update

software/android/app/src/main/java/com/rookiedev/hexapod/ControlActivity.kt

@@ -147,11 +147,16 @@ class ControlActivity : AppCompatActivity() {
                             currentState = "standby"
                             controlImage!!.setImageResource(R.drawable.ic_control_circle_standby)
 
-                            buttonRotateX!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                            buttonRotateX!!.backgroundTintList =
-                            buttonRotateY!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                                applicationContext.getColorStateList(R.color.grey_500)
-                            buttonRotateZ!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                            buttonRotateY!!.backgroundTintList =
-                            buttonClimb!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                                applicationContext.getColorStateList(R.color.grey_500)
-                            buttonTwist!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                            buttonRotateZ!!.backgroundTintList =
+                                applicationContext.getColorStateList(R.color.grey_500)
+                            buttonClimb!!.backgroundTintList =
+                                applicationContext.getColorStateList(R.color.grey_500)
+                            buttonTwist!!.backgroundTintList =
+                                applicationContext.getColorStateList(R.color.grey_500)
                         }
                     } else if (length >= radius / 3 && length < 2 * radius / 3) {
                         val angle = atan2(coorY, coorX)
@@ -184,11 +189,16 @@ class ControlActivity : AppCompatActivity() {
                                 controlImage!!.setImageResource(R.drawable.ic_control_circle_left)
                             }
                         }
-                        buttonRotateX!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                        buttonRotateX!!.backgroundTintList =
-                        buttonRotateY!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                            applicationContext.getColorStateList(R.color.grey_500)
-                        buttonRotateZ!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                        buttonRotateY!!.backgroundTintList =
-                        buttonClimb!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                            applicationContext.getColorStateList(R.color.grey_500)
-                        buttonTwist!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                        buttonRotateZ!!.backgroundTintList =
+                            applicationContext.getColorStateList(R.color.grey_500)
+                        buttonClimb!!.backgroundTintList =
+                            applicationContext.getColorStateList(R.color.grey_500)
+                        buttonTwist!!.backgroundTintList =
+                            applicationContext.getColorStateList(R.color.grey_500)
                     } else if (length >= 2 * radius / 3 && length < radius) {
                         val angle = atan2(coorY, coorX)
                         if (angle > -PI / 4 && angle <= PI / 4) {
@@ -220,79 +230,109 @@ class ControlActivity : AppCompatActivity() {
                                 controlImage!!.setImageResource(R.drawable.ic_control_circle_turnleft)
                             }
                         }
-                        buttonRotateX!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                        buttonRotateX!!.backgroundTintList =
-                        buttonRotateY!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                            applicationContext.getColorStateList(R.color.grey_500)
-                        buttonRotateZ!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                        buttonRotateY!!.backgroundTintList =
-                        buttonClimb!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                            applicationContext.getColorStateList(R.color.grey_500)
-                        buttonTwist!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                        buttonRotateZ!!.backgroundTintList =
+                            applicationContext.getColorStateList(R.color.grey_500)
+                        buttonClimb!!.backgroundTintList =
+                            applicationContext.getColorStateList(R.color.grey_500)
+                        buttonTwist!!.backgroundTintList =
+                            applicationContext.getColorStateList(R.color.grey_500)
                     }
                     return true
                 }
             }
         )
 
-        buttonRotateX!!.setOnClickListener{
+        buttonRotateX!!.setOnClickListener {
-            if (currentState != "rotatex"){
+            if (currentState != "rotatex") {
                 sendMessageAsync("rotatex")
                 currentState = "rotatex"
                 controlImage!!.setImageResource(R.drawable.ic_control_circle)
-                buttonRotateX!!.backgroundTintList = applicationContext.getColorStateList(R.color.purple_500)
+                buttonRotateX!!.backgroundTintList =
-                buttonRotateY!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                    applicationContext.getColorStateList(R.color.purple_500)
-                buttonRotateZ!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                buttonRotateY!!.backgroundTintList =
-                buttonClimb!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                    applicationContext.getColorStateList(R.color.grey_500)
-                buttonTwist!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                buttonRotateZ!!.backgroundTintList =
+                    applicationContext.getColorStateList(R.color.grey_500)
+                buttonClimb!!.backgroundTintList =
+                    applicationContext.getColorStateList(R.color.grey_500)
+                buttonTwist!!.backgroundTintList =
+                    applicationContext.getColorStateList(R.color.grey_500)
             }
         }
 
-        buttonRotateY!!.setOnClickListener{
+        buttonRotateY!!.setOnClickListener {
-            if (currentState != "rotatey"){
+            if (currentState != "rotatey") {
                 sendMessageAsync("rotatey")
                 currentState = "rotatey"
                 controlImage!!.setImageResource(R.drawable.ic_control_circle)
-                buttonRotateX!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                buttonRotateX!!.backgroundTintList =
-                buttonRotateY!!.backgroundTintList = applicationContext.getColorStateList(R.color.purple_500)
+                    applicationContext.getColorStateList(R.color.grey_500)
-                buttonRotateZ!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                buttonRotateY!!.backgroundTintList =
-                buttonClimb!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                    applicationContext.getColorStateList(R.color.purple_500)
-                buttonTwist!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                buttonRotateZ!!.backgroundTintList =
+                    applicationContext.getColorStateList(R.color.grey_500)
+                buttonClimb!!.backgroundTintList =
+                    applicationContext.getColorStateList(R.color.grey_500)
+                buttonTwist!!.backgroundTintList =
+                    applicationContext.getColorStateList(R.color.grey_500)
             }
         }
 
-        buttonRotateZ!!.setOnClickListener{
+        buttonRotateZ!!.setOnClickListener {
-            if (currentState != "rotatez"){
+            if (currentState != "rotatez") {
                 sendMessageAsync("rotatez")
                 currentState = "rotatez"
                 controlImage!!.setImageResource(R.drawable.ic_control_circle)
-                buttonRotateX!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                buttonRotateX!!.backgroundTintList =
-                buttonRotateY!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                    applicationContext.getColorStateList(R.color.grey_500)
-                buttonRotateZ!!.backgroundTintList = applicationContext.getColorStateList(R.color.purple_500)
+                buttonRotateY!!.backgroundTintList =
-                buttonClimb!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                    applicationContext.getColorStateList(R.color.grey_500)
-                buttonTwist!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                buttonRotateZ!!.backgroundTintList =
+                    applicationContext.getColorStateList(R.color.purple_500)
+                buttonClimb!!.backgroundTintList =
+                    applicationContext.getColorStateList(R.color.grey_500)
+                buttonTwist!!.backgroundTintList =
+                    applicationContext.getColorStateList(R.color.grey_500)
             }
         }
 
-        buttonClimb!!.setOnClickListener{
+        buttonClimb!!.setOnClickListener {
-            if (currentState != "climb"){
+            if (currentState != "climb") {
                 sendMessageAsync("climb")
                 currentState = "climb"
                 controlImage!!.setImageResource(R.drawable.ic_control_circle)
-                buttonRotateX!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                buttonRotateX!!.backgroundTintList =
-                buttonRotateY!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                    applicationContext.getColorStateList(R.color.grey_500)
-                buttonRotateZ!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                buttonRotateY!!.backgroundTintList =
-                buttonClimb!!.backgroundTintList = applicationContext.getColorStateList(R.color.purple_500)
+                    applicationContext.getColorStateList(R.color.grey_500)
-                buttonTwist!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                buttonRotateZ!!.backgroundTintList =
+                    applicationContext.getColorStateList(R.color.grey_500)
+                buttonClimb!!.backgroundTintList =
+                    applicationContext.getColorStateList(R.color.purple_500)
+                buttonTwist!!.backgroundTintList =
+                    applicationContext.getColorStateList(R.color.grey_500)
             }
         }
 
-        buttonTwist!!.setOnClickListener{
+        buttonTwist!!.setOnClickListener {
-            if (currentState != "twist"){
+            if (currentState != "twist") {
                 sendMessageAsync("twist")
                 currentState = "twist"
                 controlImage!!.setImageResource(R.drawable.ic_control_circle)
-                buttonRotateX!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                buttonRotateX!!.backgroundTintList =
-                buttonRotateY!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                    applicationContext.getColorStateList(R.color.grey_500)
-                buttonRotateZ!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                buttonRotateY!!.backgroundTintList =
-                buttonClimb!!.backgroundTintList = applicationContext.getColorStateList(R.color.grey_500)
+                    applicationContext.getColorStateList(R.color.grey_500)
-                buttonTwist!!.backgroundTintList = applicationContext.getColorStateList(R.color.purple_500)
+                buttonRotateZ!!.backgroundTintList =
+                    applicationContext.getColorStateList(R.color.grey_500)
+                buttonClimb!!.backgroundTintList =
+                    applicationContext.getColorStateList(R.color.grey_500)
+                buttonTwist!!.backgroundTintList =
+                    applicationContext.getColorStateList(R.color.purple_500)
             }
         }
     }
@@ -327,6 +367,20 @@ class ControlActivity : AppCompatActivity() {
         )
         this.tcpClient!!.start()
 
+        currentState = "standby"
+        controlImage!!.setImageResource(R.drawable.ic_control_circle_standby)
+
+        buttonRotateX!!.backgroundTintList =
+            applicationContext.getColorStateList(R.color.grey_500)
+        buttonRotateY!!.backgroundTintList =
+            applicationContext.getColorStateList(R.color.grey_500)
+        buttonRotateZ!!.backgroundTintList =
+            applicationContext.getColorStateList(R.color.grey_500)
+        buttonClimb!!.backgroundTintList =
+            applicationContext.getColorStateList(R.color.grey_500)
+        buttonTwist!!.backgroundTintList =
+            applicationContext.getColorStateList(R.color.grey_500)
+
     }
 
     override fun onPause() {

software/android/app/src/main/java/com/rookiedev/hexapod/MainActivity.kt

@@ -10,9 +10,13 @@ import com.google.android.material.textfield.TextInputEditText
 import android.text.Editable
 
 import android.text.TextWatcher
+import android.text.method.LinkMovementMethod
+import android.widget.TextView
+import com.google.android.material.textfield.TextInputLayout
 
 
 class MainActivity : AppCompatActivity() {
+
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         setContentView(R.layout.activity_main)
@@ -21,28 +25,48 @@ class MainActivity : AppCompatActivity() {
         val portInput = findViewById<TextInputEditText>(R.id.port_input)
         val buttonConnect = findViewById<Button>(R.id.button_connect)
 
+        val ipLayout = findViewById<TextInputLayout>(R.id.ip_input_layout)
+        val portLayout = findViewById<TextInputLayout>(R.id.port_input_layout)
+
+        val sourceLink = findViewById<TextView>(R.id.textView_github)
+        sourceLink.movementMethod = LinkMovementMethod.getInstance();
+
         buttonConnect.setOnClickListener {
             // your code to perform when the user clicks on the button
 
 //            Toast.makeText(this@MainActivity, "You clicked me.", Toast.LENGTH_SHORT).show()
+            if (isNumericAddress(ipInput.text.toString()) && portInput.text.toString()
+                    .toInt() >= 0 && portInput.text.toString().toInt() <= 65535
+            ) {
                 val intent = Intent(this, ControlActivity::class.java).apply {
                     putExtra("ip", ipInput.text.toString())
                     putExtra("port", portInput.text.toString())
                 }
                 startActivity(intent)
+            } else if (!isNumericAddress(ipInput.text.toString())) {
+                ipLayout.error = getString(R.string.invalid_ip)
+            } else {
+                portLayout.error = getString(R.string.invalid_port)
+            }
         }
 
 
         ipInput.addTextChangedListener(object : TextWatcher {
-            override fun onTextChanged(s: CharSequence, start: Int, before: Int, count: Int) {}
+            override fun onTextChanged(s: CharSequence, start: Int, before: Int, count: Int) {
-            override fun beforeTextChanged(s: CharSequence, start: Int, count: Int, after: Int) {}
+                ipLayout.error = null
-            override fun afterTextChanged(s: Editable) {
-//                if (isNumericAddress(s.toString())) {
-//                    Toast.makeText(this@MainActivity, "Correct", Toast.LENGTH_SHORT).show()
-//                } else {
-//                    Toast.makeText(this@MainActivity, "Wrong", Toast.LENGTH_SHORT).show()
-//                }
             }
+
+            override fun beforeTextChanged(s: CharSequence, start: Int, count: Int, after: Int) {}
+            override fun afterTextChanged(s: Editable) {}
+        })
+
+        portInput.addTextChangedListener(object : TextWatcher {
+            override fun onTextChanged(s: CharSequence, start: Int, before: Int, count: Int) {
+                portLayout.error = null
+            }
+
+            override fun beforeTextChanged(s: CharSequence, start: Int, count: Int, after: Int) {}
+            override fun afterTextChanged(s: Editable) {}
         })
     }
 }

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

@@ -16,9 +16,9 @@
             android:id="@+id/hexapod_logo"
             android:layout_width="120dp"
             android:layout_height="120dp"
-            android:src="@drawable/hexapod_logo"
             android:layout_marginTop="32dp"
             android:layout_marginBottom="32dp"
+            android:src="@drawable/hexapod_logo"
             app:layout_constraintBottom_toTopOf="@id/ip_input_layout"
             app:layout_constraintEnd_toEndOf="parent"
             app:layout_constraintStart_toStartOf="parent"
@@ -28,7 +28,8 @@
             android:id="@+id/ip_input_layout"
             android:layout_width="0dp"
             android:layout_height="wrap_content"
-            android:layout_marginBottom="16dp"
+            android:layout_marginBottom="4dp"
+            app:errorEnabled="true"
             app:layout_constraintBottom_toTopOf="@id/port_input_layout"
             app:layout_constraintEnd_toEndOf="parent"
             app:layout_constraintStart_toStartOf="parent"
@@ -48,7 +49,8 @@
             android:id="@+id/port_input_layout"
             android:layout_width="0dp"
             android:layout_height="wrap_content"
-            android:layout_marginBottom="16dp"
+            android:layout_marginBottom="4dp"
+            app:errorEnabled="true"
             app:layout_constraintBottom_toTopOf="@id/button_connect"
             app:layout_constraintEnd_toEndOf="parent"
             app:layout_constraintStart_toStartOf="parent"
@@ -68,7 +70,7 @@
             android:id="@+id/button_connect"
             android:layout_width="0dp"
             android:layout_height="wrap_content"
-            android:layout_marginTop="32dp"
+            android:layout_marginTop="16dp"
             android:paddingTop="16dp"
             android:paddingBottom="16dp"
             android:text="Connect"
@@ -76,5 +78,16 @@
             app:layout_constraintStart_toStartOf="parent"
             app:layout_constraintTop_toBottomOf="@id/port_input_layout" />
 
+        <TextView
+            android:id="@+id/textView_github"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:paddingTop="32dp"
+            android:paddingBottom="32dp"
+            android:text="@string/hexapod_github"
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toBottomOf="@+id/button_connect" />
+
     </androidx.constraintlayout.widget.ConstraintLayout>
 </ScrollView>

software/android/app/src/main/res/values/strings.xml

@@ -1,3 +1,7 @@
 <resources>
     <string name="app_name">Hexapod</string>
+    <string name="invalid_ip">Invalid IP address</string>
+    <string name="invalid_port">Port should be within 0 ~ 65535</string>
+
+    <string name="hexapod_github"><a href="https://github.com/rookiepeng/hexapod">Source files on GitHub</a></string>
 </resources>