Fixes for alpha constants, content color checks, etc.

Jetsurvey/app/src/main/java/com/example/compose/jetsurvey/signinsignup/SignInSignUp.kt

@@ -60,6 +60,7 @@ import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
 import com.example.compose.jetsurvey.R
 import com.example.compose.jetsurvey.theme.JetsurveyTheme
+import com.example.compose.jetsurvey.theme.stronglyDeemphasizedAlpha
 
 @Composable
 fun SignInSignUpScreen(
@@ -92,7 +93,7 @@ fun SignInSignUpScreen(
     }
 }
 
-@OptIn(ExperimentalMaterial3Api::class) // SmallTopAppBar is experimental in m3
+@OptIn(ExperimentalMaterial3Api::class) // CenterAlignedTopAppBar is experimental in m3
 @Composable
 fun SignInSignUpTopAppBar(topAppBarText: String, onBackPressed: () -> Unit) {
     CenterAlignedTopAppBar(
@@ -136,7 +137,7 @@ fun Email(
             Text(
                 text = stringResource(id = R.string.email),
                 style = MaterialTheme.typography.bodyMedium,
-                color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.6f)
+                color = MaterialTheme.colorScheme.onSurface.copy(alpha = stronglyDeemphasizedAlpha)
             )
         },
         modifier = Modifier
@@ -192,7 +193,7 @@ fun Password(
             Text(
                 text = label,
                 style = MaterialTheme.typography.bodyMedium,
-                color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.6f)
+                color = MaterialTheme.colorScheme.onSurface.copy(alpha = stronglyDeemphasizedAlpha)
             )
         },
         trailingIcon = {
@@ -259,7 +260,7 @@ fun OrSignInAsGuest(
         Text(
             text = stringResource(id = R.string.or),
             style = MaterialTheme.typography.titleSmall,
-            color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.6f),
+            color = MaterialTheme.colorScheme.onSurface.copy(alpha = stronglyDeemphasizedAlpha),
             modifier = Modifier.paddingFromBaseline(top = 25.dp)
         )
         OutlinedButton(

Jetsurvey/app/src/main/java/com/example/compose/jetsurvey/signinsignup/SignUpScreen.kt

@@ -36,6 +36,7 @@ import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
 import com.example.compose.jetsurvey.R
 import com.example.compose.jetsurvey.theme.JetsurveyTheme
+import com.example.compose.jetsurvey.theme.stronglyDeemphasizedAlpha
 import com.example.compose.jetsurvey.util.supportWideScreen
 
 sealed class SignUpEvent {
@@ -106,7 +107,7 @@ fun SignUpContent(
         Text(
             text = stringResource(id = R.string.terms_and_conditions),
             style = MaterialTheme.typography.bodySmall,
-            color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.6f)
+            color = MaterialTheme.colorScheme.onSurface.copy(alpha = stronglyDeemphasizedAlpha)
         )
 
         Spacer(modifier = Modifier.height(16.dp))

Jetsurvey/app/src/main/java/com/example/compose/jetsurvey/signinsignup/WelcomeScreen.kt

@@ -29,6 +29,7 @@ import androidx.compose.foundation.layout.wrapContentHeight
 import androidx.compose.foundation.rememberScrollState
 import androidx.compose.foundation.verticalScroll
 import androidx.compose.material3.Button
+import androidx.compose.material3.LocalContentColor
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
@@ -40,6 +41,7 @@ import androidx.compose.runtime.saveable.rememberSaveable
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.luminance
 import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.input.ImeAction
@@ -48,7 +50,7 @@ import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
 import com.example.compose.jetsurvey.R
 import com.example.compose.jetsurvey.theme.JetsurveyTheme
-import com.example.compose.jetsurvey.theme.surfaceIsLight
+import com.example.compose.jetsurvey.theme.stronglyDeemphasizedAlpha
 import com.example.compose.jetsurvey.util.supportWideScreen
 
 sealed class WelcomeEvent {
@@ -120,9 +122,8 @@ private fun Branding(modifier: Modifier = Modifier) {
 @Composable
 private fun Logo(
     modifier: Modifier = Modifier,
-    lightTheme: Boolean = surfaceIsLight()
 ) {
-    val assetId = if (lightTheme) {
+    val assetId = if (LocalContentColor.current.luminance() > 0.5f) {
         R.drawable.ic_logo_light
     } else {
         R.drawable.ic_logo_dark
@@ -147,7 +148,7 @@ private fun SignInCreateAccount(
         Text(
             text = stringResource(id = R.string.sign_in_create_account),
             style = MaterialTheme.typography.titleSmall,
-            color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.6f),
+            color = MaterialTheme.colorScheme.onSurface.copy(alpha = stronglyDeemphasizedAlpha),
             textAlign = TextAlign.Center,
             modifier = Modifier.padding(top = 64.dp, bottom = 12.dp)
         )

Jetsurvey/app/src/main/java/com/example/compose/jetsurvey/survey/SurveyQuestions.kt

@@ -45,6 +45,7 @@ import androidx.compose.material3.ButtonDefaults
 import androidx.compose.material3.Checkbox
 import androidx.compose.material3.CheckboxDefaults
 import androidx.compose.material3.Icon
+import androidx.compose.material3.LocalContentColor
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.OutlinedButton
 import androidx.compose.material3.RadioButton
@@ -61,6 +62,7 @@ import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
+import androidx.compose.ui.graphics.luminance
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.res.stringResource
@@ -71,7 +73,8 @@ import coil.compose.AsyncImage
 import coil.request.ImageRequest
 import com.example.compose.jetsurvey.R
 import com.example.compose.jetsurvey.theme.JetsurveyTheme
-import com.example.compose.jetsurvey.theme.surfaceIsLight
+import com.example.compose.jetsurvey.theme.slightlyDeemphasizedAlpha
+import com.example.compose.jetsurvey.theme.stronglyDeemphasizedAlpha
 import com.google.accompanist.permissions.ExperimentalPermissionsApi
 import com.google.accompanist.permissions.MultiplePermissionsState
 import com.google.accompanist.permissions.rememberMultiplePermissionsState
@@ -165,7 +168,8 @@ private fun QuestionContent(
             if (question.description != null) {
                 Text(
                     text = stringResource(id = question.description),
-                    color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.6f),
+                    color = MaterialTheme.colorScheme.onSurface
+                        .copy(alpha = stronglyDeemphasizedAlpha),
                     style = MaterialTheme.typography.bodySmall,
                     modifier = Modifier
                         .fillParentMaxWidth()
@@ -244,7 +248,7 @@ private fun QuestionTitle(@StringRes title: Int) {
         Text(
             text = stringResource(id = title),
             style = MaterialTheme.typography.titleMedium,
-            color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.87f),
+            color = MaterialTheme.colorScheme.onSurface.copy(alpha = slightlyDeemphasizedAlpha),
             modifier = Modifier
                 .fillMaxWidth()
                 .padding(vertical = 24.dp, horizontal = 16.dp)
@@ -671,7 +675,8 @@ private fun DateQuestion(
         onClick = { onAction(questionId, SurveyActionType.PICK_DATE) },
         colors = ButtonDefaults.buttonColors(
             containerColor = MaterialTheme.colorScheme.surface,
-            contentColor = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.87f),
+            contentColor = MaterialTheme.colorScheme.onSurface
+                .copy(alpha = slightlyDeemphasizedAlpha),
         ),
         shape = MaterialTheme.shapes.small,
         modifier = modifier
@@ -699,9 +704,8 @@ private fun DateQuestion(
 @Composable
 private fun PhotoDefaultImage(
     modifier: Modifier = Modifier,
-    lightTheme: Boolean = surfaceIsLight()
 ) {
-    val assetId = if (lightTheme) {
+    val assetId = if (LocalContentColor.current.luminance() > 0.5f) {
         R.drawable.ic_selfie_light
     } else {
         R.drawable.ic_selfie_dark

Jetsurvey/app/src/main/java/com/example/compose/jetsurvey/survey/SurveyScreen.kt

@@ -55,6 +55,7 @@ import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.unit.IntOffset
 import androidx.compose.ui.unit.dp
 import com.example.compose.jetsurvey.R
+import com.example.compose.jetsurvey.theme.stronglyDeemphasizedAlpha
 import com.example.compose.jetsurvey.util.supportWideScreen
 
 private const val CONTENT_ANIMATION_DURATION = 500
@@ -203,7 +204,7 @@ private fun TopAppBarTitle(
         Text(
             text = (questionIndex + 1).toString(),
             style = MaterialTheme.typography.labelMedium,
-            color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.6f)
+            color = MaterialTheme.colorScheme.onSurface.copy(alpha = stronglyDeemphasizedAlpha)
         )
         Text(
             text = stringResource(R.string.question_count, totalQuestionsCount),

Jetsurvey/app/src/main/java/com/example/compose/jetsurvey/theme/Theme.kt

@@ -22,9 +22,11 @@ import androidx.compose.material3.darkColorScheme
 import androidx.compose.material3.lightColorScheme
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.DisposableEffect
-import androidx.compose.ui.graphics.luminance
 import com.google.accompanist.systemuicontroller.rememberSystemUiController
 
+const val stronglyDeemphasizedAlpha = 0.6f
+const val slightlyDeemphasizedAlpha = 0.87f
+
 private val LightColors = lightColorScheme(
     primary = md_theme_light_primary,
     onPrimary = md_theme_light_onPrimary,
@@ -115,6 +117,3 @@ fun JetsurveyTheme(
         content = content,
     )
 }
-
-@Composable
-fun surfaceIsLight(): Boolean = MaterialTheme.colorScheme.surface.luminance() > 0.5f