title: Trigger on parent property changed, but Set property for a child of a specific type
body: <p>I don't know if this is possible and i don't know much about wpf.</p>
  
  <p>I have this TabControl with 2 TabItems each contain a TextBox</p>
  
  <pre><code>&lt;TabControl&gt;
          &lt;TabItem Style="{StaticResource TabStyle}" Header="TabItem1"&gt;
              &lt;TextBox/&gt;
          &lt;/TabItem&gt;
          &lt;TabItem Style="{StaticResource TabStyle}" Header="TabItem2"&gt;
              &lt;TextBox/&gt;
          &lt;/TabItem&gt;
   &lt;/TabControl&gt;
  </code></pre>
  
  <p>and I have this style for the TabItem</p>
  
  <pre><code>&lt;Style x:Key="TabStyle" TargetType="{x:Type TabItem}"&gt;
              &lt;Style.Triggers&gt;
                  &lt;Trigger Property="IsFocused" Value="true"&gt;
                      &lt;Setter Property="Text" Value="tab is focused"/&gt; &lt;!--Point this setter to the textbox inside the tab item --&gt;
                  &lt;/Trigger&gt;
                  &lt;Trigger Property="IsFocused" Value="false"&gt;
                     &lt;Setter Property="Text" Value="tab is focused"/&gt;&lt;!--Point this setter to the textbox inside the tab item --&gt;
                  &lt;/Trigger&gt;
              &lt;/Style.Triggers&gt;
     &lt;/Style&gt;
  </code></pre>
  
  <p>if my tab item has only one control of type TextBox, is it possible to modify that text box from the setter inside of the tab item trigger, how can I find the child of type TextBox without using names?</p>