angular / angular/components

bug(mat-form-field): extra lines are shown on scroll for outlined form field labels

Abierto
#31,525 1 comentario 0 reacciones 0 asignados Ver en GitHub
area: material/form-field P3
Lenguaje dominante
TypeScript
Estrellas
25k
Forks
6.8k
Merge medio
1 d 8 h
PR fusionados (30 d)
91

Descripción

### Is this a regression?

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

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

_No response_

### Description

This behavior is seen when a form field is in a vertically scrollable mat-card. When scrolled to certain positions, there's extra lines shown at the top and bottom of the form field. The length of the lines matches the length of the label, and it seems like it could be related to the "will-change: auto;" property being set since it disappears when that's deselected in devtools. This behavior is seen when scrolling with the mouse but is more reproducible when dragging the scroll bar.

Image

Image

### Reproduction

StackBlitz link: https://stackblitz.com/edit/components-issue-starter-6huqgdmq?file=src%2Fform-field-example%2Fform-field-example.ts,src%2Fform-field-example%2Fform-field-example.html,src%2Fmain.ts,src%2Fmaterial-module.ts,src%2Findex.html

Recording:

https://github.com/user-attachments/assets/bbd009f0-8a9c-4f6e-955b-e0cec6b095e5

Steps to reproduce:
1. Ensure no form fields are selected
2. Click & slowly drag the vertical scroll on the mat-card

Note: This is observed most frequently on Microsoft Edge.

### Expected Behavior

I expect the form fields to not change their appearance while scrolling

### Actual Behavior

The form fields are showing a line the length of the label at the top and bottom of the outlined form field.

### Environment

- Angular: 19.x
- CDK/Material: 19.2.19
- Browser(s):
- Microsoft Edge: Version 137.0.3296.93 (Official build) (64-bit)
- Chrome version: 137.0.7151.120 (Official Build) (64-bit)
- Firefox version: 140.0 (64-bit)
- Operating System (e.g. Windows, macOS, Ubuntu): Windows

Guía de contribución

Abrir la guía de contribución

Línea de trabajo

Comienza con la reproducción vinculada de StackBlitz, especialmente con src/form-field-example/form-field-example.ts, src/form-field-example/form-field-example.html, src/main.ts, src/material-module.ts y src/index.html. Reproduce el artefacto mientras arrastras la barra de desplazamiento de mat-card en Edge y compara el comportamiento del outlined form-field entre los navegadores. Se considera terminado cuando las líneas de longitud del label ya no aparecen al desplazarse.

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

Evaluación

Stack tecnológico
angular, typescript
Área
frontend
Tipo de issue
Error
Dificultad
4/5
Tiempo estimado
3-5 días
Estado de actividad
Estancado
Claridad
Bastante claro
Aptitud para principiantes
38/100

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