[1주차 과제] 안드로이드 UI 구현 기초

app/src/main/java/org/android/go/sopt/SignUpActivity.kt

@@ -2,6 +2,9 @@ package org.android.go.sopt
 
 import androidx.appcompat.app.AppCompatActivity
 import android.os.Bundle
+import android.text.Editable
+import android.text.TextWatcher
+import android.view.View
 import org.android.go.sopt.databinding.ActivitySignUpBinding
 
 class SignUpActivity : AppCompatActivity() {
@@ -11,5 +14,52 @@ class SignUpActivity : AppCompatActivity() {
         super.onCreate(savedInstanceState)
         binding = ActivitySignUpBinding.inflate(layoutInflater)
         setContentView(binding.root)
+
+        binding.etId.addTextChangedListener(object: TextWatcher {
+            override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {
+            }
+
+            override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {
+                if(!checkValidityOfId(s.toString())){
+                    binding.tvIdLimitError.visibility = View.VISIBLE
+                }else{
+                    binding.tvIdLimitError.visibility = View.INVISIBLE
+                }
+            }
+
+            override fun afterTextChanged(s: Editable?) {
+            }
+        })
+
+        binding.etPw.addTextChangedListener(object: TextWatcher {
+            override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {
+            }
+
+            override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {
+                if(!checkValidityOfPw(s.toString())){
+                    binding.tvPwLimitError.visibility = View.VISIBLE
+                }else{
+                    binding.tvPwLimitError.visibility = View.INVISIBLE
+                }
+            }
+
+            override fun afterTextChanged(s: Editable?) {
+            }
+        })
+
+        binding.btnSignUp.setOnClickListener {
+            val id = binding.etId.text.toString()
+            val pw = binding.etPw.text.toString()
+            val name = binding.etName.text.toString()
+            val hobby = binding.etHobby.text.toString()
+        }
+    }
+
+    private fun checkValidityOfId(id: String): Boolean {
+        return id.length in 6..10
+    }
+
+    private fun checkValidityOfPw(pw: String): Boolean {
+        return pw.length in 8..12
     }
 }

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

@@ -29,13 +29,26 @@
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintTop_toBottomOf="@id/tv_title" />
 
+    <TextView
+        android:id="@+id/tv_id_limit_error"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginStart="10dp"
+        android:text="* 6~10글자 이내만 허용"
+        android:visibility="invisible"
+        android:textColor="@color/red"
+        app:layout_constraintBottom_toBottomOf="@id/tv_id"
+        app:layout_constraintStart_toEndOf="@id/tv_id"
+        app:layout_constraintTop_toTopOf="@id/tv_id" />
+
     <EditText
         android:id="@+id/et_id"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:layout_marginTop="12dp"
         android:hint="아이디를 입력하세요."
         android:minHeight="48dp"
+        android:maxLength="10"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintTop_toBottomOf="@id/tv_id" />
@@ -58,10 +71,23 @@
         android:hint="비밀번호를 입력하세요."
         android:inputType="textPassword"
         android:minHeight="48dp"
+        android:maxLength="12"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintTop_toBottomOf="@id/tv_pw" />
 
+    <TextView
+        android:id="@+id/tv_pw_limit_error"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginStart="10dp"
+        android:text="* 8~12글자 이내만 허용"
+        android:visibility="invisible"
+        android:textColor="@color/red"
+        app:layout_constraintBottom_toBottomOf="@id/tv_pw"
+        app:layout_constraintStart_toEndOf="@id/tv_pw"
+        app:layout_constraintTop_toTopOf="@id/tv_pw" />
+
     <TextView
         android:id="@+id/tv_name"
         android:layout_width="wrap_content"

app/src/main/res/values/colors.xml

@@ -7,4 +7,5 @@
     <color name="teal_700">#FF018786</color>
     <color name="black">#FF000000</color>
     <color name="white">#FFFFFFFF</color>
+    <color name="red">#F44336</color>
 </resources>