Show pause menu on back key press (Android)

core/src/io/github/lonamiwebs/klooni/Klooni.java

@@ -32,6 +32,7 @@ public class Klooni extends Game {
         skin.add("replay_texture", new Texture(Gdx.files.internal("ui/replay.png")));
         skin.add("share_texture", new Texture(Gdx.files.internal("ui/share.png")));
 
+        Gdx.input.setCatchBackKey(true); // To show the pause menu
         setScreen(new MainMenuScreen(this));
     }
 

core/src/io/github/lonamiwebs/klooni/screens/GameScreen.java

@@ -4,7 +4,6 @@ import com.badlogic.gdx.Gdx;
 import com.badlogic.gdx.Input;
 import com.badlogic.gdx.InputProcessor;
 import com.badlogic.gdx.Screen;
-import com.badlogic.gdx.graphics.Color;
 import com.badlogic.gdx.graphics.GL20;
 import com.badlogic.gdx.graphics.g2d.SpriteBatch;
 
@@ -25,12 +24,9 @@ public class GameScreen implements Screen, InputProcessor {
 
     private SpriteBatch batch;
 
-    private final Color clearColor;
-
     private final PauseMenuStage pauseMenu;
 
     GameScreen(final Klooni game) {
-        clearColor = new Color(0.9f, 0.9f, 0.7f, 1f);
         batch = new SpriteBatch();
 
         layout = new GameLayout();
@@ -38,7 +34,6 @@ public class GameScreen implements Screen, InputProcessor {
         scorer = new Scorer(layout, 10);
         board = new Board(layout, 10);
         holder = new PieceHolder(layout, 3);
-
         pauseMenu = new PauseMenuStage(layout, game, scorer);
     }
 
@@ -60,7 +55,7 @@ public class GameScreen implements Screen, InputProcessor {
 
     @Override
     public void render(float delta) {
-        Gdx.gl.glClearColor(clearColor.r, clearColor.g, clearColor.b, clearColor.a);
+        Gdx.gl.glClearColor(0.9f, 0.9f, 0.9f, 1f);
         Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
 
         batch.begin();
@@ -114,7 +109,7 @@ public class GameScreen implements Screen, InputProcessor {
 
     @Override
     public boolean keyUp(int keycode) {
-        if (keycode == Input.Keys.P) // Pause
+        if (keycode == Input.Keys.P || keycode == Input.Keys.BACK) // Pause
             pauseMenu.show(false);
 
         return false;

core/src/io/github/lonamiwebs/klooni/screens/MainMenuScreen.java

@@ -1,11 +1,13 @@
 package io.github.lonamiwebs.klooni.screens;
 
 import com.badlogic.gdx.Gdx;
+import com.badlogic.gdx.Input;
 import com.badlogic.gdx.Screen;
 import com.badlogic.gdx.graphics.Color;
 import com.badlogic.gdx.graphics.GL20;
 import com.badlogic.gdx.graphics.g2d.SpriteBatch;
 import com.badlogic.gdx.scenes.scene2d.Actor;
+import com.badlogic.gdx.scenes.scene2d.InputListener;
 import com.badlogic.gdx.scenes.scene2d.Stage;
 import com.badlogic.gdx.scenes.scene2d.ui.ImageButton;
 import com.badlogic.gdx.scenes.scene2d.ui.Table;
@@ -13,7 +15,7 @@ import com.badlogic.gdx.scenes.scene2d.utils.ChangeListener;
 
 import io.github.lonamiwebs.klooni.Klooni;
 
-public class MainMenuScreen implements Screen {
+public class MainMenuScreen extends InputListener implements Screen {
     private Klooni game;
 
     Stage stage;
@@ -88,6 +90,10 @@ public class MainMenuScreen implements Screen {
         Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
         stage.act(Math.min(Gdx.graphics.getDeltaTime(), minDelta));
         stage.draw();
+
+        if (Gdx.input.isKeyJustPressed(Input.Keys.BACK)) {
+            Gdx.app.exit();
+        }
     }
 
     @Override

core/src/io/github/lonamiwebs/klooni/screens/PauseMenuStage.java

@@ -158,7 +158,7 @@ public class PauseMenuStage extends Stage {
 
     @Override
     public boolean keyUp(int keyCode) {
-        if (keyCode == Input.Keys.P) // Pause
+        if (keyCode == Input.Keys.P || keyCode == Input.Keys.BACK) // Pause
             hide();
 
         return super.keyUp(keyCode);