src/main/java/eu/svjatoslav/sixth/e3d/gui/humaninput/KeyboardFocusStack.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.ViewPanel;
  13
  14 import java.util.Stack;
  15
  16 public class KeyboardFocusStack {
  17
  18     private final ViewPanel viewPanel;
  19     private WorldNavigationUserInputTracker defaultInputHandler = new WorldNavigationUserInputTracker();
  20     private Stack<UserInputHandler> inputHandlers = new Stack<>();
  21     private UserInputHandler currentUserInputHandler;
  22
  23     public KeyboardFocusStack(final ViewPanel viewPanel) {
  24         this.viewPanel = viewPanel;
  25         pushFocusOwner(defaultInputHandler);
  26     }
  27
  28     public UserInputHandler getCurrentFocusOwner() {
  29         return currentUserInputHandler;
  30     }
  31
  32     public void popFocusOwner() {
  33         if (currentUserInputHandler != null)
  34             currentUserInputHandler.focusLost(viewPanel);
  35
  36         if (inputHandlers.isEmpty())
  37             return;
  38
  39         currentUserInputHandler = inputHandlers.pop();
  40         currentUserInputHandler.focusReceived(viewPanel);
  41     }
  42
  43     public boolean pushFocusOwner(final UserInputHandler newInputHandler) {
  44         boolean updateNeeded = false;
  45
  46         if (currentUserInputHandler == newInputHandler)
  47             return false;
  48
  49         if (currentUserInputHandler != null) {
  50             updateNeeded = currentUserInputHandler.focusLost(viewPanel);
  51             inputHandlers.push(currentUserInputHandler);
  52         }
  53
  54         currentUserInputHandler = newInputHandler;
  55         updateNeeded |= currentUserInputHandler.focusReceived(viewPanel);
  56
  57         return updateNeeded;
  58     }
  59 }