title: QML: disable lazy-loading of tabs in TabView (or open all of them programatically)
body: <p>I have a <code>TabView</code> with a number of <code>Tab</code>s. Some components inside tabs define <code>Component.onCompleted</code> to set up data structures (those are interfaced from c++ and must be instantiated in QML). As <code>Tab</code>s are lazy-loaded, <code>onCompleted</code> callbacks are not called until the respective tab is opened by the user.</p>
  
  <p>Is there a way to make all tabs load at startup? I am currently using <code>Component.onCompleted{ currentIndex=1; }</code> in the <code>TabView</code> to open the second tab but I'd like to cycle-open all of them, without user interaction, when the whole interface is created. I tried looping with <code>currentIndex</code> over all avilable tab indices in <code>onCompleted</code> but that did not have any effect.</p>