angular / angular/components

bug(style): Custom palette's text hue not propagated to MDC styles

Abierto
#29,076 2 comentarios 0 reacciones 0 asignados Ver en GitHub
area: material/form-field P4
Lenguaje dominante
TypeScript
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Forks
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Merge medio
1 d 8 h
PR fusionados (30 d)
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Descripción

### Is this a regression?

- [X] Yes, this behavior used to work in the previous version

### The previous version in which this bug was not present was

14.x

### Description

[Re-opening #26021 which was incorrectly closed as a duplicate of a similar but different issue]

[This is a regression insofar as the legacy non-MDC implementations do not have this problem]

Hi, after running the MDC schematic on one of my projects I have found that the MDC-based components do not use the `$text` hue specified in the theme config, which can cause accessibility issues for themes whose default hues do not provide sufficient contrast against a neutral background. In particular I have noticed this causes legibility issues for the floating placeholder on form fields and the label text on default-appearance buttons, but it might apply to other components as well.

My theme is configured as follows:

`$my-palette: mat.define-palette($greens, 600, 200, 900, 700);`
Note that the $text hue is overridden to `700` in the call to `define-palette`.

Here is a screenshot showing the 700 hue being correctly applied to the aforementioned text elements under the legacy components:

![image](https://github.com/angular/components/assets/4996462/2739e6f4-784d-41a3-81b6-4f4ee4741aa7)

And here is how the new MDC components look:

![image](https://github.com/angular/components/assets/4996462/a57571a7-f795-4c5a-8ba5-ba4d551d5b22)

I had a hard time reading the Angular Material => MDC SCSS theming code but it seems like the $text hue preference isn't being passed to the MDC mixins in any way.

### Reproduction

StackBlitz link:
Steps to reproduce:
1. https://stackblitz.com/edit/components-issue-9ugktp?file=src%2Fstyles.scss
2. Note that text hue is set to 900 but text button and form field label use 500

### Expected Behavior

MDC components should use specified text hue where applicable

### Actual Behavior

MDC components used primary hue regardless

### Environment

Environment
Angular: 15.0.0-18.0.1
CDK/Material: 15.0.0-18.0.1
Browser(s): Chrome
Operating System (e.g. Windows, macOS, Ubuntu): Windows 10

Guía de contribución

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Línea de trabajo

Comienza con src/styles.scss en el StackBlitz enlazado y sigue el código de tematización SCSS de Angular Material MDC alrededor de mat.define-palette y los mixins de MDC. Compara la salida legacy y MDC para el tono $text configurado y verifica después que los elementos de texto MDC aplicables, incluidas las etiquetas de los campos de formulario y los botones predeterminados, usen el tono especificado en la reproducción.

Escrito por el modelo de indexación a partir del texto del issue.

Evaluación

Stack tecnológico
angular, scss, typescript
Área
accessibility, frontend
Tipo de issue
Error
Dificultad
4/5
Tiempo estimado
3-5 días
Estado de actividad
Estancado
Claridad
Bastante claro
Aptitud para principiantes
35/100

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