angular / angular/components

bug(cdk/scrolling): Virtual viewport not working correctly when using mat-menu

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#29,395 1 commentaire 0 réactions 0 personnes assignées Voir sur GitHub
area: cdk/scrolling area: material/menu P3
Langage dominant
TypeScript
Étoiles
25k
Forks
6.8k
Merge moyen
1 j 8 h
PR mergées (30 j)
91

Description

### 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

The minimal reproduction of the bug shows that the viewport height is not correctly handled which leads to a lot of empty space within the viewport area since list items are not created properly. Also when scrolling through the list, closing and reopening the menu, the list is empty. Resizing the window solves all the problems. I currently got rid of the problems by creating a wrapper for the list and manually triggering the resize event if the component is visible:

```JS
constructor(public _eRef: ElementRef, private ngZone: NgZone) { }

ngAfterViewInit() {
this.observer = new IntersectionObserver(entries => {
entries.forEach(entry => {
if (entry.isIntersecting) {
this.triggerResizeEvent();
}
});
});
this.observer.observe(this._eRef.nativeElement)
}

private triggerResizeEvent() {
this.ngZone.runOutsideAngular(() => {
window.dispatchEvent(new Event('resize'));
});
}
```

### Reproduction

StackBlitz link: https://stackblitz.com/edit/stackblitz-starters-57cqqc?file=src%2Fapp%2Fviewport-error.component.html
Steps to reproduce:
1. open the mat-menu
2. the viewport is half empty
3. resize the window
4. viewport filled properly

Steps to reproduce:
1. open the mat-menu
2. scroll through list
3. close and reopen the menu
4. viewport empty

### Expected Behavior

The viewport should be completely filled with options

### Actual Behavior

The viewport is not fully filled. The list items are not created properly

### Environment

Angular CLI: 18.0.7
Node: 18.20.3
Package Manager: npm 10.2.3
OS: linux x64

Angular: 18.0.6
... animations, cdk, cdk-experimental, common, compiler
... compiler-cli, core, forms, material, platform-browser
... platform-browser-dynamic, router

Package Version
---------------------------------------------------------
@angular-devkit/architect 0.1800.7
@angular-devkit/build-angular 18.0.7
@angular-devkit/core 18.0.7
@angular-devkit/schematics 18.0.7
@angular/cli 18.0.7
@schematics/angular 18.0.7
rxjs 7.8.1
typescript 5.4.5
zone.js 0.14.7

Guide de contribution

Ouvrir le guide de contribution

Piste de recherche

Commencez par la reproduction StackBlitz liée et vérifiez les deux cas signalés : l’ouverture du mat-menu laisse un espace vide dans le viewport, et sa réouverture après un défilement laisse la liste vide jusqu’à ce qu’un redimensionnement se produise. Suivez l’intégration de Angular CDK virtual scrolling et de mat-menu ; le travail est terminé lorsque le viewport se remplit correctement à l’ouverture et à la réouverture, sans déclencher manuellement un événement de resize.

Rédigé par le modèle d'indexation à partir du texte de l'issue.

Évaluation

Stack technique
angular, typescript
Domaine
frontend
Type d'issue
Bug
Difficulté
4/5
Temps estimé
3-5 jours
Activité
À l'abandon
Clarté
Plutôt claire
Accessibilité débutants
35/100

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