first vibration.

app/src/main/AndroidManifest.xml

@@ -20,11 +20,12 @@
 
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
-
             <meta-data
                 android:name="android.app.lib_name"
                 android:value="" />
         </activity>
+
     </application>
+    <uses-permission android:name="android.permission.VIBRATE"/>
 
 </manifest>

app/src/main/cpp/CMakeLists.txt

@@ -21,7 +21,7 @@ add_library( # Sets the name of the library.
         SHARED
 
         # Provides a relative path to your source file(s).
-        native-lib.cpp)
+        native-lib.cpp app.c)
 
 # Searches for a specified prebuilt library and stores the path as a
 # variable. Because CMake includes system libraries in the search path by

app/src/main/cpp/app.c

@@ -0,0 +1,18 @@
+// The authors disclaim copyright to this source code
+
+#include <stdlib.h>
+#include <string.h>
+
+
+char *cb(const char *id, const char *event, const char *err, const char *data) {
+    char *ret;
+    ret = "";
+    if (!strcmp(id, "long")) {
+        ret = "vibrate:50;add:-;";
+    } else if (!strcmp(id, "short"))  {
+        ret = "vibrate:30;add:.;";
+    } else if (!strcmp(id, "menu")) {
+        ret = "add: ;";
+    }
+    return ret;
+}

app/src/main/cpp/native-lib.cpp

@@ -1,10 +1,25 @@
+// The authors disclaim copyright to this source code
+
 #include <jni.h>
-#include <string>
+#include <string.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+extern char *cb(const char *id, const char *event, const char *err, const char *data);
 
-extern "C" JNIEXPORT jstring JNICALL
-Java_com_cod5_deafblind_MainActivity_stringFromJNI(
+        JNIEXPORT jstring JNICALL
+Java_com_cod5_deafblind_MainActivity_cbToJNI(
         JNIEnv* env,
-        jobject /* this */) {
-    std::string hello = "Hello from C++";
-    return env->NewStringUTF(hello.c_str());
-}
+jobject self, jstring id, jstring event, jstring err, jstring data) {
+        const char *a, *b, *c, *d;
+        a = env->GetStringUTFChars(id, 0);
+        b = env->GetStringUTFChars(event, 0);
+        c = env->GetStringUTFChars(err, 0);
+        d = env->GetStringUTFChars(data, 0);
+        return env->NewStringUTF(cb(a, b, c, d));
+}
+
+#ifdef __cplusplus
+}
+#endif

app/src/main/java/com/cod5/deafblind/MainActivity.kt

@@ -1,8 +1,17 @@
+
+// The authors disclaim copyright to this source code
+
 package com.cod5.deafblind
 
+import android.os.Build
+import android.os.Vibrator;
 import androidx.appcompat.app.AppCompatActivity
 import android.os.Bundle
-import android.widget.TextView
+import android.os.VibrationEffect
+import android.os.VibratorManager
+import android.webkit.JavascriptInterface
+import android.webkit.WebView
+import androidx.core.content.getSystemService
 import com.cod5.deafblind.databinding.ActivityMainBinding
 
 class MainActivity : AppCompatActivity() {
@@ -15,18 +24,58 @@ class MainActivity : AppCompatActivity() {
         binding = ActivityMainBinding.inflate(layoutInflater)
         setContentView(binding.root)
 
-        // Example of a call to a native method
-        binding.sampleText.text = stringFromJNI()
+        binding.web.settings.javaScriptEnabled = true
+        binding.web.loadUrl("file:///android_res/raw/index.html")
+        binding.web.addJavascriptInterface(MyJs(this), "Android")
+    }
+
+    class MyJs(private val self:MainActivity) {
+        @JavascriptInterface
+        fun cb(id: String, event: String, err: String, data: String): String {
+            val r = self.cbToJNI(id, event, err, data)
+            if (r.startsWith("vibrate:")) {
+                val s = r.substring(8, r.indexOf(';'))
+                try {
+                    val l = s.toLong()
+                    if (l >= 10 && l <= 1000) {
+                        self.vibrate(l)
+                    }
+                    return r.substring(r.indexOf(';') + 1)
+                } catch (e:Exception) {
+
+                }
+            }
+            return r;
+        }
     }
+    private external fun cbToJNI(id: String, event: String, err: String, data:String): String
+
+
+    fun vibrate(tms: Long) {
+        try {
+            val v: Vibrator
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
+                    val vibratorService =
+                        this.getSystemService(VIBRATOR_MANAGER_SERVICE) as VibratorManager
+                    v = vibratorService.defaultVibrator
+                } else {
+                    @Suppress("DEPRECATION")
+                    v = getSystemService(VIBRATOR_SERVICE) as Vibrator
+                }
+                v.vibrate(VibrationEffect.createOneShot(tms, VibrationEffect.DEFAULT_AMPLITUDE))
+            } else {
+                @Suppress("DEPRECATION")
+                v = getSystemService(VIBRATOR_SERVICE) as Vibrator
+                @Suppress("DEPRECATION")
+                v.vibrate(tms)
+            }
+        } catch (e: Exception) {
 
-    /**
-     * A native method that is implemented by the 'deafblind' native library,
-     * which is packaged with this application.
-     */
-    external fun stringFromJNI(): String
+        }
+    }
 
     companion object {
-        // Used to load the 'deafblind' library on application startup.
         init {
             System.loadLibrary("deafblind")
         }

app/src/main/res/layout/activity_main.xml

@@ -6,14 +6,9 @@
     android:layout_height="match_parent"
     tools:context=".MainActivity">
 
-    <TextView
-        android:id="@+id/sample_text"
-        android:layout_width="wrap_content"
-        android:layout_height="wrap_content"
-        android:text="Hello World!"
-        app:layout_constraintBottom_toBottomOf="parent"
-        app:layout_constraintEnd_toEndOf="parent"
-        app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintTop_toTopOf="parent" />
+    <WebView
+        android:id="@+id/web"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent" />
 
 </androidx.constraintlayout.widget.ConstraintLayout>

app/src/main/res/raw/index.html

@@ -0,0 +1,20 @@
+<!DOCTYPE html>
+<html lang="en">
+ <head>
+<!-- The authors disclaim copyright to this source code -->
+  <meta charset="utf-8">
+  <meta name="viewport" content="width=device-width, initial-scale=1.0">
+  <title>Deaf - Blind</title>
+  <link rel="stylesheet" href="style.css">
+ </head>
+ <body>
+     <h1>e-mail by Morse</h1>
+     <div id="txt" style="word-wrap: break-word;white-space: pre-wrap;width:100%; max-width:100%; height:240px; max-height:240px;"></div>
+     <div style="position:fixed;bottom:0px;width:100%;text-align:center;"
+          ><button style="width:33%; height:200px;" id="short" onclick="cb(this.id, window.event.type, 0, 0)">.</button
+          ><button style="width:33%; height:200px;" id="menu" onclick="cb(this.id, window.event.type, 0, 0)">[ ]</button
+          ><button style="width:33%; height:200px;" id="long" onclick="cb(this.id, window.event.type, 0, 0)">_</button
+          ></div>
+     <script src="script.js" ></script>
+ </body>
+</html>

app/src/main/res/raw/script.js

@@ -0,0 +1,13 @@
+// The authors disclaim copyright to this source code
+
+
+function cb(id, event, err, data) {
+    let d = document.getElementById("txt");
+
+    let r = window.Android.cb(id, event, err, data);
+    if (r.startsWith("add:")) {
+        d.innerText = d.innerText + r.substr(4, r.indexOf(';') - 4);
+    }
+    console.log(r);
+    return true;
+}

app/src/main/res/raw/style.css

@@ -0,0 +1,4 @@
+/* The authors disclaim copyright to this source code */
+
+body {margin: 0px; padding: 0px;}
+button {display:inline-block;}