added repeat for web vibrate and made it consistent for both web and mobile

client/lib/HomeScreen.dart

@@ -593,25 +593,34 @@ class HomeScreenState extends State<HomeScreen>{
     if(kIsWeb){
       // different handler for web
       // showSnackBar("web");
-      Vibration.vibrate(pattern:[100,100,20]);
+      // Vibration.vibrate(pattern:[100,100,20]);
+      // Vibration.vibrate(pattern:[1000,1000,200]);
+      // off,on,off
+      Vibration.vibrate(pattern:[20,100], repeat: 0);  // short fast
+      // Vibration.vibrate(pattern:[200,2000,200], repeat: 0);  // short fast
+
+        // Vibration.vibrate(pattern:[0,20,100,30], repeat: 0);  // short fast
+        // Vibration.vibrate(pattern:[20,100,30], repeat: 0);  // short fast
+
       // HapticFeedback.heavyImpact();
     }
     else{
       // showSnackBar("mobile");
       if (await Vibration.hasVibrator()==true) {
-        Vibration.vibrate(pattern:[100,100,20], repeat: 1);  // short fast
-        // Vibration.vibrate(pattern:[100, 200, 400],repeat: 1);   // slow     
+        // off,on,off
+        Vibration.vibrate(pattern:[20,100], repeat: 0);  // short fast
+        // Vibration.vibrate(pattern:[100, 200, 400],repeat: 0);   // slow     
       }
     }
   
   }
-  void endHapticFeedback() async{
+  void endHapticFeedback(){
     if(kIsWeb){
       // different handler for web
       Vibration.cancel();
     }
     else{
-      if (await Vibration.hasVibrator()==true) {
+      if (Vibration.hasVibrator()==true) {
         Vibration.cancel();
       }
     }

client/lib/vibrate_web.dart

@@ -7,8 +7,16 @@ import 'package:flutter/material.dart';
 class Vibration{
   
   static void vibrate({List<int> pattern=const [100],int repeat=-1}){
+
+    pattern=[1]+pattern;  // to change it match vibrating pattern of android which is (off,on,off,on,off,...)
     var jsArray = js.JsObject.jsify(pattern);
-    js.context.callMethod('vibrate', [jsArray]);
+    if(repeat==-1){
+      //on,off,on,off,on
+      js.context.callMethod('vibrate', [jsArray]);
+    }
+    else{
+      js.context.callMethod('peristentVibrate', [jsArray]);
+    }
   }
 
   static Future<bool> hasVibrator(){

client/web/app.js

@@ -1,6 +1,37 @@
+var vibrateInterval;
+
 function vibrate(flutter_value) {
+    clearInterval(vibrateInterval);  
+
     if ("vibrate" in navigator){
         // alert("supported");
         navigator.vibrate(flutter_value);
     }
+}
+
+function sum(arr1){
+    if(arr1.constructor !== Array)   return arr1
+    
+    function add(accumulator, a) {
+      return accumulator + a;
+    }
+    sumvalue = arr1.reduce(add, 0);
+    return sumvalue;
+}
+
+function setIntervalAndExecute(fn, t) {
+    fn();
+    return(setInterval(fn, t));
+}
+
+function peristentVibrate(pattern) {
+    
+    // alert("supported");
+    // vibrateInterval = setInterval(() => {
+    vibrateInterval = setIntervalAndExecute(() => {
+        if ("vibrate" in navigator){
+            navigator.vibrate(pattern);
+        }
+    }, sum(pattern));
+        
 }