egui/emigui/src/region.rs

421 lines
14 KiB
Rust

use std::{hash::Hash, sync::Arc};
use crate::{color::*, font::TextFragment, layout::*, widgets::*, *};
/// Represents a region of the screen
/// with a type of layout (horizontal or vertical).
/// TODO: make Region a trait so we can have type-safe HorizontalRegion etc?
pub struct Region {
// TODO: remove pub(crate) from all members.
//
/// How we access input, output and memory
pub(crate) ctx: Arc<Context>,
/// ID of this region.
/// Generated based on id of parent region together with
/// another source of child identity (e.g. window title).
/// Acts like a namespace for child regions.
/// Hopefully unique.
pub(crate) id: Id,
/// Where to put the graphics output of this Region
pub(crate) layer: Layer,
/// Everything painte in this rect will be clipped against this.
/// This means nothing outside of this rectangle will be visible on screen.
pub(crate) clip_rect: Rect,
/// The `rect` represents where in space the region is
/// and its max size (original available_space).
/// Note that the size may be infinite in one or both dimensions.
/// The widgets will TRY to fit within the rect,
/// but may overflow (which you will see in bounding_size).
pub(crate) desired_rect: Rect, // TODO: rename desired_rect
/// Bounding box of children.
/// We keep track of our max-size along the orthogonal to self.dir
/// Initially set to zero.
/// TODO: make into `child_bounds: Rect`
pub(crate) bounding_size: Vec2,
/// Overide default style in this region
pub(crate) style: Style,
// Layout stuff follows. TODO: move to own type and abstract.
/// Doesn't change.
pub(crate) dir: Direction,
pub(crate) align: Align,
/// Where the next widget will be put.
/// Progresses along self.dir.
/// Initially set to rect.min()
pub(crate) cursor: Pos2,
}
impl Region {
pub fn new(ctx: Arc<Context>, layer: Layer, id: Id, rect: Rect) -> Self {
let style = ctx.style();
Region {
ctx,
id,
layer,
clip_rect: rect,
desired_rect: rect,
bounding_size: Vec2::default(),
style,
cursor: rect.min(),
dir: Direction::Vertical,
align: Align::Min,
}
}
pub fn child_region(&self, child_rect: Rect) -> Self {
// Allow child widgets to be just on the border and still have an outline with some thickness
const CLIP_RECT_MARGIN: f32 = 3.0;
Region {
ctx: self.ctx.clone(),
layer: self.layer,
style: self.style,
id: self.id,
clip_rect: self
.clip_rect
.intersect(child_rect.expand(CLIP_RECT_MARGIN)),
desired_rect: child_rect,
cursor: child_rect.min(),
bounding_size: vec2(0.0, 0.0),
dir: self.dir,
align: self.align,
}
}
/// It is up to the caller to make sure there is room for this.
/// Can be used for free painting.
/// NOTE: all coordinates are screen coordinates!
pub fn add_paint_cmd(&mut self, paint_cmd: PaintCmd) {
self.ctx
.graphics
.lock()
.layer(self.layer)
.push((self.clip_rect(), paint_cmd))
}
pub fn add_paint_cmds(&mut self, mut cmds: Vec<PaintCmd>) {
let clip_rect = self.clip_rect();
self.ctx
.graphics
.lock()
.layer(self.layer)
.extend(cmds.drain(..).map(|cmd| (clip_rect, cmd)));
}
/// Options for this region, and any child regions we may spawn.
pub fn style(&self) -> &Style {
&self.style
}
pub fn ctx(&self) -> &Arc<Context> {
&self.ctx
}
pub fn input(&self) -> &GuiInput {
self.ctx.input()
}
pub fn fonts(&self) -> &Fonts {
&*self.ctx.fonts
}
/// Screen-space rectangle for clipping what we paint in this region.
/// This is used, for instance, to avoid painting outside a window that is smaller
/// than its contents.
pub fn clip_rect(&self) -> Rect {
self.clip_rect
}
pub fn available_width(&self) -> f32 {
self.desired_rect.right() - self.cursor.x
}
pub fn available_height(&self) -> f32 {
self.desired_rect.bottom() - self.cursor.y
}
/// This how much more space we can take up without overflowing our parent.
/// Shrinks as cursor increments.
pub fn available_space(&self) -> Vec2 {
self.desired_rect.max() - self.cursor
}
pub fn direction(&self) -> Direction {
self.dir
}
pub fn cursor(&self) -> Pos2 {
self.cursor
}
pub fn set_align(&mut self, align: Align) {
self.align = align;
}
// ------------------------------------------------------------------------
// Sub-regions:
/// Create a child region which is indented to the right
pub fn indent<F>(&mut self, id: Id, add_contents: F)
where
F: FnOnce(&mut Region),
{
assert!(
self.dir == Direction::Vertical,
"You can only indent vertical layouts"
);
let indent = vec2(self.style.indent, 0.0);
let child_rect = Rect::from_min_max(self.cursor + indent, self.desired_rect.max());
let mut child_region = Region {
id,
align: Align::Min,
..self.child_region(child_rect)
};
add_contents(&mut child_region);
let size = child_region.bounding_size;
// draw a grey line on the left to mark the region
let line_start = child_rect.min() - indent + vec2(13.0, 2.0);
let line_start = line_start.round();
let line_end = pos2(line_start.x, line_start.y + size.y - 8.0);
self.add_paint_cmd(PaintCmd::Line {
points: vec![line_start, line_end],
color: gray(150, 255),
width: self.style.line_width,
});
self.reserve_space_without_padding(indent + size);
}
pub fn left_column(&mut self, width: f32) -> Region {
self.column(Align::Min, width)
}
pub fn centered_column(&mut self, width: f32) -> Region {
self.column(Align::Center, width)
}
pub fn right_column(&mut self, width: f32) -> Region {
self.column(Align::Max, width)
}
/// A column region with a given width.
pub fn column(&mut self, column_position: Align, width: f32) -> Region {
let x = match column_position {
Align::Min => 0.0,
Align::Center => self.available_width() / 2.0 - width / 2.0,
Align::Max => self.available_width() - width,
};
self.child_region(Rect::from_min_size(
self.cursor + vec2(x, 0.0),
vec2(width, self.available_height()),
))
}
pub fn inner_layout<F>(&mut self, dir: Direction, align: Align, add_contents: F)
where
F: FnOnce(&mut Region),
{
let child_rect = Rect::from_min_max(self.cursor, self.desired_rect.max());
let mut child_region = Region {
dir,
align,
..self.child_region(child_rect)
};
add_contents(&mut child_region);
let size = child_region.bounding_size;
self.reserve_space_without_padding(size);
}
/// Start a region with horizontal layout
pub fn horizontal<F>(&mut self, align: Align, add_contents: F)
where
F: FnOnce(&mut Region),
{
self.inner_layout(Direction::Horizontal, align, add_contents)
}
/// Start a region with vertical layout
pub fn vertical<F>(&mut self, align: Align, add_contents: F)
where
F: FnOnce(&mut Region),
{
self.inner_layout(Direction::Vertical, align, add_contents)
}
/// Temporarily split split a vertical layout into several columns.
///
/// region.columns(2, |columns| {
/// columns[0].add(emigui::widgets::label!("First column"));
/// columns[1].add(emigui::widgets::label!("Second column"));
/// });
pub fn columns<F, R>(&mut self, num_columns: usize, add_contents: F) -> R
where
F: FnOnce(&mut [Region]) -> R,
{
// TODO: ensure there is space
let padding = self.style.item_spacing.x;
let total_padding = padding * (num_columns as f32 - 1.0);
let column_width = (self.available_width() - total_padding) / (num_columns as f32);
let mut columns: Vec<Region> = (0..num_columns)
.map(|col_idx| {
let pos = self.cursor + vec2((col_idx as f32) * (column_width + padding), 0.0);
let child_rect =
Rect::from_min_max(pos, pos2(pos.x + column_width, self.desired_rect.bottom()));
Region {
id: self.make_child_region_id(&("column", col_idx)),
dir: Direction::Vertical,
..self.child_region(child_rect)
}
})
.collect();
let result = add_contents(&mut columns[..]);
let mut max_height = 0.0;
for region in columns {
let size = region.bounding_size;
max_height = size.y.max(max_height);
}
self.reserve_space_without_padding(vec2(self.available_width(), max_height));
result
}
// ------------------------------------------------------------------------
pub fn add<W: Widget>(&mut self, widget: W) -> GuiResponse {
widget.add_to(self)
}
// Convenience functions:
pub fn add_label(&mut self, text: impl Into<String>) -> GuiResponse {
self.add(Label::new(text))
}
pub fn collapsing<S, F>(&mut self, text: S, add_contents: F) -> GuiResponse
where
S: Into<String>,
F: FnOnce(&mut Region),
{
CollapsingHeader::new(text).show(self, add_contents)
}
// ------------------------------------------------------------------------
pub fn reserve_space(&mut self, size: Vec2, interaction_id: Option<Id>) -> InteractInfo {
let pos = self.reserve_space_without_padding(size + self.style.item_spacing);
let rect = Rect::from_min_size(pos, size);
self.ctx.interact(self.layer, rect, interaction_id)
}
/// Reserve this much space and move the cursor.
/// Returns where to put the widget.
pub fn reserve_space_without_padding(&mut self, size: Vec2) -> Pos2 {
let mut pos = self.cursor;
if self.dir == Direction::Horizontal {
pos.y += match self.align {
Align::Min => 0.0,
Align::Center => 0.5 * (self.available_height() - size.y),
Align::Max => self.available_height() - size.y,
};
self.cursor.x += size.x;
self.bounding_size.x += size.x;
self.bounding_size.y = self.bounding_size.y.max(size.y);
} else {
pos.x += match self.align {
Align::Min => 0.0,
Align::Center => 0.5 * (self.available_width() - size.x),
Align::Max => self.available_width() - size.x,
};
self.cursor.y += size.y;
self.bounding_size.y += size.y;
self.bounding_size.x = self.bounding_size.x.max(size.x);
}
pos
}
/// Will warn if the returned id is not guaranteed unique.
/// Use this to generate widget ids for widgets that have persistent state in Memory.
/// If the child_id_source is not unique within this region
/// then an error will be printed at the current cursor position.
pub fn make_unique_id<IdSource>(&self, child_id_source: &IdSource) -> Id
where
IdSource: Hash + std::fmt::Debug,
{
let id = self.id.with(child_id_source);
self.ctx
.register_unique_id(id, child_id_source, self.cursor)
}
/// Make an Id that is unique to this positon.
/// Can be used for widgets that do NOT persist state in Memory
/// but you still need to interact with (e.g. buttons, sliders).
pub fn make_position_id(&self) -> Id {
self.id.with(&Id::from_pos(self.cursor))
}
pub fn make_child_region_id<H: Hash>(&self, child_id: &H) -> Id {
self.id.with(child_id)
}
/// Show some text anywhere in the region.
/// To center the text at the given position, use `align: (Center, Center)`.
/// If you want to draw text floating on top of everything,
/// consider using Context.floating_text instead.
pub fn floating_text(
&mut self,
pos: Pos2,
text: &str,
text_style: TextStyle,
align: (Align, Align),
text_color: Option<Color>,
) -> Vec2 {
let font = &self.fonts()[text_style];
let (text, size) = font.layout_multiline(text, std::f32::INFINITY);
let rect = align_rect(Rect::from_min_size(pos, size), align);
self.add_text(rect.min(), text_style, text, text_color);
size
}
/// Already layed out text.
pub fn add_text(
&mut self,
pos: Pos2,
text_style: TextStyle,
text: Vec<TextFragment>,
color: Option<Color>,
) {
let color = color.unwrap_or_else(|| self.style().text_color());
for fragment in text {
self.add_paint_cmd(PaintCmd::Text {
color,
pos: pos + vec2(0.0, fragment.y_offset),
text: fragment.text,
text_style,
x_offsets: fragment.x_offsets,
});
}
}
pub fn response(&mut self, interact: InteractInfo) -> GuiResponse {
// TODO: unify GuiResponse and InteractInfo. They are the same thing!
GuiResponse {
hovered: interact.hovered,
clicked: interact.clicked,
active: interact.active,
rect: interact.rect,
ctx: self.ctx.clone(),
}
}
}