"), WITHORSANS(center_gist), BLANKAFTER, VIEW);
+
 #ifdef ENABLE_HISTORIES
        add_to_funcs(get_history_older_void, 
MWHEREIS|MREPLACE|MREPLACEWITH|MWHEREISFILE,
                N_("PrevHstory"), WITHORSANS(prevhistory_gist), TOGETHER, VIEW);
@@ -1225,10 +1230,14 @@ void shortcut_init(void)
 #ifdef ENABLE_JUSTIFY
        add_to_sclist(MMAIN|MWHEREIS, "M-J", 0, do_full_justify, 0);
 #endif
-       add_to_sclist(MMAIN|MHELP|MBROWSER, "^L", 0, total_refresh, 0);
        add_to_sclist(MMAIN, "^Z", 0, do_suspend_void, 0);
 
-#ifndef NANO_TINY
+#ifdef NANO_TINY
+       add_to_sclist(MMAIN|MHELP|MBROWSER, "^L", 0, total_refresh, 0);
+#else
+       add_to_sclist(MMAIN, "^L", 0, do_center, 0);
+       add_to_sclist(MHELP|MBROWSER, "^L", 0, total_refresh, 0);
+
        /* Group of "Appearance" toggles. */
        add_to_sclist(MMAIN, "M-X", 0, do_toggle_void, NO_HELP);
        add_to_sclist(MMAIN, "M-C", 0, do_toggle_void, CONSTANT_SHOW);
@@ -1528,6 +1537,8 @@ sc *strtosc(const char *input)
                s->func = do_scroll_up;
        else if (!strcasecmp(input, "scrolldown"))
                s->func = do_scroll_down;
+       else if (!strcasecmp(input, "center"))
+               s->func = do_center;
        else if (!strcasecmp(input, "cutwordleft"))
                s->func = do_cut_prev_word;
        else if (!strcasecmp(input, "cutwordright"))
diff --git a/src/move.c b/src/move.c
index f559fb41..2613fd20 100644
--- a/src/move.c
+++ b/src/move.c
@@ -558,6 +558,13 @@ void do_scroll_down(void)
 {
        do_down(TRUE);
 }
+
+/* Scroll the line with the cursor to the center of the screen. */
+void do_center(void)
+{
+       adjust_viewport(CENTERING);
+       total_refresh();
+}
 #endif
 
 /* Move left one character. */
diff --git a/src/proto.h b/src/proto.h
index 551aa650..9b179427 100644
--- a/src/proto.h
+++ b/src/proto.h
@@ -393,6 +393,7 @@ void do_down_void(void);
 #ifndef NANO_TINY
 void do_scroll_up(void);
 void do_scroll_down(void);
+void do_center(void);
 #endif
 void do_left(void);
 void do_right(void);
-- 
2.16.2