Add modal keyboard motion mode

This implements a basic mode for navigating inside of Alacritty's
history with keyboard bindings. They're bound by default to vi's motion
shortcuts but are fully customizable. Since this relies on key bindings
only single key bindings are currently supported (so no `ge`, or
repetition).

Other than navigating the history and moving the viewport, this mode
should enable making use of all available selection modes to copy
content to the clipboard and launch URLs below the cursor.

This also changes the rendering of the block cursor at the side of
selections, since previously it could be inverted to be completely
invisible. Since that would have caused some troubles with this keyboard
selection mode, the block cursor now is no longer inverted when it is at
the edges of a selection.

Fixes #262.

1 files changed, 4 insertions, 8 deletions

diff --git a/alacritty_terminal/src/grid/mod.rs b/alacritty_terminal/src/grid/mod.rs
index 34d989db..37cf0eb6 100644
--- a/alacritty_terminal/src/grid/mod.rs
+++ b/alacritty_terminal/src/grid/mod.rs
@@ -264,11 +264,9 @@ impl<T: GridCell + PartialEq + Copy> Grid<T> {
         let mut new_empty_lines = 0;
         let mut reversed: Vec<Row<T>> = Vec::with_capacity(self.raw.len());
         for (i, mut row) in self.raw.drain().enumerate().rev() {
-            // FIXME: Rust 1.39.0+ allows moving in pattern guard here
             // Check if reflowing shoud be performed
-            let mut last_row = reversed.last_mut();
-            let last_row = match last_row {
-                Some(ref mut last_row) if should_reflow(last_row) => last_row,
+            let last_row = match reversed.last_mut() {
+                Some(last_row) if should_reflow(last_row) => last_row,
                 _ => {
                     reversed.push(row);
                     continue;
@@ -356,11 +354,9 @@ impl<T: GridCell + PartialEq + Copy> Grid<T> {
             }
 
             loop {
-                // FIXME: Rust 1.39.0+ allows moving in pattern guard here
                 // Check if reflowing shoud be performed
-                let wrapped = row.shrink(cols);
-                let mut wrapped = match wrapped {
-                    Some(_) if reflow => wrapped.unwrap(),
+                let mut wrapped = match row.shrink(cols) {
+                    Some(wrapped) if reflow => wrapped,
                     _ => {
                         new_raw.push(row);
                         break;