From ddcf5156c0260debc522b0420f93e0c523697eb4 Mon Sep 17 00:00:00 2001 From: Blaž Hrastnik Date: Mon, 8 Mar 2021 17:13:45 +0900 Subject: ui: menu: Adjust scroll via required_size area caching. --- helix-term/src/ui/menu.rs | 45 ++++++++++++++++++++++++++++----------------- 1 file changed, 28 insertions(+), 17 deletions(-) (limited to 'helix-term/src/ui') diff --git a/helix-term/src/ui/menu.rs b/helix-term/src/ui/menu.rs index c129420d..7cfeb811 100644 --- a/helix-term/src/ui/menu.rs +++ b/helix-term/src/ui/menu.rs @@ -8,7 +8,6 @@ use tui::{ }; use std::borrow::Cow; -use std::cell::Cell; use helix_core::Position; use helix_view::Editor; @@ -24,7 +23,8 @@ pub struct Menu { format_fn: Box Cow>, callback_fn: Box, MenuEvent)>, - scroll: Cell, + scroll: usize, + size: (u16, u16), } impl Menu { @@ -40,7 +40,8 @@ impl Menu { cursor: None, format_fn: Box::new(format_fn), callback_fn: Box::new(callback_fn), - scroll: Cell::new(0), + scroll: 0, + size: (0, 0), } } @@ -48,11 +49,28 @@ impl Menu { // TODO: wrap around to end let pos = self.cursor.map(|i| i.saturating_sub(1)).unwrap_or(0) % self.options.len(); self.cursor = Some(pos); + self.adjust_scroll(); } pub fn move_down(&mut self) { let pos = self.cursor.map(|i| i + 1).unwrap_or(0) % self.options.len(); self.cursor = Some(pos); + self.adjust_scroll(); + } + + fn adjust_scroll(&mut self) { + let win_height = self.size.1 as usize; + if let Some(cursor) = self.cursor { + let mut scroll = self.scroll; + if cursor > (win_height + scroll).saturating_sub(1) { + // scroll down + scroll += cursor - (win_height + scroll).saturating_sub(1) + } else if cursor < scroll { + // scroll up + scroll = cursor + } + self.scroll = scroll; + } } pub fn selection(&self) -> Option<&T> { @@ -156,30 +174,23 @@ impl Component for Menu { let height = std::cmp::min(self.options.len(), MAX); let height = std::cmp::min(height, viewport.1 as usize); - Some((width as u16, height as u16)) + self.size = (width as u16, height as u16); + + // adjust scroll offsets if size changed + self.adjust_scroll(); + + Some(self.size) } fn render(&self, area: Rect, surface: &mut Surface, cx: &mut Context) { let style = Style::default().fg(Color::Rgb(164, 160, 232)); // lavender let selected = Style::default().fg(Color::Rgb(255, 255, 255)); - // TODO: instead of a cell, all these numbers should be precomputed in handle_event + init - let mut scroll = self.scroll.get(); + let scroll = self.scroll; let len = self.options.len(); let win_height = area.height as usize; - if let Some(cursor) = self.cursor { - if cursor > (win_height + scroll).saturating_sub(1) { - // scroll down - scroll += cursor - (win_height + scroll).saturating_sub(1) - } else if cursor < scroll { - // scroll up - scroll = cursor - } - self.scroll.set(scroll); - } - fn div_ceil(a: usize, b: usize) -> usize { (a + b - 1) / a } -- cgit v1.2.3-70-g09d2