// #![warn(missing_docs)]
use std::hash::Hash;
use crate::{
color::*, containers::*, epaint::text::Fonts, layout::*, mutex::MutexGuard, placer::Placer,
widgets::*, *,
};
// ----------------------------------------------------------------------------
/// This is what you use to place widgets.
///
/// Represents a region of the screen with a type of layout (horizontal or vertical).
///
/// ```
/// # let mut ui = egui::Ui::__test();
/// ui.add(egui::Label::new("Hello World!"));
/// ui.label("A shorter and more convenient way to add a label.");
/// ui.horizontal(|ui| {
/// ui.label("Add widgets");
/// if ui.button("on the same row!").clicked() {
/// /* … */
/// }
/// });
/// ```
pub struct Ui {
/// ID of this ui.
/// Generated based on id of parent ui together with
/// another source of child identity (e.g. window title).
/// Acts like a namespace for child uis.
/// Should be unique and persist predictably from one frame to next
/// so it can be used as a source for storing state (e.g. window position, or if a collapsing header is open).
id: Id,
/// This is used to create a unique interact ID for some widgets.
/// This value is based on where in the hierarchy of widgets this Ui is in,
/// and the value is increment with each added child widget.
/// This works as an Id source only as long as new widgets aren't added or removed.
/// They are therefore only good for Id:s that has no state.
next_auto_id: u64,
/// Specifies paint layer, clip rectangle and a reference to `Context`.
painter: Painter,
/// The `Style` (visuals, spacing, etc) of this ui.
/// Commonly many `Ui`:s share the same `Style`.
/// The `Ui` implements copy-on-write for this.
style: std::sync::Arc<Style>,
/// Handles the `Ui` size and the placement of new widgets.
placer: Placer,
/// If false we are unresponsive to input,
/// and all widgets will assume a gray style.
enabled: bool,
}
impl Ui {
// ------------------------------------------------------------------------
// Creation:
pub fn new(ctx: CtxRef, layer_id: LayerId, id: Id, max_rect: Rect, clip_rect: Rect) -> Self {
let style = ctx.style();
Ui {
id,
next_auto_id: id.with("auto").value(),
painter: Painter::new(ctx, layer_id, clip_rect),
style,
placer: Placer::new(max_rect, Layout::default()),
enabled: true,
}
}
pub fn child_ui(&mut self, max_rect: Rect, layout: Layout) -> Self {
self.next_auto_id = self.next_auto_id.wrapping_add(1);
Ui {
id: self.id.with("child"),
next_auto_id: Id::new(self.next_auto_id).with("child").value(),
painter: self.painter.clone(),
style: self.style.clone(),
placer: Placer::new(max_rect, layout),
enabled: self.enabled,
}
}
/// Empty `Ui` for use in tests.
pub fn __test() -> Self {
let mut ctx = CtxRef::default();
ctx.begin_frame(Default::default());
let id = Id::new("__test");
let layer_id = LayerId::new(Order::Middle, id);
let rect = Rect::from_min_size(Pos2::new(0.0, 0.0), vec2(1000.0, 1000.0));
Self::new(ctx, layer_id, id, rect, rect)
}
// -------------------------------------------------
/// A unique identity of this `Ui`.
pub fn id(&self) -> Id {
self.id
}
/// Style options for this `Ui` and its children.
pub fn style(&self) -> &std::sync::Arc<Style> {
&self.style
}
/// Mutably borrow internal `Style`.
/// Changes apply to this `Ui` and its subsequent children.
///
/// To set the style of all `Ui`:s, use [`Context::set_style`].
///
/// Example:
/// ```
/// # let ui = &mut egui::Ui::__test();
/// ui.style_mut().body_text_style = egui::TextStyle::Heading;
/// ```
pub fn style_mut(&mut self) -> &mut Style {
std::sync::Arc::make_mut(&mut self.style) // clone-on-write
}
/// Changes apply to this `Ui` and its subsequent children.
///
/// To set the visuals of all `Ui`:s, use [`Context::set_visuals`].
pub fn set_style(&mut self, style: impl Into<std::sync::Arc<Style>>) {
self.style = style.into();
}
/// The current spacing options for this `Ui`.
/// Short for `ui.style().spacing`.
pub fn spacing(&self) -> &crate::style::Spacing {
&self.style.spacing
}
/// Mutably borrow internal `Spacing`.
/// Changes apply to this `Ui` and its subsequent children.
///
/// Example:
/// ```
/// # let ui = &mut egui::Ui::__test();
/// ui.spacing_mut().item_spacing = egui::vec2(10.0, 2.0);
/// ```
pub fn spacing_mut(&mut self) -> &mut crate::style::Spacing {
&mut self.style_mut().spacing
}
/// The current visuals settings of this `Ui`.
/// Short for `ui.style().visuals`.
pub fn visuals(&self) -> &crate::Visuals {
&self.style.visuals
}
/// Mutably borrow internal `visuals`.
/// Changes apply to this `Ui` and its subsequent children.
///
/// To set the visuals of all `Ui`:s, use [`Context::set_visuals`].
///
/// Example:
/// ```
/// # let ui = &mut egui::Ui::__test();
/// ui.visuals_mut().override_text_color = Some(egui::Color32::RED);
/// ```
pub fn visuals_mut(&mut self) -> &mut crate::Visuals {
&mut self.style_mut().visuals
}
/// Get a reference to the parent [`CtxRef`].
pub fn ctx(&self) -> &CtxRef {
self.painter.ctx()
}
/// Use this to paint stuff within this `Ui`.
pub fn painter(&self) -> &Painter {
&self.painter
}
/// If `false`, the `Ui` does not allow any interaction and
/// the widgets in it will draw with a gray look.
pub fn enabled(&self) -> bool {
self.enabled
}
/// Calling `set_enabled(false)` will cause the `Ui` to deny all future interaction
/// and all the widgets will draw with a gray look.
///
/// Calling `set_enabled(true)` has no effect - it will NOT re-enable the `Ui` once disabled.
///
/// ### Example
/// ```
/// # let ui = &mut egui::Ui::__test();
/// # let mut enabled = true;
/// ui.group(|ui|{
/// ui.checkbox(&mut enabled, "Enable subsection");
/// ui.set_enabled(enabled);
/// if ui.button("Button that is not always clickable").clicked() {
/// /* … */
/// }
/// });
/// ```
pub fn set_enabled(&mut self, enabled: bool) {
self.enabled &= enabled;
if self.enabled {
self.painter.set_fade_to_color(None);
} else {
self.painter
.set_fade_to_color(Some(self.visuals().window_fill()));
}
}
pub fn layout(&self) -> &Layout {
self.placer.layout()
}
/// Should text wrap in this `Ui`?
/// This is determined first by [`Style::wrap`], and then by the layout of this `Ui`.
pub fn wrap_text(&self) -> bool {
if let Some(wrap) = self.style.wrap {
wrap
} else if let Some(grid) = self.placer.grid() {
grid.wrap_text()
} else {
// In vertical layouts we wrap text, but in horizontal we keep going.
self.layout().is_vertical()
}
}
/// Create a painter for a sub-region of this Ui.
///
/// The clip-rect of the returned `Painter` will be the intersection
/// of the given rectangle and the `clip_rect()` of this `Ui`.
pub fn painter_at(&self, rect: Rect) -> Painter {
self.painter().sub_region(rect)
}
/// Use this to paint stuff within this `Ui`.
pub fn layer_id(&self) -> LayerId {
self.painter().layer_id()
}
/// The `Input` of the `Context` associated with the `Ui`.
/// Equivalent to `.ctx().input()`.
pub fn input(&self) -> &InputState {
self.ctx().input()
}
/// The `Memory` of the `Context` associated with the `Ui`.
/// Equivalent to `.ctx().memory()`.
pub fn memory(&self) -> MutexGuard<'_, Memory> {
self.ctx().memory()
}
/// The `Output` of the `Context` associated with the `Ui`.
/// Equivalent to `.ctx().output()`.
pub fn output(&self) -> MutexGuard<'_, Output> {
self.ctx().output()
}
/// The `Fonts` of the `Context` associated with the `Ui`.
/// Equivalent to `.ctx().fonts()`.
pub fn fonts(&self) -> &Fonts {
self.ctx().fonts()
}
/// Screen-space rectangle for clipping what we paint in this ui.
/// This is used, for instance, to avoid painting outside a window that is smaller than its contents.
pub fn clip_rect(&self) -> Rect {
self.painter.clip_rect()
}
/// Screen-space rectangle for clipping what we paint in this ui.
/// This is used, for instance, to avoid painting outside a window that is smaller than its contents.
pub fn set_clip_rect(&mut self, clip_rect: Rect) {
self.painter.set_clip_rect(clip_rect);
}
}
// ------------------------------------------------------------------------
/// # Sizes etc
impl Ui {
/// Where and how large the `Ui` is already.
/// All widgets that have been added ot this `Ui` fits within this rectangle.
///
/// No matter what, the final Ui will be at least this large.
///
/// This will grow as new widgets are added, but never shrink.
pub fn min_rect(&self) -> Rect {
self.placer.min_rect()
}
/// Size of content; same as `min_rect().size()`
pub fn min_size(&self) -> Vec2 {
self.min_rect().size()
}
/// New widgets will *try* to fit within this rectangle.
///
/// Text labels will wrap to fit within `max_rect`.
/// Separator lines will span the `max_rect`.
///
/// If a new widget doesn't fit within the `max_rect` then the
/// `Ui` will make room for it by expanding both `min_rect` and `max_rect`.
pub fn max_rect(&self) -> Rect {
self.placer.max_rect()
}
/// This is like `max_rect()`, but will never be infinite.
/// This can be useful for widgets that expand to fit the available space.
pub fn max_rect_finite(&self) -> Rect {
self.placer.max_rect_finite()
}
/// Used for animation, kind of hacky
pub(crate) fn force_set_min_rect(&mut self, min_rect: Rect) {
self.placer.force_set_min_rect(min_rect)
}
// ------------------------------------------------------------------------
/// Set the maximum size of the ui.
/// You won't be able to shrink it below the current minimum size.
pub fn set_max_size(&mut self, size: Vec2) {
self.set_max_width(size.x);
self.set_max_height(size.y);
}
/// Set the maximum width of the ui.
/// You won't be able to shrink it below the current minimum size.
pub fn set_max_width(&mut self, width: f32) {
self.placer.set_max_width(width);
}
/// Set the maximum height of the ui.
/// You won't be able to shrink it below the current minimum size.
pub fn set_max_height(&mut self, height: f32) {
self.placer.set_max_height(height);
}
// ------------------------------------------------------------------------
/// Set the minimum size of the ui.
/// This can't shrink the ui, only make it larger.
pub fn set_min_size(&mut self, size: Vec2) {
self.set_min_width(size.x);
self.set_min_height(size.y);
}
/// Set the minimum width of the ui.
/// This can't shrink the ui, only make it larger.
pub fn set_min_width(&mut self, width: f32) {
self.placer.set_min_width(width);
}
/// Set the minimum height of the ui.
/// This can't shrink the ui, only make it larger.
pub fn set_min_height(&mut self, height: f32) {
self.placer.set_min_height(height);
}
// ------------------------------------------------------------------------
/// Helper: shrinks the max width to the current width,
/// so further widgets will try not to be wider than previous widgets.
/// Useful for normal vertical layouts.
pub fn shrink_width_to_current(&mut self) {
self.set_max_width(self.min_rect().width())
}
/// Helper: shrinks the max height to the current height,
/// so further widgets will try not to be wider than previous widgets.
pub fn shrink_height_to_current(&mut self) {
self.set_max_height(self.min_rect().height())
}
/// Expand the `min_rect` and `max_rect` of this ui to include a child at the given rect.
pub fn expand_to_include_rect(&mut self, rect: Rect) {
self.placer.expand_to_include_rect(rect);
}
/// `ui.set_width_range(min..=max);` is equivalent to `ui.set_min_width(min); ui.set_max_width(max);`.
pub fn set_width_range(&mut self, width: std::ops::RangeInclusive<f32>) {
self.set_min_width(*width.start());
self.set_max_width(*width.end());
}
/// `ui.set_width_range(width);` is equivalent to `ui.set_min_width(width); ui.set_max_width(width);`.
pub fn set_width(&mut self, width: f32) {
self.set_min_width(width);
self.set_max_width(width);
}
/// Ensure we are big enough to contain the given x-coordinate.
/// This is sometimes useful to expand an ui to stretch to a certain place.
pub fn expand_to_include_x(&mut self, x: f32) {
self.placer.expand_to_include_x(x);
}
// ------------------------------------------------------------------------
// Layout related measures:
/// The available space at the moment, given the current cursor.
/// This how much more space we can take up without overflowing our parent.
/// Shrinks as widgets allocate space and the cursor moves.
/// A small size should be interpreted as "as little as possible".
/// An infinite size should be interpreted as "as much as you want".
pub fn available_size(&self) -> Vec2 {
self.placer.available_size()
}
pub fn available_width(&self) -> f32 {
self.available_size().x
}
/// In case of a wrapping layout, how much space is left on this row/column?
pub fn available_size_before_wrap(&self) -> Vec2 {
self.placer.available_rect_before_wrap().size()
}
/// This is like `available_size_before_wrap()`, but will never be infinite.
/// This can be useful for widgets that expand to fit the available space.
/// In most layouts the next widget will be put in the top left corner of this `Rect`.
pub fn available_size_before_wrap_finite(&self) -> Vec2 {
self.placer.available_rect_before_wrap_finite().size()
}
pub fn available_rect_before_wrap(&self) -> Rect {
self.placer.available_rect_before_wrap()
}
/// This is like `available_rect_before_wrap()`, but will never be infinite.
/// This can be useful for widgets that expand to fit the available space.
/// In most layouts the next widget will be put in the top left corner of this `Rect`.
pub fn available_rect_before_wrap_finite(&self) -> Rect {
self.placer.available_rect_before_wrap_finite()
}
}
/// # `Id` creation
impl Ui {
/// Use this to generate widget ids for widgets that have persistent state in `Memory`.
pub fn make_persistent_id<IdSource>(&self, id_source: IdSource) -> Id
where
IdSource: Hash + std::fmt::Debug,
{
self.id.with(&id_source)
}
#[deprecated = "This id now returned from ui.allocate_space"]
pub fn make_position_id(&self) -> Id {
Id::new(self.next_auto_id)
}
pub(crate) fn auto_id_with<IdSource>(&self, id_source: IdSource) -> Id
where
IdSource: Hash + std::fmt::Debug,
{
Id::new(self.next_auto_id).with(id_source)
}
}
/// # Interaction
impl Ui {
pub fn interact(&self, rect: Rect, id: Id, sense: Sense) -> Response {
self.ctx().interact(
self.clip_rect(),
self.spacing().item_spacing,
self.layer_id(),
id,
rect,
sense,
self.enabled,
)
}
/// Is the pointer (mouse/touch) above this rectangle in this `Ui`?
///
/// The `clip_rect` and layer of this `Ui` will be respected, so, for instance,
/// if this `Ui` is behind some other window, this will always return `false`.
pub fn rect_contains_pointer(&self, rect: Rect) -> bool {
self.ctx()
.rect_contains_pointer(self.layer_id(), self.clip_rect().intersect(rect))
}
/// Is the pointer (mouse/touch) above this `Ui`?
/// Equivalent to `ui.rect_contains_pointer(ui.min_rect())`
pub fn ui_contains_pointer(&self) -> bool {
self.rect_contains_pointer(self.min_rect())
}
#[deprecated = "renamed rect_contains_pointer"]
pub fn rect_contains_mouse(&self, rect: Rect) -> bool {
self.rect_contains_pointer(rect)
}
#[deprecated = "renamed ui_contains_pointer"]
pub fn ui_contains_mouse(&self) -> bool {
self.ui_contains_pointer()
}
#[deprecated = "Use: interact(rect, id, Sense::hover())"]
pub fn interact_hover(&self, rect: Rect) -> Response {
self.interact(rect, self.auto_id_with("hover_rect"), Sense::hover())
}
#[deprecated = "Use: rect_contains_pointer()"]
pub fn hovered(&self, rect: Rect) -> bool {
self.interact(rect, self.id, Sense::hover()).hovered
}
// ------------------------------------------------------------------------
// Stuff that moves the cursor, i.e. allocates space in this ui!
/// Advance the cursor (where the next widget is put) by this many points.
///
/// The direction is dependent on the layout.
/// This is useful for creating some extra space between widgets.
///
/// [`Self::min_rect`] will expand to contain the cursor.
pub fn advance_cursor(&mut self, amount: f32) {
self.placer.advance_cursor(amount);
}
}
/// # Allocating space: where do I put my widgets?
impl Ui {
/// Allocate space for a widget and check for interaction in the space.
/// Returns a `Response` which contains a rectangle, id, and interaction info.
///
/// ## How sizes are negotiated
/// Each widget should have a *minimum desired size* and a *desired size*.
/// When asking for space, ask AT LEAST for you minimum, and don't ask for more than you need.
/// If you want to fill the space, ask about `available().size()` and use that.
///
/// You may get MORE space than you asked for, for instance
/// for justified layouts, like in menus.
///
/// You will never get a rectangle that is smaller than the amount of space you asked for.
///
/// ```
/// # let mut ui = egui::Ui::__test();
/// let response = ui.allocate_response(egui::vec2(100.0, 200.0), egui::Sense::click());
/// if response.clicked() { /* … */ }
/// ui.painter().rect_stroke(response.rect, 0.0, (1.0, egui::Color32::WHITE));
/// ```
pub fn allocate_response(&mut self, desired_size: Vec2, sense: Sense) -> Response {
let (id, rect) = self.allocate_space(desired_size);
self.interact(rect, id, sense)
}
/// Returns a `Rect` with exactly what you asked for.
///
/// The response rect will be larger if this is part of a justified layout or similar.
/// This means that iof this is a narrow widget in a wide justified layout, then
/// the widget will react to interactions outside the returned `Rect`.
pub fn allocate_exact_size(&mut self, desired_size: Vec2, sense: Sense) -> (Rect, Response) {
let response = self.allocate_response(desired_size, sense);
let rect = self
.placer
.align_size_within_rect(desired_size, response.rect);
(rect, response)
}
/// Allocate at least as much space as needed, and interact with that rect.
///
/// The returned `Rect` will be the same size as `Response::rect`.
pub fn allocate_at_least(&mut self, desired_size: Vec2, sense: Sense) -> (Rect, Response) {
let response = self.allocate_response(desired_size, sense);
(response.rect, response)
}
/// Reserve this much space and move the cursor.
/// Returns where to put the widget.
///
/// ## How sizes are negotiated
/// Each widget should have a *minimum desired size* and a *desired size*.
/// When asking for space, ask AT LEAST for you minimum, and don't ask for more than you need.
/// If you want to fill the space, ask about `available().size()` and use that.
///
/// You may get MORE space than you asked for, for instance
/// for justified layouts, like in menus.
///
/// You will never get a rectangle that is smaller than the amount of space you asked for.
///
/// Returns an automatic `Id` (which you can use for interaction) and the `Rect` of where to put your widget.
///
/// ```
/// # let mut ui = egui::Ui::__test();
/// let (id, rect) = ui.allocate_space(egui::vec2(100.0, 200.0));
/// let response = ui.interact(rect, id, egui::Sense::click());
/// ```
pub fn allocate_space(&mut self, desired_size: Vec2) -> (Id, Rect) {
// For debug rendering
let original_available = self.available_size_before_wrap();
let too_wide = desired_size.x > original_available.x;
let too_high = desired_size.y > original_available.y;
let rect = self.allocate_space_impl(desired_size);
let debug_expand_width = self.visuals().debug_expand_width;
let debug_expand_height = self.visuals().debug_expand_height;
if (debug_expand_width && too_wide) || (debug_expand_height && too_high) {
self.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| self.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(
pos2(rect.left() + original_available.x, rect.top()),
pos2(rect.left() + original_available.x, rect.bottom()),
);
paint_line_seg(rect.right_top(), rect.right_bottom());
}
if debug_expand_height && too_high {
paint_line_seg(rect.left_top(), rect.right_top());
paint_line_seg(rect.center_top(), rect.center_bottom());
paint_line_seg(rect.left_bottom(), rect.right_bottom());
}
}
self.next_auto_id = self.next_auto_id.wrapping_add(1);
let id = Id::new(self.next_auto_id);
(id, rect)
}
/// Reserve this much space and move the cursor.
/// Returns where to put the widget.
fn allocate_space_impl(&mut self, desired_size: Vec2) -> Rect {
let item_spacing = self.spacing().item_spacing;
let frame_rect = self.placer.next_space(desired_size, item_spacing);
let widget_rect = self.placer.justify_and_align(frame_rect, desired_size);
self.placer
.advance_after_rects(frame_rect, widget_rect, item_spacing);
widget_rect
}
/// Allocate a specific part of the `Ui‘.
/// Ignore the layout of the `Ui‘: just put my widget here!
pub(crate) fn allocate_rect(&mut self, rect: Rect, sense: Sense) -> Response {
let id = self.advance_cursor_after_rect(rect);
self.interact(rect, id, sense)
}
pub(crate) fn advance_cursor_after_rect(&mut self, rect: Rect) -> Id {
let item_spacing = self.spacing().item_spacing;
self.placer.advance_after_rects(rect, rect, item_spacing);
self.next_auto_id = self.next_auto_id.wrapping_add(1);
Id::new(self.next_auto_id)
}
pub(crate) fn cursor(&self) -> Pos2 {
self.placer.cursor()
}
/// Allocated the given space and then adds content to that space.
/// If the contents overflow, more space will be allocated.
/// When finished, the amount of space actually used (`min_rect`) will be allocated.
/// So you can request a lot of space and then use less.
pub fn allocate_ui<R>(
&mut self,
desired_size: Vec2,
add_contents: impl FnOnce(&mut Self) -> R,
) -> InnerResponse<R> {
let item_spacing = self.spacing().item_spacing;
let outer_child_rect = self.placer.next_space(desired_size, item_spacing);
let inner_child_rect = self
.placer
.justify_and_align(outer_child_rect, desired_size);
let mut child_ui = self.child_ui(inner_child_rect, *self.layout());
let ret = add_contents(&mut child_ui);
let final_child_rect = child_ui.min_rect();
self.placer.advance_after_rects(
outer_child_rect.union(final_child_rect),
final_child_rect,
item_spacing,
);
let response = self.interact(final_child_rect, child_ui.id, Sense::hover());
InnerResponse::new(ret, response)
}
/// Allocated the given rectangle and then adds content to that rectangle.
/// If the contents overflow, more space will be allocated.
/// When finished, the amount of space actually used (`min_rect`) will be allocated.
/// So you can request a lot of space and then use less.
pub fn allocate_ui_at_rect<R>(
&mut self,
max_rect: Rect,
add_contents: impl FnOnce(&mut Self) -> R,
) -> InnerResponse<R> {
let mut child_ui = self.child_ui(max_rect, *self.layout());
let ret = add_contents(&mut child_ui);
let final_child_rect = child_ui.min_rect();
self.placer.advance_after_rects(
final_child_rect,
final_child_rect,
self.spacing().item_spacing,
);
let response = self.interact(final_child_rect, child_ui.id, Sense::hover());
InnerResponse::new(ret, response)
}
/// Convenience function to get a region to paint on
pub fn allocate_painter(&mut self, desired_size: Vec2, sense: Sense) -> (Response, Painter) {
let response = self.allocate_response(desired_size, sense);
let clip_rect = self.clip_rect().intersect(response.rect); // Make sure we don't paint out of bounds
let painter = Painter::new(self.ctx().clone(), self.layer_id(), clip_rect);
(response, painter)
}
/// Move the scroll to this cursor position with the specified alignment.
///
/// ```
/// # use egui::Align;
/// # let mut ui = &mut egui::Ui::__test();
/// egui::ScrollArea::auto_sized().show(ui, |ui| {
/// let scroll_bottom = ui.button("Scroll to bottom.").clicked();
/// for i in 0..1000 {
/// ui.label(format!("Item {}", i));
/// }
///
/// if scroll_bottom {
/// ui.scroll_to_cursor(Align::BOTTOM);
/// }
/// });
/// ```
pub fn scroll_to_cursor(&mut self, align: Align) {
let scroll_y = self.cursor().y;
self.ctx().frame_state().scroll_target = Some((scroll_y, align));
}
}
/// # Adding widgets
impl Ui {
/// Add a [`Widget`] to this `Ui` at a location dependent on the current [`Layout`].
///
/// The returned [`Response`] can be used to check for interactions,
/// as well as adding tooltips using [`Response::on_hover_text`].
///
/// ```
/// # let mut ui = egui::Ui::__test();
/// # let mut my_value = 42;
/// let response = ui.add(egui::Slider::i32(&mut my_value, 0..=100));
/// response.on_hover_text("Drag me!");
/// ```
pub fn add(&mut self, widget: impl Widget) -> Response {
widget.ui(self)
}
/// Add a [`Widget`] to this `Ui` with a given max size.
pub fn add_sized(&mut self, max_size: Vec2, widget: impl Widget) -> Response {
self.allocate_ui(max_size, |ui| {
ui.centered_and_justified(|ui| ui.add(widget)).inner
})
.inner
}
/// Add a [`Widget`] to this `Ui` at a specific location (manual layout).
pub fn put(&mut self, max_rect: Rect, widget: impl Widget) -> Response {
self.allocate_ui_at_rect(max_rect, |ui| {
ui.centered_and_justified(|ui| ui.add(widget)).inner
})
.inner
}
/// Shortcut for `add(Label::new(text))`
///
/// Se also [`Label`].
pub fn label(&mut self, label: impl Into<Label>) -> Response {
self.add(label.into())
}
/// Shortcut for `add(Label::new(text).text_color(color))`
pub fn colored_label(
&mut self,
color: impl Into<Color32>,
label: impl Into<Label>,
) -> Response {
self.add(label.into().text_color(color))
}
/// Shortcut for `add(Label::new(text).heading())`
pub fn heading(&mut self, label: impl Into<Label>) -> Response {
self.add(label.into().heading())
}
/// Shortcut for `add(Label::new(text).monospace())`
pub fn monospace(&mut self, label: impl Into<Label>) -> Response {
self.add(label.into().monospace())
}
/// Show text as monospace with a gray background.
///
/// Shortcut for `add(Label::new(text).code())`
pub fn code(&mut self, label: impl Into<Label>) -> Response {
self.add(label.into().code())
}
/// Shortcut for `add(Label::new(text).small())`
pub fn small(&mut self, label: impl Into<Label>) -> Response {
self.add(label.into().small())
}
/// Shortcut for `add(Hyperlink::new(url))`
///
/// Se also [`Hyperlink`].
pub fn hyperlink(&mut self, url: impl Into<String>) -> Response {
self.add(Hyperlink::new(url))
}
/// Shortcut for `add(Hyperlink::new(url).text(label))`
///
/// ```
/// # let ui = &mut egui::Ui::__test();
/// ui.hyperlink_to("egui on GitHub", "https://www.github.com/emilk/egui/");
/// ```
///
/// Se also [`Hyperlink`].
pub fn hyperlink_to(&mut self, label: impl Into<String>, url: impl Into<String>) -> Response {
self.add(Hyperlink::new(url).text(label))
}
#[deprecated = "Use `text_edit_singleline` or `text_edit_multiline`"]
pub fn text_edit(&mut self, text: &mut String) -> Response {
self.text_edit_multiline(text)
}
/// Now newlines (`\n`) allowed. Pressing enter key will result in the `TextEdit` loosing focus (`response.lost_kb_focus`).
///
/// Se also [`TextEdit`].
pub fn text_edit_singleline(&mut self, text: &mut String) -> Response {
self.add(TextEdit::singleline(text))
}
/// A `TextEdit` for multiple lines. Pressing enter key will create a new line.
///
/// Se also [`TextEdit`].
pub fn text_edit_multiline(&mut self, text: &mut String) -> Response {
self.add(TextEdit::multiline(text))
}
/// Usage: `if ui.button("Click me").clicked() { … }`
///
/// Shortcut for `add(Button::new(text))`
///
/// Se also [`Button`].
#[must_use = "You should check if the user clicked this with `if ui.button(…).clicked() { … } "]
pub fn button(&mut self, text: impl Into<String>) -> Response {
self.add(Button::new(text))
}
/// A button as small as normal body text.
///
/// Usage: `if ui.small_button("Click me").clicked() { … }`
///
/// Shortcut for `add(Button::new(text).small())`
#[must_use = "You should check if the user clicked this with `if ui.small_button(…).clicked() { … } "]
pub fn small_button(&mut self, text: impl Into<String>) -> Response {
self.add(Button::new(text).small())
}
/// Show a checkbox.
pub fn checkbox(&mut self, checked: &mut bool, text: impl Into<String>) -> Response {
self.add(Checkbox::new(checked, text))
}
/// Show a [`RadioButton`].
/// Often you want to use [`Self::radio_value`] instead.
#[must_use = "You should check if the user clicked this with `if ui.radio(…).clicked() { … } "]
pub fn radio(&mut self, selected: bool, text: impl Into<String>) -> Response {
self.add(RadioButton::new(selected, text))
}
/// Show a [`RadioButton`]. It is selected if `*current_value == selected_value`.
/// If clicked, `selected_value` is assigned to `*current_value`.
///
/// ```
/// # let ui = &mut egui::Ui::__test();
///
/// #[derive(PartialEq)]
/// enum Enum { First, Second, Third }
/// let mut my_enum = Enum::First;
///
/// ui.radio_value(&mut my_enum, Enum::First, "First");
///
/// // is equivalent to:
///
/// if ui.add(egui::RadioButton::new(my_enum == Enum::First, "First")).clicked() {
/// my_enum = Enum::First
/// }
pub fn radio_value<Value: PartialEq>(
&mut self,
current_value: &mut Value,
selected_value: Value,
text: impl Into<String>,
) -> Response {
let mut response = self.radio(*current_value == selected_value, text);
if response.clicked() {
*current_value = selected_value;
response.mark_changed();
}
response
}
/// Show a label which can be selected or not.
///
/// Se also [`SelectableLabel`].
#[must_use = "You should check if the user clicked this with `if ui.selectable_label(…).clicked() { … } "]
pub fn selectable_label(&mut self, checked: bool, text: impl Into<String>) -> Response {
self.add(SelectableLabel::new(checked, text))
}
/// Show selectable text. It is selected if `*current_value == selected_value`.
/// If clicked, `selected_value` is assigned to `*current_value`.
///
/// Example: `ui.selectable_value(&mut my_enum, Enum::Alternative, "Alternative")`.
///
/// Se also [`SelectableLabel`].
pub fn selectable_value<Value: PartialEq>(
&mut self,
current_value: &mut Value,
selected_value: Value,
text: impl Into<String>,
) -> Response {
let mut response = self.selectable_label(*current_value == selected_value, text);
if response.clicked() {
*current_value = selected_value;
response.mark_changed();
}
response
}
/// Shortcut for `add(Separator::new())` (see [`Separator`]).
pub fn separator(&mut self) -> Response {
self.add(Separator::new())
}
/// Modify an angle. The given angle should be in radians, but is shown to the user in degrees.
/// The angle is NOT wrapped, so the user may select, for instance 720° = 2𝞃 = 4π
pub fn drag_angle(&mut self, radians: &mut f32) -> Response {
#![allow(clippy::float_cmp)]
let mut degrees = radians.to_degrees();
let mut response = self.add(DragValue::f32(&mut degrees).speed(1.0).suffix("°"));
// only touch `*radians` if we actually changed the degree value
if degrees != radians.to_degrees() {
*radians = degrees.to_radians();
response.changed = true;
}
response
}
/// Modify an angle. The given angle should be in radians,
/// but is shown to the user in fractions of one Tau (i.e. fractions of one turn).
/// The angle is NOT wrapped, so the user may select, for instance 2𝞃 (720°)
pub fn drag_angle_tau(&mut self, radians: &mut f32) -> Response {
#![allow(clippy::float_cmp)]
use std::f32::consts::TAU;
let mut taus = *radians / TAU;
let mut response = self
.add(DragValue::f32(&mut taus).speed(0.01).suffix("τ"))
.on_hover_text("1τ = one turn, 0.5τ = half a turn, etc. 0.25τ = 90°");
// only touch `*radians` if we actually changed the value
if taus != *radians / TAU {
*radians = taus * TAU;
response.changed = true;
}
response
}
/// Show an image here with the given size.
///
/// See also [`Image`].
pub fn image(&mut self, texture_id: TextureId, size: impl Into<Vec2>) -> Response {
self.add(Image::new(texture_id, size))
}
}
/// # Colors
impl Ui {
/// Shows a button with the given color.
/// If the user clicks the button, a full color picker is shown.
pub fn color_edit_button_srgba(&mut self, srgba: &mut Color32) -> Response {
color_picker::color_edit_button_srgba(self, srgba, color_picker::Alpha::BlendOrAdditive)
}
/// Shows a button with the given color.
/// If the user clicks the button, a full color picker is shown.
pub fn color_edit_button_hsva(&mut self, hsva: &mut Hsva) -> Response {
color_picker::color_edit_button_hsva(self, hsva, color_picker::Alpha::BlendOrAdditive)
}
/// Shows a button with the given color.
/// If the user clicks the button, a full color picker is shown.
/// The given color is in `sRGB` space.
pub fn color_edit_button_srgb(&mut self, srgb: &mut [u8; 3]) -> Response {
let mut hsva = Hsva::from_srgb(*srgb);
let response =
color_picker::color_edit_button_hsva(self, &mut hsva, color_picker::Alpha::Opaque);
*srgb = hsva.to_srgb();
response
}
/// Shows a button with the given color.
/// If the user clicks the button, a full color picker is shown.
/// The given color is in linear RGB space.
pub fn color_edit_button_rgb(&mut self, rgb: &mut [f32; 3]) -> Response {
let mut hsva = Hsva::from_rgb(*rgb);
let response =
color_picker::color_edit_button_hsva(self, &mut hsva, color_picker::Alpha::Opaque);
*rgb = hsva.to_rgb();
response
}
/// Shows a button with the given color.
/// If the user clicks the button, a full color picker is shown.
/// The given color is in `sRGBA` space with premultiplied alpha
pub fn color_edit_button_srgba_premultiplied(&mut self, srgba: &mut [u8; 4]) -> Response {
let mut color = Color32::from_rgba_premultiplied(srgba[0], srgba[1], srgba[2], srgba[3]);
let response = self.color_edit_button_srgba(&mut color);
*srgba = color.to_array();
response
}
/// Shows a button with the given color.
/// If the user clicks the button, a full color picker is shown.
/// The given color is in `sRGBA` space without premultiplied alpha.
/// If unsure, what "premultiplied alpha" is, then this is probably the function you want to use.
pub fn color_edit_button_srgba_unmultiplied(&mut self, srgba: &mut [u8; 4]) -> Response {
let mut hsva = Hsva::from_srgba_unmultiplied(*srgba);
let response =
color_picker::color_edit_button_hsva(self, &mut hsva, color_picker::Alpha::OnlyBlend);
*srgba = hsva.to_srgba_unmultiplied();
response
}
/// Shows a button with the given color.
/// If the user clicks the button, a full color picker is shown.
/// The given color is in linear RGBA space with premultiplied alpha
pub fn color_edit_button_rgba_premultiplied(&mut self, rgba: &mut [f32; 4]) -> Response {
let mut hsva = Hsva::from_rgba_premultiplied(*rgba);
let response = color_picker::color_edit_button_hsva(
self,
&mut hsva,
color_picker::Alpha::BlendOrAdditive,
);
*rgba = hsva.to_rgba_premultiplied();
response
}
/// Shows a button with the given color.
/// If the user clicks the button, a full color picker is shown.
/// The given color is in linear RGBA space without premultiplied alpha.
/// If unsure, what "premultiplied alpha" is, then this is probably the function you want to use.
pub fn color_edit_button_rgba_unmultiplied(&mut self, rgba: &mut [f32; 4]) -> Response {
let mut hsva = Hsva::from_rgba_unmultiplied(*rgba);
let response =
color_picker::color_edit_button_hsva(self, &mut hsva, color_picker::Alpha::OnlyBlend);
*rgba = hsva.to_rgba_unmultiplied();
response
}
}
/// # Adding Containers / Sub-uis:
impl Ui {
/// Put into a `Frame::group`, visually grouping the contents together
pub fn group<R>(&mut self, add_contents: impl FnOnce(&mut Ui) -> R) -> R {
crate::Frame::group(self.style()).show(self, add_contents)
}
/// Create a child ui. You can use this to temporarily change the Style of a sub-region, for instance.
pub fn wrap<R>(&mut self, add_contents: impl FnOnce(&mut Ui) -> R) -> InnerResponse<R> {
let child_rect = self.available_rect_before_wrap();
let mut child_ui = self.child_ui(child_rect, *self.layout());
let ret = add_contents(&mut child_ui);
let size = child_ui.min_size();
let response = self.allocate_response(size, Sense::hover());
InnerResponse::new(ret, response)
}
/// Redirect shapes to another paint layer.
pub fn with_layer_id<R>(
&mut self,
layer_id: LayerId,
add_contents: impl FnOnce(&mut Self) -> R,
) -> InnerResponse<R> {
self.wrap(|ui| {
ui.painter.set_layer_id(layer_id);
add_contents(ui)
})
}
#[deprecated = "Use `ui.allocate_ui` instead"]
pub fn add_custom_contents(
&mut self,
desired_size: Vec2,
add_contents: impl FnOnce(&mut Ui),
) -> Rect {
self.allocate_ui(desired_size, add_contents).response.rect
}
/// A [`CollapsingHeader`] that starts out collapsed.
pub fn collapsing<R>(
&mut self,
heading: impl Into<String>,
add_contents: impl FnOnce(&mut Ui) -> R,
) -> CollapsingResponse<R> {
CollapsingHeader::new(heading).show(self, add_contents)
}
/// Create a child ui which is indented to the right.
pub fn indent<R>(
&mut self,
id_source: impl Hash,
add_contents: impl FnOnce(&mut Ui) -> R,
) -> InnerResponse<R> {
assert!(
self.layout().is_vertical(),
"You can only indent vertical layouts, found {:?}",
self.layout()
);
let indent = vec2(self.spacing().indent, 0.0);
let child_rect = Rect::from_min_max(self.cursor() + indent, self.max_rect().right_bottom()); // TODO: wrong for reversed layouts
let mut child_ui = Self {
id: self.id.with(id_source),
..self.child_ui(child_rect, *self.layout())
};
let ret = add_contents(&mut child_ui);
let end_with_horizontal_line = true;
if end_with_horizontal_line {
child_ui.advance_cursor(4.0);
}
let size = child_ui.min_size();
// draw a faint line on the left to mark the indented section
let stroke = self.visuals().widgets.noninteractive.bg_stroke;
let left_top = child_rect.min - indent * 0.5;
let left_top = self.painter().round_pos_to_pixels(left_top);
let left_bottom = pos2(left_top.x, left_top.y + size.y - 2.0);
let left_bottom = self.painter().round_pos_to_pixels(left_bottom);
self.painter.line_segment([left_top, left_bottom], stroke);
if end_with_horizontal_line {
let fudge = 2.0; // looks nicer with button rounding in collapsing headers
let right_bottom = pos2(child_ui.min_rect().right() - fudge, left_bottom.y);
self.painter
.line_segment([left_bottom, right_bottom], stroke);
}
let response = self.allocate_response(indent + size, Sense::hover());
InnerResponse::new(ret, response)
}
#[deprecated]
pub fn left_column(&mut self, width: f32) -> Self {
#[allow(deprecated)]
self.column(Align::Min, width)
}
#[deprecated]
pub fn centered_column(&mut self, width: f32) -> Self {
#[allow(deprecated)]
self.column(Align::Center, width)
}
#[deprecated]
pub fn right_column(&mut self, width: f32) -> Self {
#[allow(deprecated)]
self.column(Align::Max, width)
}
/// A column ui with a given width.
#[deprecated]
pub fn column(&mut self, column_position: Align, width: f32) -> Self {
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_ui(
Rect::from_min_size(
self.cursor() + vec2(x, 0.0),
vec2(width, self.available_size_before_wrap().y),
),
*self.layout(),
)
}
/// Start a ui with horizontal layout.
/// After you have called this, the function registers the contents as any other widget.
///
/// Elements will be centered on the Y axis, i.e.
/// adjusted up and down to lie in the center of the horizontal layout.
/// The initial height is `style.spacing.interact_size.y`.
/// Centering is almost always what you want if you are
/// planning to to mix widgets or use different types of text.
///
/// The returned `Response` will only have checked for mouse hover
/// but can be used for tooltips (`on_hover_text`).
/// It also contains the `Rect` used by the horizontal layout.
pub fn horizontal<R>(&mut self, add_contents: impl FnOnce(&mut Ui) -> R) -> InnerResponse<R> {
self.horizontal_with_main_wrap(false, add_contents)
}
/// Like `horizontal`, but will set up the spacing to match that of a normal label.
///
/// In particular, the space between widgets is the same width as the space character.
///
/// You can still add any widgets to the layout (not only Labels).
pub fn horizontal_for_text<R>(
&mut self,
text_style: TextStyle,
add_contents: impl FnOnce(&mut Ui) -> R,
) -> InnerResponse<R> {
self.wrap(|ui| {
let font = &ui.fonts()[text_style];
let row_height = font.row_height();
let space_width = font.glyph_width(' ');
let spacing = ui.spacing_mut();
spacing.interact_size.y = row_height;
spacing.item_spacing.x = space_width;
spacing.item_spacing.y = 0.0;
ui.horizontal(add_contents).inner
})
}
/// Start a ui with horizontal layout that wraps to a new row
/// when it reaches the right edge of the `max_size`.
/// After you have called this, the function registers the contents as any other widget.
///
/// Elements will be centered on the Y axis, i.e.
/// adjusted up and down to lie in the center of the horizontal layout.
/// The initial height is `style.spacing.interact_size.y`.
/// Centering is almost always what you want if you are
/// planning to to mix widgets or use different types of text.
///
/// The returned `Response` will only have checked for mouse hover
/// but can be used for tooltips (`on_hover_text`).
/// It also contains the `Rect` used by the horizontal layout.
pub fn horizontal_wrapped<R>(
&mut self,
add_contents: impl FnOnce(&mut Ui) -> R,
) -> InnerResponse<R> {
self.horizontal_with_main_wrap(true, add_contents)
}
/// Like `horizontal_wrapped`, but will set up the spacing and
/// line size to match that of a normal label.
///
/// In particular, the space between widgets is the same width as the space character
/// and the line spacing is the same as that for text.
///
/// You can still add any widgets to the layout (not only Labels).
pub fn horizontal_wrapped_for_text<R>(
&mut self,
text_style: TextStyle,
add_contents: impl FnOnce(&mut Ui) -> R,
) -> InnerResponse<R> {
self.wrap(|ui| {
let font = &ui.fonts()[text_style];
let row_height = font.row_height();
let space_width = font.glyph_width(' ');
let spacing = ui.spacing_mut();
spacing.interact_size.y = row_height;
spacing.item_spacing.x = space_width;
spacing.item_spacing.y = 0.0;
ui.horizontal_wrapped(add_contents).inner
})
}
fn horizontal_with_main_wrap<R>(
&mut self,
main_wrap: bool,
add_contents: impl FnOnce(&mut Ui) -> R,
) -> InnerResponse<R> {
let initial_size = vec2(
self.available_size_before_wrap_finite().x,
self.spacing().interact_size.y, // Assume there will be something interactive on the horizontal layout
);
let layout = if self.placer.prefer_right_to_left() {
Layout::right_to_left()
} else {
Layout::left_to_right()
}
.with_main_wrap(main_wrap);
self.allocate_ui(initial_size, |ui| {
ui.with_layout(layout, add_contents).inner
})
}
/// Start a ui with vertical layout.
/// Widgets will be left-justified.
pub fn vertical<R>(&mut self, add_contents: impl FnOnce(&mut Ui) -> R) -> InnerResponse<R> {
self.with_layout(Layout::top_down(Align::Min), add_contents)
}
/// Start a ui with vertical layout.
/// Widgets will be horizontally centered.
pub fn vertical_centered<R>(
&mut self,
add_contents: impl FnOnce(&mut Ui) -> R,
) -> InnerResponse<R> {
self.with_layout(Layout::top_down(Align::Center), add_contents)
}
/// Start a ui with vertical layout.
/// Widgets will be horizontally centered and justified (fill full width).
pub fn vertical_centered_justified<R>(
&mut self,
add_contents: impl FnOnce(&mut Ui) -> R,
) -> InnerResponse<R> {
self.with_layout(
Layout::top_down(Align::Center).with_cross_justify(true),
add_contents,
)
}
pub fn with_layout<R>(
&mut self,
layout: Layout,
add_contents: impl FnOnce(&mut Self) -> R,
) -> InnerResponse<R> {
let mut child_ui = self.child_ui(self.available_rect_before_wrap(), layout);
let inner = add_contents(&mut child_ui);
let rect = child_ui.min_rect();
let item_spacing = self.spacing().item_spacing;
self.placer.advance_after_rects(rect, rect, item_spacing);
InnerResponse::new(inner, self.interact(rect, child_ui.id, Sense::hover()))
}
/// This will make the next added widget centered and justified in the available space.
pub fn centered_and_justified<R>(
&mut self,
add_contents: impl FnOnce(&mut Self) -> R,
) -> InnerResponse<R> {
self.with_layout(
Layout::centered_and_justified(Direction::TopDown),
add_contents,
)
}
pub(crate) fn set_grid(&mut self, grid: grid::GridLayout) {
self.placer.set_grid(grid);
}
pub(crate) fn save_grid(&mut self) {
self.placer.save_grid();
}
pub(crate) fn is_grid(&self) -> bool {
self.placer.is_grid()
}
pub(crate) fn grid(&self) -> Option<&grid::GridLayout> {
self.placer.grid()
}
/// Move to the next row in a grid layout or wrapping layout.
/// Otherwise does nothing.
pub fn end_row(&mut self) {
self.placer
.end_row(self.spacing().item_spacing, &self.painter().clone());
}
/// Temporarily split split an Ui into several columns.
///
/// ```
/// # let mut ui = egui::Ui::__test();
/// ui.columns(2, |columns| {
/// columns[0].label("First column");
/// columns[1].label("Second column");
/// });
/// ```
pub fn columns<F, R>(&mut self, num_columns: usize, add_contents: F) -> R
where
F: FnOnce(&mut [Self]) -> R,
{
// TODO: ensure there is space
let spacing = self.spacing().item_spacing.x;
let total_spacing = spacing * (num_columns as f32 - 1.0);
let column_width = (self.available_width() - total_spacing) / (num_columns as f32);
let top_left = self.cursor();
let mut columns: Vec<Self> = (0..num_columns)
.map(|col_idx| {
let pos = top_left + vec2((col_idx as f32) * (column_width + spacing), 0.0);
let child_rect = Rect::from_min_max(
pos,
pos2(pos.x + column_width, self.max_rect().right_bottom().y),
);
let mut column_ui =
self.child_ui(child_rect, Layout::top_down_justified(Align::LEFT));
column_ui.set_width(column_width);
column_ui
})
.collect();
let result = add_contents(&mut columns[..]);
let mut max_column_width = column_width;
let mut max_height = 0.0;
for column in &columns {
max_column_width = max_column_width.max(column.min_rect().width());
max_height = column.min_size().y.max(max_height);
}
// Make sure we fit everything next frame:
let total_required_width = total_spacing + max_column_width * (num_columns as f32);
let size = vec2(self.available_width().max(total_required_width), max_height);
self.advance_cursor_after_rect(Rect::from_min_size(top_left, size));
result
}
}
// ----------------------------------------------------------------------------
/// # Debug stuff
impl Ui {
/// Shows where the next widget is going to be placed
pub fn debug_paint_cursor(&self) {
self.placer.debug_paint_cursor(&self.painter);
}
}