# Objective
- The current `EventReader::iter` has been determined to cause confusion
among new Bevy users. It was suggested by @JoJoJet to rename the method
to better clarify its usage.
- Solves #9624
## Solution
- Rename `EventReader::iter` to `EventReader::read`.
- Rename `EventReader::iter_with_id` to `EventReader::read_with_id`.
- Rename `ManualEventReader::iter` to `ManualEventReader::read`.
- Rename `ManualEventReader::iter_with_id` to
`ManualEventReader::read_with_id`.
---
## Changelog
- `EventReader::iter` has been renamed to `EventReader::read`.
- `EventReader::iter_with_id` has been renamed to
`EventReader::read_with_id`.
- `ManualEventReader::iter` has been renamed to
`ManualEventReader::read`.
- `ManualEventReader::iter_with_id` has been renamed to
`ManualEventReader::read_with_id`.
- Deprecated `EventReader::iter`
- Deprecated `EventReader::iter_with_id`
- Deprecated `ManualEventReader::iter`
- Deprecated `ManualEventReader::iter_with_id`
## Migration Guide
- Existing usages of `EventReader::iter` and `EventReader::iter_with_id`
will have to be changed to `EventReader::read` and
`EventReader::read_with_id` respectively.
- Existing usages of `ManualEventReader::iter` and
`ManualEventReader::iter_with_id` will have to be changed to
`ManualEventReader::read` and `ManualEventReader::read_with_id`
respectively.
# Objective
`round_ties_up` checks the predicate:
```rust
0. <= value || value.fract() != 0.5
```
which is meant to determine if the value is negative with a fractional
part of `0.5`.
However given a negative value, `fract` returns a negative fraction so
the predicate is true for all numeric values and `ceil` is never called.
## Solution
Changed the predicate to `value.fract() != -0.5` and added a test.
Also improved the comments a bit.
# Objective
Inconvenient initialization of `UiScale`
## Solution
Change `UiScale` to a tuple struct
## Migration Guide
Replace initialization of `UiScale` like ```UiScale { scale: 1.0 }```
with ```UiScale(1.0)```
# Objective
fixes#8911, #7712
## Solution
Rounding was added to Taffy which fixed issue #7712.
The implementation uses the f32 `round` method which rounds ties
(fractional part is a half) away from zero. Issue #8911 occurs when a
node's min and max bounds on either axis are "ties" and zero is between
them. Then the bounds are rounded away from each other, and the node
grows by a pixel. This alone shouldn't cause the node to expand
continuously, but I think there is some interaction with the way Taffy
recomputes a layout from its cached data that I didn't identify.
This PR fixes#8911 by first disabling Taffy's internal rounding and
using an alternative rounding function that rounds ties up.
Then, instead of rounding the values of the internal layout tree as
Taffy's built-in rounding does, we leave those values unmodified and
only the values stored in the components are rounded. This requires
walking the tree for the UI node geometry update rather than iterating
through a query.
Because the component values are regenerated each update, that should
mean that UI updates are idempotent (ish) now and make the growing node
behaviour seen in issue #8911 impossible.
I expected a performance regression, but it's an improvement on main:
```
cargo run --profile stress-test --features trace_tracy --example many_buttons
```
<img width="461" alt="ui-rounding-fix-compare"
src="https://github.com/bevyengine/bevy/assets/27962798/914bfd50-e18a-4642-b262-fafa69005432">
I guess it makes sense to do the rounding together with the node size
and position updates.
---
## Changelog
`bevy_ui::layout`:
* Taffy's built-in rounding is disabled and rounding is now performed by
`ui_layout_system`.
* Instead of rounding the values of the internal layout tree as Taffy's
built-in rounding does, we leave those values unmodified and only the
values stored in the components are rounded. This requires walking the
tree for the UI node geometry update rather than iterating through a
query. Because the component values are regenerated each update, that
should mean that UI updates are idempotent now and make the growing node
behaviour seen in issue #8911 impossible.
* Added two helper functions `round_ties_up` and
`round_layout_coordinates`.
---------
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
After the UI layout is computed when the coordinates are converted back
from physical coordinates to logical coordinates the `UiScale` is
ignored. This results in a confusing situation where we have two
different systems of logical coordinates.
Example:
```rust
use bevy::prelude::*;
fn main() {
App::new()
.add_plugins(DefaultPlugins)
.add_systems(Startup, setup)
.add_systems(Update, update)
.run();
}
fn setup(mut commands: Commands, mut ui_scale: ResMut<UiScale>) {
ui_scale.scale = 4.;
commands.spawn(Camera2dBundle::default());
commands.spawn(NodeBundle {
style: Style {
align_items: AlignItems::Center,
justify_content: JustifyContent::Center,
width: Val::Percent(100.),
..Default::default()
},
..Default::default()
})
.with_children(|builder| {
builder.spawn(NodeBundle {
style: Style {
width: Val::Px(100.),
height: Val::Px(100.),
..Default::default()
},
background_color: Color::MAROON.into(),
..Default::default()
}).with_children(|builder| {
builder.spawn(TextBundle::from_section("", TextStyle::default());
});
});
}
fn update(
mut text_query: Query<(&mut Text, &Parent)>,
node_query: Query<Ref<Node>>,
) {
for (mut text, parent) in text_query.iter_mut() {
let node = node_query.get(parent.get()).unwrap();
if node.is_changed() {
text.sections[0].value = format!("size: {}", node.size());
}
}
}
```
result:
We asked for a 100x100 UI node but the Node's size is multiplied by the
value of `UiScale` to give a logical size of 400x400.
## Solution
Divide the output physical coordinates by `UiScale` in
`ui_layout_system` and multiply the logical viewport size by `UiScale`
when creating the projection matrix for the UI's `ExtractedView` in
`extract_default_ui_camera_view`.
---
## Changelog
* The UI layout's physical coordinates are divided by both the window
scale factor and `UiScale` when converting them back to logical
coordinates. The logical size of Ui nodes now matches the values given
to their size constraints.
* Multiply the logical viewport size by `UiScale` before creating the
projection matrix for the UI's `ExtractedView` in
`extract_default_ui_camera_view`.
* In `ui_focus_system` the cursor position returned from `Window` is
divided by `UiScale`.
* Added a scale factor parameter to `Node::physical_size` and
`Node::physical_rect`.
* The example `viewport_debug` now uses a `UiScale` of 2. to ensure that
viewport coordinates are working correctly with a non-unit `UiScale`.
## Migration Guide
Physical UI coordinates are now divided by both the `UiScale` and the
window's scale factor to compute the logical sizes and positions of UI
nodes.
This ensures that UI Node size and position values, held by the `Node`
and `GlobalTransform` components, conform to the same logical coordinate
system as the style constraints from which they are derived,
irrespective of the current `scale_factor` and `UiScale`.
---------
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
Replace `Query<&T, Changed<T>>` style queries with the more efficient
`Query<Ref<T>>` form in two of the UI systems.
---
## Changelog
Replaced use of `Changed` with `Ref` in queries in the
`ui_layout_system` and `calc_bounds` UI systems.
# Objective
Copy the `debug::print_tree` function from Taffy except display entity
ids instead of Taffy's node ids and indicate which ui nodes have a
measure func.
# Objective
fixes#8516
* Give `CalculatedSize` a more specific and intuitive name.
* `MeasureFunc`s should only be updated when their `CalculatedSize` is
modified by the systems managing their content.
For example, suppose that you have a UI displaying an image using an
`ImageNode`. When the window is resized, the node's `MeasureFunc` will
be updated even though the dimensions of the texture contained by the
node are unchanged.
* Fix the `CalculatedSize` API so that it no longer requires the extra
boxing and the `dyn_clone` method.
## Solution
* Rename `CalculatedSize` to `ContentSize`
* Only update `MeasureFunc`s on `CalculatedSize` changes.
* Remove the `dyn_clone` method from `Measure` and move the `Measure`
from the `ContentSize` component rather than cloning it.
* Change the measure_func field of `ContentSize` to type
`Option<taffy::node::MeasureFunc>`. Add a `set` method that wraps the
given measure appropriately.
---
## Changelog
* Renamed `CalculatedSize` to `ContentSize`.
* Replaced `upsert_leaf` with a function `update_measure` that only
updates the node's `MeasureFunc`.
* `MeasureFunc`s are only updated when the `ContentSize` changes and not
when the layout changes.
* Scale factor is no longer applied to the size values passed to the
`MeasureFunc`.
* Remove the `ContentSize` scaling in `text_system`.
* The `dyn_clone` method has been removed from the `Measure` trait.
* `Measure`s are moved from the `ContentSize` component instead of
cloning them.
* Added `set` method to `ContentSize` that replaces the `new` function.
## Migration Guide
* `CalculatedSize` has been renamed to `ContentSize`.
* The `upsert_leaf` function has been removed from `UiSurface` and
replaced with `update_measure` which updates the `MeasureFunc` without
node insertion.
* The `dyn_clone` method has been removed from the `Measure` trait.
* The new function of `CalculatedSize` has been replaced with the method
`set`.
# Objective
If a UI node has a changed `CalculatedSize` component and either the UI
does a full update or the node also has a changed `Style` component, the
node's corresponding Taffy node will be updated twice by
`flex_node_system`.
## Solution
Add a `Without<Calculated>` query filter so that the two changed node
queries in `flex_node_system` are mutually exclusive and move the
`CalculatedSize` node updater into the else block of the full-update if
conditional.
# Objective
An easy way to create 2D grid layouts
## Solution
Enable the `grid` feature in Taffy and add new style types for defining
grids.
## Notes
- ~I'm having a bit of trouble getting `#[derive(Reflect)]` to work
properly. Help with that would be appreciated (EDIT: got it to compile
by ignoring the problematic fields, but this presumably can't be
merged).~ This is now fixed
- ~The alignment types now have a `Normal` variant because I couldn't
get reflect to work with `Option`.~ I've decided to stick with the
flattened variant, as it saves a level of wrapping when authoring
styles. But I've renamed the variants from `Normal` to `Default`.
- ~This currently exposes a simplified API on top of grid. In particular
the following is not currently supported:~
- ~Negative grid indices~ Now supported.
- ~Custom `end` values for grid placement (you can only use `start` and
`span`)~ Now supported
- ~`minmax()` track sizing functions~ minmax is now support through a
`GridTrack::minmax()` constructor
- ~`repeat()`~ repeat is now implemented as `RepeatedGridTrack`
- ~Documentation still needs to be improved.~ An initial pass over the
documentation has been completed.
## Screenshot
<img width="846" alt="Screenshot 2023-03-10 at 17 56 21"
src="https://user-images.githubusercontent.com/1007307/224435332-69aa9eac-123d-4856-b75d-5449d3f1d426.png">
---
## Changelog
- Support for CSS Grid layout added to `bevy_ui`
---------
Co-authored-by: Rob Parrett <robparrett@gmail.com>
Co-authored-by: Andreas Weibye <13300393+Weibye@users.noreply.github.com>
