title: Sharing function through classes in Kotlin
body: <p>I'm new to Kotlin and I don't get one basic thing. How to share functions through folders, files and classes using Kotlin. I want to let my function hide_bar(), start in another class.</p>
  
  <p>Theme.kt (located inside a folder)</p>
  
  <pre><code>class theme : AppCompatActivity()
  {
      fun hide_bars() {
          window.decorView.apply {
              systemUiVisibility = View.SYSTEM_UI_FLAG_HIDE_NAVIGATION or View.SYSTEM_UI_FLAG_FULLSCREEN
          }
      }
  }
  </code></pre>
  
  <p>Dock.kt</p>
  
  <pre><code>class dock : AppCompatActivity()
  {
      override fun onCreate(savedInstanceState: Bundle?)
      {
          super.onCreate(savedInstanceState)
          setContentView(R.layout.dock)
          hide_bar()
      }
  }
  </code></pre>
  
  <p>Please help me with this code.
  Thanks</p>