ZIm/crates/ui/src/components/indent_guides.rs
2025-03-31 20:55:27 +02:00

547 lines
19 KiB
Rust

use std::{cmp::Ordering, ops::Range, rc::Rc};
use gpui::{
AnyElement, App, Bounds, Entity, Hsla, Point, UniformListDecoration, fill, point, size,
};
use smallvec::SmallVec;
use crate::prelude::*;
/// Represents the colors used for different states of indent guides.
#[derive(Debug, Clone)]
pub struct IndentGuideColors {
/// The color of the indent guide when it's neither active nor hovered.
pub default: Hsla,
/// The color of the indent guide when it's hovered.
pub hover: Hsla,
/// The color of the indent guide when it's active.
pub active: Hsla,
}
impl IndentGuideColors {
/// Returns the indent guide colors that should be used for panels.
pub fn panel(cx: &App) -> Self {
Self {
default: cx.theme().colors().panel_indent_guide,
hover: cx.theme().colors().panel_indent_guide_hover,
active: cx.theme().colors().panel_indent_guide_active,
}
}
}
pub struct IndentGuides {
colors: IndentGuideColors,
indent_size: Pixels,
compute_indents_fn: Box<dyn Fn(Range<usize>, &mut Window, &mut App) -> SmallVec<[usize; 64]>>,
render_fn: Option<
Box<
dyn Fn(
RenderIndentGuideParams,
&mut Window,
&mut App,
) -> SmallVec<[RenderedIndentGuide; 12]>,
>,
>,
on_click: Option<Rc<dyn Fn(&IndentGuideLayout, &mut Window, &mut App)>>,
}
pub fn indent_guides<V: Render>(
entity: Entity<V>,
indent_size: Pixels,
colors: IndentGuideColors,
compute_indents_fn: impl Fn(
&mut V,
Range<usize>,
&mut Window,
&mut Context<V>,
) -> SmallVec<[usize; 64]>
+ 'static,
) -> IndentGuides {
let compute_indents_fn = Box::new(move |range, window: &mut Window, cx: &mut App| {
entity.update(cx, |this, cx| compute_indents_fn(this, range, window, cx))
});
IndentGuides {
colors,
indent_size,
compute_indents_fn,
render_fn: None,
on_click: None,
}
}
impl IndentGuides {
/// Sets the callback that will be called when the user clicks on an indent guide.
pub fn on_click(
mut self,
on_click: impl Fn(&IndentGuideLayout, &mut Window, &mut App) + 'static,
) -> Self {
self.on_click = Some(Rc::new(on_click));
self
}
/// Sets a custom callback that will be called when the indent guides need to be rendered.
pub fn with_render_fn<V: Render>(
mut self,
entity: Entity<V>,
render_fn: impl Fn(
&mut V,
RenderIndentGuideParams,
&mut Window,
&mut App,
) -> SmallVec<[RenderedIndentGuide; 12]>
+ 'static,
) -> Self {
let render_fn = move |params, window: &mut Window, cx: &mut App| {
entity.update(cx, |this, cx| render_fn(this, params, window, cx))
};
self.render_fn = Some(Box::new(render_fn));
self
}
}
/// Parameters for rendering indent guides.
pub struct RenderIndentGuideParams {
/// The calculated layouts for the indent guides to be rendered.
pub indent_guides: SmallVec<[IndentGuideLayout; 12]>,
/// The size of each indentation level in pixels.
pub indent_size: Pixels,
/// The height of each item in pixels.
pub item_height: Pixels,
}
/// Represents a rendered indent guide with its visual properties and interaction areas.
pub struct RenderedIndentGuide {
/// The bounds of the rendered indent guide in pixels.
pub bounds: Bounds<Pixels>,
/// The layout information for the indent guide.
pub layout: IndentGuideLayout,
/// Indicates whether the indent guide is currently active.
pub is_active: bool,
/// Can be used to customize the hitbox of the indent guide,
/// if this is set to `None`, the bounds of the indent guide will be used.
pub hitbox: Option<Bounds<Pixels>>,
}
/// Represents the layout information for an indent guide.
#[derive(Debug, PartialEq, Eq, Hash)]
pub struct IndentGuideLayout {
/// The starting position of the indent guide, where x is the indentation level
/// and y is the starting row.
pub offset: Point<usize>,
/// The length of the indent guide in rows.
pub length: usize,
/// Indicates whether the indent guide continues beyond the visible bounds.
pub continues_offscreen: bool,
}
/// Implements the necessary functionality for rendering indent guides inside a uniform list.
mod uniform_list {
use gpui::{DispatchPhase, Hitbox, MouseButton, MouseDownEvent, MouseMoveEvent};
use super::*;
impl UniformListDecoration for IndentGuides {
fn compute(
&self,
visible_range: Range<usize>,
bounds: Bounds<Pixels>,
item_height: Pixels,
item_count: usize,
window: &mut Window,
cx: &mut App,
) -> AnyElement {
let mut visible_range = visible_range.clone();
let includes_trailing_indent = visible_range.end < item_count;
// Check if we have entries after the visible range,
// if so extend the visible range so we can fetch a trailing indent,
// which is needed to compute indent guides correctly.
if includes_trailing_indent {
visible_range.end += 1;
}
let visible_entries = &(self.compute_indents_fn)(visible_range.clone(), window, cx);
let indent_guides = compute_indent_guides(
&visible_entries,
visible_range.start,
includes_trailing_indent,
);
let mut indent_guides = if let Some(ref custom_render) = self.render_fn {
let params = RenderIndentGuideParams {
indent_guides,
indent_size: self.indent_size,
item_height,
};
custom_render(params, window, cx)
} else {
indent_guides
.into_iter()
.map(|layout| RenderedIndentGuide {
bounds: Bounds::new(
point(
layout.offset.x * self.indent_size,
layout.offset.y * item_height,
),
size(px(1.), layout.length * item_height),
),
layout,
is_active: false,
hitbox: None,
})
.collect()
};
for guide in &mut indent_guides {
guide.bounds.origin += bounds.origin;
if let Some(hitbox) = guide.hitbox.as_mut() {
hitbox.origin += bounds.origin;
}
}
let indent_guides = IndentGuidesElement {
indent_guides: Rc::new(indent_guides),
colors: self.colors.clone(),
on_hovered_indent_guide_click: self.on_click.clone(),
};
indent_guides.into_any_element()
}
}
struct IndentGuidesElement {
colors: IndentGuideColors,
indent_guides: Rc<SmallVec<[RenderedIndentGuide; 12]>>,
on_hovered_indent_guide_click:
Option<Rc<dyn Fn(&IndentGuideLayout, &mut Window, &mut App)>>,
}
enum IndentGuidesElementPrepaintState {
Static,
Interactive {
hitboxes: Rc<SmallVec<[Hitbox; 12]>>,
on_hovered_indent_guide_click: Rc<dyn Fn(&IndentGuideLayout, &mut Window, &mut App)>,
},
}
impl Element for IndentGuidesElement {
type RequestLayoutState = ();
type PrepaintState = IndentGuidesElementPrepaintState;
fn id(&self) -> Option<ElementId> {
None
}
fn request_layout(
&mut self,
_id: Option<&gpui::GlobalElementId>,
window: &mut Window,
cx: &mut App,
) -> (gpui::LayoutId, Self::RequestLayoutState) {
(window.request_layout(gpui::Style::default(), [], cx), ())
}
fn prepaint(
&mut self,
_id: Option<&gpui::GlobalElementId>,
_bounds: Bounds<Pixels>,
_request_layout: &mut Self::RequestLayoutState,
window: &mut Window,
_cx: &mut App,
) -> Self::PrepaintState {
if let Some(on_hovered_indent_guide_click) = self.on_hovered_indent_guide_click.clone()
{
let hitboxes = self
.indent_guides
.as_ref()
.iter()
.map(|guide| window.insert_hitbox(guide.hitbox.unwrap_or(guide.bounds), false))
.collect();
Self::PrepaintState::Interactive {
hitboxes: Rc::new(hitboxes),
on_hovered_indent_guide_click,
}
} else {
Self::PrepaintState::Static
}
}
fn paint(
&mut self,
_id: Option<&gpui::GlobalElementId>,
_bounds: Bounds<Pixels>,
_request_layout: &mut Self::RequestLayoutState,
prepaint: &mut Self::PrepaintState,
window: &mut Window,
_cx: &mut App,
) {
let current_view = window.current_view();
match prepaint {
IndentGuidesElementPrepaintState::Static => {
for indent_guide in self.indent_guides.as_ref() {
let fill_color = if indent_guide.is_active {
self.colors.active
} else {
self.colors.default
};
window.paint_quad(fill(indent_guide.bounds, fill_color));
}
}
IndentGuidesElementPrepaintState::Interactive {
hitboxes,
on_hovered_indent_guide_click,
} => {
window.on_mouse_event({
let hitboxes = hitboxes.clone();
let indent_guides = self.indent_guides.clone();
let on_hovered_indent_guide_click = on_hovered_indent_guide_click.clone();
move |event: &MouseDownEvent, phase, window, cx| {
if phase == DispatchPhase::Bubble && event.button == MouseButton::Left {
let mut active_hitbox_ix = None;
for (i, hitbox) in hitboxes.iter().enumerate() {
if hitbox.is_hovered(window) {
active_hitbox_ix = Some(i);
break;
}
}
let Some(active_hitbox_ix) = active_hitbox_ix else {
return;
};
let active_indent_guide = &indent_guides[active_hitbox_ix].layout;
on_hovered_indent_guide_click(active_indent_guide, window, cx);
cx.stop_propagation();
window.prevent_default();
}
}
});
let mut hovered_hitbox_id = None;
for (i, hitbox) in hitboxes.iter().enumerate() {
window.set_cursor_style(gpui::CursorStyle::PointingHand, Some(hitbox));
let indent_guide = &self.indent_guides[i];
let fill_color = if hitbox.is_hovered(window) {
hovered_hitbox_id = Some(hitbox.id);
self.colors.hover
} else if indent_guide.is_active {
self.colors.active
} else {
self.colors.default
};
window.paint_quad(fill(indent_guide.bounds, fill_color));
}
window.on_mouse_event({
let prev_hovered_hitbox_id = hovered_hitbox_id;
let hitboxes = hitboxes.clone();
move |_: &MouseMoveEvent, phase, window, cx| {
let mut hovered_hitbox_id = None;
for hitbox in hitboxes.as_ref() {
if hitbox.is_hovered(window) {
hovered_hitbox_id = Some(hitbox.id);
break;
}
}
if phase == DispatchPhase::Capture {
// If the hovered hitbox has changed, we need to re-paint the indent guides.
match (prev_hovered_hitbox_id, hovered_hitbox_id) {
(Some(prev_id), Some(id)) => {
if prev_id != id {
cx.notify(current_view)
}
}
(None, Some(_)) => cx.notify(current_view),
(Some(_), None) => cx.notify(current_view),
(None, None) => {}
}
}
}
});
}
}
}
}
impl IntoElement for IndentGuidesElement {
type Element = Self;
fn into_element(self) -> Self::Element {
self
}
}
}
fn compute_indent_guides(
indents: &[usize],
offset: usize,
includes_trailing_indent: bool,
) -> SmallVec<[IndentGuideLayout; 12]> {
let mut indent_guides = SmallVec::<[IndentGuideLayout; 12]>::new();
let mut indent_stack = SmallVec::<[IndentGuideLayout; 8]>::new();
let mut min_depth = usize::MAX;
for (row, &depth) in indents.iter().enumerate() {
if includes_trailing_indent && row == indents.len() - 1 {
continue;
}
let current_row = row + offset;
let current_depth = indent_stack.len();
if depth < min_depth {
min_depth = depth;
}
match depth.cmp(&current_depth) {
Ordering::Less => {
for _ in 0..(current_depth - depth) {
if let Some(guide) = indent_stack.pop() {
indent_guides.push(guide);
}
}
}
Ordering::Greater => {
for new_depth in current_depth..depth {
indent_stack.push(IndentGuideLayout {
offset: Point::new(new_depth, current_row),
length: current_row,
continues_offscreen: false,
});
}
}
_ => {}
}
for indent in indent_stack.iter_mut() {
indent.length = current_row - indent.offset.y + 1;
}
}
indent_guides.extend(indent_stack);
for guide in indent_guides.iter_mut() {
if includes_trailing_indent
&& guide.offset.y + guide.length == offset + indents.len().saturating_sub(1)
{
guide.continues_offscreen = indents
.last()
.map(|last_indent| guide.offset.x < *last_indent)
.unwrap_or(false);
}
}
indent_guides
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_compute_indent_guides() {
fn assert_compute_indent_guides(
input: &[usize],
offset: usize,
includes_trailing_indent: bool,
expected: Vec<IndentGuideLayout>,
) {
use std::collections::HashSet;
assert_eq!(
compute_indent_guides(input, offset, includes_trailing_indent)
.into_vec()
.into_iter()
.collect::<HashSet<_>>(),
expected.into_iter().collect::<HashSet<_>>(),
);
}
assert_compute_indent_guides(
&[0, 1, 2, 2, 1, 0],
0,
false,
vec![
IndentGuideLayout {
offset: Point::new(0, 1),
length: 4,
continues_offscreen: false,
},
IndentGuideLayout {
offset: Point::new(1, 2),
length: 2,
continues_offscreen: false,
},
],
);
assert_compute_indent_guides(
&[2, 2, 2, 1, 1],
0,
false,
vec![
IndentGuideLayout {
offset: Point::new(0, 0),
length: 5,
continues_offscreen: false,
},
IndentGuideLayout {
offset: Point::new(1, 0),
length: 3,
continues_offscreen: false,
},
],
);
assert_compute_indent_guides(
&[1, 2, 3, 2, 1],
0,
false,
vec![
IndentGuideLayout {
offset: Point::new(0, 0),
length: 5,
continues_offscreen: false,
},
IndentGuideLayout {
offset: Point::new(1, 1),
length: 3,
continues_offscreen: false,
},
IndentGuideLayout {
offset: Point::new(2, 2),
length: 1,
continues_offscreen: false,
},
],
);
assert_compute_indent_guides(
&[0, 1, 0],
0,
true,
vec![IndentGuideLayout {
offset: Point::new(0, 1),
length: 1,
continues_offscreen: false,
}],
);
assert_compute_indent_guides(
&[0, 1, 1],
0,
true,
vec![IndentGuideLayout {
offset: Point::new(0, 1),
length: 1,
continues_offscreen: true,
}],
);
assert_compute_indent_guides(
&[0, 1, 2],
0,
true,
vec![IndentGuideLayout {
offset: Point::new(0, 1),
length: 1,
continues_offscreen: true,
}],
);
}
}