~hime/protochat: (linetest/ui/buffer) return more generalized iterator

559893d95dedad1b45696bafb0af3ca41f475c6d — drbawb 1 year, 11 months ago 08d3df1

(linetest/ui/buffer) return more generalized iterator

This returns a double ended iterator, which gives callers
downstream a bit more flexibility in how lines are presented
to the client.

This may be useful if we later add buffers that are painted from
top-down, rather than bottom-up.

patch browse

1 files changed, 5 insertions(+), 4 deletions(-)

M linetest/src/shell/ui/buffer.rs

M linetest/src/shell/ui/buffer.rs => linetest/src/shell/ui/buffer.rs +5 -4

@@ 1,4 1,3 @@
-
 use crossterm::{
     cursor,
     style::{self, Print},


@@ 26,8 25,8 @@ impl Span {
         Self { lines: lines }
     }
 
-    pub fn line_iter(&self) -> impl Iterator<Item = &String> {
-        self.lines.iter().rev()
+    pub fn line_iter(&self) -> impl DoubleEndedIterator<Item = &String> {
+        self.lines.iter()
     }
 }
 /// The `Buffer` stores a list of lines which need to be displayed 


@@ 103,11 102,13 @@ impl Buffer {
         .map(|line| Span::new(line, self.cols))
         .collect::<Vec<_>>();
 
+        // grab at most a buffer's worth of lines
         let viewport_lines = self.viewport_spans
             .iter()
-            .flat_map(|span| span.line_iter())
+            .flat_map(|span| span.line_iter().rev())
             .take(self.rows as usize);
 
+        // blit lines to the viewport
         let mut rows_drawn = 0;
         for line in viewport_lines {
             rows_drawn += 1;