From a5c4314940e2ef875026f52ffb6f285725d3fb02 Mon Sep 17 00:00:00 2001 From: Blaž Hrastnik Date: Thu, 4 Mar 2021 16:13:26 +0900 Subject: commands: Improve scroll functions. Followed kakoune's implementation, it's no longer janky and can scroll all the way in either direction. --- helix-term/src/commands.rs | 80 +++++++++++++++++++++++----------------------- 1 file changed, 40 insertions(+), 40 deletions(-) (limited to 'helix-term') diff --git a/helix-term/src/commands.rs b/helix-term/src/commands.rs index 60359ef0..d45e7168 100644 --- a/helix-term/src/commands.rs +++ b/helix-term/src/commands.rs @@ -4,8 +4,8 @@ use helix_core::{ object, regex::{self, Regex}, register, selection, - state::{Direction, Granularity, State}, - Change, ChangeSet, Range, Selection, Tendril, Transaction, + state::{coords_at_pos, pos_at_coords, Direction, Granularity, State}, + Change, ChangeSet, Position, Range, Selection, Tendril, Transaction, }; use once_cell::sync::Lazy; @@ -222,62 +222,60 @@ pub fn extend_next_word_end(cx: &mut Context) { doc.set_selection(selection); } -pub fn page_up(cx: &mut Context) { - let view = cx.view(); - if view.first_line < PADDING { +fn scroll(view: &mut View, offset: usize, direction: Direction) { + use Direction::*; + let text = view.doc.text().slice(..); + + let last_line = view.last_line(); + let cursor = coords_at_pos(text, view.doc.selection().cursor()); + let doc_last_line = text.len_lines() - 1; + + if direction == Backward && view.first_line == 0 + || direction == Forward && last_line == doc_last_line + { return; } - view.first_line = view.first_line.saturating_sub(view.area.height as usize); + let scrolloff = PADDING; // min(user pref, half win width/height) + + // cursor visual offset + let cursor_off = cursor.row - view.first_line; - if !view.check_cursor_in_view() { - let text = view.doc.text(); - let pos = text.line_to_char(view.last_line().saturating_sub(PADDING)); - view.doc.set_selection(Selection::point(pos)); + view.first_line = match direction { + Forward => view.first_line + offset, + Backward => view.first_line.saturating_sub(offset), } + .min(doc_last_line); + + // clamp into viewport + let line = (view.first_line + cursor_off).clamp( + view.first_line + scrolloff, + view.first_line + view.last_line().saturating_sub(scrolloff), + ); + + let pos = pos_at_coords(text, Position::new(line, cursor.col)); // this func will properly truncate to line end + view.doc.set_selection(Selection::point(pos)); } -pub fn page_down(cx: &mut Context) { +pub fn page_up(cx: &mut Context) { let view = cx.view(); - view.first_line += view.area.height as usize + PADDING; + scroll(view, view.area.height as usize, Direction::Backward); +} - if view.first_line < view.doc.text().len_lines() { - let text = view.doc.text(); - let pos = text.line_to_char(view.first_line as usize); - view.doc.set_selection(Selection::point(pos)); - } +pub fn page_down(cx: &mut Context) { + let view = cx.view(); + scroll(view, view.area.height as usize, Direction::Forward); } pub fn half_page_up(cx: &mut Context) { let view = cx.view(); - if view.first_line < PADDING { - return; - } - - view.first_line = view - .first_line - .saturating_sub(view.area.height as usize / 2); - - if !view.check_cursor_in_view() { - let text = &view.doc.text(); - let pos = text.line_to_char(view.last_line() - PADDING); - view.doc.set_selection(Selection::point(pos)); - } + scroll(view, view.area.height as usize / 2, Direction::Backward); } pub fn half_page_down(cx: &mut Context) { let view = cx.view(); - let lines = view.doc.text().len_lines(); - if view.first_line < lines.saturating_sub(view.area.height as usize) { - view.first_line += view.area.height as usize / 2; - } - if !view.check_cursor_in_view() { - let text = view.doc.text(); - let pos = text.line_to_char(view.first_line as usize); - view.doc.set_selection(Selection::point(pos)); - } + scroll(view, view.area.height as usize / 2, Direction::Forward); } -// avoid select by default by having a visual mode switch that makes movements into selects pub fn extend_char_left(cx: &mut Context) { let count = cx.count; @@ -439,8 +437,10 @@ pub fn search_selection(cx: &mut Context) { pub fn select_line(cx: &mut Context) { let count = cx.count; let doc = cx.doc(); + let pos = doc.selection().primary(); let text = doc.text(); + let line = text.char_to_line(pos.head); let start = text.line_to_char(line); let end = text.line_to_char(line + count).saturating_sub(1); -- cgit v1.2.3-70-g09d2