Add better focus color for accessibility

app/src/main/kotlin/ee/ria/DigiDoc/ui/theme/FocusIndication.kt

@@ -0,0 +1,74 @@
+/*
+ * Copyright 2017 - 2026 Riigi Infosüsteemi Amet
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+@file:Suppress("PackageName")
+
+package ee.ria.DigiDoc.ui.theme
+
+import androidx.compose.foundation.IndicationNodeFactory
+import androidx.compose.foundation.interaction.FocusInteraction
+import androidx.compose.foundation.interaction.InteractionSource
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.geometry.CornerRadius
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.drawscope.ContentDrawScope
+import androidx.compose.ui.node.DelegatableNode
+import androidx.compose.ui.node.DrawModifierNode
+import androidx.compose.ui.node.invalidateDraw
+import ee.ria.DigiDoc.ui.theme.Dimensions.MSCornerRadius
+import kotlinx.coroutines.launch
+
+data class FocusIndication(
+    private val color: Color,
+    private val alpha: Float = 1.0f,
+) : IndicationNodeFactory {
+    override fun create(interactionSource: InteractionSource): DelegatableNode =
+        FocusIndicationNode(interactionSource, color.copy(alpha = alpha))
+}
+
+private class FocusIndicationNode(
+    private val interactionSource: InteractionSource,
+    private val color: Color,
+) : Modifier.Node(),
+    DrawModifierNode {
+    private var isFocused = false
+
+    override fun onAttach() {
+        coroutineScope.launch {
+            interactionSource.interactions.collect { interaction ->
+                when (interaction) {
+                    is FocusInteraction.Focus -> isFocused = true
+                    is FocusInteraction.Unfocus -> isFocused = false
+                }
+                invalidateDraw()
+            }
+        }
+    }
+
+    override fun ContentDrawScope.draw() {
+        if (isFocused) {
+            drawRoundRect(
+                color = color,
+                size = size,
+                cornerRadius = CornerRadius(MSCornerRadius.toPx()),
+            )
+        }
+        drawContent()
+    }
+}

app/src/main/kotlin/ee/ria/DigiDoc/ui/theme/Theme.kt

@@ -22,16 +22,24 @@
 package ee.ria.DigiDoc.ui.theme
 
 import android.app.Activity
+import androidx.compose.foundation.LocalIndication
 import androidx.compose.foundation.isSystemInDarkTheme
 import androidx.compose.foundation.layout.ExperimentalLayoutApi
 import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material.ripple.RippleAlpha
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.LocalRippleConfiguration
 import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.RippleConfiguration
 import androidx.compose.material3.darkColorScheme
 import androidx.compose.material3.dynamicDarkColorScheme
 import androidx.compose.material3.dynamicLightColorScheme
 import androidx.compose.material3.lightColorScheme
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.CompositionLocalProvider
 import androidx.compose.runtime.SideEffect
+import androidx.compose.runtime.remember
+import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.toArgb
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.platform.LocalView
@@ -120,15 +128,30 @@ fun RIADigiDocTheme(
     dynamicColor: Boolean = false,
     content: @Composable () -> Unit,
 ) {
+    val accessibilityFocusColor =
+        if (isSystemInDarkTheme()) {
+            LightColorScheme.primary
+        } else {
+            DarkColorScheme.primary
+        }
+
+    val accessibilityFocusAlpha =
+        RippleAlpha(
+            pressedAlpha = 0.1f,
+            focusedAlpha = 0.4f,
+            draggedAlpha = 0.16f,
+            hoveredAlpha = 0.08f,
+        )
+
     val useDarkTheme = darkTheme ?: isSystemInDarkTheme()
     val colorScheme =
         when {
             dynamicColor -> {
                 val context = LocalContext.current
-                if (useDarkTheme == true) dynamicDarkColorScheme(context) else dynamicLightColorScheme(context)
+                if (useDarkTheme) dynamicDarkColorScheme(context) else dynamicLightColorScheme(context)
             }
 
-            useDarkTheme == true -> DarkColorScheme
+            useDarkTheme -> DarkColorScheme
             else -> LightColorScheme
         }
     val view = LocalView.current
@@ -147,6 +170,36 @@ fun RIADigiDocTheme(
     MaterialTheme(
         colorScheme = colorScheme,
         typography = getTypography(),
+        content = {
+            AccessibilityFocusProvider(
+                focusColor = accessibilityFocusColor,
+                alpha = accessibilityFocusAlpha,
+                content = content,
+            )
+        },
+    )
+}
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+private fun AccessibilityFocusProvider(
+    focusColor: Color,
+    alpha: RippleAlpha,
+    content: @Composable () -> Unit,
+) {
+    CompositionLocalProvider(
+        LocalIndication provides
+            remember(focusColor) {
+                FocusIndication(
+                    color = focusColor,
+                    alpha = alpha.focusedAlpha,
+                )
+            },
+        LocalRippleConfiguration provides
+            RippleConfiguration(
+                color = focusColor,
+                rippleAlpha = alpha,
+            ),
         content = content,
     )
 }