src/main/java/eu/svjatoslav/sixth/e3d/gui/humaninput/KeyboardFocusTracker.java

   1 /*
   2  * Sixth 3D engine. Copyright ©2012-2018, Svjatoslav Agejenko, svjatoslav@svjatoslav.eu
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of version 3 of the GNU Lesser General Public License
   6  * or later as published by the Free Software Foundation.
   7  *
   8  */
   9
  10 package eu.svjatoslav.sixth.e3d.gui.humaninput;
  11
  12 import eu.svjatoslav.sixth.e3d.gui.ViewContext;
  13
  14 import java.util.Stack;
  15
  16 public class KeyboardFocusTracker {
  17
  18     private final ViewContext viewContext;
  19     WorldNavigationTracker defaultInputHandler = new WorldNavigationTracker();
  20     Stack<UserInputHandler> inputHandlers = new Stack<>();
  21     private UserInputHandler currentUserInputHandler;
  22
  23     public KeyboardFocusTracker(final ViewContext viewContext) {
  24         this.viewContext = viewContext;
  25         setFocusOwner(defaultInputHandler);
  26     }
  27
  28     public UserInputHandler getCurrentFocusOwner() {
  29         return currentUserInputHandler;
  30     }
  31
  32     public void popFocusOwner() {
  33         if (currentUserInputHandler == null)
  34             return;
  35
  36         if (inputHandlers.isEmpty())
  37             return;
  38
  39         currentUserInputHandler.focusLost(viewContext);
  40
  41         currentUserInputHandler = inputHandlers.pop();
  42
  43         currentUserInputHandler.focusReceived(viewContext);
  44     }
  45
  46     public void setFocusOwner(final UserInputHandler inputHandler) {
  47         if (currentUserInputHandler == inputHandler)
  48             return;
  49
  50         if (currentUserInputHandler != null) {
  51             currentUserInputHandler.focusLost(viewContext);
  52             inputHandlers.push(currentUserInputHandler);
  53         }
  54
  55         currentUserInputHandler = inputHandler;
  56
  57         currentUserInputHandler.focusReceived(viewContext);
  58     }
  59 }