Added: Add support for ~/.termux/termux.float.properties

termux-shared/src/main/java/com/termux/shared/terminal/io/BellHandler.java

@@ -0,0 +1,79 @@
+package com.termux.shared.terminal.io;
+
+import android.content.Context;
+import android.os.Build;
+import android.os.Handler;
+import android.os.Looper;
+import android.os.SystemClock;
+import android.os.VibrationEffect;
+import android.os.Vibrator;
+
+import com.termux.shared.logger.Logger;
+
+public class BellHandler {
+    private static BellHandler instance = null;
+    private static final Object lock = new Object();
+
+    private static final String LOG_TAG = "BellHandler";
+
+    public static BellHandler getInstance(Context context) {
+        if (instance == null) {
+            synchronized (lock) {
+                if (instance == null) {
+                    instance = new BellHandler((Vibrator) context.getApplicationContext().getSystemService(Context.VIBRATOR_SERVICE));
+                }
+            }
+        }
+
+        return instance;
+    }
+
+    private static final long DURATION = 50;
+    private static final long MIN_PAUSE = 3 * DURATION;
+
+    private final Handler handler = new Handler(Looper.getMainLooper());
+    private long lastBell = 0;
+    private final Runnable bellRunnable;
+
+    private BellHandler(final Vibrator vibrator) {
+        bellRunnable = new Runnable() {
+            @Override
+            public void run() {
+                if (vibrator != null) {
+                    try {
+                        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+                            vibrator.vibrate(VibrationEffect.createOneShot(DURATION, VibrationEffect.DEFAULT_AMPLITUDE));
+                        } else {
+                            vibrator.vibrate(DURATION);
+                        }
+                    } catch (Exception e) {
+                        // Issue on samsung devices on android 8
+                        // java.lang.NullPointerException: Attempt to read from field 'android.os.VibrationEffect com.android.server.VibratorService$Vibration.mEffect' on a null object reference
+                        Logger.logStackTraceWithMessage(LOG_TAG, "Failed to run vibrator", e);
+                    }
+                }
+            }
+        };
+    }
+
+    public synchronized void doBell() {
+        long now = now();
+        long timeSinceLastBell = now - lastBell;
+
+        if (timeSinceLastBell < 0) {
+            // there is a next bell pending; don't schedule another one
+        } else if (timeSinceLastBell < MIN_PAUSE) {
+            // there was a bell recently, schedule the next one
+            handler.postDelayed(bellRunnable, MIN_PAUSE - timeSinceLastBell);
+            lastBell = lastBell + MIN_PAUSE;
+        } else {
+            // the last bell was long ago, do it now
+            bellRunnable.run();
+            lastBell = now;
+        }
+    }
+
+    private long now() {
+        return SystemClock.uptimeMillis();
+    }
+}