update fab position and hide fab button when page open

lib/src/power_logger.dart

@@ -34,6 +34,8 @@ class _LoggerFABState extends State<LoggerFAB> {
   double get screenWidth => MediaQuery.of(context).size.width;
   double get screenHeight => MediaQuery.of(context).size.height;
   bool _moving = false;
+
+  bool showSubPage = false;
   @override
   Widget build(BuildContext context) {
     return AnimatedPositioned(
@@ -41,45 +43,56 @@ class _LoggerFABState extends State<LoggerFAB> {
       duration: _moving ? Duration.zero : Duration(milliseconds: 300),
       left: _x - 25,
       top: _y - 25,
-      child: GestureDetector(
-        onPanStart: (detail) {
-          _moving = true;
-        },
-        onPanUpdate: (details) {
-          setState(() {
-            _x = details.globalPosition.dx;
-            _y = details.globalPosition.dy;
-          });
-        },
-        onPanEnd: (detail) {
-          if ((_x < screenWidth / 2)) {
-            _x = 50;
-          } else
-            _x = screenWidth - 50;
-          if ((_y < screenHeight / 2)) {
-            _y = 70;
-          } else
-            _y = screenHeight - 50;
-          _moving = false;
-          setState(() {});
-        },
-        onTap: () => Navigator.push(
-          context,
-          MaterialPageRoute(builder: (context) => PowerLoggerView()),
-        ),
-        child: ClipOval(
-          child: BackdropFilter(
-            filter: ImageFilter.blur(sigmaX: 5, sigmaY: 5),
-            child: Container(
-              decoration: BoxDecoration(
-                color: Colors.blueAccent.withOpacity(0.4),
-                borderRadius: BorderRadius.circular(25),
-              ),
-              height: 50,
-              width: 50,
-              child: Icon(
-                Icons.code,
-                color: Colors.white70,
+      child: AnimatedOpacity(
+        duration: Duration(milliseconds: 300),
+        curve: Curves.easeInOutCubic,
+        opacity: showSubPage ? 0 : 1,
+        child: GestureDetector(
+          onPanStart: (detail) {
+            _moving = true;
+          },
+          onPanUpdate: (details) {
+            setState(() {
+              _x = details.globalPosition.dx;
+              _y = details.globalPosition.dy;
+            });
+          },
+          onPanEnd: (detail) {
+            if ((_x < screenWidth / 2)) {
+              _x = 50;
+            } else
+              _x = screenWidth - 50;
+            if (_y > screenHeight - 50) {
+              _y = screenHeight - 50;
+            } else if (_y < 50) _y = 50;
+
+            _moving = false;
+            setState(() {});
+          },
+          onTap: showSubPage
+              ? null
+              : () async {
+                  showSubPage = true;
+                  await Navigator.push(
+                    context,
+                    MaterialPageRoute(builder: (context) => PowerLoggerView()),
+                  );
+                  showSubPage = false;
+                },
+          child: ClipOval(
+            child: BackdropFilter(
+              filter: ImageFilter.blur(sigmaX: 5, sigmaY: 5),
+              child: Container(
+                decoration: BoxDecoration(
+                  color: Colors.blueAccent.withOpacity(0.4),
+                  borderRadius: BorderRadius.circular(25),
+                ),
+                height: 50,
+                width: 50,
+                child: Icon(
+                  Icons.code,
+                  color: Colors.white70,
+                ),
               ),
             ),
           ),