src/com/googlecode/lanterna/gui2/AbstractTextGUIThread.java

   1 package com.googlecode.lanterna.gui2;
   2
   3 import java.io.IOException;
   4 import java.util.Queue;
   5 import java.util.concurrent.CountDownLatch;
   6 import java.util.concurrent.LinkedBlockingQueue;
   7
   8 /**
   9  * Created by martin on 20/06/15.
  10  */
  11 public abstract class AbstractTextGUIThread implements TextGUIThread {
  12
  13     protected final TextGUI textGUI;
  14     protected final Queue<Runnable> customTasks;
  15     protected ExceptionHandler exceptionHandler;
  16
  17     public AbstractTextGUIThread(TextGUI textGUI) {
  18         this.exceptionHandler = new ExceptionHandler() {
  19             @Override
  20             public boolean onIOException(IOException e) {
  21                 e.printStackTrace();
  22                 return true;
  23             }
  24
  25             @Override
  26             public boolean onRuntimeException(RuntimeException e) {
  27                 e.printStackTrace();
  28                 return true;
  29             }
  30         };
  31         this.textGUI = textGUI;
  32         this.customTasks = new LinkedBlockingQueue<Runnable>();
  33     }
  34
  35     @Override
  36     public void invokeLater(Runnable runnable) throws IllegalStateException {
  37         if(Thread.currentThread() == getThread()) {
  38             runnable.run();
  39         }
  40         else {
  41             customTasks.add(runnable);
  42         }
  43     }
  44
  45     @Override
  46     public void setExceptionHandler(ExceptionHandler exceptionHandler) {
  47         if(exceptionHandler == null) {
  48             throw new IllegalArgumentException("Cannot call setExceptionHandler(null)");
  49         }
  50         this.exceptionHandler = exceptionHandler;
  51     }
  52
  53     @Override
  54     public synchronized boolean processEventsAndUpdate() throws IOException {
  55         if(getThread() != Thread.currentThread()) {
  56             throw new IllegalStateException("Calling processEventAndUpdate outside of GUI thread");
  57         }
  58         textGUI.processInput();
  59         while(!customTasks.isEmpty()) {
  60             Runnable r = customTasks.poll();
  61             if(r != null) {
  62                 r.run();
  63             }
  64         }
  65         if(textGUI.isPendingUpdate()) {
  66             textGUI.updateScreen();
  67             return true;
  68         }
  69         return false;
  70     }
  71
  72     @Override
  73     public void invokeAndWait(final Runnable runnable) throws IllegalStateException, InterruptedException {
  74         final CountDownLatch countDownLatch = new CountDownLatch(1);
  75         invokeLater(new Runnable() {
  76             @Override
  77             public void run() {
  78                 runnable.run();
  79                 countDownLatch.countDown();
  80             }
  81         });
  82         countDownLatch.await();
  83     }
  84 }