From ae1bc2f1665bd79b50330ff1f6960101a5f2d2a7 Mon Sep 17 00:00:00 2001
From: m1ngsama <contact@m1ng.space>
Date: Sun, 17 May 2026 13:49:00 +0800
Subject: [PATCH] input: vim-style paging keys in the help screen (UX-5)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The NORMAL chat mode has Ctrl+D/U (half page) and Ctrl+F/B (full page)
scrolling, which is what vim users reach for.  The help screen had
none of these — only j/k single-line and g/G top/bottom — so reaching
the bottom of a help dump meant mashing j.

Now the help screen accepts the same four shortcuts.  The page size
is computed from client->height (matching what NORMAL mode does), so
half/full page scroll size scales with the terminal.

Both the EN and ZH help text have been updated to advertise the new
shortcuts.
---
 src/input.c | 20 ++++++++++++++++++++
 src/tui.c   |  4 ++++
 2 files changed, 24 insertions(+)

diff --git a/src/input.c b/src/input.c
index 9bc55f9..d564ba6 100644
--- a/src/input.c
+++ b/src/input.c
@@ -167,6 +167,12 @@ static bool handle_key(client_t *client, unsigned char key, char *input) {
 
     /* Handle help screen */
     if (client->show_help) {
+        /* Page size: roughly the visible help body region. */
+        int page = client->height - 2;
+        if (page < 1) page = 1;
+        int half = page / 2;
+        if (half < 1) half = 1;
+
         if (key == 'q' || key == 27) {
             client->show_help = false;
             tui_render_screen(client);
@@ -184,6 +190,20 @@ static bool handle_key(client_t *client, unsigned char key, char *input) {
         } else if (key == 'k' && client->help_scroll_pos > 0) {
             client->help_scroll_pos--;
             tui_render_help(client);
+        } else if (key == 4) {  /* Ctrl+D: half page down */
+            client->help_scroll_pos += half;
+            tui_render_help(client);
+        } else if (key == 21) {  /* Ctrl+U: half page up */
+            client->help_scroll_pos -= half;
+            if (client->help_scroll_pos < 0) client->help_scroll_pos = 0;
+            tui_render_help(client);
+        } else if (key == 6) {  /* Ctrl+F: full page down */
+            client->help_scroll_pos += page;
+            tui_render_help(client);
+        } else if (key == 2) {  /* Ctrl+B: full page up */
+            client->help_scroll_pos -= page;
+            if (client->help_scroll_pos < 0) client->help_scroll_pos = 0;
+            tui_render_help(client);
         } else if (key == 'g') {
             client->help_scroll_pos = 0;
             tui_render_help(client);
diff --git a/src/tui.c b/src/tui.c
index 9778719..a96371b 100644
--- a/src/tui.c
+++ b/src/tui.c
@@ -730,6 +730,8 @@ const char* tui_get_help_text(help_lang_t lang) {
                "HELP SCREEN KEYS:\n"
                "  q, ESC     - Close help\n"
                "  j/k        - Scroll down/up\n"
+               "  Ctrl+D/U   - Scroll half page down/up\n"
+               "  Ctrl+F/B   - Scroll full page down/up\n"
                "  g/G        - Jump to top/bottom\n"
                "  e/z        - Switch English/Chinese\n";
     } else {
@@ -777,6 +779,8 @@ const char* tui_get_help_text(help_lang_t lang) {
                "帮助界面按键:\n"
                "  q, ESC     - 关闭帮助\n"
                "  j/k        - 向下/上滚动\n"
+               "  Ctrl+D/U   - 向下/上滚动半页\n"
+               "  Ctrl+F/B   - 向下/上滚动整页\n"
                "  g/G        - 跳到顶部/底部\n"
                "  e/z        - 切换英文/中文\n";
     }