chore: initial commit

Signed-off-by: Alan Brault <alan.brault@visus.io>

core/ui/.gitignore

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+/build

core/ui/build.gradle.kts

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+plugins {
+    alias(libs.plugins.android.library)
+    alias(libs.plugins.kotlin.compose)
+    alias(libs.plugins.lumo)
+}
+
+android {
+    namespace = "io.visus.orbis.core.ui"
+    compileSdk {
+        version = release(36)
+    }
+
+    defaultConfig {
+        minSdk = 24
+
+        testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
+        consumerProguardFiles("consumer-rules.pro")
+    }
+
+    buildTypes {
+        release {
+            isMinifyEnabled = false
+            proguardFiles(
+                getDefaultProguardFile("proguard-android-optimize.txt"),
+                "proguard-rules.pro"
+            )
+        }
+    }
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_17
+        targetCompatibility = JavaVersion.VERSION_17
+    }
+    buildFeatures {
+        compose = true
+    }
+}
+
+dependencies {
+    // AndroidX
+    implementation(libs.androidx.core.ktx)
+    implementation(libs.androidx.appcompat)
+    implementation(libs.material)
+
+    // Compose
+    implementation(platform(libs.androidx.compose.bom))
+    implementation(libs.androidx.compose.ui)
+    implementation(libs.androidx.compose.ui.graphics)
+    implementation(libs.androidx.compose.foundation)
+    implementation(libs.androidx.compose.animation)
+    implementation(libs.androidx.compose.material)
+    implementation(libs.androidx.compose.runtime)
+
+    // Testing
+    testImplementation(libs.junit)
+    androidTestImplementation(libs.androidx.junit)
+    androidTestImplementation(libs.androidx.espresso.core)
+}

core/ui/proguard-rules.pro

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+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+#-renamesourcefileattribute SourceFile

core/ui/src/androidTest/java/io/visus/orbis/core/ui/ExampleInstrumentedTest.kt

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+package io.visus.orbis.core.ui
+
+import androidx.test.platform.app.InstrumentationRegistry
+import androidx.test.ext.junit.runners.AndroidJUnit4
+
+import org.junit.Test
+import org.junit.runner.RunWith
+
+import org.junit.Assert.*
+
+/**
+ * Instrumented test, which will execute on an Android device.
+ *
+ * See [testing documentation](http://d.android.com/tools/testing).
+ */
+@RunWith(AndroidJUnit4::class)
+class ExampleInstrumentedTest {
+    @Test
+    fun useAppContext() {
+        // Context of the app under test.
+        val appContext = InstrumentationRegistry.getInstrumentation().targetContext
+        assertEquals("io.visus.orbis.core.ui.test", appContext.packageName)
+    }
+}

core/ui/src/main/AndroidManifest.xml

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+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+
+</manifest>

core/ui/src/main/java/io/visus/orbis/core/ui/Color.kt

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+package io.visus.orbis.core.ui
+
+import androidx.compose.runtime.Immutable
+import androidx.compose.runtime.compositionLocalOf
+import androidx.compose.runtime.staticCompositionLocalOf
+import androidx.compose.ui.graphics.Color
+
+val Black: Color = Color(0xFF000000)
+val Gray900: Color = Color(0xFF282828)
+val Gray800: Color = Color(0xFF4b4b4b)
+val Gray700: Color = Color(0xFF5e5e5e)
+val Gray600: Color = Color(0xFF727272)
+val Gray500: Color = Color(0xFF868686)
+val Gray400: Color = Color(0xFFC7C7C7)
+val Gray300: Color = Color(0xFFDFDFDF)
+val Gray200: Color = Color(0xFFE2E2E2)
+val Gray100: Color = Color(0xFFF7F7F7)
+val Gray50: Color = Color(0xFFFFFFFF)
+val White: Color = Color(0xFFFFFFFF)
+
+val Red900: Color = Color(0xFF520810)
+val Red800: Color = Color(0xFF950f22)
+val Red700: Color = Color(0xFFbb032a)
+val Red600: Color = Color(0xFFde1135)
+val Red500: Color = Color(0xFFf83446)
+val Red400: Color = Color(0xFFfc7f79)
+val Red300: Color = Color(0xFFffb2ab)
+val Red200: Color = Color(0xFFffd2cd)
+val Red100: Color = Color(0xFFffe1de)
+val Red50: Color = Color(0xFFfff0ee)
+
+val Blue900: Color = Color(0xFF276EF1)
+val Blue800: Color = Color(0xFF3F7EF2)
+val Blue700: Color = Color(0xFF578EF4)
+val Blue600: Color = Color(0xFF6F9EF5)
+val Blue500: Color = Color(0xFF87AEF7)
+val Blue400: Color = Color(0xFF9FBFF8)
+val Blue300: Color = Color(0xFFB7CEFA)
+val Blue200: Color = Color(0xFFCFDEFB)
+val Blue100: Color = Color(0xFFE7EEFD)
+val Blue50: Color = Color(0xFFFFFFFF)
+
+val Green950: Color = Color(0xFF0B4627)
+val Green900: Color = Color(0xFF16643B)
+val Green800: Color = Color(0xFF1A7544)
+val Green700: Color = Color(0xFF178C4E)
+val Green600: Color = Color(0xFF1DAF61)
+val Green500: Color = Color(0xFF1FC16B)
+val Green400: Color = Color(0xFF3EE089)
+val Green300: Color = Color(0xFF84EBB4)
+val Green200: Color = Color(0xFFC2F5DA)
+val Green100: Color = Color(0xFFD0FBE9)
+val Green50: Color = Color(0xFFE0FAEC)
+
+@Immutable
+data class Colors(
+    val primary: Color,
+    val onPrimary: Color,
+    val secondary: Color,
+    val onSecondary: Color,
+    val tertiary: Color,
+    val onTertiary: Color,
+    val error: Color,
+    val onError: Color,
+    val success: Color,
+    val onSuccess: Color,
+    val disabled: Color,
+    val onDisabled: Color,
+    val surface: Color,
+    val onSurface: Color,
+    val background: Color,
+    val onBackground: Color,
+    val outline: Color,
+    val transparent: Color = Color.Transparent,
+    val white: Color = White,
+    val black: Color = Black,
+    val text: Color,
+    val textSecondary: Color,
+    val textDisabled: Color,
+    val scrim: Color,
+    val elevation: Color,
+)
+
+internal val LightColors =
+    Colors(
+        primary = Black,
+        onPrimary = White,
+        secondary = Gray400,
+        onSecondary = Black,
+        tertiary = Blue900,
+        onTertiary = White,
+        surface = Gray200,
+        onSurface = Black,
+        error = Red600,
+        onError = White,
+        success = Green600,
+        onSuccess = White,
+        disabled = Gray100,
+        onDisabled = Gray500,
+        background = White,
+        onBackground = Black,
+        outline = Gray300,
+        transparent = Color.Transparent,
+        white = White,
+        black = Black,
+        text = Black,
+        textSecondary = Gray700,
+        textDisabled = Gray400,
+        scrim = Color.Black.copy(alpha = 0.32f),
+        elevation = Gray700,
+    )
+
+internal val DarkColors =
+    Colors(
+        primary = White,
+        onPrimary = Black,
+        secondary = Gray400,
+        onSecondary = White,
+        tertiary = Blue300,
+        onTertiary = Black,
+        surface = Gray900,
+        onSurface = White,
+        error = Red400,
+        onError = Black,
+        success = Green700,
+        onSuccess = Black,
+        disabled = Gray700,
+        onDisabled = Gray500,
+        background = Black,
+        onBackground = White,
+        outline = Gray800,
+        transparent = Color.Transparent,
+        white = White,
+        black = Black,
+        text = White,
+        textSecondary = Gray300,
+        textDisabled = Gray600,
+        scrim = Color.Black.copy(alpha = 0.72f),
+        elevation = Gray200,
+    )
+
+val LocalColors = staticCompositionLocalOf { LightColors }
+val LocalContentColor = compositionLocalOf { Color.Black }
+val LocalContentAlpha = compositionLocalOf { 1f }
+
+fun Colors.contentColorFor(backgroundColor: Color): Color {
+    return when (backgroundColor) {
+        primary -> onPrimary
+        secondary -> onSecondary
+        tertiary -> onTertiary
+        surface -> onSurface
+        error -> onError
+        success -> onSuccess
+        disabled -> onDisabled
+        background -> onBackground
+        else -> Color.Unspecified
+    }
+}

core/ui/src/main/java/io/visus/orbis/core/ui/Theme.kt

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+package io.visus.orbis.core.ui
+
+import androidx.compose.foundation.LocalIndication
+import androidx.compose.foundation.isSystemInDarkTheme
+import androidx.compose.foundation.text.selection.LocalTextSelectionColors
+import androidx.compose.foundation.text.selection.TextSelectionColors
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.CompositionLocalProvider
+import androidx.compose.runtime.ReadOnlyComposable
+import androidx.compose.runtime.remember
+import androidx.compose.ui.graphics.Color
+import io.visus.orbis.core.ui.foundation.ripple
+
+object OrbisTheme {
+    val colors: Colors
+        @ReadOnlyComposable @Composable
+        get() = LocalColors.current
+
+    val typography: Typography
+        @ReadOnlyComposable @Composable
+        get() = LocalTypography.current
+}
+
+@Composable
+fun OrbisTheme(
+    isDarkTheme: Boolean = isSystemInDarkTheme(),
+    content: @Composable () -> Unit,
+) {
+    val rippleIndication = ripple()
+    val selectionColors = rememberTextSelectionColors(LightColors)
+    val typography = provideTypography()
+    val colors = if (isDarkTheme) DarkColors else LightColors
+
+    CompositionLocalProvider(
+        LocalColors provides colors,
+        LocalTypography provides typography,
+        LocalIndication provides rippleIndication,
+        LocalTextSelectionColors provides selectionColors,
+        LocalContentColor provides colors.contentColorFor(colors.background),
+        LocalTextStyle provides typography.body1,
+        content = content,
+    )
+}
+
+@Composable
+fun contentColorFor(color: Color): Color {
+    return OrbisTheme.colors.contentColorFor(color)
+}
+
+@Composable
+internal fun rememberTextSelectionColors(colorScheme: Colors): TextSelectionColors {
+    val primaryColor = colorScheme.primary
+    return remember(primaryColor) {
+        TextSelectionColors(
+            handleColor = primaryColor,
+            backgroundColor = primaryColor.copy(alpha = TextSelectionBackgroundOpacity),
+        )
+    }
+}
+
+internal const val TextSelectionBackgroundOpacity = 0.4f

core/ui/src/main/java/io/visus/orbis/core/ui/Typography.kt

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+package io.visus.orbis.core.ui
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.compositionLocalOf
+import androidx.compose.runtime.staticCompositionLocalOf
+import androidx.compose.runtime.structuralEqualityPolicy
+import androidx.compose.ui.text.TextStyle
+import androidx.compose.ui.text.font.FontFamily
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.unit.sp
+
+@Composable
+fun fontFamily() = FontFamily.Default
+
+data class Typography(
+    val h1: TextStyle,
+    val h2: TextStyle,
+    val h3: TextStyle,
+    val h4: TextStyle,
+    val body1: TextStyle,
+    val body2: TextStyle,
+    val body3: TextStyle,
+    val label1: TextStyle,
+    val label2: TextStyle,
+    val label3: TextStyle,
+    val button: TextStyle,
+    val input: TextStyle,
+)
+
+private val defaultTypography =
+    Typography(
+        h1 =
+            TextStyle(
+                fontWeight = FontWeight.Bold,
+                fontSize = 24.sp,
+                lineHeight = 32.sp,
+                letterSpacing = 0.sp,
+            ),
+        h2 =
+            TextStyle(
+                fontWeight = FontWeight.Bold,
+                fontSize = 20.sp,
+                lineHeight = 28.sp,
+                letterSpacing = 0.sp,
+            ),
+        h3 =
+            TextStyle(
+                fontWeight = FontWeight.Bold,
+                fontSize = 16.sp,
+                lineHeight = 24.sp,
+                letterSpacing = 0.sp,
+            ),
+        h4 =
+            TextStyle(
+                fontWeight = FontWeight.SemiBold,
+                fontSize = 16.sp,
+                lineHeight = 24.sp,
+                letterSpacing = 0.sp,
+            ),
+        body1 =
+            TextStyle(
+                fontWeight = FontWeight.Normal,
+                fontSize = 16.sp,
+                lineHeight = 24.sp,
+                letterSpacing = 0.sp,
+            ),
+        body2 =
+            TextStyle(
+                fontWeight = FontWeight.Normal,
+                fontSize = 14.sp,
+                lineHeight = 20.sp,
+                letterSpacing = 0.15.sp,
+            ),
+        body3 =
+            TextStyle(
+                fontWeight = FontWeight.Normal,
+                fontSize = 12.sp,
+                lineHeight = 16.sp,
+                letterSpacing = 0.15.sp,
+            ),
+        label1 =
+            TextStyle(
+                fontWeight = FontWeight.W500,
+                fontSize = 14.sp,
+                lineHeight = 20.sp,
+                letterSpacing = 0.1.sp,
+            ),
+        label2 =
+            TextStyle(
+                fontWeight = FontWeight.W500,
+                fontSize = 12.sp,
+                lineHeight = 16.sp,
+                letterSpacing = 0.5.sp,
+            ),
+        label3 =
+            TextStyle(
+                fontWeight = FontWeight.W500,
+                fontSize = 10.sp,
+                lineHeight = 12.sp,
+                letterSpacing = 0.5.sp,
+            ),
+        button =
+            TextStyle(
+                fontWeight = FontWeight.W500,
+                fontSize = 14.sp,
+                lineHeight = 20.sp,
+                letterSpacing = 1.sp,
+            ),
+        input =
+            TextStyle(
+                fontWeight = FontWeight.Normal,
+                fontSize = 16.sp,
+                lineHeight = 24.sp,
+                letterSpacing = 0.sp,
+            ),
+    )
+
+@Composable
+fun provideTypography(): Typography {
+    val fontFamily = fontFamily()
+
+    return defaultTypography.copy(
+        h1 = defaultTypography.h1.copy(fontFamily = fontFamily),
+        h2 = defaultTypography.h2.copy(fontFamily = fontFamily),
+        h3 = defaultTypography.h3.copy(fontFamily = fontFamily),
+        h4 = defaultTypography.h4.copy(fontFamily = fontFamily),
+        body1 = defaultTypography.body1.copy(fontFamily = fontFamily),
+        body2 = defaultTypography.body2.copy(fontFamily = fontFamily),
+        body3 = defaultTypography.body3.copy(fontFamily = fontFamily),
+        label1 = defaultTypography.label1.copy(fontFamily = fontFamily),
+        label2 = defaultTypography.label2.copy(fontFamily = fontFamily),
+        label3 = defaultTypography.label3.copy(fontFamily = fontFamily),
+        button = defaultTypography.button.copy(fontFamily = fontFamily),
+        input = defaultTypography.input.copy(fontFamily = fontFamily),
+    )
+}
+
+val LocalTypography = staticCompositionLocalOf { defaultTypography }
+val LocalTextStyle = compositionLocalOf(structuralEqualityPolicy()) { TextStyle.Default }

core/ui/src/main/java/io/visus/orbis/core/ui/components/Scaffold.kt

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+package io.visus.orbis.core.ui.components
+
+import androidx.compose.foundation.layout.PaddingValues
+import androidx.compose.foundation.layout.WindowInsets
+import androidx.compose.foundation.layout.asPaddingValues
+import androidx.compose.foundation.layout.calculateEndPadding
+import androidx.compose.foundation.layout.calculateStartPadding
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.CompositionLocalProvider
+import androidx.compose.runtime.Immutable
+import androidx.compose.runtime.staticCompositionLocalOf
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.layout.SubcomposeLayout
+import androidx.compose.ui.unit.LayoutDirection
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.offset
+import io.visus.orbis.core.ui.OrbisTheme
+import io.visus.orbis.core.ui.contentColorFor
+import io.visus.orbis.core.ui.foundation.systemBarsForVisualComponents
+import kotlin.jvm.JvmInline
+
+@Composable
+fun Scaffold(
+    modifier: Modifier = Modifier,
+    topBar: @Composable () -> Unit = {},
+    bottomBar: @Composable () -> Unit = {},
+    snackbarHost: @Composable () -> Unit = {},
+    floatingActionButton: @Composable () -> Unit = {},
+    floatingActionButtonPosition: FabPosition = FabPosition.End,
+    containerColor: Color = OrbisTheme.colors.background,
+    contentColor: Color = contentColorFor(containerColor),
+    contentWindowInsets: WindowInsets = ScaffoldDefaults.contentWindowInsets,
+    content: @Composable (PaddingValues) -> Unit,
+) {
+    Surface(modifier = modifier, color = containerColor, contentColor = contentColor) {
+        ScaffoldLayout(
+            fabPosition = floatingActionButtonPosition,
+            topBar = topBar,
+            bottomBar = bottomBar,
+            content = content,
+            snackbar = snackbarHost,
+            contentWindowInsets = contentWindowInsets,
+            fab = floatingActionButton,
+        )
+    }
+}
+
+@Composable
+private fun ScaffoldLayout(
+    fabPosition: FabPosition,
+    topBar: @Composable () -> Unit,
+    content: @Composable (PaddingValues) -> Unit,
+    snackbar: @Composable () -> Unit,
+    fab: @Composable () -> Unit,
+    contentWindowInsets: WindowInsets,
+    bottomBar: @Composable () -> Unit,
+) {
+    SubcomposeLayout { constraints ->
+        val layoutWidth = constraints.maxWidth
+        val layoutHeight = constraints.maxHeight
+
+        val looseConstraints = constraints.copy(minWidth = 0, minHeight = 0)
+
+        layout(layoutWidth, layoutHeight) {
+            val topBarPlaceables =
+                subcompose(ScaffoldLayoutContent.TopBar, topBar).map {
+                    it.measure(looseConstraints)
+                }
+
+            val topBarHeight = topBarPlaceables.maxByOrNull { it.height }?.height ?: 0
+
+            val snackbarPlaceables =
+                subcompose(ScaffoldLayoutContent.Snackbar, snackbar).map {
+                    // respect only bottom and horizontal for snackbar and fab
+                    val leftInset =
+                        contentWindowInsets
+                            .getLeft(this@SubcomposeLayout, layoutDirection)
+                    val rightInset =
+                        contentWindowInsets
+                            .getRight(this@SubcomposeLayout, layoutDirection)
+                    val bottomInset = contentWindowInsets.getBottom(this@SubcomposeLayout)
+                    // offset the snackbar constraints by the insets values
+                    it.measure(
+                        looseConstraints.offset(
+                            -leftInset - rightInset,
+                            -bottomInset,
+                        ),
+                    )
+                }
+
+            val snackbarHeight = snackbarPlaceables.maxByOrNull { it.height }?.height ?: 0
+            val snackbarWidth = snackbarPlaceables.maxByOrNull { it.width }?.width ?: 0
+
+            val fabPlaceables =
+                subcompose(ScaffoldLayoutContent.Fab, fab).mapNotNull { measurable ->
+                    // respect only bottom and horizontal for snackbar and fab
+                    val leftInset =
+                        contentWindowInsets.getLeft(
+                            this@SubcomposeLayout,
+                            layoutDirection,
+                        )
+                    val rightInset =
+                        contentWindowInsets.getRight(
+                            this@SubcomposeLayout,
+                            layoutDirection,
+                        )
+                    val bottomInset = contentWindowInsets.getBottom(this@SubcomposeLayout)
+                    measurable.measure(
+                        looseConstraints.offset(
+                            -leftInset - rightInset,
+                            -bottomInset,
+                        ),
+                    )
+                        .takeIf { it.height != 0 && it.width != 0 }
+                }
+
+            val fabPlacement =
+                if (fabPlaceables.isNotEmpty()) {
+                    val fabWidth = fabPlaceables.maxByOrNull { it.width }!!.width
+                    val fabHeight = fabPlaceables.maxByOrNull { it.height }!!.height
+                    // FAB distance from the left of the layout, taking into account LTR / RTL
+                    val fabLeftOffset =
+                        if (fabPosition == FabPosition.End) {
+                            if (layoutDirection == LayoutDirection.Ltr) {
+                                layoutWidth - FabSpacing.roundToPx() - fabWidth
+                            } else {
+                                FabSpacing.roundToPx()
+                            }
+                        } else {
+                            (layoutWidth - fabWidth) / 2
+                        }
+
+                    FabPlacement(
+                        left = fabLeftOffset,
+                        width = fabWidth,
+                        height = fabHeight,
+                    )
+                } else {
+                    null
+                }
+
+            val bottomBarPlaceables =
+                subcompose(ScaffoldLayoutContent.BottomBar) {
+                    CompositionLocalProvider(
+                        LocalFabPlacement provides fabPlacement,
+                        content = bottomBar,
+                    )
+                }.map { it.measure(looseConstraints) }
+
+            val bottomBarHeight = bottomBarPlaceables.maxByOrNull { it.height }?.height
+            val fabOffsetFromBottom =
+                fabPlacement?.let {
+                    if (bottomBarHeight == null) {
+                        it.height + FabSpacing.roundToPx() +
+                            contentWindowInsets.getBottom(this@SubcomposeLayout)
+                    } else {
+                        // Total height is the bottom bar height + the FAB height + the padding
+                        // between the FAB and bottom bar
+                        bottomBarHeight + it.height + FabSpacing.roundToPx()
+                    }
+                }
+
+            val snackbarOffsetFromBottom =
+                if (snackbarHeight != 0) {
+                    snackbarHeight +
+                        (
+                            fabOffsetFromBottom ?: bottomBarHeight
+                                ?: contentWindowInsets.getBottom(this@SubcomposeLayout)
+                        )
+                } else {
+                    0
+                }
+
+            val bodyContentPlaceables =
+                subcompose(ScaffoldLayoutContent.MainContent) {
+                    val insets = contentWindowInsets.asPaddingValues(this@SubcomposeLayout)
+                    val innerPadding =
+                        PaddingValues(
+                            top =
+                                if (topBarPlaceables.isEmpty()) {
+                                    insets.calculateTopPadding()
+                                } else {
+                                    topBarHeight.toDp()
+                                },
+                            bottom =
+                                if (bottomBarPlaceables.isEmpty() || bottomBarHeight == null) {
+                                    insets.calculateBottomPadding()
+                                } else {
+                                    bottomBarHeight.toDp()
+                                },
+                            start = insets.calculateStartPadding((this@SubcomposeLayout).layoutDirection),
+                            end = insets.calculateEndPadding((this@SubcomposeLayout).layoutDirection),
+                        )
+                    content(innerPadding)
+                }.map { it.measure(looseConstraints) }
+
+            // Placing to control drawing order to match default elevation of each placeable
+
+            bodyContentPlaceables.forEach {
+                it.place(0, 0)
+            }
+            topBarPlaceables.forEach {
+                it.place(0, 0)
+            }
+            snackbarPlaceables.forEach {
+                it.place(
+                    (layoutWidth - snackbarWidth) / 2 +
+                        contentWindowInsets.getLeft(
+                            this@SubcomposeLayout,
+                            layoutDirection,
+                        ),
+                    layoutHeight - snackbarOffsetFromBottom,
+                )
+            }
+            // The bottom bar is always at the bottom of the layout
+            bottomBarPlaceables.forEach {
+                it.place(0, layoutHeight - (bottomBarHeight ?: 0))
+            }
+            // Explicitly not using placeRelative here as `leftOffset` already accounts for RTL
+            fabPlacement?.let { placement ->
+                fabPlaceables.forEach {
+                    it.place(placement.left, layoutHeight - fabOffsetFromBottom!!)
+                }
+            }
+        }
+    }
+}
+
+object ScaffoldDefaults {
+    val contentWindowInsets: WindowInsets
+        @Composable
+        get() = WindowInsets.systemBarsForVisualComponents
+}
+
+@JvmInline
+value class FabPosition internal constructor(
+    @Suppress("unused") private val value: Int,
+) {
+    companion object {
+        val Center = FabPosition(0)
+
+        val End = FabPosition(1)
+    }
+
+    override fun toString(): String {
+        return when (this) {
+            Center -> "FabPosition.Center"
+            else -> "FabPosition.End"
+        }
+    }
+}
+
+@Immutable
+internal class FabPlacement(
+    val left: Int,
+    val width: Int,
+    val height: Int,
+)
+
+internal val LocalFabPlacement = staticCompositionLocalOf<FabPlacement?> { null }
+
+private val FabSpacing = 16.dp
+
+private enum class ScaffoldLayoutContent { TopBar, MainContent, Snackbar, Fab, BottomBar }

core/ui/src/main/java/io/visus/orbis/core/ui/components/Surface.kt

@@ -0,0 +1,202 @@
+package io.visus.orbis.core.ui.components
+
+import androidx.compose.foundation.BorderStroke
+import androidx.compose.foundation.background
+import androidx.compose.foundation.border
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.interaction.MutableInteractionSource
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.selection.selectable
+import androidx.compose.foundation.selection.toggleable
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.CompositionLocalProvider
+import androidx.compose.runtime.NonRestartableComposable
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.draw.shadow
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.RectangleShape
+import androidx.compose.ui.graphics.Shape
+import androidx.compose.ui.input.pointer.pointerInput
+import androidx.compose.ui.semantics.isTraversalGroup
+import androidx.compose.ui.semantics.semantics
+import androidx.compose.ui.unit.Dp
+import androidx.compose.ui.unit.dp
+import io.visus.orbis.core.ui.OrbisTheme
+import io.visus.orbis.core.ui.LocalContentColor
+import io.visus.orbis.core.ui.contentColorFor
+import io.visus.orbis.core.ui.foundation.ripple
+
+@Composable
+@NonRestartableComposable
+fun Surface(
+    modifier: Modifier = Modifier,
+    shape: Shape = RectangleShape,
+    color: Color = OrbisTheme.colors.surface,
+    contentColor: Color = contentColorFor(color),
+    shadowElevation: Dp = 0.dp,
+    border: BorderStroke? = null,
+    content: @Composable () -> Unit,
+) {
+    CompositionLocalProvider(
+        LocalContentColor provides contentColor,
+    ) {
+        Box(
+            modifier =
+                modifier
+                    .surface(
+                        shape = shape,
+                        backgroundColor = color,
+                        border = border,
+                        shadowElevation = shadowElevation,
+                    )
+                    .semantics(mergeDescendants = false) {
+                        isTraversalGroup = true
+                    }
+                    .pointerInput(Unit) {},
+            propagateMinConstraints = true,
+        ) {
+            content()
+        }
+    }
+}
+
+@Composable
+@NonRestartableComposable
+fun Surface(
+    onClick: () -> Unit,
+    modifier: Modifier = Modifier,
+    enabled: Boolean = true,
+    shape: Shape = RectangleShape,
+    color: Color = OrbisTheme.colors.background,
+    contentColor: Color = contentColorFor(color),
+    shadowElevation: Dp = 0.dp,
+    border: BorderStroke? = null,
+    interactionSource: MutableInteractionSource = remember { MutableInteractionSource() },
+    content: @Composable () -> Unit,
+) {
+    CompositionLocalProvider(
+        LocalContentColor provides contentColor,
+    ) {
+        Box(
+            modifier =
+                modifier
+                    .surface(
+                        shape = shape,
+                        backgroundColor = color,
+                        border = border,
+                        shadowElevation = shadowElevation,
+                    )
+                    .clickable(
+                        interactionSource = interactionSource,
+                        indication = ripple(color = contentColor),
+                        enabled = enabled,
+                        onClick = onClick,
+                    ),
+            propagateMinConstraints = true,
+        ) {
+            content()
+        }
+    }
+}
+
+@Composable
+@NonRestartableComposable
+fun Surface(
+    selected: Boolean,
+    onClick: () -> Unit,
+    modifier: Modifier = Modifier,
+    enabled: Boolean = true,
+    shape: Shape = RectangleShape,
+    color: Color = OrbisTheme.colors.background,
+    contentColor: Color = contentColorFor(color),
+    shadowElevation: Dp = 0.dp,
+    border: BorderStroke? = null,
+    interactionSource: MutableInteractionSource = remember { MutableInteractionSource() },
+    content: @Composable () -> Unit,
+) {
+    CompositionLocalProvider(
+        LocalContentColor provides contentColor,
+    ) {
+        Box(
+            modifier =
+                modifier
+                    .surface(
+                        shape = shape,
+                        backgroundColor = color,
+                        border = border,
+                        shadowElevation = shadowElevation,
+                    )
+                    .selectable(
+                        selected = selected,
+                        interactionSource = interactionSource,
+                        indication = ripple(),
+                        enabled = enabled,
+                        onClick = onClick,
+                    ),
+            propagateMinConstraints = true,
+        ) {
+            content()
+        }
+    }
+}
+
+@Composable
+@NonRestartableComposable
+fun Surface(
+    checked: Boolean,
+    onCheckedChange: (Boolean) -> Unit,
+    modifier: Modifier = Modifier,
+    enabled: Boolean = true,
+    shape: Shape = RectangleShape,
+    color: Color = OrbisTheme.colors.background,
+    contentColor: Color = contentColorFor(color),
+    shadowElevation: Dp = 0.dp,
+    border: BorderStroke? = null,
+    interactionSource: MutableInteractionSource = remember { MutableInteractionSource() },
+    content: @Composable () -> Unit,
+) {
+    CompositionLocalProvider(
+        LocalContentColor provides contentColor,
+    ) {
+        Box(
+            modifier =
+                modifier
+                    .surface(
+                        shape = shape,
+                        backgroundColor = color,
+                        border = border,
+                        shadowElevation = shadowElevation,
+                    )
+                    .toggleable(
+                        value = checked,
+                        interactionSource = interactionSource,
+                        indication = ripple(),
+                        enabled = enabled,
+                        onValueChange = onCheckedChange,
+                    ),
+            propagateMinConstraints = true,
+        ) {
+            content()
+        }
+    }
+}
+
+@Composable
+private fun Modifier.surface(
+    shape: Shape,
+    backgroundColor: Color,
+    border: BorderStroke?,
+    shadowElevation: Dp,
+) = this
+    .shadow(
+        ambientColor = OrbisTheme.colors.elevation,
+        spotColor = OrbisTheme.colors.elevation,
+        elevation = shadowElevation,
+        shape = shape,
+        clip = false,
+    )
+    .then(if (border != null) Modifier.border(border, shape) else Modifier)
+    .background(color = backgroundColor, shape = shape)
+    .clip(shape)

core/ui/src/main/java/io/visus/orbis/core/ui/foundation/Elevation.kt

@@ -0,0 +1,74 @@
+package io.visus.orbis.core.ui.foundation
+
+import androidx.compose.animation.core.Animatable
+import androidx.compose.animation.core.AnimationSpec
+import androidx.compose.animation.core.CubicBezierEasing
+import androidx.compose.animation.core.Easing
+import androidx.compose.animation.core.FastOutSlowInEasing
+import androidx.compose.animation.core.TweenSpec
+import androidx.compose.foundation.interaction.DragInteraction
+import androidx.compose.foundation.interaction.FocusInteraction
+import androidx.compose.foundation.interaction.HoverInteraction
+import androidx.compose.foundation.interaction.Interaction
+import androidx.compose.foundation.interaction.PressInteraction
+import androidx.compose.ui.unit.Dp
+
+internal suspend fun Animatable<Dp, *>.animateElevation(
+    target: Dp,
+    from: Interaction? = null,
+    to: Interaction? = null,
+) {
+    val spec =
+        when {
+            // Moving to a new state
+            to != null -> ElevationDefaults.incomingAnimationSpecForInteraction(to)
+            // Moving to default, from a previous state
+            from != null -> ElevationDefaults.outgoingAnimationSpecForInteraction(from)
+            // Loading the initial state, or moving back to the baseline state from a disabled /
+            // unknown state, so just snap to the final value.
+            else -> null
+        }
+    if (spec != null) animateTo(target, spec) else snapTo(target)
+}
+
+private object ElevationDefaults {
+    fun incomingAnimationSpecForInteraction(interaction: Interaction): AnimationSpec<Dp>? {
+        return when (interaction) {
+            is PressInteraction.Press -> DefaultIncomingSpec
+            is DragInteraction.Start -> DefaultIncomingSpec
+            is HoverInteraction.Enter -> DefaultIncomingSpec
+            is FocusInteraction.Focus -> DefaultIncomingSpec
+            else -> null
+        }
+    }
+
+    fun outgoingAnimationSpecForInteraction(interaction: Interaction): AnimationSpec<Dp>? {
+        return when (interaction) {
+            is PressInteraction.Press -> DefaultOutgoingSpec
+            is DragInteraction.Start -> DefaultOutgoingSpec
+            is HoverInteraction.Enter -> HoveredOutgoingSpec
+            is FocusInteraction.Focus -> DefaultOutgoingSpec
+            else -> null
+        }
+    }
+}
+
+private val OutgoingSpecEasing: Easing = CubicBezierEasing(0.40f, 0.00f, 0.60f, 1.00f)
+
+private val DefaultIncomingSpec =
+    TweenSpec<Dp>(
+        durationMillis = 120,
+        easing = FastOutSlowInEasing,
+    )
+
+private val DefaultOutgoingSpec =
+    TweenSpec<Dp>(
+        durationMillis = 150,
+        easing = OutgoingSpecEasing,
+    )
+
+private val HoveredOutgoingSpec =
+    TweenSpec<Dp>(
+        durationMillis = 120,
+        easing = OutgoingSpecEasing,
+    )

core/ui/src/main/java/io/visus/orbis/core/ui/foundation/Ripple.kt

@@ -0,0 +1,216 @@
+package io.visus.orbis.core.ui.foundation
+
+import androidx.compose.foundation.IndicationNodeFactory
+import androidx.compose.foundation.interaction.InteractionSource
+import androidx.compose.material.ripple.RippleAlpha
+import androidx.compose.material.ripple.createRippleModifierNode
+import androidx.compose.runtime.Immutable
+import androidx.compose.runtime.ProvidableCompositionLocal
+import androidx.compose.runtime.Stable
+import androidx.compose.runtime.compositionLocalOf
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.ColorProducer
+import androidx.compose.ui.graphics.isSpecified
+import androidx.compose.ui.node.CompositionLocalConsumerModifierNode
+import androidx.compose.ui.node.DelegatableNode
+import androidx.compose.ui.node.DelegatingNode
+import androidx.compose.ui.node.ObserverModifierNode
+import androidx.compose.ui.node.currentValueOf
+import androidx.compose.ui.node.observeReads
+import androidx.compose.ui.unit.Dp
+import io.visus.orbis.core.ui.LocalContentColor
+
+@Stable
+fun ripple(
+    bounded: Boolean = true,
+    radius: Dp = Dp.Unspecified,
+    color: Color = Color.Unspecified,
+): IndicationNodeFactory {
+    return if (radius == Dp.Unspecified && color == Color.Unspecified) {
+        if (bounded) return DefaultBoundedRipple else DefaultUnboundedRipple
+    } else {
+        RippleNodeFactory(bounded, radius, color)
+    }
+}
+
+@Stable
+fun ripple(
+    color: ColorProducer,
+    bounded: Boolean = true,
+    radius: Dp = Dp.Unspecified,
+): IndicationNodeFactory {
+    return RippleNodeFactory(bounded, radius, color)
+}
+
+/** Default values used by [ripple]. */
+object RippleDefaults {
+    /**
+     * Represents the default [RippleAlpha] that will be used for a ripple to indicate different
+     * states.
+     */
+    val RippleAlpha: RippleAlpha =
+        RippleAlpha(
+            pressedAlpha = StateTokens.PressedStateLayerOpacity,
+            focusedAlpha = StateTokens.FocusStateLayerOpacity,
+            draggedAlpha = StateTokens.DraggedStateLayerOpacity,
+            hoveredAlpha = StateTokens.HoverStateLayerOpacity,
+        )
+}
+
+val LocalRippleConfiguration: ProvidableCompositionLocal<RippleConfiguration?> =
+    compositionLocalOf {
+        RippleConfiguration()
+    }
+
+@Immutable
+class RippleConfiguration(
+    val color: Color = Color.Unspecified,
+    val rippleAlpha: RippleAlpha? = null,
+) {
+    override fun equals(other: Any?): Boolean {
+        if (this === other) return true
+        if (other !is RippleConfiguration) return false
+
+        if (color != other.color) return false
+        if (rippleAlpha != other.rippleAlpha) return false
+
+        return true
+    }
+
+    override fun hashCode(): Int {
+        var result = color.hashCode()
+        result = 31 * result + (rippleAlpha?.hashCode() ?: 0)
+        return result
+    }
+
+    override fun toString(): String {
+        return "RippleConfiguration(color=$color, rippleAlpha=$rippleAlpha)"
+    }
+}
+
+@Stable
+private class RippleNodeFactory
+    private constructor(
+        private val bounded: Boolean,
+        private val radius: Dp,
+        private val colorProducer: ColorProducer?,
+        private val color: Color,
+    ) : IndicationNodeFactory {
+        constructor(
+            bounded: Boolean,
+            radius: Dp,
+            colorProducer: ColorProducer,
+        ) : this(bounded, radius, colorProducer, Color.Unspecified)
+
+        constructor(bounded: Boolean, radius: Dp, color: Color) : this(bounded, radius, null, color)
+
+        override fun create(interactionSource: InteractionSource): DelegatableNode {
+            val colorProducer = colorProducer ?: ColorProducer { color }
+            return DelegatingThemeAwareRippleNode(interactionSource, bounded, radius, colorProducer)
+        }
+
+        override fun equals(other: Any?): Boolean {
+            if (this === other) return true
+            if (other !is RippleNodeFactory) return false
+
+            if (bounded != other.bounded) return false
+            if (radius != other.radius) return false
+            if (colorProducer != other.colorProducer) return false
+            return color == other.color
+        }
+
+        override fun hashCode(): Int {
+            var result = bounded.hashCode()
+            result = 31 * result + radius.hashCode()
+            result = 31 * result + colorProducer.hashCode()
+            result = 31 * result + color.hashCode()
+            return result
+        }
+    }
+
+private class DelegatingThemeAwareRippleNode(
+    private val interactionSource: InteractionSource,
+    private val bounded: Boolean,
+    private val radius: Dp,
+    private val color: ColorProducer,
+) : DelegatingNode(), CompositionLocalConsumerModifierNode, ObserverModifierNode {
+    private var rippleNode: DelegatableNode? = null
+
+    override fun onAttach() {
+        updateConfiguration()
+    }
+
+    override fun onObservedReadsChanged() {
+        updateConfiguration()
+    }
+
+    /**
+     * Handles [LocalRippleConfiguration] changing between null / non-null. Changes to
+     * [RippleConfiguration.color] and [RippleConfiguration.rippleAlpha] are handled as part of the
+     * ripple definition.
+     */
+    private fun updateConfiguration() {
+        observeReads {
+            val configuration = currentValueOf(LocalRippleConfiguration)
+            if (configuration == null) {
+                removeRipple()
+            } else {
+                if (rippleNode == null) attachNewRipple()
+            }
+        }
+    }
+
+    private fun attachNewRipple() {
+        val calculateColor =
+            ColorProducer {
+                val userDefinedColor = color()
+                if (userDefinedColor.isSpecified) {
+                    userDefinedColor
+                } else {
+                    // If this is null, the ripple will be removed, so this should always be non-null in
+                    // normal use
+                    val rippleConfiguration = currentValueOf(LocalRippleConfiguration)
+                    if (rippleConfiguration?.color?.isSpecified == true) {
+                        rippleConfiguration.color
+                    } else {
+                        currentValueOf(LocalContentColor)
+                    }
+                }
+            }
+
+        val calculateRippleAlpha = {
+            // If this is null, the ripple will be removed, so this should always be non-null in
+            // normal use
+            val rippleConfiguration = currentValueOf(LocalRippleConfiguration)
+            rippleConfiguration?.rippleAlpha ?: RippleDefaults.RippleAlpha
+        }
+
+        rippleNode =
+            delegate(
+                createRippleModifierNode(
+                    interactionSource,
+                    bounded,
+                    radius,
+                    calculateColor,
+                    calculateRippleAlpha,
+                ),
+            )
+    }
+
+    private fun removeRipple() {
+        rippleNode?.let { undelegate(it) }
+        rippleNode = null
+    }
+}
+
+private object StateTokens {
+    const val DraggedStateLayerOpacity = 0.16f
+    const val FocusStateLayerOpacity = 0.1f
+    const val HoverStateLayerOpacity = 0.08f
+    const val PressedStateLayerOpacity = 0.1f
+}
+
+private val DefaultBoundedRipple =
+    RippleNodeFactory(bounded = true, radius = Dp.Unspecified, color = Color.Unspecified)
+private val DefaultUnboundedRipple =
+    RippleNodeFactory(bounded = false, radius = Dp.Unspecified, color = Color.Unspecified)

core/ui/src/main/java/io/visus/orbis/core/ui/foundation/SystemBarsDefaultInsets.kt

@@ -0,0 +1,10 @@
+
+package io.visus.orbis.core.ui.foundation
+
+import androidx.compose.foundation.layout.WindowInsets
+import androidx.compose.foundation.layout.systemBars
+import androidx.compose.runtime.Composable
+
+val WindowInsets.Companion.systemBarsForVisualComponents: WindowInsets
+    @Composable
+    get() = systemBars

core/ui/src/test/java/io/visus/orbis/core/ui/ExampleUnitTest.kt

@@ -0,0 +1,17 @@
+package io.visus.orbis.core.ui
+
+import org.junit.Test
+
+import org.junit.Assert.*
+
+/**
+ * Example local unit test, which will execute on the development machine (host).
+ *
+ * See [testing documentation](http://d.android.com/tools/testing).
+ */
+class ExampleUnitTest {
+    @Test
+    fun addition_isCorrect() {
+        assertEquals(4, 2 + 2)
+    }
+}