angular / angular/components

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

Aperta
#29,076 2 commenti 0 reazioni 0 assegnatari Vedi su GitHub
area: material/form-field P4
Lingua principale
TypeScript
Stelle
25k
Fork
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Merge medio
1g 8h
PR unite (30g)
91

Descrizione

### 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

Guida per i contributori

Apri la guida per i contributori

Direzione di ricerca

Inizia da src/styles.scss nello StackBlitz collegato e segui il codice di tematizzazione SCSS di Angular Material MDC intorno a mat.define-palette e ai mixin MDC. Confronta l'output legacy e MDC per la tonalità $text configurata, quindi verifica che gli elementi di testo MDC pertinenti, incluse le etichette dei campi del modulo e i pulsanti predefiniti, utilizzino la tonalità specificata nella riproduzione.

Scritto dal modello di indicizzazione a partire dal testo della issue.

Valutazione

Stack tecnologico
angular, scss, typescript
Ambito
accessibility, frontend
Tipo di issue
Bug
Difficoltà
4/5
Tempo stimato
3-5 giorni
Stato di attività
Ferma
Chiarezza
Abbastanza chiara
Idoneità per principianti
35/100

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