Text

Fission

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Text is the default text widget in Fission.

It solves the most common content problem in an application: showing one block of text with one coherent style. That includes labels, body copy, values, helper text, headings, and translated product strings. If the text needs mixed emphasis or inline widgets, move to RichText. Otherwise, Text is the right starting point.

Example

use fission::prelude::*;
let title = Text::new(TextContent::Key("settings.profile_title".into()))
    .size(20.0)
    .weight(700)
    .into();

Text::new(...) is the most beginner-friendly entry point because it gives you a text widget with wrapping already enabled.

Content table

Field	Type	Meaning	Notes / default behavior
id	Option<WidgetId>	Stable widget identity.	Defaults to None.
content	TextContent	The text source to render.	Use Literal(...) for direct strings or Key(...) for translated lookup.
semantics	Option<Semantics>	Optional wrapper semantics for the text block.	Defaults to None. Builder helpers can also attach labels and actions.

Typography table

Field	Type	Meaning	Notes / default behavior
font_size	Option<f32>	Font size override.	Falls back to the theme's body size.
color	Option<IrColor>	Text color override.	Falls back to the theme's primary text color.
underline	bool	Whether the text is underlined.	Defaults to false.
font_family	Option<String>	Font family override.	Defaults to None.
font_weight	Option<u16>	Font weight override.	Defaults to 400 when absent.
font_style	TextFontStyle	Normal or italic posture.	Defaults to Normal.
line_height	Option<f32>	Explicit line height.	Defaults to None.
letter_spacing	Option<f32>	Extra letter spacing.	Defaults to None.
locale	Option<String>	Locale override used during shaping.	Defaults to None.
text_scale	Option<f32>	Text scale multiplier.	Defaults to None, which behaves like 1.0.

Layout and interaction table

Field	Type	Meaning	Notes / default behavior
width / height	Option<f32>	Fixed layout size.	Defaults to None.
min_width / max_width	Option<f32>	Width bounds.	Defaults to None.
min_height / max_height	Option<f32>	Height bounds.	Defaults to None.
wrap	bool	Whether text may wrap to multiple lines.	Text::new(...) sets this to true. Raw Default construction does not.
text_align	IrTextAlign	Paragraph alignment.	Defaults to the intermediate representation (IR) default.
text_direction	IrTextDirection	Paragraph direction.	Defaults to the IR default.
text_width_basis	IrTextWidthBasis	Width calculation policy.	Defaults to the IR default.
max_lines	Option<usize>	Maximum visible line count.	Defaults to None.
overflow	IrTextOverflow	Overflow handling.	Defaults to visible overflow.
strut_line_height	Option<f32>	Paragraph strut line height.	Defaults to None.
text_height_behavior	IrTextHeightBehavior	Height trimming behavior.	Defaults to the IR default.
selection_range	Option<(usize, usize)>	Highlighted selection range.	Defaults to None.
selection_color	Option<IrColor>	Selection highlight override.	Defaults to None.
selection_text_color	Option<IrColor>	Selected text color override.	Defaults to None.
flex_grow / flex_shrink	f32	Flex behavior inside parent layout.	Defaults to 0.0.

Plain language behavior

TextContent::Literal renders exactly the string you provide. TextContent::Key looks up the current locale in Env.i18n. In the checked-in implementation, a missing translation key renders visibly as MISSING:key, which is useful during development because it fails loudly instead of silently disappearing.

Text can also carry semantics and actions through helper methods like .semantics_label(...) and .on_tap(...). That is useful for interactive labels or annotated text, but if different parts of one sentence need different actions, RichText is the better model.

Specific advice

Prefer Text::new(...) over manual Text { ..Default::default() } when starting out. It gives you a more natural default by enabling wrapping, which avoids a common beginner surprise.

Production checklist

For Text, review the fields that change behavior before treating the widget as finished: id, content, semantics. The goal is to make the product rule visible in state and actions, not hidden inside ad-hoc construction code.

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If this widget appears inside an interactive flow, keep the surrounding action binding in the parent component and test that the flow still has one clear reducer path.

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When child widgets are generated from data, give reordered or filtered rows an explicit WidgetId so retained local state and scroll behavior do not drift between items.

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Set id only when identity must be stable across filtering, reordering, diagnostics, or tests; otherwise let Fission derive identity from structure.

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Use semantics when visible content alone is not enough for assistive technology, especially for icon-only controls or custom surfaces.

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Add at least one component or harness test that confirms the visible text, semantic role, action dispatch, and layout constraint that matter for this widget in context.

If a screen starts repeating the same Text setup, extract a named component around this widget. That keeps the reference API small while making product code easier to read and safer for generated code to copy.

TextContent, RichText, TextFontStyle, and Link.