# Objective
`text_system` runs before the UI layout is calculated and the size of
the text node is determined, so it cannot correctly shape the text to
fit the layout, and has no way of determining if the text needs to be
wrapped.
The function `text_constraint` attempts to determine the size of the
node from the local size constraints in the `Style` component. It can't
be made to work, you have to compute the whole layout to get the correct
size. A simple example of where this fails completely is a text node set
to stretch to fill the empty space adjacent to a node with size
constraints set to `Val::Percent(50.)`. The text node will take up half
the space, even though its size constraints are `Val::Auto`
Also because the `text_system` queries for changes to the `Style`
component, when a style value is changed that doesn't affect the node's
geometry the text is recomputed unnecessarily.
Querying on changes to `Node` is not much better. The UI layout is
changed to fit the `CalculatedSize` of the text, so the size of the node
is changed and so the text and UI layout get recalculated multiple times
from a single change to a `Text`.
Also, the `MeasureFunc` doesn't work at all, it doesn't have enough
information to fit the text correctly and makes no attempt.
Fixes#7663, #6717, #5834, #1490,
## Solution
Split the `text_system` into two functions:
* `measure_text_system` which calculates the size constraints for the
text node and runs before `UiSystem::Flex`
* `text_system` which runs after `UiSystem::Flex` and generates the
actual text.
* Fix the `MeasureFunc` calculations.
---
Text wrapping in main:
<img width="961" alt="Capturemain"
src="https://user-images.githubusercontent.com/27962798/220425740-4fe4bf46-24fb-4685-a1cf-bc01e139e72d.PNG">
With this PR:
<img width="961" alt="captured_wrap"
src="https://user-images.githubusercontent.com/27962798/220425807-949996b0-f127-4637-9f33-56a6da944fb0.PNG">
## Changelog
* Removed the previous fields from `CalculatedSize`. `CalculatedSize`
now contains a boxed `Measure`.
* Added `measurement` module to `bevy_ui`.
* Added the method `create_text_measure` to `TextPipeline`.
* Added a new system `measure_text_system` that runs before
`UiSystem::Flex` that creates a `MeasureFunc` for the text.
* Rescheduled `text_system` to run after `UiSystem::Flex`.
* Added a trait `Measure`. A `Measure` is used to compute the size of a
UI node when the size of that node is based on its content.
* Added `ImageMeasure` and `TextMeasure` which implement `Measure`.
* Added a new component `UiImageSize` which is used by
`update_image_calculated_size_system` to track image size changes.
* Added a `UiImageSize` component to `ImageBundle`.
## Migration Guide
`ImageBundle` has a new component `UiImageSize` which contains the size
of the image bundle's texture and is updated automatically by
`update_image_calculated_size_system`
---------
Co-authored-by: François <mockersf@gmail.com>
# Objective
Current `Node` doc comment:
```rust
/// The size of the node as width and height in pixels
/// automatically calculated by [`super::flex::flex_node_system`]
```
It should be changed to make it clear that `Node` stores the size in logical pixels, not physical.
# Objective
- `bevy_text` used to be "optional". the feature could be disabled, which meant that the systems were not added but `bevy_text` was still compiled because of a hard dependency in `bevy_ui`
- Running something without `bevy_text` enabled and with `bevy_ui` enabled now crashes:
```
thread 'main' panicked at 'called `Option::unwrap()` on a `None` value', /bevy/crates/bevy_ecs/src/schedule/schedule.rs:1147:34
```
- This is because `bevy_ui` declares some of its systems in ambiguity sets with systems from `bevy_text`, which were not added if `bevy_text` is disabled
## Solution
- Make `bevy_text` completely optional
## Migration Guide
- feature `bevy_text` now completely removes `bevy_text` from the dependencies when not enabled. Enable feature `bevy_text` if you use Bevy to render text
# Objective
`TextBundle` should have a `BackgroundColor` component.
Apart from adding emphasis etc to text, adding a background color to text nodes can be extremely useful for understanding how Bevy aligns, sizes and positions text, and identifying and debugging problems.
It's easy for users to insert the `BackgroundColor` component themselves but not immediately obvious or discoverable that it's possible. A `BackgroundColor` component allows us to add a `with_background_color` helper function to `TextBundle`.
related issue: #5935
## Solution
Add a `BackgroundColor` component to `TextBundle`.
---
## Changelog
* Added a `BackgroundColor` component to `TextBundle`.
* Added a helper method `with_background_color` to `TextBundle`.
## Migration Guide
`TextBundle` now has a `BackgroundColor` component.
Use `TextBundle`'s `background_color` field or the `with_background_color` method to set a background color for text when spawning a text node, in place of manual insertion of a `BackgroundColor` component.
# Objective
- While building UI, it makes more sense for most nodes to have a `FocusPolicy` of `Pass`, so that user interaction can correctly bubble
- Only `ButtonBundle` blocks by default
This change means that for someone adding children to a button, it's not needed to change the focus policy of those children to `Pass` for the button to continue to work.
---
## Changelog
- `FocusPolicy` default has changed from `FocusPolicy::Block` to `FocusPolicy::Pass`
## Migration Guide
- `FocusPolicy` default has changed from `FocusPolicy::Block` to `FocusPolicy::Pass`
# Objective
Delete `ImageMode`. It doesn't do anything except mislead people into thinking it controls the aspect ratio of images somehow.
Fixes#3933 and #6637
## Solution
Delete `ImageMode`
## Changelog
Removes the `ImageMode` enum.
Removes the `image_mode` field from `ImageBundle`
Removes the `With<ImageMode>` query filter from `image_node_system`
Renames `image_node_system` to` update_image_calculated_size_system`
# Objective
`NodeBundle` contains an `image` field, which can be misleading, because if you do supply an image there, nothing will be shown to screen. You need to use an `ImageBundle` instead.
## Solution
* `image` (`UiImage`) field is removed from `NodeBundle`,
* extraction stage queries now make an optional query for `UiImage`, if one is not found, use the image handle that is used as a default by `UiImage`: c019a60b39/crates/bevy_ui/src/ui_node.rs (L464)
* touching up docs for `NodeBundle` to help guide what `NodeBundle` should be used for
* renamed `entity.rs` to `node_bundle.rs` as that gives more of a hint regarding the module's purpose
* separating `camera_config` stuff from the pre-made UI node bundles so that `node_bundle.rs` makes more sense as a module name.
2022-11-05 20:48:15 +00:00
Renamed from crates/bevy_ui/src/entity.rs (Browse further)
