title: How to create a floating window like Clipboard Pro App?
body: <p>The following image is a window of the app <a href="https://play.google.com/store/apps/details?id=jp.snowlife01.android.clipboard" rel="nofollow noreferrer">https://play.google.com/store/apps/details?id=jp.snowlife01.android.clipboard</a>. i named it as main window.</p>
  
  <p>It's seem that main window is not a normal window. it's on the top of other windows, the main window can't be moved.</p>
  
  <p>A small point icon will be displayed when I click the minimized button in the main window,  the small point icon can be moved, the main window can be restored when I click the small point icon.</p>
  
  <p>I think the small point icon  is a <code>SYSTEM_ALERT_WINDOW</code>, but how about the main window?</p>
  
  <p><strong>Image</strong></p>
  
  <p><a href="https://i.stack.imgur.com/IKt38.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/IKt38.png" alt="enter image description here"></a></p>