除非填充文本字段，否则复选框呈灰色显示

Question

我有一个要求，我需要将启用（复选框按钮）灰显，直到文本框被填充，一旦我们在文本框中输入任何内容，签出按钮就应该启用它。

HTML、Angular.js 和 Webobject 中的编码

   <div class="carbon-copy-text"
     *ngIf="ticketItem.clientCcEnabled">
  <whd-autocomplete *ngIf="ticketItem.preference.allowUserLookupByClient; else autocompleteBlock"
                    [textBoxValue]="carbonCopy"
                    [itemSource]="userLookupSource"
                    (onAutoCompleteSearchChange)="searchForClients($event)"
                    (onAutoCompleteSelectionChange)="emitCarbonCopyEmails($event)">
  </whd-autocomplete>
  <div class="carbon-copy_enabled">
    <nui-checkbox [value]="getCarbonCopyState()"
                  [checked]="getCarbonCopyState()"
                  (valueChange)="changeCarbonCopyEnable($event)">
      Enabled
    </nui-checkbox>
  </div>