projects/mat-video/src/lib/ui/mat-fullscreen-button/mat-fullscreen-button.component.html
<button mat-icon-button [disabled]="!canFullscreen" (click)="toggleFullscreen()">
<mat-icon *ngIf="!fullscreen">fullscreen</mat-icon>
<mat-icon *ngIf="fullscreen">fullscreen_exit</mat-icon>
</button>