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

   1 /*
   2  * Sixth 3D engine. Author: Svjatoslav Agejenko.
   3  * This project is released under Creative Commons Zero (CC0) license.
   4  *
   5 *
   6  */
   7
   8 package eu.svjatoslav.sixth.e3d.gui.humaninput;
   9
  10 import eu.svjatoslav.sixth.e3d.gui.ViewPanel;
  11
  12 import java.util.Stack;
  13
  14 public class KeyboardFocusStack {
  15
  16     private final ViewPanel viewPanel;
  17     private WorldNavigationUserInputTracker defaultInputHandler = new WorldNavigationUserInputTracker();
  18     private Stack<UserInputHandler> inputHandlers = new Stack<>();
  19     private UserInputHandler currentUserInputHandler;
  20
  21     public KeyboardFocusStack(final ViewPanel viewPanel) {
  22         this.viewPanel = viewPanel;
  23         pushFocusOwner(defaultInputHandler);
  24     }
  25
  26     public UserInputHandler getCurrentFocusOwner() {
  27         return currentUserInputHandler;
  28     }
  29
  30     public void popFocusOwner() {
  31         if (currentUserInputHandler != null)
  32             currentUserInputHandler.focusLost(viewPanel);
  33
  34         if (inputHandlers.isEmpty())
  35             return;
  36
  37         currentUserInputHandler = inputHandlers.pop();
  38         currentUserInputHandler.focusReceived(viewPanel);
  39     }
  40
  41     public boolean pushFocusOwner(final UserInputHandler newInputHandler) {
  42         boolean updateNeeded = false;
  43
  44         if (currentUserInputHandler == newInputHandler)
  45             return false;
  46
  47         if (currentUserInputHandler != null) {
  48             updateNeeded = currentUserInputHandler.focusLost(viewPanel);
  49             inputHandlers.push(currentUserInputHandler);
  50         }
  51
  52         currentUserInputHandler = newInputHandler;
  53         updateNeeded |= currentUserInputHandler.focusReceived(viewPanel);
  54
  55         return updateNeeded;
  56     }
  57 }