EditableText::visible_width

[ickshonpe]

Objective

Horizontal equivalent of the visible_lines option.

Allow users to set the width of a text input widget by number of glyphs. Or for proportional fonts, where the glyph widths are non-uniform, it would use a multiple of the advance width for "0".

Solution

• New visible_width: Option<f32> field on EditableText.
• TextInputMeasure now has both a width and height field and both are Option<f32>.
• update_editable_text_content_size calculates the width if visible_width is Some.
• The width is calculated by multiplying the advance width of "0" by the visible_width (if set) and the current scale factor.

Testing

I altered the hex input in the feathers example to so it's sized to fit 10 characters (includes space for the cursor).

cargo run --example feathers --features="experimental_bevy_feathers"