egui/crates/egui/src/grid.rs
2022-08-20 10:41:49 +02:00

390 lines
13 KiB
Rust

use crate::*;
#[derive(Clone, Debug, Default, PartialEq)]
pub(crate) struct State {
col_widths: Vec<f32>,
row_heights: Vec<f32>,
}
impl State {
pub fn load(ctx: &Context, id: Id) -> Option<Self> {
ctx.data().get_temp(id)
}
pub fn store(self, ctx: &Context, id: Id) {
// We don't persist Grids, because
// A) there are potentially a lot of them, using up a lot of space (and therefore serialization time)
// B) if the code changes, the grid _should_ change, and not remember old sizes
ctx.data().insert_temp(id, self);
}
fn set_min_col_width(&mut self, col: usize, width: f32) {
self.col_widths
.resize(self.col_widths.len().max(col + 1), 0.0);
self.col_widths[col] = self.col_widths[col].max(width);
}
fn set_min_row_height(&mut self, row: usize, height: f32) {
self.row_heights
.resize(self.row_heights.len().max(row + 1), 0.0);
self.row_heights[row] = self.row_heights[row].max(height);
}
fn col_width(&self, col: usize) -> Option<f32> {
self.col_widths.get(col).copied()
}
fn row_height(&self, row: usize) -> Option<f32> {
self.row_heights.get(row).copied()
}
fn full_width(&self, x_spacing: f32) -> f32 {
self.col_widths.iter().sum::<f32>()
+ (self.col_widths.len().at_least(1) - 1) as f32 * x_spacing
}
}
// ----------------------------------------------------------------------------
pub(crate) struct GridLayout {
ctx: Context,
style: std::sync::Arc<Style>,
id: Id,
/// State previous frame (if any).
/// This can be used to predict future sizes of cells.
prev_state: State,
/// State accumulated during the current frame.
curr_state: State,
initial_available: Rect,
// Options:
num_columns: Option<usize>,
spacing: Vec2,
min_cell_size: Vec2,
max_cell_size: Vec2,
striped: bool,
// Cursor:
col: usize,
row: usize,
}
impl GridLayout {
pub(crate) fn new(ui: &Ui, id: Id) -> Self {
let prev_state = State::load(ui.ctx(), id).unwrap_or_default();
// TODO(emilk): respect current layout
let initial_available = ui.placer().max_rect().intersect(ui.cursor());
crate::egui_assert!(
initial_available.min.x.is_finite(),
"Grid not yet available for right-to-left layouts"
);
ui.ctx().check_for_id_clash(id, initial_available, "Grid");
Self {
ctx: ui.ctx().clone(),
style: ui.style().clone(),
id,
prev_state,
curr_state: State::default(),
initial_available,
num_columns: None,
spacing: ui.spacing().item_spacing,
min_cell_size: ui.spacing().interact_size,
max_cell_size: Vec2::INFINITY,
striped: false,
col: 0,
row: 0,
}
}
}
impl GridLayout {
fn prev_col_width(&self, col: usize) -> f32 {
self.prev_state
.col_width(col)
.unwrap_or(self.min_cell_size.x)
}
fn prev_row_height(&self, row: usize) -> f32 {
self.prev_state
.row_height(row)
.unwrap_or(self.min_cell_size.y)
}
pub(crate) fn wrap_text(&self) -> bool {
self.max_cell_size.x.is_finite()
}
pub(crate) fn available_rect(&self, region: &Region) -> Rect {
let is_last_column = Some(self.col + 1) == self.num_columns;
let width = if is_last_column {
(self.initial_available.right() - region.cursor.left()).at_most(self.max_cell_size.x)
} else if self.max_cell_size.x.is_finite() {
// TODO(emilk): should probably heed `prev_state` here too
self.max_cell_size.x
} else {
// If we want to allow width-filling widgets like [`Separator`] in one of the first cells
// then we need to make sure they don't spill out of the first cell:
self.prev_state
.col_width(self.col)
.or_else(|| self.curr_state.col_width(self.col))
.unwrap_or(self.min_cell_size.x)
};
// If something above was wider, we can be wider:
let width = width.max(self.curr_state.col_width(self.col).unwrap_or(0.0));
let available = region.max_rect.intersect(region.cursor);
let height = region.max_rect.max.y - available.top();
let height = height
.at_least(self.min_cell_size.y)
.at_most(self.max_cell_size.y);
Rect::from_min_size(available.min, vec2(width, height))
}
pub(crate) fn next_cell(&self, cursor: Rect, child_size: Vec2) -> Rect {
let width = self.prev_state.col_width(self.col).unwrap_or(0.0);
let height = self.prev_row_height(self.row);
let size = child_size.max(vec2(width, height));
Rect::from_min_size(cursor.min, size)
}
#[allow(clippy::unused_self)]
pub(crate) fn align_size_within_rect(&self, size: Vec2, frame: Rect) -> Rect {
// TODO(emilk): allow this alignment to be customized
Align2::LEFT_CENTER.align_size_within_rect(size, frame)
}
pub(crate) fn justify_and_align(&self, frame: Rect, size: Vec2) -> Rect {
self.align_size_within_rect(size, frame)
}
pub(crate) fn advance(&mut self, cursor: &mut Rect, _frame_rect: Rect, widget_rect: Rect) {
let debug_expand_width = self.style.debug.show_expand_width;
let debug_expand_height = self.style.debug.show_expand_height;
if debug_expand_width || debug_expand_height {
let rect = widget_rect;
let too_wide = rect.width() > self.prev_col_width(self.col);
let too_high = rect.height() > self.prev_row_height(self.row);
if (debug_expand_width && too_wide) || (debug_expand_height && too_high) {
let painter = self.ctx.debug_painter();
painter.rect_stroke(rect, 0.0, (1.0, Color32::LIGHT_BLUE));
let stroke = Stroke::new(2.5, Color32::from_rgb(200, 0, 0));
let paint_line_seg = |a, b| painter.line_segment([a, b], stroke);
if debug_expand_width && too_wide {
paint_line_seg(rect.left_top(), rect.left_bottom());
paint_line_seg(rect.left_center(), rect.right_center());
paint_line_seg(rect.right_top(), rect.right_bottom());
}
}
}
self.curr_state
.set_min_col_width(self.col, widget_rect.width().max(self.min_cell_size.x));
self.curr_state
.set_min_row_height(self.row, widget_rect.height().max(self.min_cell_size.y));
cursor.min.x += self.prev_col_width(self.col) + self.spacing.x;
self.col += 1;
}
pub(crate) fn end_row(&mut self, cursor: &mut Rect, painter: &Painter) {
cursor.min.x = self.initial_available.min.x;
cursor.min.y += self.spacing.y;
cursor.min.y += self
.curr_state
.row_height(self.row)
.unwrap_or(self.min_cell_size.y);
self.col = 0;
self.row += 1;
if self.striped && self.row % 2 == 1 {
if let Some(height) = self.prev_state.row_height(self.row) {
// Paint background for coming row:
let size = Vec2::new(self.prev_state.full_width(self.spacing.x), height);
let rect = Rect::from_min_size(cursor.min, size);
let rect = rect.expand2(0.5 * self.spacing.y * Vec2::Y);
let rect = rect.expand2(2.0 * Vec2::X); // HACK: just looks better with some spacing on the sides
painter.rect_filled(rect, 2.0, self.style.visuals.faint_bg_color);
}
}
}
pub(crate) fn save(&self) {
if self.curr_state != self.prev_state {
self.curr_state.clone().store(&self.ctx, self.id);
self.ctx.request_repaint();
}
}
}
// ----------------------------------------------------------------------------
/// A simple grid layout.
///
/// The cells are always layed out left to right, top-down.
/// The contents of each cell will be aligned to the left and center.
///
/// If you want to add multiple widgets to a cell you need to group them with
/// [`Ui::horizontal`], [`Ui::vertical`] etc.
///
/// ```
/// # egui::__run_test_ui(|ui| {
/// egui::Grid::new("some_unique_id").show(ui, |ui| {
/// ui.label("First row, first column");
/// ui.label("First row, second column");
/// ui.end_row();
///
/// ui.label("Second row, first column");
/// ui.label("Second row, second column");
/// ui.label("Second row, third column");
/// ui.end_row();
///
/// ui.horizontal(|ui| { ui.label("Same"); ui.label("cell"); });
/// ui.label("Third row, second column");
/// ui.end_row();
/// });
/// # });
/// ```
#[must_use = "You should call .show()"]
pub struct Grid {
id_source: Id,
num_columns: Option<usize>,
striped: bool,
min_col_width: Option<f32>,
min_row_height: Option<f32>,
max_cell_size: Vec2,
spacing: Option<Vec2>,
start_row: usize,
}
impl Grid {
/// Create a new [`Grid`] with a locally unique identifier.
pub fn new(id_source: impl std::hash::Hash) -> Self {
Self {
id_source: Id::new(id_source),
num_columns: None,
striped: false,
min_col_width: None,
min_row_height: None,
max_cell_size: Vec2::INFINITY,
spacing: None,
start_row: 0,
}
}
/// Setting this will allow the last column to expand to take up the rest of the space of the parent [`Ui`].
pub fn num_columns(mut self, num_columns: usize) -> Self {
self.num_columns = Some(num_columns);
self
}
/// If `true`, add a subtle background color to every other row.
///
/// This can make a table easier to read.
/// Default: `false`.
pub fn striped(mut self, striped: bool) -> Self {
self.striped = striped;
self
}
/// Set minimum width of each column.
/// Default: [`crate::style::Spacing::interact_size`]`.x`.
pub fn min_col_width(mut self, min_col_width: f32) -> Self {
self.min_col_width = Some(min_col_width);
self
}
/// Set minimum height of each row.
/// Default: [`crate::style::Spacing::interact_size`]`.y`.
pub fn min_row_height(mut self, min_row_height: f32) -> Self {
self.min_row_height = Some(min_row_height);
self
}
/// Set soft maximum width (wrapping width) of each column.
pub fn max_col_width(mut self, max_col_width: f32) -> Self {
self.max_cell_size.x = max_col_width;
self
}
/// Set spacing between columns/rows.
/// Default: [`crate::style::Spacing::item_spacing`].
pub fn spacing(mut self, spacing: impl Into<Vec2>) -> Self {
self.spacing = Some(spacing.into());
self
}
/// Change which row number the grid starts on.
/// This can be useful when you have a large [`Grid`] inside of [`ScrollArea::show_rows`].
pub fn start_row(mut self, start_row: usize) -> Self {
self.start_row = start_row;
self
}
}
impl Grid {
pub fn show<R>(self, ui: &mut Ui, add_contents: impl FnOnce(&mut Ui) -> R) -> InnerResponse<R> {
self.show_dyn(ui, Box::new(add_contents))
}
fn show_dyn<'c, R>(
self,
ui: &mut Ui,
add_contents: Box<dyn FnOnce(&mut Ui) -> R + 'c>,
) -> InnerResponse<R> {
let Self {
id_source,
num_columns,
striped,
min_col_width,
min_row_height,
max_cell_size,
spacing,
start_row,
} = self;
let min_col_width = min_col_width.unwrap_or_else(|| ui.spacing().interact_size.x);
let min_row_height = min_row_height.unwrap_or_else(|| ui.spacing().interact_size.y);
let spacing = spacing.unwrap_or_else(|| ui.spacing().item_spacing);
// Each grid cell is aligned LEFT_CENTER.
// If somebody wants to wrap more things inside a cell,
// then we should pick a default layout that matches that alignment,
// which we do here:
let max_rect = ui.cursor().intersect(ui.max_rect());
ui.allocate_ui_at_rect(max_rect, |ui| {
ui.horizontal(|ui| {
let id = ui.make_persistent_id(id_source);
let grid = GridLayout {
num_columns,
striped,
min_cell_size: vec2(min_col_width, min_row_height),
max_cell_size,
spacing,
row: start_row,
..GridLayout::new(ui, id)
};
ui.set_grid(grid);
let r = add_contents(ui);
ui.save_grid();
r
})
.inner
})
}
}