1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690
//! Area is a [`Ui`] that has no parent, it floats on the background.
//! It has no frame or own size. It is potentially movable.
//! It is the foundation for windows and popups.
use crate::{
emath, pos2, Align2, Context, Id, InnerResponse, LayerId, NumExt, Order, Pos2, Rect, Response,
Sense, Ui, UiBuilder, UiKind, UiStackInfo, Vec2, WidgetRect, WidgetWithState,
};
/// State of an [`Area`] that is persisted between frames.
///
/// Areas back [`crate::Window`]s and other floating containers,
/// like tooltips and the popups of [`crate::ComboBox`].
#[derive(Clone, Copy, Debug)]
#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
pub struct AreaState {
/// Last known position of the pivot.
pub pivot_pos: Option<Pos2>,
/// The anchor point of the area, i.e. where on the area the [`Self::pivot_pos`] refers to.
pub pivot: Align2,
/// Last known size.
///
/// Area size is intentionally NOT persisted between sessions,
/// so that a bad tooltip or menu size won't be remembered forever.
/// A resizable [`crate::Window`] remembers the size the user picked using
/// the state in the [`crate::Resize`] container.
#[cfg_attr(feature = "serde", serde(skip))]
pub size: Option<Vec2>,
/// If false, clicks goes straight through to what is behind us. Useful for tooltips etc.
pub interactable: bool,
/// At what time was this area first shown?
///
/// Used to fade in the area.
#[cfg_attr(feature = "serde", serde(skip))]
pub last_became_visible_at: Option<f64>,
}
impl Default for AreaState {
fn default() -> Self {
Self {
pivot_pos: None,
pivot: Align2::LEFT_TOP,
size: None,
interactable: true,
last_became_visible_at: None,
}
}
}
impl AreaState {
/// Load the state of an [`Area`] from memory.
pub fn load(ctx: &Context, id: Id) -> Option<Self> {
// TODO(emilk): Area state is not currently stored in `Memory::data`, but maybe it should be?
ctx.memory(|mem| mem.areas().get(id).copied())
}
/// The left top positions of the area.
pub fn left_top_pos(&self) -> Pos2 {
let pivot_pos = self.pivot_pos.unwrap_or_default();
let size = self.size.unwrap_or_default();
pos2(
pivot_pos.x - self.pivot.x().to_factor() * size.x,
pivot_pos.y - self.pivot.y().to_factor() * size.y,
)
}
/// Move the left top positions of the area.
pub fn set_left_top_pos(&mut self, pos: Pos2) {
let size = self.size.unwrap_or_default();
self.pivot_pos = Some(pos2(
pos.x + self.pivot.x().to_factor() * size.x,
pos.y + self.pivot.y().to_factor() * size.y,
));
}
/// Where the area is on screen.
pub fn rect(&self) -> Rect {
let size = self.size.unwrap_or_default();
Rect::from_min_size(self.left_top_pos(), size)
}
}
/// An area on the screen that can be moved by dragging.
///
/// This forms the base of the [`crate::Window`] container.
///
/// ```
/// # egui::__run_test_ctx(|ctx| {
/// egui::Area::new(egui::Id::new("my_area"))
/// .fixed_pos(egui::pos2(32.0, 32.0))
/// .show(ctx, |ui| {
/// ui.label("Floating text!");
/// });
/// # });
/// ```
///
/// The previous rectangle used by this area can be obtained through [`crate::Memory::area_rect()`].
#[must_use = "You should call .show()"]
#[derive(Clone, Copy, Debug)]
pub struct Area {
pub(crate) id: Id,
kind: UiKind,
sense: Option<Sense>,
movable: bool,
interactable: bool,
enabled: bool,
constrain: bool,
constrain_rect: Option<Rect>,
order: Order,
default_pos: Option<Pos2>,
default_size: Vec2,
pivot: Align2,
anchor: Option<(Align2, Vec2)>,
new_pos: Option<Pos2>,
fade_in: bool,
}
impl WidgetWithState for Area {
type State = AreaState;
}
impl Area {
/// The `id` must be globally unique.
pub fn new(id: Id) -> Self {
Self {
id,
kind: UiKind::GenericArea,
sense: None,
movable: true,
interactable: true,
constrain: true,
constrain_rect: None,
enabled: true,
order: Order::Middle,
default_pos: None,
default_size: Vec2::NAN,
new_pos: None,
pivot: Align2::LEFT_TOP,
anchor: None,
fade_in: true,
}
}
/// Let's you change the `id` that you assigned in [`Self::new`].
///
/// The `id` must be globally unique.
#[inline]
pub fn id(mut self, id: Id) -> Self {
self.id = id;
self
}
/// Change the [`UiKind`] of the arena.
///
/// Default to [`UiKind::GenericArea`].
#[inline]
pub fn kind(mut self, kind: UiKind) -> Self {
self.kind = kind;
self
}
pub fn layer(&self) -> LayerId {
LayerId::new(self.order, self.id)
}
/// If false, no content responds to click
/// and widgets will be shown grayed out.
/// You won't be able to move the window.
/// Default: `true`.
#[inline]
pub fn enabled(mut self, enabled: bool) -> Self {
self.enabled = enabled;
self
}
/// Moveable by dragging the area?
#[inline]
pub fn movable(mut self, movable: bool) -> Self {
self.movable = movable;
self.interactable |= movable;
self
}
pub fn is_enabled(&self) -> bool {
self.enabled
}
pub fn is_movable(&self) -> bool {
self.movable && self.enabled
}
/// If false, clicks goes straight through to what is behind us.
///
/// Can be used for semi-invisible areas that the user should be able to click through.
///
/// Default: `true`.
#[inline]
pub fn interactable(mut self, interactable: bool) -> Self {
self.interactable = interactable;
self.movable &= interactable;
self
}
/// Explicitly set a sense.
///
/// If not set, this will default to `Sense::drag()` if movable, `Sense::click()` if interactable, and `Sense::hover()` otherwise.
#[inline]
pub fn sense(mut self, sense: Sense) -> Self {
self.sense = Some(sense);
self
}
/// `order(Order::Foreground)` for an Area that should always be on top
#[inline]
pub fn order(mut self, order: Order) -> Self {
self.order = order;
self
}
#[inline]
pub fn default_pos(mut self, default_pos: impl Into<Pos2>) -> Self {
self.default_pos = Some(default_pos.into());
self
}
/// The size used for the [`Ui::max_rect`] the first frame.
///
/// Text will wrap at this width, and images that expand to fill the available space
/// will expand to this size.
///
/// If the contents are smaller than this size, the area will shrink to fit the contents.
/// If the contents overflow, the area will grow.
///
/// If not set, [`crate::style::Spacing::default_area_size`] will be used.
#[inline]
pub fn default_size(mut self, default_size: impl Into<Vec2>) -> Self {
self.default_size = default_size.into();
self
}
/// See [`Self::default_size`].
#[inline]
pub fn default_width(mut self, default_width: f32) -> Self {
self.default_size.x = default_width;
self
}
/// See [`Self::default_size`].
#[inline]
pub fn default_height(mut self, default_height: f32) -> Self {
self.default_size.y = default_height;
self
}
/// Positions the window and prevents it from being moved
#[inline]
pub fn fixed_pos(mut self, fixed_pos: impl Into<Pos2>) -> Self {
self.new_pos = Some(fixed_pos.into());
self.movable = false;
self
}
/// Constrains this area to [`Context::screen_rect`]?
///
/// Default: `true`.
#[inline]
pub fn constrain(mut self, constrain: bool) -> Self {
self.constrain = constrain;
self
}
/// Constrain the movement of the window to the given rectangle.
///
/// For instance: `.constrain_to(ctx.screen_rect())`.
#[inline]
pub fn constrain_to(mut self, constrain_rect: Rect) -> Self {
self.constrain = true;
self.constrain_rect = Some(constrain_rect);
self
}
/// Where the "root" of the area is.
///
/// For instance, if you set this to [`Align2::RIGHT_TOP`]
/// then [`Self::fixed_pos`] will set the position of the right-top
/// corner of the area.
///
/// Default: [`Align2::LEFT_TOP`].
#[inline]
pub fn pivot(mut self, pivot: Align2) -> Self {
self.pivot = pivot;
self
}
/// Positions the window but you can still move it.
#[inline]
pub fn current_pos(mut self, current_pos: impl Into<Pos2>) -> Self {
self.new_pos = Some(current_pos.into());
self
}
/// Set anchor and distance.
///
/// An anchor of `Align2::RIGHT_TOP` means "put the right-top corner of the window
/// in the right-top corner of the screen".
///
/// The offset is added to the position, so e.g. an offset of `[-5.0, 5.0]`
/// would move the window left and down from the given anchor.
///
/// Anchoring also makes the window immovable.
///
/// It is an error to set both an anchor and a position.
#[inline]
pub fn anchor(mut self, align: Align2, offset: impl Into<Vec2>) -> Self {
self.anchor = Some((align, offset.into()));
self.movable(false)
}
pub(crate) fn get_pivot(&self) -> Align2 {
if let Some((pivot, _)) = self.anchor {
pivot
} else {
Align2::LEFT_TOP
}
}
/// If `true`, quickly fade in the area.
///
/// Default: `true`.
#[inline]
pub fn fade_in(mut self, fade_in: bool) -> Self {
self.fade_in = fade_in;
self
}
}
pub(crate) struct Prepared {
kind: UiKind,
layer_id: LayerId,
state: AreaState,
move_response: Response,
enabled: bool,
constrain: bool,
constrain_rect: Rect,
/// We always make windows invisible the first frame to hide "first-frame-jitters".
///
/// This is so that we use the first frame to calculate the window size,
/// and then can correctly position the window and its contents the next frame,
/// without having one frame where the window is wrongly positioned or sized.
sizing_pass: bool,
fade_in: bool,
}
impl Area {
pub fn show<R>(
self,
ctx: &Context,
add_contents: impl FnOnce(&mut Ui) -> R,
) -> InnerResponse<R> {
let prepared = self.begin(ctx);
let mut content_ui = prepared.content_ui(ctx);
let inner = add_contents(&mut content_ui);
let response = prepared.end(ctx, content_ui);
InnerResponse { inner, response }
}
pub(crate) fn begin(self, ctx: &Context) -> Prepared {
let Self {
id,
kind,
sense,
movable,
order,
interactable,
enabled,
default_pos,
default_size,
new_pos,
pivot,
anchor,
constrain,
constrain_rect,
fade_in,
} = self;
let constrain_rect = constrain_rect.unwrap_or_else(|| ctx.screen_rect());
let layer_id = LayerId::new(order, id);
let state = AreaState::load(ctx, id);
let mut sizing_pass = state.is_none();
let mut state = state.unwrap_or(AreaState {
pivot_pos: None,
pivot,
size: None,
interactable,
last_became_visible_at: None,
});
state.pivot = pivot;
state.interactable = interactable;
if let Some(new_pos) = new_pos {
state.pivot_pos = Some(new_pos);
}
state.pivot_pos.get_or_insert_with(|| {
default_pos.unwrap_or_else(|| automatic_area_position(ctx, layer_id))
});
state.interactable = interactable;
let size = *state.size.get_or_insert_with(|| {
sizing_pass = true;
// during the sizing pass we will use this as the max size
let mut size = default_size;
let default_area_size = ctx.style().spacing.default_area_size;
if size.x.is_nan() {
size.x = default_area_size.x;
}
if size.y.is_nan() {
size.y = default_area_size.y;
}
if constrain {
size = size.at_most(constrain_rect.size());
}
size
});
// TODO(emilk): if last frame was sizing pass, it should be considered invisible for smoother fade-in
let visible_last_frame = ctx.memory(|mem| mem.areas().visible_last_frame(&layer_id));
if !visible_last_frame || state.last_became_visible_at.is_none() {
state.last_became_visible_at = Some(ctx.input(|i| i.time));
}
if let Some((anchor, offset)) = anchor {
state.set_left_top_pos(
anchor
.align_size_within_rect(size, constrain_rect)
.left_top()
+ offset,
);
}
// interact right away to prevent frame-delay
let mut move_response = {
let interact_id = layer_id.id.with("move");
let sense = sense.unwrap_or_else(|| {
if movable {
Sense::drag()
} else if interactable {
Sense::click() // allow clicks to bring to front
} else {
Sense::hover()
}
});
let move_response = ctx.create_widget(
WidgetRect {
id: interact_id,
layer_id,
rect: state.rect(),
interact_rect: state.rect().intersect(constrain_rect),
sense,
enabled,
},
true,
);
if movable && move_response.dragged() {
if let Some(pivot_pos) = &mut state.pivot_pos {
*pivot_pos += move_response.drag_delta();
}
}
if (move_response.dragged() || move_response.clicked())
|| pointer_pressed_on_area(ctx, layer_id)
|| !ctx.memory(|m| m.areas().visible_last_frame(&layer_id))
{
ctx.memory_mut(|m| m.areas_mut().move_to_top(layer_id));
ctx.request_repaint();
}
move_response
};
if constrain {
state.set_left_top_pos(
ctx.constrain_window_rect_to_area(state.rect(), constrain_rect)
.min,
);
}
state.set_left_top_pos(ctx.round_pos_to_pixels(state.left_top_pos()));
// Update response with possibly moved/constrained rect:
move_response.rect = state.rect();
move_response.interact_rect = state.rect();
Prepared {
kind,
layer_id,
state,
move_response,
enabled,
constrain,
constrain_rect,
sizing_pass,
fade_in,
}
}
}
impl Prepared {
pub(crate) fn state(&self) -> &AreaState {
&self.state
}
pub(crate) fn state_mut(&mut self) -> &mut AreaState {
&mut self.state
}
pub(crate) fn constrain(&self) -> bool {
self.constrain
}
pub(crate) fn constrain_rect(&self) -> Rect {
self.constrain_rect
}
pub(crate) fn content_ui(&self, ctx: &Context) -> Ui {
let max_rect = self.state.rect();
let mut ui_builder = UiBuilder::new()
.ui_stack_info(UiStackInfo::new(self.kind))
.layer_id(self.layer_id)
.max_rect(max_rect);
if !self.enabled {
ui_builder = ui_builder.disabled();
}
if self.sizing_pass {
ui_builder = ui_builder.sizing_pass().invisible();
}
let mut ui = Ui::new(ctx.clone(), self.layer_id.id, ui_builder);
ui.set_clip_rect(self.constrain_rect); // Don't paint outside our bounds
if self.fade_in {
if let Some(last_became_visible_at) = self.state.last_became_visible_at {
let age =
ctx.input(|i| (i.time - last_became_visible_at) as f32 + i.predicted_dt / 2.0);
let opacity = crate::remap_clamp(age, 0.0..=ctx.style().animation_time, 0.0..=1.0);
let opacity = emath::easing::quadratic_out(opacity); // slow fade-out = quick fade-in
ui.multiply_opacity(opacity);
if opacity < 1.0 {
ctx.request_repaint();
}
}
}
ui
}
pub(crate) fn with_widget_info(&self, make_info: impl Fn() -> crate::WidgetInfo) {
self.move_response.widget_info(make_info);
}
pub(crate) fn id(&self) -> Id {
self.move_response.id
}
#[allow(clippy::needless_pass_by_value)] // intentional to swallow up `content_ui`.
pub(crate) fn end(self, ctx: &Context, content_ui: Ui) -> Response {
let Self {
kind: _,
layer_id,
mut state,
move_response: mut response,
sizing_pass,
..
} = self;
state.size = Some(content_ui.min_size());
// Make sure we report back the correct size.
// Very important after the initial sizing pass, when the initial estimate of the size is way off.
let final_rect = state.rect();
response.rect = final_rect;
response.interact_rect = final_rect;
ctx.memory_mut(|m| m.areas_mut().set_state(layer_id, state));
if sizing_pass {
// If we didn't know the size, we were likely drawing the area in the wrong place.
ctx.request_repaint();
}
response
}
}
fn pointer_pressed_on_area(ctx: &Context, layer_id: LayerId) -> bool {
if let Some(pointer_pos) = ctx.pointer_interact_pos() {
let any_pressed = ctx.input(|i| i.pointer.any_pressed());
any_pressed && ctx.layer_id_at(pointer_pos) == Some(layer_id)
} else {
false
}
}
fn automatic_area_position(ctx: &Context, layer_id: LayerId) -> Pos2 {
let mut existing: Vec<Rect> = ctx.memory(|mem| {
mem.areas()
.visible_windows()
.filter(|(id, _)| id != &layer_id) // ignore ourselves
.filter(|(_, state)| state.pivot_pos.is_some() && state.size.is_some())
.map(|(_, state)| state.rect())
.collect()
});
existing.sort_by_key(|r| r.left().round() as i32);
// NOTE: for the benefit of the egui demo, we position the windows so they don't
// cover the side panels, which means we use `available_rect` here instead of `constrain_rect` or `screen_rect`.
let available_rect = ctx.available_rect();
let spacing = 16.0;
let left = available_rect.left() + spacing;
let top = available_rect.top() + spacing;
if existing.is_empty() {
return pos2(left, top);
}
// Separate existing rectangles into columns:
let mut column_bbs = vec![existing[0]];
for &rect in &existing {
let current_column_bb = column_bbs.last_mut().unwrap();
if rect.left() < current_column_bb.right() {
// same column
*current_column_bb = current_column_bb.union(rect);
} else {
// new column
column_bbs.push(rect);
}
}
{
// Look for large spaces between columns (empty columns):
let mut x = left;
for col_bb in &column_bbs {
let available = col_bb.left() - x;
if available >= 300.0 {
return pos2(x, top);
}
x = col_bb.right() + spacing;
}
}
// Find first column with some available space at the bottom of it:
for col_bb in &column_bbs {
if col_bb.bottom() < available_rect.center().y {
return pos2(col_bb.left(), col_bb.bottom() + spacing);
}
}
// Maybe we can fit a new column?
let rightmost = column_bbs.last().unwrap().right();
if rightmost + 200.0 < available_rect.right() {
return pos2(rightmost + spacing, top);
}
// Ok, just put us in the column with the most space at the bottom:
let mut best_pos = pos2(left, column_bbs[0].bottom() + spacing);
for col_bb in &column_bbs {
let col_pos = pos2(col_bb.left(), col_bb.bottom() + spacing);
if col_pos.y < best_pos.y {
best_pos = col_pos;
}
}
best_pos
}