Rework auto-scrolling options

This changes two things, the first thing it does is that now whenever a
keybinding sends an escape sequence, the viewport is automatically
scrolled to the bottom.
This is enabled by default and fixes #1187.

The second thing is automatic scrolling when a command writes to the
terminal. So when running a command like `sleep 3; ls -lah`, alacritty
will scroll to the bottom once the output is sent, even if the viewport
is currently not at the bottom of the scrollback.
Because this can have an impact on performance, and is not enabled by
default in terminals like iTerm or Termite (VTE), it is an opt-in
setting in the config.

1 files changed, 10 insertions, 0 deletions

diff --git a/src/term/mod.rs b/src/term/mod.rs
index 3c7ef87c..198f8cea 100644
--- a/src/term/mod.rs
+++ b/src/term/mod.rs
@@ -756,6 +756,9 @@ pub struct Term {
 
     /// Number of spaces in one tab
     tabspaces: usize,
+
+    /// Automatically scroll to bottom when new lines are added
+    auto_scroll: bool,
 }
 
 /// Terminal size info
@@ -879,6 +882,7 @@ impl Term {
             default_cursor_style: config.cursor_style(),
             dynamic_title: config.dynamic_title(),
             tabspaces,
+            auto_scroll: config.scrolling().auto_scroll,
         }
     }
 
@@ -905,6 +909,7 @@ impl Term {
         self.visual_bell.update_config(config);
         self.default_cursor_style = config.cursor_style();
         self.dynamic_title = config.dynamic_title();
+        self.auto_scroll = config.scrolling().auto_scroll;
     }
 
     #[inline]
@@ -1255,6 +1260,11 @@ impl ansi::Handler for Term {
     /// A character to be displayed
     #[inline]
     fn input(&mut self, c: char) {
+        // If enabled, scroll to bottom when character is received
+        if self.auto_scroll {
+            self.scroll_display(Scroll::Bottom);
+        }
+
         if self.input_needs_wrap {
             if !self.mode.contains(mode::TermMode::LINE_WRAP) {
                 return;