allow the number of lines to scroll at a time to be configurable

3 files changed, 17 insertions, 8 deletions

diff --git a/src/config.c b/src/config.c
index 1179a3d..3a4ae4a 100644
--- a/src/config.c
+++ b/src/config.c
@@ -310,6 +310,8 @@ static void runes_config_set_defaults(RunesTerm *t)
 
     config->default_rows = 24;
     config->default_cols = 80;
+
+    config->scroll_lines = 3;
 }
 
 static FILE *runes_config_get_config_file()
@@ -494,6 +496,9 @@ static void runes_config_set(RunesTerm *t, char *key, char *val)
     else if (!strcmp(key, "cols")) {
         config->default_cols = runes_config_parse_uint(val);
     }
+    else if (!strcmp(key, "scroll_lines")) {
+        config->scroll_lines = runes_config_parse_uint(val);
+    }
     else if (!strcmp(key, "command")) {
         config->cmd = runes_config_parse_string(val);
     }
diff --git a/src/config.h b/src/config.h
index c22f32e..a98d9d0 100644
--- a/src/config.h
+++ b/src/config.h
@@ -12,6 +12,8 @@ struct runes_config {
     int default_rows;
     int default_cols;
 
+    int scroll_lines;
+
     char *cmd;
     char *font_name;
 
diff --git a/src/window-xlib.c b/src/window-xlib.c
index d792cfc..96d2558 100644
--- a/src/window-xlib.c
+++ b/src/window-xlib.c
@@ -759,18 +759,20 @@ static int runes_window_backend_handle_builtin_button_press(
         return 1;
         break;
     case Button4:
-        if (t->scr.row_visible_offset < t->scr.row_count - t->scr.max.row) {
-            t->scr.row_visible_offset++;
-            t->scr.dirty = 1;
-            runes_window_backend_flush(t);
+        t->scr.row_visible_offset += t->config.scroll_lines;
+        if (t->scr.row_visible_offset > t->scr.row_count - t->scr.max.row) {
+            t->scr.row_visible_offset = t->scr.row_count - t->scr.max.row;
         }
+        t->scr.dirty = 1;
+        runes_window_backend_flush(t);
         break;
     case Button5:
-        if (t->scr.row_visible_offset > 0) {
-            t->scr.row_visible_offset--;
-            t->scr.dirty = 1;
-            runes_window_backend_flush(t);
+        t->scr.row_visible_offset -= t->config.scroll_lines;
+        if (t->scr.row_visible_offset < 0) {
+            t->scr.row_visible_offset = 0;
         }
+        t->scr.dirty = 1;
+        runes_window_backend_flush(t);
         break;
     default:
         break;