demo1.html

<div class="container">

  <div class="page-header">
    <h1 class="text-danger text-center">Foo T-Shirt Company</h1>
  </div>

  <hr />
  <br />

  <div class="row">
    <div class="col-md-7">
      <div *ngFor="let t of tshirts" class="card mb-3" style="max-width: 540px;">
        <div class="row no-gutters">
          <div class="col-md-4">
            <img (mouseenter)='t.imggsrc = t.bimage' (mouseleave)='t.imggsrc = t.fimage' [src]="t.imggsrc || t.fimage"
              class="card-img" alt="...">
          </div>
          <div class="col-md-8">
            <div class="card-body">
              <h5 class="card-title">{{t.name}}</h5>
              <p class="card-text">{{t.description}}</p>
              <div class="card-text alert alert-success" role="alert">
                Price : {{t.price}}
              </div>

              <div class="row">
                <div class="col-md-7">
                  <button [disabled]="buyButton" class="btn btn-danger" (click)='addtocart(t)'>Add to Cart</button>
                </div>
                <div class="col-md-5">
                  Quantity :<span [style.color]="t.quanity < 25 ? 'blue' : 'red'">{{t.quanity}}</span>
                </div>
              </div>

            </div>

          </div>
        </div>
      </div>
    </div>
    <div class="col-md-5">
      <app-child *ngIf="showDetails" (buyevent)='update($event)' (cancelevent)='cancel($event)'
        [tshirt]='tshirtdetails'></app-child>
    </div>
  </div>
</div>