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 package eu.svjatoslav.sixth.e3d.gui.humaninput;
   6
   7 import eu.svjatoslav.sixth.e3d.gui.ViewPanel;
   8
   9 import java.util.Stack;
  10
  11 public class KeyboardFocusStack {
  12
  13     private final ViewPanel viewPanel;
  14     private final WorldNavigationUserInputTracker defaultInputHandler = new WorldNavigationUserInputTracker();
  15     private final Stack<KeyboardInputHandler> inputHandlers = new Stack<>();
  16     private KeyboardInputHandler currentUserInputHandler;
  17
  18     public KeyboardFocusStack(final ViewPanel viewPanel) {
  19         this.viewPanel = viewPanel;
  20         pushFocusOwner(defaultInputHandler);
  21     }
  22
  23     public KeyboardInputHandler getCurrentFocusOwner() {
  24         return currentUserInputHandler;
  25     }
  26
  27     public void popFocusOwner() {
  28         if (currentUserInputHandler != null)
  29             currentUserInputHandler.focusLost(viewPanel);
  30
  31         if (inputHandlers.isEmpty())
  32             return;
  33
  34         currentUserInputHandler = inputHandlers.pop();
  35         currentUserInputHandler.focusReceived(viewPanel);
  36     }
  37
  38     public boolean pushFocusOwner(final KeyboardInputHandler newInputHandler) {
  39         boolean updateNeeded = false;
  40
  41         if (currentUserInputHandler == newInputHandler)
  42             return false;
  43
  44         if (currentUserInputHandler != null) {
  45             updateNeeded = currentUserInputHandler.focusLost(viewPanel);
  46             inputHandlers.push(currentUserInputHandler);
  47         }
  48
  49         currentUserInputHandler = newInputHandler;
  50         updateNeeded |= currentUserInputHandler.focusReceived(viewPanel);
  51
  52         return updateNeeded;
  53     }
  54 }