Fix login screen buttons crop when the keyboard is opened

app/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedOff/LoginScreen.kt

@@ -1,37 +1,18 @@
 package com.vitorpamplona.amethyst.ui.screen
 
 import androidx.compose.foundation.Image
-import androidx.compose.foundation.layout.Arrangement
-import androidx.compose.foundation.layout.Box
-import androidx.compose.foundation.layout.Column
-import androidx.compose.foundation.layout.Row
-import androidx.compose.foundation.layout.Spacer
-import androidx.compose.foundation.layout.fillMaxSize
-import androidx.compose.foundation.layout.fillMaxWidth
-import androidx.compose.foundation.layout.height
-import androidx.compose.foundation.layout.padding
-import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.rememberScrollState
 import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.foundation.text.ClickableText
 import androidx.compose.foundation.text.KeyboardActions
 import androidx.compose.foundation.text.KeyboardOptions
-import androidx.compose.material.Button
-import androidx.compose.material.ButtonDefaults
-import androidx.compose.material.Checkbox
-import androidx.compose.material.Icon
-import androidx.compose.material.IconButton
-import androidx.compose.material.LocalTextStyle
-import androidx.compose.material.MaterialTheme
-import androidx.compose.material.OutlinedTextField
-import androidx.compose.material.Text
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material.*
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.outlined.Visibility
 import androidx.compose.material.icons.outlined.VisibilityOff
-import androidx.compose.runtime.Composable
-import androidx.compose.runtime.getValue
-import androidx.compose.runtime.mutableStateOf
-import androidx.compose.runtime.remember
-import androidx.compose.runtime.setValue
+import androidx.compose.runtime.*
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
@@ -40,16 +21,13 @@ import androidx.compose.ui.platform.LocalUriHandler
 import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.text.AnnotatedString
 import androidx.compose.ui.text.TextStyle
-import androidx.compose.ui.text.input.ImeAction
-import androidx.compose.ui.text.input.KeyboardType
-import androidx.compose.ui.text.input.PasswordVisualTransformation
-import androidx.compose.ui.text.input.TextFieldValue
-import androidx.compose.ui.text.input.VisualTransformation
+import androidx.compose.ui.text.input.*
+import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.text.style.TextDecoration
+import androidx.compose.ui.unit.Dp
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import com.vitorpamplona.amethyst.R
-import com.vitorpamplona.amethyst.ui.components.sendMail
 
 @Composable
 fun LoginPage(accountViewModel: AccountStateViewModel) {
@@ -59,12 +37,144 @@ fun LoginPage(accountViewModel: AccountStateViewModel) {
     var termsAcceptanceIsRequired by remember { mutableStateOf("") }
     val uri = LocalUriHandler.current
 
-    Box(modifier = Modifier.fillMaxSize()) {
+    Column(
+        modifier = Modifier
+            .fillMaxSize()
+            .verticalScroll(rememberScrollState()),
+        verticalArrangement = Arrangement.SpaceBetween
+    ) {
+        // The first child is glued to the top.
+        // Hence we have nothing at the top, an empty box is used.
+        Box(modifier = Modifier.height(0.dp))
+
+        // The second child, this column, is centered vertically.
+        Column(
+            modifier = Modifier
+                .padding(20.dp)
+                .fillMaxSize(),
+            horizontalAlignment = Alignment.CenterHorizontally,
+        ) {
+
+            Image(
+                painterResource(id = R.drawable.amethyst),
+                contentDescription = "App Logo",
+                modifier = Modifier.size(200.dp),
+                contentScale = ContentScale.Inside
+            )
+
+            Spacer(modifier = Modifier.height(40.dp))
+
+            var showPassword by remember {
+                mutableStateOf(false)
+            }
+
+            OutlinedTextField(
+                value = key.value,
+                onValueChange = { key.value = it },
+                keyboardOptions = KeyboardOptions(
+                    autoCorrect = false,
+                    keyboardType = KeyboardType.Ascii,
+                    imeAction = ImeAction.Go
+                ),
+                placeholder = {
+                    Text(
+                        text = "nsec / npub / hex private key",
+                        color = MaterialTheme.colors.onSurface.copy(alpha = 0.32f)
+                    )
+                },
+                trailingIcon = {
+                    IconButton(onClick = { showPassword = !showPassword }) {
+                        Icon(
+                            imageVector = if (showPassword) Icons.Outlined.VisibilityOff else Icons.Outlined.Visibility,
+                            contentDescription = if (showPassword) "Show Password" else "Hide Password"
+                        )
+                    }
+                },
+                visualTransformation = if (showPassword) VisualTransformation.None else PasswordVisualTransformation(),
+                keyboardActions = KeyboardActions(
+                    onGo = {
+                        try {
+                            accountViewModel.login(key.value.text)
+                        } catch (e: Exception) {
+                            errorMessage = "Invalid key"
+                        }
+                    }
+                )
+            )
+            if (errorMessage.isNotBlank()) {
+                Text(
+                    text = errorMessage,
+                    color = MaterialTheme.colors.error,
+                    style = MaterialTheme.typography.caption
+                )
+            }
+
+            Spacer(modifier = Modifier.height(20.dp))
+
+            Row(verticalAlignment = Alignment.CenterVertically) {
+                Checkbox(
+                    checked = acceptedTerms.value,
+                    onCheckedChange = { acceptedTerms.value = it }
+                )
+
+                Text(text = "I accept the ")
+
+                ClickableText(
+                    text = AnnotatedString("terms of use"),
+                    onClick = { runCatching { uri.openUri("https://github.com/vitorpamplona/amethyst/blob/main/PRIVACY.md") } },
+                    style = LocalTextStyle.current.copy(color = MaterialTheme.colors.primary),
+                )
+            }
+
+            if (termsAcceptanceIsRequired.isNotBlank()) {
+                Text(
+                    text = termsAcceptanceIsRequired,
+                    color = MaterialTheme.colors.error,
+                    style = MaterialTheme.typography.caption
+                )
+            }
+
+            Spacer(modifier = Modifier.height(20.dp))
+
+            Box(modifier = Modifier.padding(40.dp, 0.dp, 40.dp, 0.dp)) {
+                Button(
+                    onClick = {
+                        if (!acceptedTerms.value) {
+                            termsAcceptanceIsRequired = "Acceptance of terms is required"
+                        }
+
+                        if (key.value.text.isBlank()) {
+                            errorMessage = "Key is required"
+                        }
+
+                        if (acceptedTerms.value && key.value.text.isNotBlank()) {
+                            try {
+                                accountViewModel.login(key.value.text)
+                            } catch (e: Exception) {
+                                errorMessage = "Invalid key"
+                            }
+                        }
+                    },
+                    shape = RoundedCornerShape(35.dp),
+                    modifier = Modifier
+                        .fillMaxWidth()
+                        .height(50.dp),
+                    colors = ButtonDefaults
+                        .buttonColors(
+                            backgroundColor = if (acceptedTerms.value) MaterialTheme.colors.primary else Color.Gray
+                        )
+                ) {
+                    Text(text = "Login")
+                }
+            }
+        }
+
+        // The last child is glued to the bottom.
         ClickableText(
             text = AnnotatedString("Generate a new key"),
             modifier = Modifier
-                .align(Alignment.BottomCenter)
-                .padding(20.dp),
+                .padding(20.dp)
+                .fillMaxWidth(),
             onClick = {
                 if (acceptedTerms.value) {
                     accountViewModel.newKey()
@@ -75,127 +185,9 @@ fun LoginPage(accountViewModel: AccountStateViewModel) {
             style = TextStyle(
                 fontSize = 14.sp,
                 textDecoration = TextDecoration.Underline,
-                color = MaterialTheme.colors.primary
+                color = MaterialTheme.colors.primary,
+                textAlign = TextAlign.Center
             )
         )
     }
-    Column(
-        modifier = Modifier.padding(20.dp).fillMaxSize(),
-        verticalArrangement = Arrangement.Center,
-        horizontalAlignment = Alignment.CenterHorizontally,
-    ) {
-
-        Image(
-            painterResource(id = R.drawable.amethyst),
-            contentDescription = "App Logo",
-            modifier = Modifier.size(200.dp),
-            contentScale = ContentScale.Inside
-        )
-
-        Spacer(modifier = Modifier.height(40.dp))
-
-        var showPassword by remember {
-            mutableStateOf(false)
-        }
-
-        OutlinedTextField(
-            value = key.value,
-            onValueChange = { key.value = it },
-            keyboardOptions = KeyboardOptions(
-                autoCorrect = false,
-                keyboardType = KeyboardType.Ascii,
-                imeAction = ImeAction.Go
-            ),
-            placeholder = {
-                Text(
-                    text = "nsec / npub / hex private key",
-                    color = MaterialTheme.colors.onSurface.copy(alpha = 0.32f)
-                )
-            },
-            trailingIcon = {
-                IconButton(onClick = { showPassword = !showPassword }) {
-                    Icon(
-                        imageVector = if (showPassword) Icons.Outlined.VisibilityOff else Icons.Outlined.Visibility,
-                        contentDescription = if (showPassword) "Show Password" else "Hide Password"
-                    )
-                }
-            },
-            visualTransformation = if (showPassword) VisualTransformation.None else PasswordVisualTransformation(),
-            keyboardActions = KeyboardActions(
-                onGo = {
-                    try {
-                        accountViewModel.login(key.value.text)
-                    } catch (e: Exception) {
-                        errorMessage = "Invalid key"
-                    }
-                }
-            )
-        )
-        if (errorMessage.isNotBlank()) {
-            Text(
-                text = errorMessage,
-                color = MaterialTheme.colors.error,
-                style = MaterialTheme.typography.caption
-            )
-        }
-
-        Spacer(modifier = Modifier.height(20.dp))
-
-        Row(verticalAlignment = Alignment.CenterVertically) {
-            Checkbox(
-                checked = acceptedTerms.value,
-                onCheckedChange = { acceptedTerms.value = it }
-            )
-
-            Text(text = "I accept the ")
-
-            ClickableText(
-                text = AnnotatedString("terms of use"),
-                onClick = { runCatching { uri.openUri("https://github.com/vitorpamplona/amethyst/blob/main/PRIVACY.md") } },
-                style = LocalTextStyle.current.copy(color = MaterialTheme.colors.primary),
-            )
-        }
-
-        if (termsAcceptanceIsRequired.isNotBlank()) {
-            Text(
-                text = termsAcceptanceIsRequired,
-                color = MaterialTheme.colors.error,
-                style = MaterialTheme.typography.caption
-            )
-        }
-
-        Spacer(modifier = Modifier.height(20.dp))
-
-        Box(modifier = Modifier.padding(40.dp, 0.dp, 40.dp, 0.dp)) {
-            Button(
-                onClick = {
-                    if (!acceptedTerms.value) {
-                        termsAcceptanceIsRequired = "Acceptance of terms is required"
-                    }
-
-                    if (key.value.text.isBlank()) {
-                        errorMessage = "Key is required"
-                    }
-
-                    if (acceptedTerms.value && key.value.text.isNotBlank()) {
-                        try {
-                            accountViewModel.login(key.value.text)
-                        } catch (e: Exception) {
-                            errorMessage = "Invalid key"
-                        }
-                    }
-                },
-                shape = RoundedCornerShape(35.dp),
-                modifier = Modifier
-                    .fillMaxWidth()
-                    .height(50.dp),
-                colors = ButtonDefaults
-                  .buttonColors(
-                  backgroundColor = if (acceptedTerms.value) MaterialTheme.colors.primary else Color.Gray
-                  )
-            ) {
-                Text(text = "Login")
-            }
-        }
-    }
 }