Minimal unstyled Text Input with Parley

[Zeophlite]

Objective

• Minimal unstyled Text Input, using Parley, Text Input #23014

Solution

• Initial work based off of @alice-i-cecile parley-text-input and @ickshonpe 's text-editing and parley-input branches
• EditableText component wraps a parley::PlainEditor
• Edits to the text are made via a queue of TextEdit items
• We use the PlainEditor for layout, and render from there

Relevant schedules are:

• PreUpdate, bevy_ui_widgets::process_text_inputs
• PostUpdate, bevy_text::apply_text_edits
• PostUpdate, bevy_ui::editable_text_system

And in render_app:

• ExtractSchedule, bevy_ui_render::extract_text_editable
• ExtractSchedule, bevy_ui_render::extract_text_cursor

Testing

• cargo run --example editable_text

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Showcase

[github-actions]

The generated examples/README.md is out of sync with the example metadata in Cargo.toml or the example readme template. Please run cargo run -p build-templated-pages -- update examples to update it, and commit the file change.

[ickshonpe]

I feel like EditableText should just be newtype around PlainEditor and not have any requirements. Maybe no helper functions even.

IMO the basic design should instead use a primary TextInput (or whatever) component that newtypes a string and require's everything. Then the widget's update system keeps the TextInput component synchronised with the PlainEditor's text buffer, for seamless change detection. So users can modify the TextInput's String to update the PlainEditors text buffer and they can use change detection on TextInput to watch for any changes due to edits on the PlainEditor. We can just clone the strings, it doesn't matter as only one input will be active at a time and we aren't building a text editor for giant text files.

[Zeophlite]

This is a pretty big change, and I'm kinda lost on it. Could this be followup?

[ickshonpe]

It's not as complicated as I'm making it sound but we can look into it in a follow up, sure.

[ickshonpe]

The primary component should be in this module, then there's no need to bother with this.

[Zeophlite]

I want to have a Text2d version in bevy_sprite and reuse EditableText

[alice-i-cecile]

This was my rationale too for moving it higher in our crate web.

[ickshonpe]

I want to have a Text2d version in bevy_sprite and reuse EditableText

That would only work exclusively though, wouldn't it? You couldn't enable both an EditableTextPlugin and an EditableText2dPlugin as then the EditableText entities would require both the UI and the sprite components.

[ickshonpe]

This PR only implements a UI text input though, so it's okay to leave it for now.

[shanecelis]

An exciting merge!