How to make mat-icon disabled in angular?

Use ngClass directive to add disable

<mat-icon color="warn" [ngClass]="{'disable':payloadArray.enabled !== true}"(click)="onClick()">delete</mat-icon>

Example:https://stackblitz.com/edit/angular-4jdvc9

it's all post but what about two mat-icon?

<mat-icon *ngIf="payloadArray.enabled == 'true'" 
  color="warn" style="cursor: pointer;">
    delete
</mat-icon>
<mat-icon *ngIf="payloadArray.enabled != 'true'" 
  "color="warn" style="opacity:.5">
    delete
</mat-icon>

Use mat-icon inside button tag and then you can use disabled

Try this,

<button mat-icon-button [disabled]="payloadArray.enabled != 'true' " color="primary" >
   <mat-icon color="warn" style="cursor: pointer;" >delete</mat-icon>
</button>

Although late at the party I figured out the following CSS with [ngClass]="{'disable':condition...}"

.disable:hover{
    cursor: not-allowed;
}
.disable:active{
    pointer-events: none;
}
mat-icon.disable {
    filter:opacity(0.5);
}