fix scrolling and clamping

This commit is contained in:
alice pellerin
2026-04-29 17:41:05 -05:00
parent 162046d13e
commit 15132d44af
8 changed files with 136 additions and 131 deletions
+2
View File
@@ -144,9 +144,11 @@ impl Buffer {
};
assert!(self.scroll_position.is_multiple_of(BYTES_PER_LINE));
if !self.contents.is_empty() {
assert!(self.scroll_position < self.contents.len());
assert!(self.primary_cursor.head < self.contents.len());
assert!(self.primary_cursor.tail < self.contents.len());
}
assert!(self.scroll_position <= self.primary_cursor.head);
assert!(self.primary_cursor.head < self.scroll_position + window_size.visible_byte_count());
+87 -104
View File
@@ -1,7 +1,7 @@
use std::{cmp::min, collections::hash_set::Entry, convert::identity, fs::File, io::Write, iter, mem::{replace, swap}};
use itertools::Itertools;
use ratatui::{style::{Color, Stylize}, text::Span};
use crate::{BYTES_OF_PADDING, BYTES_PER_LINE, LINES_OF_PADDING, action::BufferAction, buffer::{Buffer, InspectionStatus, Mode, PartialAction}, cursor::Cursor, edit_action::EditAction, popup::Popup, window_size::WindowSize};
use crate::{BYTES_OF_PADDING, BYTES_PER_LINE, LINES_OF_PADDING, action::BufferAction, buffer::{Buffer, InspectionStatus, Mode, PartialAction}, cursor::Cursor, edit_action::EditAction, popup::Popup, utilities::{Floorable, SaturatingSubtract}, window_size::WindowSize};
impl Buffer {
pub fn execute(&mut self, action: BufferAction, window_size: WindowSize) {
@@ -60,7 +60,7 @@ impl Buffer {
BufferAction::AlignViewCenter => self.align_view_center(window_size),
BufferAction::AlignViewBottom => self.align_view_bottom(window_size),
BufferAction::AlignViewTop => self.align_view_top(),
BufferAction::AlignViewTop => self.align_view_top(window_size),
BufferAction::FindTillMark => self.till_mark(false, window_size), // extend: false
BufferAction::FindTillNull => self.till_null(false, window_size), // extend: false
@@ -110,131 +110,75 @@ impl Buffer {
}
pub fn scroll_down(&mut self, window_size: WindowSize) {
if self.contents.len() <= BYTES_OF_PADDING { return; }
self.scroll_position = min(
self.scroll_position + BYTES_PER_LINE,
self.contents.len() - BYTES_OF_PADDING - self.contents.len() % BYTES_PER_LINE
);
if window_size.hex_rows() > LINES_OF_PADDING * 2 {
self.primary_cursor.clamp(
self.scroll_position + BYTES_OF_PADDING,
window_size.visible_byte_count() - BYTES_OF_PADDING * 2
);
} else {
self.primary_cursor.clamp(self.scroll_position, window_size.visible_byte_count());
}
self.scroll_position += BYTES_PER_LINE;
self.clamp_screen_to_contents(window_size);
self.clamp_primary_cursor_to_screen(window_size);
self.combine_cursors_if_overlapping();
}
pub fn scroll_up(&mut self, window_size: WindowSize) {
self.scroll_position = self.scroll_position.saturating_sub(BYTES_PER_LINE);
if window_size.hex_rows() > LINES_OF_PADDING * 2 {
self.primary_cursor.clamp(
self.scroll_position + BYTES_OF_PADDING,
window_size.visible_byte_count() - BYTES_OF_PADDING * 2
);
} else {
self.primary_cursor.clamp(self.scroll_position, window_size.visible_byte_count());
}
self.scroll_position.saturating_subtract(BYTES_PER_LINE);
self.clamp_primary_cursor_to_screen(window_size);
self.combine_cursors_if_overlapping();
}
fn page_cursor_half_down(&mut self, window_size: WindowSize) {
if self.contents.len() <= BYTES_OF_PADDING { return; }
let scroll_amount = (window_size.visible_byte_count() / 2).next_multiple_of(BYTES_PER_LINE);
let old_scroll_position = self.scroll_position;
self.scroll_position += scroll_amount;
self.clamp_screen_to_contents(window_size);
self.scroll_position = min(
self.scroll_position + (window_size.visible_byte_count() / 2).next_multiple_of(BYTES_PER_LINE),
self.contents.len() - BYTES_OF_PADDING - self.contents.len() % BYTES_PER_LINE
);
self.primary_cursor.head += scroll_amount;
if self.mode != Mode::Select {
self.primary_cursor.tail += scroll_amount;
}
self.primary_cursor.clamp(0, self.max_contents_index());
self.clamp_screen_to_primary_cursor(window_size);
let scroll_position_change = self.scroll_position - old_scroll_position;
let max_contents_index = self.max_contents_index();
self.primary_cursor.head = min(
self.primary_cursor.head + scroll_position_change,
max_contents_index
);
self.primary_cursor.tail = min(
self.primary_cursor.tail + scroll_position_change,
max_contents_index
);
for cursor in &mut self.cursors {
cursor.head = (cursor.head + scroll_position_change).min(max_contents_index);
cursor.tail = (cursor.tail + scroll_position_change).min(max_contents_index);
cursor.head += scroll_amount;
if self.mode != Mode::Select {
cursor.tail += scroll_amount;
}
cursor.clamp(0, max_contents_index);
}
self.combine_cursors_if_overlapping();
}
fn page_cursor_half_up(&mut self, window_size: WindowSize) {
let old_scroll_position = self.scroll_position;
let scroll_amount = (window_size.visible_byte_count() / 2).next_multiple_of(BYTES_PER_LINE);
self.scroll_position = self.scroll_position.saturating_sub(
(window_size.visible_byte_count() / 2).next_multiple_of(BYTES_PER_LINE)
);
self.scroll_position.saturating_subtract(scroll_amount);
let scroll_position_change = old_scroll_position - self.scroll_position;
let max_contents_index = self.max_contents_index();
self.primary_cursor.head = min(
self.primary_cursor.head - scroll_position_change,
max_contents_index
);
self.primary_cursor.tail = min(
self.primary_cursor.tail - scroll_position_change,
max_contents_index
);
self.primary_cursor.head.saturating_subtract(scroll_amount);
if self.mode != Mode::Select {
self.primary_cursor.tail.saturating_subtract(scroll_amount);
}
for cursor in &mut self.cursors {
cursor.head = (cursor.head - scroll_position_change).min(max_contents_index);
cursor.tail = (cursor.tail - scroll_position_change).min(max_contents_index);
cursor.head.saturating_subtract(scroll_amount);
if self.mode != Mode::Select {
cursor.tail.saturating_subtract(scroll_amount);
}
}
self.combine_cursors_if_overlapping();
}
fn page_down(&mut self, window_size: WindowSize) {
if self.contents.len() <= BYTES_OF_PADDING { return; }
self.scroll_position = min(
self.scroll_position + window_size.visible_byte_count(),
self.max_contents_index() - BYTES_OF_PADDING - self.max_contents_index() % BYTES_PER_LINE
);
if window_size.hex_rows() > LINES_OF_PADDING * 2 {
self.primary_cursor.clamp(
self.scroll_position + BYTES_OF_PADDING,
window_size.visible_byte_count() - BYTES_OF_PADDING * 2
);
} else {
self.primary_cursor.clamp(self.scroll_position, window_size.visible_byte_count());
}
self.scroll_position += window_size.visible_byte_count();
self.clamp_screen_to_contents(window_size);
self.clamp_primary_cursor_to_screen(window_size);
self.combine_cursors_if_overlapping();
}
fn page_up(&mut self, window_size: WindowSize) {
self.scroll_position = self.scroll_position.saturating_sub(
window_size.visible_byte_count()
);
if window_size.hex_rows() > LINES_OF_PADDING * 2 {
self.primary_cursor.clamp(
self.scroll_position + BYTES_OF_PADDING,
window_size.visible_byte_count() - BYTES_OF_PADDING * 2
);
} else {
self.primary_cursor.clamp(self.scroll_position, window_size.visible_byte_count());
}
self.scroll_position.saturating_subtract(window_size.visible_byte_count());
self.clamp_screen_to_contents(window_size);
self.clamp_primary_cursor_to_screen(window_size);
self.combine_cursors_if_overlapping();
}
@@ -540,25 +484,25 @@ impl Buffer {
let half_a_screen = window_size.visible_byte_count() / 2;
self.scroll_position = self.primary_cursor.head
.saturating_sub(self.primary_cursor.head % BYTES_PER_LINE)
.saturating_sub(half_a_screen - (half_a_screen % BYTES_PER_LINE));
.floored_to_the_nearest(BYTES_PER_LINE)
.saturating_sub(half_a_screen.floored_to_the_nearest(BYTES_PER_LINE));
}
fn align_view_bottom(&mut self, window_size: WindowSize) {
self.scroll_position = self.primary_cursor.head
.saturating_sub(self.primary_cursor.head % BYTES_PER_LINE)
.floored_to_the_nearest(BYTES_PER_LINE)
.saturating_sub(
window_size
.visible_byte_count()
.saturating_sub(BYTES_PER_LINE + BYTES_OF_PADDING)
.saturating_sub(BYTES_PER_LINE + Self::bottom_padding(window_size))
)
.min(self.max_contents_index() - self.max_contents_index() % BYTES_PER_LINE);
.min(self.max_contents_index().floored_to_the_nearest(BYTES_PER_LINE));
}
const fn align_view_top(&mut self) {
const fn align_view_top(&mut self, window_size: WindowSize) {
self.scroll_position = self.primary_cursor.head
.saturating_sub(self.primary_cursor.head % BYTES_PER_LINE)
.saturating_sub(BYTES_OF_PADDING);
.floored_to_the_nearest(BYTES_PER_LINE)
.saturating_sub(self.top_padding(window_size));
}
fn till_mark(&mut self, extend: bool, window_size: WindowSize) {
@@ -870,13 +814,52 @@ fn inspect_color(selection: &[u8]) -> Vec<Span<'static>> {
// MARK: helpers
impl Buffer {
const fn bottom_padding(window_size: WindowSize) -> usize {
if window_size.hex_rows() <= LINES_OF_PADDING * 2 {
0
} else {
BYTES_OF_PADDING
}
}
const fn top_padding(&self, window_size: WindowSize) -> usize {
if window_size.hex_rows() <= LINES_OF_PADDING * 2 || self.scroll_position == 0 {
0
} else {
BYTES_OF_PADDING
}
}
pub const fn clamp_screen_to_contents(&mut self, window_size: WindowSize) {
let max_scroll_position = self.max_contents_index()
.floored_to_the_nearest(BYTES_PER_LINE)
.saturating_sub(Self::bottom_padding(window_size));
if self.scroll_position > max_scroll_position {
self.scroll_position = max_scroll_position;
}
}
pub fn clamp_screen_to_primary_cursor(&mut self, window_size: WindowSize) {
if self.primary_cursor.head < self.scroll_position + BYTES_OF_PADDING {
self.align_view_top();
} else if self.primary_cursor.head > self.scroll_position + (window_size.visible_byte_count() - 1).saturating_sub(BYTES_OF_PADDING) {
if self.primary_cursor.head < self.scroll_position + self.top_padding(window_size) {
self.align_view_top(window_size);
} else if self.primary_cursor.head > self.scroll_position + (window_size.visible_byte_count() - 1).saturating_sub(Self::bottom_padding(window_size)) {
self.align_view_bottom(window_size);
}
}
fn clamp_primary_cursor_to_screen(&mut self, window_size: WindowSize) {
let min = self.scroll_position + self.top_padding(window_size);
let max = self.scroll_position + window_size.visible_byte_count()
.saturating_sub(Self::bottom_padding(window_size))
.saturating_sub(BYTES_PER_LINE);
if self.mode == Mode::Select {
self.primary_cursor.head = self.primary_cursor.head.clamp(min, max);
} else {
self.primary_cursor.clamp(min, max);
}
}
}
pub fn bytes_to_nat(bytes: &[u8]) -> Option<u64> {
+3 -6
View File
@@ -59,12 +59,9 @@ impl Cursor {
swap(&mut self.head, &mut self.tail);
}
// TODO: in visual mode, should only clamp head
pub fn clamp(&mut self, scroll_position: usize, screen_size: usize) {
let max_row = scroll_position + screen_size - 1;
self.head = self.head.clamp(scroll_position, max_row);
self.tail = self.tail.clamp(scroll_position, max_row);
pub fn clamp(&mut self, min: usize, max: usize) {
self.head = self.head.clamp(min, max);
self.tail = self.tail.clamp(min, max);
}
pub fn combine_with(&mut self, other: Self) {
+11 -15
View File
@@ -1,5 +1,5 @@
use std::{cmp::min, mem::swap};
use crate::{BYTES_PER_LINE, action::CursorAction, cursor::Cursor};
use crate::{BYTES_PER_LINE, action::CursorAction, cursor::Cursor, utilities::{Floorable, SaturatingSubtract}};
impl Cursor {
pub fn execute(
@@ -114,12 +114,12 @@ impl Cursor {
}
pub const fn extend_line_start(&mut self) {
self.head -= self.head % BYTES_PER_LINE;
self.head.floor_to_the_nearest(BYTES_PER_LINE);
}
pub fn extend_line_end(&mut self, max: usize) {
self.head = min(
self.head + BYTES_PER_LINE - 1 - (self.head % BYTES_PER_LINE),
self.head.floored_to_the_nearest(BYTES_PER_LINE) + BYTES_PER_LINE - 1,
max
);
}
@@ -164,7 +164,7 @@ impl Cursor {
self.tail = self.head - 1;
self.head -= 4;
} else {
self.head -= self.head % 4;
self.head.floor_to_the_nearest(4);
}
}
@@ -194,7 +194,7 @@ impl Cursor {
if self.head.is_multiple_of(4) { // at the beginning of a word
self.head -= 4;
} else {
self.head -= self.head % 4;
self.head.floor_to_the_nearest(4);
}
}
@@ -208,9 +208,9 @@ impl Cursor {
{
self.head = min(self.head + BYTES_PER_LINE, max);
} else {
self.tail -= self.tail % BYTES_PER_LINE;
self.tail.floor_to_the_nearest(BYTES_PER_LINE);
self.head = min(
self.head + BYTES_PER_LINE - 1 - (self.head % BYTES_PER_LINE),
self.head.floored_to_the_nearest(BYTES_PER_LINE) + BYTES_PER_LINE - 1,
max
);
}
@@ -225,11 +225,11 @@ impl Cursor {
(self.tail % BYTES_PER_LINE == BYTES_PER_LINE - 1 ||
self.tail == max)
{
self.head = self.head.saturating_sub(BYTES_PER_LINE);
self.head.saturating_subtract(BYTES_PER_LINE);
} else {
self.head -= self.head % BYTES_PER_LINE;
self.head.floor_to_the_nearest(BYTES_PER_LINE);
self.tail = min(
self.tail + BYTES_PER_LINE - 1 - (self.tail % BYTES_PER_LINE),
self.tail.floored_to_the_nearest(BYTES_PER_LINE) + BYTES_PER_LINE - 1,
max
);
}
@@ -237,11 +237,7 @@ impl Cursor {
}
const fn previous_multiple_of(multiple: usize, number: usize) -> usize {
if number == 0 {
0
} else {
(number - 1) - ((number - 1) % multiple)
}
number.saturating_sub(1).floored_to_the_nearest(multiple)
}
mod tests {
+1 -3
View File
@@ -5,6 +5,7 @@
#![feature(exact_bitshifts)]
#![feature(hash_set_entry)]
#![feature(trim_prefix_suffix)]
#![feature(const_trait_impl)]
use arguments::Arguments;
use clap::Parser;
@@ -33,9 +34,6 @@ const LINES_OF_PADDING: usize = 5;
const BYTES_OF_PADDING: usize = LINES_OF_PADDING * BYTES_PER_LINE;
// TODO:
// - fix scroll clamping
// - fix scrolling in select mode
// - shouldn't clamp tail
// - `go` goto entered offset
// - search
// - `/` hex, `A-/` ascii
+4
View File
@@ -1,7 +1,11 @@
mod cardinality;
mod empty_span;
mod custom_greys;
mod floor_to_the_nearest;
mod saturating_subtract;
pub use cardinality::HasCardinality;
pub use empty_span::empty_span;
pub use custom_greys::CustomGreys;
pub use floor_to_the_nearest::Floorable;
pub use saturating_subtract::SaturatingSubtract;
+16
View File
@@ -0,0 +1,16 @@
pub const trait Floorable {
fn floor_to_the_nearest(&mut self, step: Self);
fn floored_to_the_nearest(self, step: Self) -> Self;
}
const impl Floorable for usize {
fn floor_to_the_nearest(&mut self, step: Self) {
*self -= *self % step;
}
fn floored_to_the_nearest(self, step: Self) -> Self {
self - (self % step)
}
}
+9
View File
@@ -0,0 +1,9 @@
pub trait SaturatingSubtract {
fn saturating_subtract(&mut self, other: Self);
}
impl SaturatingSubtract for usize {
fn saturating_subtract(&mut self, other: Self) {
*self = self.saturating_sub(other);
}
}