Files
feresaria/crates/ferese-layout/src/scrolling.rs
T

1425 lines
49 KiB
Rust

use std::collections::{HashMap, HashSet};
use crate::{
ConstraintKind, ConstraintWarning, Direction, GapConfig, LayoutError, LayoutResult, Rect,
SizeConstraints, WindowId, normalized_constraints, record_minimum_warnings,
};
const DEFAULT_WIDTH: f64 = 0.5;
const MIN_COLUMN_WIDTH: f64 = 0.1;
const MAX_COLUMN_WIDTH: f64 = 2.0;
const MIN_ROW_HEIGHT: f64 = 0.05;
const COMFORT_START: f64 = 0.2;
const COMFORT_END: f64 = 0.8;
#[derive(Clone, Copy, Debug, PartialEq)]
pub enum ColumnWidth {
Proportion(f64),
Fixed(f64),
Full,
}
#[derive(Clone, Copy, Debug, Default, Eq, PartialEq)]
pub enum ViewportFocusStrategy {
#[default]
Minimal,
Center,
Paged,
}
impl Default for ColumnWidth {
fn default() -> Self {
Self::Proportion(DEFAULT_WIDTH)
}
}
#[derive(Clone, Debug, PartialEq)]
pub struct Column {
pub windows: Vec<WindowId>,
pub active: usize,
pub width: ColumnWidth,
pub heights: Vec<f64>,
}
impl Column {
fn new(window: WindowId, width: ColumnWidth) -> Self {
Self {
windows: vec![window],
active: 0,
width: normalized_width(width),
heights: vec![1.0],
}
}
fn normalize_heights(&mut self) {
if self.windows.is_empty() {
self.heights.clear();
return;
}
if self.heights.len() != self.windows.len() {
self.heights.resize(self.windows.len(), 1.0);
}
self.heights.iter_mut().for_each(|height| {
if !height.is_finite() || *height <= 0.0 {
*height = 1.0;
}
});
let total = self.heights.iter().sum::<f64>();
self.heights.iter_mut().for_each(|height| *height /= total);
self.active = self.active.min(self.windows.len() - 1);
}
}
#[derive(Clone, Debug, PartialEq)]
pub struct ScrollingLayout {
columns: Vec<Column>,
active_column: Option<usize>,
viewport_x: f64,
neighbor_context: f64,
default_width: ColumnWidth,
focus_strategy: ViewportFocusStrategy,
reveal_pending: bool,
width_cycle_pending: bool,
last_viewport_width: Option<f64>,
}
impl Default for ScrollingLayout {
fn default() -> Self {
Self {
columns: Vec::new(),
active_column: None,
viewport_x: 0.0,
neighbor_context: 48.0,
default_width: ColumnWidth::default(),
focus_strategy: ViewportFocusStrategy::Minimal,
reveal_pending: false,
width_cycle_pending: false,
last_viewport_width: None,
}
}
}
impl ScrollingLayout {
pub fn with_default_width(default_width: ColumnWidth) -> Self {
Self {
default_width: normalized_width(default_width),
..Self::default()
}
}
pub fn set_focus_strategy(&mut self, strategy: ViewportFocusStrategy) {
self.focus_strategy = strategy;
self.reveal_pending = true;
}
pub fn default_width(&self) -> ColumnWidth {
self.default_width
}
pub fn columns(&self) -> &[Column] {
&self.columns
}
pub fn active_column(&self) -> Option<usize> {
self.active_column
}
pub fn active_window(&self) -> Option<WindowId> {
let column = self.columns.get(self.active_column?)?;
column.windows.get(column.active).copied()
}
pub fn viewport_x(&self) -> f64 {
self.viewport_x
}
pub fn contains(&self, window: WindowId) -> bool {
self.window_location(window).is_some()
}
pub fn window_ids(&self) -> impl Iterator<Item = WindowId> + '_ {
self.columns
.iter()
.flat_map(|column| column.windows.iter().copied())
}
pub fn insert(
&mut self,
window: WindowId,
focused: Option<WindowId>,
) -> Result<(), LayoutError> {
if self.contains(window) {
return Err(LayoutError::DuplicateWindow(window));
}
let index = focused
.and_then(|focused| self.window_location(focused))
.map(|(column, _)| column + 1)
.unwrap_or(self.columns.len());
self.columns
.insert(index, Column::new(window, self.default_width));
self.active_column = Some(index);
self.reveal_pending = self.columns.len() > 1;
debug_assert!(self.validate().is_ok());
Ok(())
}
pub fn remove(&mut self, window: WindowId) -> Result<(), LayoutError> {
let (column_index, window_index) = self
.window_location(window)
.ok_or(LayoutError::UnknownWindow(window))?;
let column = &mut self.columns[column_index];
let removed_active_column =
self.active_column == Some(column_index) && column.windows.len() == 1;
column.windows.remove(window_index);
column.heights.remove(window_index);
if column.windows.is_empty() {
self.columns.remove(column_index);
self.active_column = match self.active_column {
None => None,
Some(_) if self.columns.is_empty() => None,
Some(active) if active > column_index => Some(active - 1),
Some(active) => Some(active.min(self.columns.len() - 1)),
};
} else {
column.active = column.active.min(column.windows.len() - 1);
column.normalize_heights();
}
self.reveal_pending |= (removed_active_column
|| self.focus_strategy == ViewportFocusStrategy::Paged)
&& !self.columns.is_empty();
debug_assert!(self.validate().is_ok());
Ok(())
}
pub fn focus(&mut self, window: WindowId) -> Result<(), LayoutError> {
let (column, index) = self
.window_location(window)
.ok_or(LayoutError::UnknownWindow(window))?;
let changed_column = self.active_column != Some(column);
self.active_column = Some(column);
self.columns[column].active = index;
self.reveal_pending |= changed_column;
Ok(())
}
pub fn move_into_column(
&mut self,
window: WindowId,
target: WindowId,
) -> Result<(), LayoutError> {
if window == target {
return Ok(());
}
self.window_location(target)
.ok_or(LayoutError::UnknownWindow(target))?;
self.remove(window)?;
let (target_column, target_index) = self
.window_location(target)
.expect("removing another window preserves the target");
let column = &mut self.columns[target_column];
let insertion = (target_index + 1).min(column.windows.len());
column.windows.insert(insertion, window);
column.heights.insert(insertion, 1.0);
column.active = insertion;
column.normalize_heights();
self.active_column = Some(target_column);
self.reveal_pending = true;
debug_assert!(self.validate().is_ok());
Ok(())
}
pub fn extract_to_column(&mut self, window: WindowId) -> Result<(), LayoutError> {
let (source, _) = self
.window_location(window)
.ok_or(LayoutError::UnknownWindow(window))?;
if self.columns[source].windows.len() == 1 {
self.active_column = Some(source);
return Ok(());
}
self.remove(window)?;
let insertion = (source + 1).min(self.columns.len());
self.columns
.insert(insertion, Column::new(window, self.default_width));
self.active_column = Some(insertion);
self.reveal_pending = true;
debug_assert!(self.validate().is_ok());
Ok(())
}
pub fn set_column_width(
&mut self,
window: WindowId,
width: ColumnWidth,
) -> Result<(), LayoutError> {
let (column, _) = self
.window_location(window)
.ok_or(LayoutError::UnknownWindow(window))?;
self.columns[column].width = normalized_width(width);
self.reveal_pending = true;
Ok(())
}
pub fn cycle_column_width(
&mut self,
window: WindowId,
presets: &[ColumnWidth],
) -> Result<bool, LayoutError> {
let (column, _) = self
.window_location(window)
.ok_or(LayoutError::UnknownWindow(window))?;
let presets = presets
.iter()
.copied()
.map(normalized_width)
.collect::<Vec<_>>();
if presets.is_empty() {
return Ok(false);
}
let current = normalized_width(self.columns[column].width);
let next = presets
.iter()
.position(|preset| *preset == current)
.map(|index| presets[(index + 1) % presets.len()])
.unwrap_or(presets[0]);
self.columns[column].width = next;
self.width_cycle_pending = next != current;
Ok(next != current)
}
pub fn center_window(
&mut self,
window: WindowId,
bounds: Rect,
gaps: GapConfig,
constraints: &HashMap<WindowId, SizeConstraints>,
) -> Result<bool, LayoutError> {
let before = self.viewport_x;
let result = self.geometry_with_constraints(bounds, gaps, constraints, Some(window))?;
let rect = result
.geometry
.get(&window)
.copied()
.ok_or(LayoutError::UnknownWindow(window))?;
let viewport_center = bounds.x + bounds.width / 2.0;
let window_center = rect.x + rect.width / 2.0;
self.viewport_x += window_center - viewport_center;
self.geometry_with_constraints(bounds, gaps, constraints, Some(window))?;
Ok(self.viewport_x != before)
}
pub fn directional_neighbor(
&self,
window: WindowId,
direction: Direction,
) -> Result<Option<WindowId>, LayoutError> {
let (column, row) = self
.window_location(window)
.ok_or(LayoutError::UnknownWindow(window))?;
let neighbor = match direction {
Direction::Up => row
.checked_sub(1)
.map(|row| self.columns[column].windows[row]),
Direction::Down => self.columns[column].windows.get(row + 1).copied(),
Direction::Left => column.checked_sub(1).map(|column| {
let column = &self.columns[column];
column.windows[column.active]
}),
Direction::Right => self
.columns
.get(column + 1)
.map(|column| column.windows[column.active]),
};
Ok(neighbor)
}
pub fn move_window(
&mut self,
window: WindowId,
direction: Direction,
) -> Result<bool, LayoutError> {
let (column, row) = self
.window_location(window)
.ok_or(LayoutError::UnknownWindow(window))?;
match direction {
Direction::Up if row > 0 => {
self.columns[column].windows.swap(row, row - 1);
self.columns[column].heights.swap(row, row - 1);
self.columns[column].active = row - 1;
}
Direction::Down if row + 1 < self.columns[column].windows.len() => {
self.columns[column].windows.swap(row, row + 1);
self.columns[column].heights.swap(row, row + 1);
self.columns[column].active = row + 1;
}
Direction::Left if column > 0 => self.move_horizontally(window, column - 1)?,
Direction::Right if column + 1 < self.columns.len() => {
self.move_horizontally(window, column + 1)?
}
_ => return Ok(false),
}
debug_assert!(self.validate().is_ok());
Ok(true)
}
pub fn resize_window(
&mut self,
window: WindowId,
direction: Direction,
amount: f64,
) -> Result<bool, LayoutError> {
let (column, row) = self
.window_location(window)
.ok_or(LayoutError::UnknownWindow(window))?;
let amount = if amount.is_finite() {
amount.abs()
} else {
0.0
};
if amount == 0.0 {
return Ok(false);
}
let changed = match direction {
Direction::Left | Direction::Right => {
let current = match normalized_width(self.columns[column].width) {
ColumnWidth::Proportion(value) => value,
ColumnWidth::Fixed(_) | ColumnWidth::Full => DEFAULT_WIDTH,
};
let adjustment = if direction == Direction::Right {
amount
} else {
-amount
};
let resized = (current + adjustment).clamp(MIN_COLUMN_WIDTH, MAX_COLUMN_WIDTH);
self.columns[column].width = ColumnWidth::Proportion(resized);
resized != current
}
Direction::Up if row > 0 => {
resize_rows(&mut self.columns[column], row, row - 1, amount)
}
Direction::Down if row + 1 < self.columns[column].windows.len() => {
resize_rows(&mut self.columns[column], row, row + 1, amount)
}
Direction::Up | Direction::Down => false,
};
debug_assert!(self.validate().is_ok());
Ok(changed)
}
pub fn geometry_with_constraints(
&mut self,
bounds: Rect,
gaps: GapConfig,
constraints: &HashMap<WindowId, SizeConstraints>,
focused: Option<WindowId>,
) -> Result<LayoutResult, LayoutError> {
if let Some(focused) = focused {
self.focus(focused)?;
}
self.validate()?;
if self.columns.is_empty() {
self.viewport_x = 0.0;
return Ok(LayoutResult::default());
}
let window_count = self.window_ids().count();
let inner = finite_nonnegative(gaps.inner);
let outer = if gaps.smart && window_count == 1 {
0.0
} else {
finite_nonnegative(gaps.outer)
};
let viewport_width = (bounds.width - outer * 2.0).max(1.0);
let viewport_height = (bounds.height - outer * 2.0).max(1.0);
let mut column_positions = Vec::with_capacity(self.columns.len());
let mut next_column_x = 0.0;
for column in &self.columns {
let requested = match normalized_width(column.width) {
ColumnWidth::Proportion(proportion) => {
((viewport_width + inner) * proportion - inner).max(1.0)
}
ColumnWidth::Fixed(width) => width,
ColumnWidth::Full => viewport_width,
};
let minimum = column
.windows
.iter()
.map(|window| {
constraints
.get(window)
.copied()
.map(normalized_constraints)
.unwrap_or_default()
.min_width
})
.fold(1.0_f64, f64::max);
let width = requested.max(minimum).max(1.0);
column_positions.push((next_column_x, width));
next_column_x += width + inner;
}
let viewport_resized = self.last_viewport_width != Some(viewport_width);
self.last_viewport_width = Some(viewport_width);
if self.width_cycle_pending {
self.retarget_after_width_cycle(&column_positions, viewport_width);
self.width_cycle_pending = false;
self.reveal_pending = false;
} else if self.reveal_pending
|| (viewport_resized && self.focus_strategy == ViewportFocusStrategy::Paged)
{
self.reveal_active_column(&column_positions, viewport_width);
self.reveal_pending = false;
}
let mut result = LayoutResult::default();
for (column_index, column) in self.columns.iter().enumerate() {
let (column_x, column_width) = column_positions[column_index];
let available_height = (viewport_height
- inner * (column.windows.len().saturating_sub(1) as f64))
.max(1.0);
let mut y = bounds.y + outer;
for (window_index, window) in column.windows.iter().enumerate() {
let mut rect = Rect::new(
bounds.x + outer + column_x - self.viewport_x,
y,
column_width,
available_height * column.heights[window_index],
);
let constraint = constraints
.get(window)
.copied()
.map(normalized_constraints)
.unwrap_or_default();
record_minimum_warnings(*window, rect, constraint, &mut result.warnings);
apply_maximums(*window, &mut rect, constraint, &mut result.warnings);
y += available_height * column.heights[window_index] + inner;
result.geometry.insert(*window, rect);
}
}
Ok(result)
}
fn reveal_active_column(&mut self, positions: &[(f64, f64)], viewport_width: f64) {
if let Some(start) = self.paged_viewport(positions, viewport_width) {
self.viewport_x = start;
return;
}
let Some(active) = self.active_column else {
return;
};
let (start, width) = positions[active];
let end = start + width;
if self.focus_strategy == ViewportFocusStrategy::Center {
self.viewport_x = start + width / 2.0 - viewport_width / 2.0;
return;
}
if start >= self.viewport_x && end <= self.viewport_x + viewport_width {
return;
}
let comfort_start = viewport_width * COMFORT_START;
let comfort_end = viewport_width * COMFORT_END;
let comfort_width = comfort_end - comfort_start;
if width > comfort_width {
let context = finite_nonnegative(self.neighbor_context).min(viewport_width / 3.0);
if start > self.viewport_x + comfort_start {
self.viewport_x = start - context;
} else if end < self.viewport_x + comfort_end {
self.viewport_x = end - viewport_width + context;
}
} else if start < self.viewport_x + comfort_start {
self.viewport_x = start - comfort_start;
} else if end > self.viewport_x + comfort_end {
self.viewport_x = end - comfort_end;
}
}
fn paged_viewport(&self, positions: &[(f64, f64)], viewport_width: f64) -> Option<f64> {
if self.focus_strategy != ViewportFocusStrategy::Paged {
return None;
}
let active = self.active_column?;
// Pack actual allocated widths, including gaps and client constraints.
// Page boundaries are independent of focus direction. An oversized
// column occupies its own page rather than overlapping its neighbors.
let mut first = 0;
while first < positions.len() {
let (start, _) = positions[first];
let mut last = first;
while let Some(&(next_start, next_width)) = positions.get(last + 1) {
if next_start + next_width - start > viewport_width + 1e-6 {
break;
}
last += 1;
}
if active <= last {
return Some(start);
}
first = last + 1;
}
None
}
fn retarget_after_width_cycle(&mut self, positions: &[(f64, f64)], viewport_width: f64) {
if let Some(start) = self.paged_viewport(positions, viewport_width) {
self.viewport_x = start;
return;
}
let Some(active) = self.active_column else {
return;
};
let Some(&(start, width)) = positions.get(active) else {
return;
};
let Some(&(last_start, last_width)) = positions.last() else {
return;
};
let strip_width = last_start + last_width;
if strip_width <= viewport_width {
self.viewport_x = 0.0;
} else if width >= viewport_width {
self.viewport_x = start;
} else {
self.viewport_x = (start + width - viewport_width).max(0.0);
}
}
fn move_horizontally(
&mut self,
window: WindowId,
destination: usize,
) -> Result<(), LayoutError> {
let (source, _) = self
.window_location(window)
.ok_or(LayoutError::UnknownWindow(window))?;
if self.columns[source].windows.len() == 1 {
self.columns.swap(source, destination);
self.active_column = Some(destination);
self.reveal_pending = true;
return Ok(());
}
let insertion = if destination < source {
source
} else {
source + 1
};
self.remove(window)?;
let insertion = insertion.min(self.columns.len());
self.columns
.insert(insertion, Column::new(window, self.default_width));
self.active_column = Some(insertion);
self.reveal_pending = true;
Ok(())
}
fn window_location(&self, window: WindowId) -> Option<(usize, usize)> {
self.columns.iter().enumerate().find_map(|(column, data)| {
data.windows
.iter()
.position(|candidate| *candidate == window)
.map(|index| (column, index))
})
}
pub fn validate(&self) -> Result<(), LayoutError> {
if !self.viewport_x.is_finite() {
return Err(LayoutError::InvalidTree(
"scrolling viewport offset is invalid",
));
}
if normalized_width(self.default_width) != self.default_width {
return Err(LayoutError::InvalidTree(
"scrolling default column width is invalid",
));
}
if self.columns.is_empty() {
return if self.active_column.is_none() {
Ok(())
} else {
Err(LayoutError::InvalidTree(
"empty scrolling layout has an active column",
))
};
}
if self
.active_column
.is_none_or(|active| active >= self.columns.len())
{
return Err(LayoutError::InvalidTree(
"scrolling active column is invalid",
));
}
let mut windows = HashSet::new();
for column in &self.columns {
if normalized_width(column.width) != column.width {
return Err(LayoutError::InvalidTree(
"scrolling column width is invalid",
));
}
if column.windows.is_empty() {
return Err(LayoutError::InvalidTree("scrolling column is empty"));
}
if column.active >= column.windows.len() || column.heights.len() != column.windows.len()
{
return Err(LayoutError::InvalidTree(
"scrolling column metadata is invalid",
));
}
if !column
.heights
.iter()
.all(|height| height.is_finite() && *height > 0.0)
{
return Err(LayoutError::InvalidTree("scrolling height is invalid"));
}
for window in &column.windows {
if !windows.insert(*window) {
return Err(LayoutError::DuplicateWindow(*window));
}
}
}
Ok(())
}
}
fn resize_rows(column: &mut Column, row: usize, neighbor: usize, amount: f64) -> bool {
let transferable = (column.heights[neighbor] - MIN_ROW_HEIGHT).max(0.0);
let adjustment = amount.min(transferable);
if adjustment == 0.0 {
return false;
}
column.heights[row] += adjustment;
column.heights[neighbor] -= adjustment;
true
}
fn normalized_width(width: ColumnWidth) -> ColumnWidth {
match width {
ColumnWidth::Proportion(value) if value.is_finite() && value > 0.0 => {
ColumnWidth::Proportion(value)
}
ColumnWidth::Fixed(value) if value.is_finite() && value > 0.0 => ColumnWidth::Fixed(value),
ColumnWidth::Full => ColumnWidth::Full,
_ => ColumnWidth::default(),
}
}
fn finite_nonnegative(value: f64) -> f64 {
if value.is_finite() {
value.max(0.0)
} else {
0.0
}
}
fn apply_maximums(
window: WindowId,
rect: &mut Rect,
constraints: SizeConstraints,
warnings: &mut Vec<ConstraintWarning>,
) {
if let Some(maximum) = constraints.max_width
&& rect.width > maximum
{
warnings.push(ConstraintWarning {
window,
kind: ConstraintKind::MaximumWidth,
requested: maximum,
assigned: rect.width,
});
rect.width = maximum;
}
if let Some(maximum) = constraints.max_height
&& rect.height > maximum
{
warnings.push(ConstraintWarning {
window,
kind: ConstraintKind::MaximumHeight,
requested: maximum,
assigned: rect.height,
});
rect.height = maximum;
}
}
#[cfg(test)]
mod tests {
use super::*;
fn window(id: u64) -> WindowId {
WindowId(id)
}
#[test]
fn inserts_new_columns_after_focus() {
let mut layout = ScrollingLayout::default();
layout.insert(window(1), None).unwrap();
layout.insert(window(2), Some(window(1))).unwrap();
layout.insert(window(3), Some(window(1))).unwrap();
assert_eq!(
layout.window_ids().collect::<Vec<_>>(),
vec![window(1), window(3), window(2)]
);
assert_eq!(layout.active_column(), Some(1));
}
#[test]
fn configured_default_width_is_applied_to_new_columns() {
let mut layout = ScrollingLayout::with_default_width(ColumnWidth::Full);
layout.insert(window(1), None).unwrap();
layout.insert(window(2), Some(window(1))).unwrap();
assert_eq!(layout.default_width(), ColumnWidth::Full);
assert!(
layout
.columns()
.iter()
.all(|column| column.width == ColumnWidth::Full)
);
}
#[test]
fn focus_reveal_scrolls_only_as_far_as_needed() {
let mut layout = ScrollingLayout::default();
for id in 1..=4 {
layout
.insert(window(id), Some(window(id.saturating_sub(1))))
.unwrap();
}
let bounds = Rect::new(0.0, 0.0, 1_000.0, 800.0);
let gaps = GapConfig {
inner: 0.0,
outer: 0.0,
smart: false,
};
let result = layout
.geometry_with_constraints(bounds, gaps, &HashMap::new(), Some(window(4)))
.unwrap();
assert_eq!(layout.viewport_x(), 1_200.0);
assert_eq!(result.geometry[&window(4)].x, 300.0);
}
#[test]
fn two_half_width_columns_fit_without_focus_scrolling() {
let mut layout = ScrollingLayout::default();
layout.insert(window(1), None).unwrap();
layout.insert(window(2), Some(window(1))).unwrap();
let bounds = Rect::new(0.0, 0.0, 1_000.0, 800.0);
let gaps = GapConfig {
inner: 10.0,
outer: 10.0,
smart: false,
};
let first = layout
.geometry_with_constraints(bounds, gaps, &HashMap::new(), Some(window(1)))
.unwrap();
assert_eq!(layout.viewport_x(), 0.0);
let second = layout
.geometry_with_constraints(bounds, gaps, &HashMap::new(), Some(window(2)))
.unwrap();
assert_eq!(layout.viewport_x(), 0.0);
assert_eq!(first.geometry, second.geometry);
assert_eq!(
second.geometry[&window(1)],
Rect::new(10.0, 10.0, 485.0, 780.0)
);
assert_eq!(
second.geometry[&window(2)],
Rect::new(505.0, 10.0, 485.0, 780.0)
);
}
#[test]
fn full_width_column_stays_in_strip_when_new_half_window_opens() {
let (mut layout, bounds, gaps) = two_half_width_layout();
layout.set_focus_strategy(ViewportFocusStrategy::Paged);
layout
.set_column_width(window(2), ColumnWidth::Proportion(1.0))
.unwrap();
let zoomed = layout
.geometry_with_constraints(bounds, gaps, &HashMap::new(), Some(window(2)))
.unwrap();
assert_eq!(zoomed.geometry[&window(2)].width, 980.0);
layout.insert(window(3), Some(window(2))).unwrap();
let opened = layout
.geometry_with_constraints(bounds, gaps, &HashMap::new(), Some(window(3)))
.unwrap();
let previous = opened.geometry[&window(2)];
let new = opened.geometry[&window(3)];
assert_eq!(previous.width, 980.0);
assert_eq!(new, Rect::new(10.0, 10.0, 485.0, 780.0));
assert_eq!(previous.x + previous.width + gaps.inner, new.x);
assert_eq!(layout.active_window(), Some(window(3)));
layout
.set_column_width(window(2), ColumnWidth::Proportion(0.5))
.unwrap();
let restored = layout
.geometry_with_constraints(bounds, gaps, &HashMap::new(), Some(window(2)))
.unwrap();
assert_eq!(restored.geometry[&window(2)].width, 485.0);
}
fn paged_layout(count: u64) -> (ScrollingLayout, Rect, GapConfig) {
let (mut layout, bounds, gaps) = two_half_width_layout();
layout.set_focus_strategy(ViewportFocusStrategy::Paged);
for id in 3..=count {
layout.insert(window(id), Some(window(id - 1))).unwrap();
}
(layout, bounds, gaps)
}
#[test]
fn paged_focus_snaps_six_half_columns_in_both_directions() {
let (mut layout, bounds, gaps) = paged_layout(6);
for focused in [1, 2, 3, 4, 5, 6, 5, 4, 3, 2, 1] {
let geometry = layout
.geometry_with_constraints(bounds, gaps, &HashMap::new(), Some(window(focused)))
.unwrap()
.geometry;
let first = (focused - 1) / 2 * 2 + 1;
assert_eq!(layout.viewport_x(), ((first - 1) / 2) as f64 * 990.0);
assert_eq!(geometry[&window(first)].x, 10.0);
assert_eq!(geometry[&window(first + 1)].x, 505.0);
assert_eq!(
geometry[&window(first + 1)].x + geometry[&window(first + 1)].width,
990.0
);
}
}
#[test]
fn paged_focus_realigns_after_output_resize() {
let (mut layout, bounds, gaps) = paged_layout(6);
layout
.geometry_with_constraints(bounds, gaps, &HashMap::new(), Some(window(5)))
.unwrap();
let bounds = Rect::new(20.0, 48.0, 1400.0, 800.0);
let result = layout
.geometry_with_constraints(bounds, gaps, &HashMap::new(), Some(window(5)))
.unwrap();
assert_eq!(layout.viewport_x(), 2780.0);
assert_eq!(result.geometry[&window(5)].x, 30.0);
assert_eq!(result.geometry[&window(6)].x, 725.0);
}
#[test]
fn paged_focus_preserves_explicit_center_until_focus_changes() {
let (mut layout, bounds, gaps) = paged_layout(4);
layout
.center_window(window(2), bounds, gaps, &HashMap::new())
.unwrap();
let result = layout
.geometry_with_constraints(bounds, gaps, &HashMap::new(), Some(window(2)))
.unwrap();
let rect = result.geometry[&window(2)];
assert_eq!(rect.x + rect.width / 2.0, 500.0);
let result = layout
.geometry_with_constraints(bounds, gaps, &HashMap::new(), Some(window(1)))
.unwrap();
assert_eq!(result.geometry[&window(1)].x, 10.0);
}
#[test]
fn full_width_column_occupies_its_own_page() {
let (mut layout, bounds, gaps) = paged_layout(4);
layout.columns[0].width = ColumnWidth::Full;
let result = layout
.geometry_with_constraints(bounds, gaps, &HashMap::new(), Some(window(3)))
.unwrap();
assert_eq!(result.geometry[&window(2)].x, 10.0);
assert_eq!(result.geometry[&window(3)].x, 505.0);
let result = layout
.geometry_with_constraints(bounds, gaps, &HashMap::new(), Some(window(4)))
.unwrap();
assert_eq!(result.geometry[&window(4)].x, 10.0);
}
#[test]
fn client_minimums_split_columns_across_pages() {
let (mut layout, bounds, gaps) = paged_layout(2);
let constraints = HashMap::from([(
window(1),
SizeConstraints {
min_width: 700.0,
..Default::default()
},
)]);
let result = layout
.geometry_with_constraints(bounds, gaps, &constraints, Some(window(2)))
.unwrap();
assert!(layout.viewport_x() > 0.0);
let rect = result.geometry[&window(2)];
assert!(rect.x >= 10.0 && rect.x + rect.width <= 990.0);
}
#[test]
fn paged_focus_groups_thirds_in_both_directions_at_fractional_sizes() {
let (mut layout, _, gaps) = paged_layout(6);
for column in &mut layout.columns {
column.width = ColumnWidth::Proportion(1.0 / 3.0);
}
let bounds = Rect::new(13.25, 48.5, 1000.5, 800.25);
for focused in [1, 2, 3, 4, 5, 6, 5, 4, 3, 2, 1] {
let result = layout
.geometry_with_constraints(bounds, gaps, &HashMap::new(), Some(window(focused)))
.unwrap();
let first = (focused - 1) / 3 * 3 + 1;
assert!((result.geometry[&window(first)].x - 23.25).abs() < 1e-6);
let last = result.geometry[&window(first + 2)];
assert!((last.x + last.width - 1003.75).abs() < 1e-6);
}
}
#[test]
fn paged_focus_packs_mixed_widths_by_actual_fit() {
let (mut layout, bounds, gaps) = paged_layout(5);
let widths = [0.6, 0.4, 0.25, 0.5, 0.25];
for (column, width) in layout.columns.iter_mut().zip(widths) {
column.width = ColumnWidth::Proportion(width);
}
for (focused, first) in [(1, 1), (2, 1), (3, 3), (4, 3), (5, 3), (2, 1)] {
let result = layout
.geometry_with_constraints(bounds, gaps, &HashMap::new(), Some(window(focused)))
.unwrap();
assert_eq!(result.geometry[&window(first)].x, 10.0);
let rect = result.geometry[&window(focused)];
assert!(rect.x >= 10.0 && rect.x + rect.width <= 990.0 + 1e-6);
}
}
#[test]
fn oversized_page_does_not_absorb_neighbor_and_removal_repacks() {
let (mut layout, bounds, gaps) = paged_layout(4);
let constraints = HashMap::from([(
window(1),
SizeConstraints {
min_width: 1200.0,
..Default::default()
},
)]);
let result = layout
.geometry_with_constraints(bounds, gaps, &constraints, Some(window(2)))
.unwrap();
assert_eq!(result.geometry[&window(2)].x, 10.0);
assert_eq!(result.geometry[&window(3)].x, 505.0);
layout.remove(window(1)).unwrap();
let result = layout
.geometry_with_constraints(bounds, gaps, &HashMap::new(), Some(window(2)))
.unwrap();
assert_eq!(layout.viewport_x(), 0.0);
assert_eq!(result.geometry[&window(2)].x, 10.0);
assert_eq!(result.geometry[&window(3)].x, 505.0);
}
#[test]
fn manual_resize_does_not_retarget_the_viewport() {
let mut layout = ScrollingLayout::default();
let bounds = Rect::new(0.0, 0.0, 1_000.0, 800.0);
let gaps = GapConfig {
inner: 0.0,
outer: 0.0,
smart: false,
};
for id in 1..=3 {
layout
.insert(window(id), (id > 1).then(|| window(id - 1)))
.unwrap();
layout
.geometry_with_constraints(bounds, gaps, &HashMap::new(), Some(window(id)))
.unwrap();
}
let before = layout.viewport_x();
layout
.resize_window(window(3), Direction::Right, 0.5)
.unwrap();
layout
.geometry_with_constraints(bounds, gaps, &HashMap::new(), Some(window(3)))
.unwrap();
assert_eq!(layout.viewport_x(), before);
}
#[test]
fn viewport_is_not_clamped_to_the_column_strip() {
let mut layout = ScrollingLayout::default();
let bounds = Rect::new(0.0, 0.0, 1_000.0, 800.0);
let gaps = GapConfig {
inner: 0.0,
outer: 0.0,
smart: false,
};
for id in 1..=3 {
layout.insert(window(id), None).unwrap();
}
layout
.geometry_with_constraints(bounds, gaps, &HashMap::new(), Some(window(3)))
.unwrap();
layout
.geometry_with_constraints(bounds, gaps, &HashMap::new(), Some(window(1)))
.unwrap();
assert_eq!(layout.viewport_x(), -200.0);
}
#[test]
fn closing_non_focused_column_does_not_move_viewport() {
let mut layout = ScrollingLayout::default();
let bounds = Rect::new(0.0, 0.0, 1_000.0, 800.0);
let gaps = GapConfig {
inner: 0.0,
outer: 0.0,
smart: false,
};
for id in 1..=4 {
layout.insert(window(id), None).unwrap();
}
layout
.geometry_with_constraints(bounds, gaps, &HashMap::new(), Some(window(4)))
.unwrap();
let before = layout.viewport_x();
layout.remove(window(1)).unwrap();
layout
.geometry_with_constraints(bounds, gaps, &HashMap::new(), Some(window(4)))
.unwrap();
assert_eq!(layout.viewport_x(), before);
}
#[test]
fn grouping_and_extracting_preserve_membership() {
let mut layout = ScrollingLayout::default();
layout.insert(window(1), None).unwrap();
layout.insert(window(2), Some(window(1))).unwrap();
layout.move_into_column(window(2), window(1)).unwrap();
assert_eq!(layout.columns().len(), 1);
assert_eq!(layout.columns()[0].windows, vec![window(1), window(2)]);
layout.extract_to_column(window(2)).unwrap();
assert_eq!(layout.columns().len(), 2);
assert_eq!(
layout.window_ids().collect::<HashSet<_>>(),
HashSet::from([window(1), window(2)])
);
}
#[test]
fn later_column_changes_do_not_move_the_first_column() {
let mut layout = ScrollingLayout::default();
layout.insert(window(1), None).unwrap();
let bounds = Rect::new(0.0, 0.0, 1_000.0, 800.0);
let gaps = GapConfig {
smart: false,
..GapConfig::default()
};
let first = layout
.geometry_with_constraints(bounds, gaps, &HashMap::new(), Some(window(1)))
.unwrap()
.geometry[&window(1)];
layout.insert(window(2), Some(window(1))).unwrap();
let second = layout
.geometry_with_constraints(bounds, gaps, &HashMap::new(), Some(window(1)))
.unwrap()
.geometry[&window(1)];
assert_eq!(first.x, second.x);
assert_eq!(first.width, second.width);
}
#[test]
fn directional_navigation_follows_columns_and_rows() {
let mut layout = ScrollingLayout::default();
layout.insert(window(1), None).unwrap();
layout.insert(window(2), Some(window(1))).unwrap();
layout.insert(window(3), Some(window(2))).unwrap();
layout.move_into_column(window(3), window(2)).unwrap();
assert_eq!(
layout.directional_neighbor(window(1), Direction::Right),
Ok(Some(window(3)))
);
assert_eq!(
layout.directional_neighbor(window(3), Direction::Up),
Ok(Some(window(2)))
);
assert_eq!(
layout.directional_neighbor(window(2), Direction::Down),
Ok(Some(window(3)))
);
}
#[test]
fn vertical_moves_reorder_rows_and_horizontal_moves_extract_them() {
let mut layout = ScrollingLayout::default();
layout.insert(window(1), None).unwrap();
layout.insert(window(2), Some(window(1))).unwrap();
layout.insert(window(3), Some(window(2))).unwrap();
layout.move_into_column(window(3), window(2)).unwrap();
assert!(layout.move_window(window(3), Direction::Up).unwrap());
assert_eq!(layout.columns()[1].windows, vec![window(3), window(2)]);
assert!(layout.move_window(window(3), Direction::Left).unwrap());
assert_eq!(layout.columns().len(), 3);
assert_eq!(
layout.window_ids().collect::<Vec<_>>(),
vec![window(1), window(3), window(2)]
);
}
#[test]
fn resize_changes_column_width_and_neighboring_row_weights() {
let mut layout = ScrollingLayout::default();
layout.insert(window(1), None).unwrap();
layout.insert(window(2), Some(window(1))).unwrap();
layout.move_into_column(window(2), window(1)).unwrap();
assert!(
layout
.resize_window(window(1), Direction::Right, 0.1)
.unwrap()
);
assert_eq!(layout.columns()[0].width, ColumnWidth::Proportion(0.6));
assert!(
layout
.resize_window(window(1), Direction::Down, 0.1)
.unwrap()
);
assert_eq!(layout.columns()[0].heights, vec![0.6, 0.4]);
}
#[test]
fn width_cycle_wraps_through_configured_presets() {
let mut layout = ScrollingLayout::default();
layout.insert(window(1), None).unwrap();
let presets = [
ColumnWidth::Proportion(0.5),
ColumnWidth::Proportion(2.0 / 3.0),
ColumnWidth::Full,
];
assert!(layout.cycle_column_width(window(1), &presets).unwrap());
assert_eq!(
layout.columns()[0].width,
ColumnWidth::Proportion(2.0 / 3.0)
);
assert!(layout.cycle_column_width(window(1), &presets).unwrap());
assert_eq!(layout.columns()[0].width, ColumnWidth::Full);
assert!(layout.cycle_column_width(window(1), &presets).unwrap());
assert_eq!(layout.columns()[0].width, ColumnWidth::Proportion(0.5));
}
#[test]
fn left_column_zoom_pushes_and_restores_the_right_column() {
let (mut layout, bounds, gaps) = two_half_width_layout();
let presets = [ColumnWidth::Proportion(0.5), ColumnWidth::Full];
layout.focus(window(1)).unwrap();
layout
.geometry_with_constraints(bounds, gaps, &HashMap::new(), Some(window(1)))
.unwrap();
layout.cycle_column_width(window(1), &presets).unwrap();
let zoomed = layout
.geometry_with_constraints(bounds, gaps, &HashMap::new(), Some(window(1)))
.unwrap();
assert_eq!(layout.viewport_x(), 0.0);
assert_eq!(zoomed.geometry[&window(1)].x, 10.0);
assert_eq!(zoomed.geometry[&window(1)].width, 980.0);
assert_eq!(zoomed.geometry[&window(2)].x, 1_000.0);
layout.cycle_column_width(window(1), &presets).unwrap();
let restored = layout
.geometry_with_constraints(bounds, gaps, &HashMap::new(), Some(window(1)))
.unwrap();
assert_eq!(layout.viewport_x(), 0.0);
assert_eq!(restored.geometry[&window(1)].x, 10.0);
assert_eq!(restored.geometry[&window(2)].x, 505.0);
}
#[test]
fn right_column_zoom_moves_left_neighbor_out_and_back() {
let (mut layout, bounds, gaps) = two_half_width_layout();
let presets = [ColumnWidth::Proportion(0.5), ColumnWidth::Full];
layout
.geometry_with_constraints(bounds, gaps, &HashMap::new(), Some(window(2)))
.unwrap();
layout.cycle_column_width(window(2), &presets).unwrap();
let zoomed = layout
.geometry_with_constraints(bounds, gaps, &HashMap::new(), Some(window(2)))
.unwrap();
assert_eq!(layout.viewport_x(), 495.0);
assert_eq!(zoomed.geometry[&window(1)].x, -485.0);
assert_eq!(zoomed.geometry[&window(2)].x, 10.0);
assert_eq!(zoomed.geometry[&window(2)].width, 980.0);
layout.cycle_column_width(window(2), &presets).unwrap();
let restored = layout
.geometry_with_constraints(bounds, gaps, &HashMap::new(), Some(window(2)))
.unwrap();
assert_eq!(layout.viewport_x(), 0.0);
assert_eq!(restored.geometry[&window(1)].x, 10.0);
assert_eq!(restored.geometry[&window(2)].x, 505.0);
}
fn two_half_width_layout() -> (ScrollingLayout, Rect, GapConfig) {
let mut layout = ScrollingLayout::default();
layout.insert(window(1), None).unwrap();
layout.insert(window(2), Some(window(1))).unwrap();
(
layout,
Rect::new(0.0, 0.0, 1_000.0, 800.0),
GapConfig {
inner: 10.0,
outer: 10.0,
smart: false,
},
)
}
#[test]
fn explicit_center_places_a_middle_column_in_the_viewport_center() {
let mut layout = ScrollingLayout::default();
for id in 1_u64..=4 {
layout
.insert(
window(id),
id.checked_sub(1).filter(|id| *id > 0).map(window),
)
.unwrap();
}
let bounds = Rect::new(0.0, 0.0, 1_000.0, 800.0);
let gaps = GapConfig {
inner: 0.0,
outer: 0.0,
smart: false,
};
layout
.geometry_with_constraints(bounds, gaps, &HashMap::new(), Some(window(4)))
.unwrap();
assert!(
layout
.center_window(window(2), bounds, gaps, &HashMap::new())
.unwrap()
);
let result = layout
.geometry_with_constraints(bounds, gaps, &HashMap::new(), Some(window(2)))
.unwrap();
let rect = result.geometry[&window(2)];
assert_eq!(rect.x + rect.width / 2.0, 500.0);
}
#[test]
fn randomized_scrolling_operations_preserve_invariants() {
let mut layout = ScrollingLayout::default();
let mut windows = Vec::new();
let mut next_window = 1_u64;
let mut random = 0x5c40_11ab_u64;
for _ in 0..2_000 {
random = random
.wrapping_mul(2_862_933_555_777_941_757)
.wrapping_add(3_037_000_493);
match random % 7 {
0 if windows.len() < 48 => {
let new_window = window(next_window);
next_window += 1;
let focused = windows.get(random as usize % windows.len().max(1)).copied();
layout.insert(new_window, focused).unwrap();
windows.push(new_window);
}
1 if !windows.is_empty() => {
let index = random as usize % windows.len();
layout.remove(windows.swap_remove(index)).unwrap();
}
2 if windows.len() > 1 => {
let first = random as usize % windows.len();
let mut second = random.rotate_left(17) as usize % windows.len();
if first == second {
second = (second + 1) % windows.len();
}
layout
.move_into_column(windows[first], windows[second])
.unwrap();
}
3 if !windows.is_empty() => {
let index = random as usize % windows.len();
layout.extract_to_column(windows[index]).unwrap();
}
4 if !windows.is_empty() => {
let index = random as usize % windows.len();
let direction = random_direction(random.rotate_left(9));
layout.move_window(windows[index], direction).unwrap();
}
5 if !windows.is_empty() => {
let index = random as usize % windows.len();
let direction = random_direction(random.rotate_left(23));
layout
.resize_window(windows[index], direction, 0.05)
.unwrap();
}
6 if !windows.is_empty() => {
let index = random as usize % windows.len();
layout.focus(windows[index]).unwrap();
}
_ => {}
}
layout.validate().unwrap();
assert_eq!(
layout.window_ids().collect::<HashSet<_>>().len(),
windows.len()
);
}
}
fn random_direction(random: u64) -> Direction {
match random % 4 {
0 => Direction::Left,
1 => Direction::Right,
2 => Direction::Up,
_ => Direction::Down,
}
}
}