cove/src/ui/chat/blocks.rs
2022-07-28 12:57:01 +02:00

126 lines
3.6 KiB
Rust

use std::collections::VecDeque;
use std::ops::Range;
use toss::frame::Frame;
use crate::macros::some_or_return;
use crate::ui::widgets::BoxedWidget;
pub struct Block<I> {
id: I,
top_line: i32,
height: i32,
/// The lines of the block that should be made visible if the block is
/// focused on. By default, the focus encompasses the entire block.
///
/// If not all of these lines can be made visible, the top of the range
/// should be preferred over the bottom.
focus: Range<i32>,
widget: BoxedWidget,
}
impl<I> Block<I> {
pub fn new<W: Into<BoxedWidget>>(frame: &mut Frame, width: u16, id: I, widget: W) -> Self {
// Interestingly, rust-analyzer fails to deduce the type of `widget`
// here but rustc knows it's a `BoxedWidget`.
let widget = widget.into();
let size = widget.size(frame, Some(width), None);
let height = size.height.into();
Self {
id,
top_line: 0,
height,
focus: 0..height,
widget,
}
}
pub fn focus(mut self, focus: Range<i32>) -> Self {
self.focus = focus;
self
}
}
pub struct Blocks<I> {
pub blocks: VecDeque<Block<I>>,
/// The top line of the first block. Useful for prepending blocks,
/// especially to empty [`Blocks`]s.
pub top_line: i32,
/// The bottom line of the last block. Useful for appending blocks,
/// especially to empty [`Blocks`]s.
pub bottom_line: i32,
}
impl<I> Blocks<I> {
pub fn new() -> Self {
Self::new_below(0)
}
/// Create a new [`Blocks`] such that the first prepended line will be on
/// `line`.
pub fn new_below(line: i32) -> Self {
Self {
blocks: VecDeque::new(),
top_line: line + 1,
bottom_line: line,
}
}
pub fn offset(&mut self, delta: i32) {
self.top_line += delta;
self.bottom_line += delta;
for block in &mut self.blocks {
block.top_line += delta;
}
}
pub fn push_front(&mut self, mut block: Block<I>) {
self.top_line -= block.height;
block.top_line = self.top_line;
self.blocks.push_front(block);
}
pub fn push_back(&mut self, mut block: Block<I>) {
block.top_line = self.bottom_line + 1;
self.bottom_line += block.height;
self.blocks.push_back(block);
}
pub fn prepend(&mut self, mut layout: Self) {
while let Some(block) = layout.blocks.pop_back() {
self.push_front(block);
}
}
pub fn append(&mut self, mut layout: Self) {
while let Some(block) = layout.blocks.pop_front() {
self.push_back(block);
}
}
}
impl<I: Eq> Blocks<I> {
pub fn recalculate_offsets(&mut self, id: I, top_line: i32) {
let idx = some_or_return!(self
.blocks
.iter()
.enumerate()
.find(|(_, b)| b.id == id)
.map(|(i, _)| i));
self.blocks[idx].top_line = top_line;
// Propagate changes to top
for i in (0..idx).rev() {
self.blocks[i].top_line = self.blocks[i + 1].top_line - self.blocks[i].height;
}
self.top_line = self.blocks.front().expect("blocks nonempty").top_line;
// Propagate changes to bottom
for i in (idx + 1)..self.blocks.len() {
self.blocks[i].top_line = self.blocks[i - 1].top_line + self.blocks[i - 1].height;
}
let bottom = self.blocks.back().expect("blocks nonempty");
self.bottom_line = bottom.top_line + bottom.height - 1;
}
}