I know mat-expansion-panel-headers is a button. clicking anywhere on that button toggles the expansion opens/closes. But I don't want to let users click anywhere on the header and open it. There should be a small button. One click on that button will open/close the expansion panel. How can I do that?
I have tried this, but it didn't work.
<mat-expansion-panel>
<mat-expansion-panel-header (click)="$event.preventDefault()">
<mat-panel-title>
MENU
</mat-panel-title>
</mat-expansion-panel-header>