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// Copyright 2019 The Druid Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//! Convenience methods for widgets.
use super::invalidation::DebugInvalidation;
#[allow(deprecated)]
use super::Parse;
use super::{
Added, Align, BackgroundBrush, Click, Container, Controller, ControllerHost, EnvScope,
IdentityWrapper, LensWrap, Padding, SizedBox, WidgetId,
};
use crate::widget::{DisabledIf, Scroll};
use crate::{
Color, Data, Env, EventCtx, Insets, KeyOrValue, Lens, LifeCycleCtx, UnitPoint, Widget,
};
/// A trait that provides extra methods for combining `Widget`s.
pub trait WidgetExt<T: Data>: Widget<T> + Sized + 'static {
/// Wrap this widget in a [`Padding`] widget with the given [`Insets`].
///
/// Like [`Padding::new`], this can accept a variety of arguments, including
/// a [`Key`] referring to [`Insets`] in the [`Env`].
///
/// [`Key`]: crate::Key
fn padding(self, insets: impl Into<KeyOrValue<Insets>>) -> Padding<T, Self> {
Padding::new(insets, self)
}
/// Wrap this widget in an [`Align`] widget, configured to center it.
fn center(self) -> Align<T> {
Align::centered(self)
}
/// Wrap this widget in an [`Align`] widget, configured to align left.
fn align_left(self) -> Align<T> {
Align::left(self)
}
/// Wrap this widget in an [`Align`] widget, configured to align right.
fn align_right(self) -> Align<T> {
Align::right(self)
}
/// Wrap this widget in an [`Align`] widget, configured to align vertically.
fn align_vertical(self, align: UnitPoint) -> Align<T> {
Align::vertical(align, self)
}
/// Wrap this widget in an [`Align`] widget, configured to align horizontally.
fn align_horizontal(self, align: UnitPoint) -> Align<T> {
Align::horizontal(align, self)
}
/// Wrap this widget in a [`SizedBox`] with an explicit width.
fn fix_width(self, width: impl Into<KeyOrValue<f64>>) -> SizedBox<T> {
SizedBox::new(self).width(width)
}
/// Wrap this widget in a [`SizedBox`] with an explicit height.
fn fix_height(self, height: impl Into<KeyOrValue<f64>>) -> SizedBox<T> {
SizedBox::new(self).height(height)
}
/// Wrap this widget in an [`SizedBox`] with an explicit width and height
fn fix_size(
self,
width: impl Into<KeyOrValue<f64>>,
height: impl Into<KeyOrValue<f64>>,
) -> SizedBox<T> {
SizedBox::new(self).width(width).height(height)
}
/// Wrap this widget in a [`SizedBox`] with an infinite width and height.
///
/// Only call this method if you want your widget to occupy all available
/// space. If you only care about expanding in one of width or height, use
/// [`expand_width`] or [`expand_height`] instead.
///
/// [`expand_height`]: WidgetExt::expand_height
/// [`expand_width`]: WidgetExt::expand_width
fn expand(self) -> SizedBox<T> {
SizedBox::new(self).expand()
}
/// Wrap this widget in a [`SizedBox`] with an infinite width.
///
/// This will force the child to use all available space on the x-axis.
fn expand_width(self) -> SizedBox<T> {
SizedBox::new(self).expand_width()
}
/// Wrap this widget in a [`SizedBox`] with an infinite width.
///
/// This will force the child to use all available space on the y-axis.
fn expand_height(self) -> SizedBox<T> {
SizedBox::new(self).expand_height()
}
/// Wrap this widget in a [`Container`] with the provided background `brush`.
///
/// See [`Container::background`] for more information.
fn background(self, brush: impl Into<BackgroundBrush<T>>) -> Container<T> {
Container::new(self).background(brush)
}
/// Wrap this widget in a [`Container`] with the provided foreground `brush`.
///
/// See [`Container::foreground`] for more information.
fn foreground(self, brush: impl Into<BackgroundBrush<T>>) -> Container<T> {
Container::new(self).foreground(brush)
}
/// Wrap this widget in a [`Container`] with the given border.
///
/// Arguments can be either concrete values, or a [`Key`] of the respective
/// type.
///
/// [`Key`]: crate::Key
fn border(
self,
color: impl Into<KeyOrValue<Color>>,
width: impl Into<KeyOrValue<f64>>,
) -> Container<T> {
Container::new(self).border(color, width)
}
/// Wrap this widget in a [`EnvScope`] widget, modifying the parent
/// [`Env`] with the provided closure.
fn env_scope(self, f: impl Fn(&mut Env, &T) + 'static) -> EnvScope<T, Self> {
EnvScope::new(f, self)
}
/// Wrap this widget with the provided [`Controller`].
fn controller<C: Controller<T, Self>>(self, controller: C) -> ControllerHost<Self, C> {
ControllerHost::new(self, controller)
}
/// Provide a closure that will be called when this widget is added to the widget tree.
///
/// You can use this to perform any initial setup.
///
/// This is equivalent to handling the [`LifeCycle::WidgetAdded`] event in a
/// custom [`Controller`].
///
/// [`LifeCycle::WidgetAdded`]: crate::LifeCycle::WidgetAdded
fn on_added(
self,
f: impl Fn(&mut Self, &mut LifeCycleCtx, &T, &Env) + 'static,
) -> ControllerHost<Self, Added<T, Self>> {
ControllerHost::new(self, Added::new(f))
}
/// Control the events of this widget with a [`Click`] widget. The closure
/// provided will be called when the widget is clicked with the left mouse
/// button.
///
/// The child widget will also be updated on [`LifeCycle::HotChanged`] and
/// mouse down, which can be useful for painting based on `ctx.is_active()`
/// and `ctx.is_hot()`.
///
/// [`LifeCycle::HotChanged`]: crate::LifeCycle::HotChanged
fn on_click(
self,
f: impl Fn(&mut EventCtx, &mut T, &Env) + 'static,
) -> ControllerHost<Self, Click<T>> {
ControllerHost::new(self, Click::new(f))
}
/// Draw the [`layout`] `Rect`s of this widget and its children.
///
/// [`layout`]: Widget::layout
fn debug_paint_layout(self) -> EnvScope<T, Self> {
EnvScope::new(|env, _| env.set(Env::DEBUG_PAINT, true), self)
}
/// Display the `WidgetId`s for this widget and its children, when hot.
///
/// When this is `true`, widgets that are `hot` (are under the mouse cursor)
/// will display their ids in their bottom right corner.
///
/// These ids may overlap; in this case the id of a child will obscure
/// the id of its parent.
fn debug_widget_id(self) -> EnvScope<T, Self> {
EnvScope::new(|env, _| env.set(Env::DEBUG_WIDGET_ID, true), self)
}
/// Draw a color-changing rectangle over this widget, allowing you to see the
/// invalidation regions.
fn debug_invalidation(self) -> DebugInvalidation<T, Self> {
DebugInvalidation::new(self)
}
/// Set the [`DEBUG_WIDGET`] env variable for this widget (and its descendants).
///
/// This does nothing by default, but you can use this variable while
/// debugging to only print messages from particular instances of a widget.
///
/// [`DEBUG_WIDGET`]: crate::Env::DEBUG_WIDGET
fn debug_widget(self) -> EnvScope<T, Self> {
EnvScope::new(|env, _| env.set(Env::DEBUG_WIDGET, true), self)
}
/// Wrap this widget in a [`LensWrap`] widget for the provided [`Lens`].
fn lens<S: Data, L: Lens<S, T>>(self, lens: L) -> LensWrap<S, T, L, Self> {
LensWrap::new(self, lens)
}
/// Parse a `Widget<String>`'s contents
#[doc(hidden)]
#[deprecated(since = "0.7.0", note = "Use TextBox::with_formatter instead")]
#[allow(deprecated)]
fn parse(self) -> Parse<Self>
where
Self: Widget<String>,
{
Parse::new(self)
}
/// Assign the widget a specific [`WidgetId`].
///
/// You must ensure that a given [`WidgetId`] is only ever used for
/// a single widget at a time.
///
/// An id _may_ be reused over time; for instance if you replace one
/// widget with another, you may reuse the first widget's id.
fn with_id(self, id: WidgetId) -> IdentityWrapper<Self> {
IdentityWrapper::wrap(self, id)
}
/// Wrap this widget in a `Box`.
fn boxed(self) -> Box<dyn Widget<T>> {
Box::new(self)
}
/// Wrap this widget in a [`Scroll`] widget.
fn scroll(self) -> Scroll<T, Self> {
Scroll::new(self)
}
/// Wrap this widget in a [`DisabledIf`] widget.
///
/// The provided closure will determine if the widget is disabled.
/// See [`is_disabled`] or [`set_disabled`] for more info about disabled state.
///
/// [`is_disabled`]: EventCtx::is_disabled
/// [`set_disabled`]: EventCtx::set_disabled
fn disabled_if(self, disabled_if: impl Fn(&T, &Env) -> bool + 'static) -> DisabledIf<T, Self> {
DisabledIf::new(self, disabled_if)
}
}
impl<T: Data, W: Widget<T> + 'static> WidgetExt<T> for W {}
// these are 'soft overrides' of methods on WidgetExt; resolution
// will choose an impl on a type over an impl in a trait for methods with the same
// name.
#[doc(hidden)]
impl<T: Data> SizedBox<T> {
pub fn fix_width(self, width: impl Into<KeyOrValue<f64>>) -> SizedBox<T> {
self.width(width)
}
pub fn fix_height(self, height: impl Into<KeyOrValue<f64>>) -> SizedBox<T> {
self.height(height)
}
}
// if two things are modifying an env one after another, just combine the modifications
#[doc(hidden)]
impl<T: Data, W> EnvScope<T, W> {
pub fn env_scope(self, f2: impl Fn(&mut Env, &T) + 'static) -> EnvScope<T, W> {
let EnvScope { f, child } = self;
let new_f = move |env: &mut Env, data: &T| {
f(env, data);
f2(env, data);
};
EnvScope {
f: Box::new(new_f),
child,
}
}
pub fn debug_paint_layout(self) -> EnvScope<T, W> {
self.env_scope(|env, _| env.set(Env::DEBUG_PAINT, true))
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::widget::Slider;
use crate::{Color, Key};
use test_log::test;
#[test]
fn container_reuse() {
// this should be Container<Align<Container<Slider>>>
let widget = Slider::new()
.background(Color::BLACK)
.foreground(Color::WHITE)
.align_left()
.border(Color::BLACK, 1.0);
assert!(widget.border_is_some());
assert!(!widget.background_is_some());
assert!(!widget.foreground_is_some());
// this should be Container<Slider>
let widget = Slider::new()
.background(Color::BLACK)
.border(Color::BLACK, 1.0)
.foreground(Color::WHITE);
assert!(widget.background_is_some());
assert!(widget.border_is_some());
assert!(widget.foreground_is_some());
}
#[test]
fn sized_box_reuse() {
let mut env = Env::empty();
// this should be SizedBox<Align<SizedBox<Slider>>>
let widget = Slider::new().fix_height(10.0).align_left().fix_width(1.0);
assert_eq!(widget.width_and_height(&env), (Some(1.0), None));
// this should be SizedBox<Slider>
let widget = Slider::new().fix_height(10.0).fix_width(1.0);
assert_eq!(widget.width_and_height(&env), (Some(1.0), Some(10.0)));
const HEIGHT_KEY: Key<f64> = Key::new("test-sized-box-reuse-height");
const WIDTH_KEY: Key<f64> = Key::new("test-sized-box-reuse-width");
env.set(HEIGHT_KEY, 10.0);
env.set(WIDTH_KEY, 1.0);
// this should be SizedBox<Align<SizedBox<Slider>>>
let widget = Slider::new()
.fix_height(HEIGHT_KEY)
.align_left()
.fix_width(WIDTH_KEY);
assert_eq!(widget.width_and_height(&env), (Some(1.0), None));
// this should be SizedBox<Slider>
let widget = Slider::new().fix_height(HEIGHT_KEY).fix_width(WIDTH_KEY);
assert_eq!(widget.width_and_height(&env), (Some(1.0), Some(10.0)));
}
/// we only care that this will compile; see
/// https://github.com/linebender/druid/pull/1414/
#[test]
fn lens_with_generic_param() {
use crate::widget::{Checkbox, Flex, Slider};
#[derive(Debug, Clone, Data, Lens)]
struct MyData<T> {
data: T,
floatl: f64,
}
#[allow(dead_code)]
fn make_widget() -> impl Widget<MyData<bool>> {
Flex::row()
.with_child(Slider::new().lens(MyData::<bool>::floatl))
.with_child(Checkbox::new("checkbox").lens(MyData::<bool>::data))
}
}
}