WebView: add mechanism to show a D-pad

android/app/src/main/java/org/arianne/stendhal/client/DPad.java

@@ -0,0 +1,120 @@
+/***************************************************************************
+ *                     Copyright © 2022 - Arianne                          *
+ ***************************************************************************
+ ***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+package org.arianne.stendhal.client;
+
+import android.content.Context;
+import android.graphics.Point;
+import android.view.Display;
+import android.view.View;
+import android.widget.ImageView;
+import androidx.constraintlayout.widget.ConstraintLayout;
+import androidx.constraintlayout.widget.ConstraintLayout.LayoutParams;
+
+import java.util.LinkedList;
+import java.util.List;
+
+
+public class DPad {
+
+	private static DPad instance;
+
+	private static Context ctx;
+
+	private final List<ArrowView> arrows;
+	private final ConstraintLayout layout;
+
+
+	public static DPad get() {
+		if (instance == null) {
+			instance = new DPad();
+		}
+
+		return instance;
+	}
+
+	private DPad() {
+		ctx = (Context) MainActivity.get();
+
+		arrows = new LinkedList<>();
+		layout = new ConstraintLayout(ctx);
+		layout.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
+
+		final ArrowView arrow_l = new ArrowView(ctx, R.drawable.dpad_arrow_left);
+		final ArrowView arrow_r = new ArrowView(ctx, R.drawable.dpad_arrow_right);
+		final ArrowView arrow_u = new ArrowView(ctx, R.drawable.dpad_arrow_up);
+		final ArrowView arrow_d = new ArrowView(ctx, R.drawable.dpad_arrow_down);
+
+		arrows.add(arrow_l);
+		arrows.add(arrow_r);
+		arrows.add(arrow_u);
+		arrows.add(arrow_d);
+
+		for (final ArrowView av: arrows) {
+			layout.addView(av);
+		}
+	}
+
+	public ConstraintLayout getLayout() {
+		return layout;
+	}
+
+	public void setVisibility(final int vis) {
+		for (final ArrowView av: arrows) {
+			av.setVisibility(vis);
+		}
+	}
+
+	public void setPosition(final int x, final int y) {
+		ArrowView av = arrows.get(0);
+		av.setX(x);
+		av.setY(y + 40);
+
+		av = arrows.get(1);
+		av.setX(x + 100);
+		av.setY(y + 40);
+
+		av = arrows.get(2);
+		av.setX(x + 40);
+		av.setY(y);
+
+		av = arrows.get(3);
+		av.setX(x + 40);
+		av.setY(y + 100);
+	}
+
+	public void onRefreshView() {
+		final Point size = new Point();
+		final Display disp = MainActivity.get().getWindowManager().getDefaultDisplay();
+		disp.getSize(size);
+
+		int x = 100;
+		int y = size.y - 300;
+
+		setPosition(x, y);
+
+		if (PreferencesActivity.getSharedPreferences().getBoolean("show_dpad", false)) {
+			setVisibility(View.VISIBLE);
+		} else {
+			setVisibility(View.INVISIBLE);
+		}
+	}
+
+
+	private static class ArrowView extends ImageView {
+		public ArrowView(final Context ctx, final int id) {
+			super(ctx);
+
+			setBackgroundColor(android.graphics.Color.TRANSPARENT);
+			setImageResource(id);
+		}
+	}
+}

android/app/src/main/java/org/arianne/stendhal/client/MainActivity.java

@@ -14,14 +14,17 @@
 import android.app.AlertDialog;
 import android.content.DialogInterface;
 import android.content.Intent;
+import android.content.res.Configuration;
 import android.os.Bundle;
 import androidx.appcompat.app.AppCompatActivity;
+import androidx.constraintlayout.widget.ConstraintLayout;
 
 
 public class MainActivity extends AppCompatActivity {
 
 	private static MainActivity instance;
 
+	private ConstraintLayout layout;
 	private StendhalWebView client;
 	private Menu menu;
 
@@ -43,8 +46,10 @@ protected void onCreate(final Bundle savedInstanceState) {
 			DebugLog.init(getExternalFilesDir(null), this);
 
 			setContentView(R.layout.activity_main);
+			layout = (ConstraintLayout) findViewById(R.id.content);
 			menu = new Menu(this);
 			client = new StendhalWebView(this);
+			layout.addView(DPad.get().getLayout()); // initialize d-pad
 		} catch (final Exception e) {
 			e.printStackTrace();
 			DebugLog.error(e.toString());
@@ -99,6 +104,20 @@ public void onClick(final DialogInterface dialog, final int id) {
 		confirmQuit.show();
 	}
 
+	@Override
+	protected void onResume() {
+		super.onResume();
+
+		DPad.get().onRefreshView();
+	}
+
+	@Override
+	public void onConfigurationChanged(final Configuration config) {
+		super.onConfigurationChanged(config);
+
+		DPad.get().onRefreshView();
+	}
+
 	@Override
 	public void finish() {
 		DebugLog.debug(MainActivity.class.getName() + ".finish() called");

android/app/src/main/java/org/arianne/stendhal/client/PreferencesActivity.java

@@ -11,32 +11,71 @@
  ***************************************************************************/
 package org.arianne.stendhal.client;
 
+import android.content.SharedPreferences;
+import android.content.SharedPreferences.OnSharedPreferenceChangeListener;
 import android.os.Bundle;
 import android.preference.PreferenceFragment;
+import android.preference.PreferenceManager;
 import androidx.appcompat.app.AppCompatActivity;
 
 
 public class PreferencesActivity extends AppCompatActivity {
 
+	private static PreferencesActivity instance;
+
+
+	public static PreferencesActivity get() {
+		return instance;
+	}
+
 	@Override
 	protected void onCreate(final Bundle savedInstanceState) {
 		super.onCreate(savedInstanceState);
+		instance = this;
+
 		setContentView(R.layout.activity_preferences);
 
 		if (findViewById(R.id.preferencesFrame) != null) {
 			if (savedInstanceState != null) {
 				return;
 			}
 
-			final PreferenceFragment frag = new PreferenceFragment() {
-				@Override
-				public void onCreate(final Bundle savedInstanceState) {
-					super.onCreate(savedInstanceState);
-					addPreferencesFromResource(R.xml.preferences);
-				}
-			};
+			getFragmentManager().beginTransaction().add(R.id.preferencesFrame,
+				new PFragment()).commit();
+		}
+	}
+
+	public static SharedPreferences getSharedPreferences() {
+		return PreferenceManager.getDefaultSharedPreferences(MainActivity.get());
+	}
+
+
+	private static class PFragment extends PreferenceFragment
+			implements OnSharedPreferenceChangeListener {
+
+		@Override
+		public void onCreate(final Bundle savedInstanceState) {
+			super.onCreate(savedInstanceState);
+			addPreferencesFromResource(R.xml.preferences);
+		}
+
+		@Override
+		public void onSharedPreferenceChanged(final SharedPreferences sp, final String key) {
+			if (key.equals("show_dpad")) {
+				DPad.get().onRefreshView();
+			}
+		}
+
+		@Override
+		public void onResume() {
+			super.onResume();
+			getPreferenceManager().getSharedPreferences().registerOnSharedPreferenceChangeListener(this);
+		}
 
-			getFragmentManager().beginTransaction().add(R.id.preferencesFrame, frag).commit();
+		@Override
+		public void onPause() {
+			getPreferenceManager().getSharedPreferences().unregisterOnSharedPreferenceChangeListener(this);
+			super.onPause();
 		}
 	}
 }