Updated on 2026-08-14

core/ui/src/main/java/com/tangem/core/ui/utils/ImageBackgroundContrastChecker.kt

@@ -0,0 +1,44 @@
+package com.tangem.core.ui.utils
+
+import android.graphics.Bitmap
+import android.graphics.drawable.Drawable
+import androidx.compose.ui.graphics.Color
+import androidx.core.graphics.ColorUtils
+import androidx.core.graphics.drawable.toBitmap
+import androidx.palette.graphics.Palette
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+
+class ImageBackgroundContrastChecker(
+    private val image: Bitmap,
+    private val backgroundColor: Int,
+) {
+    constructor(drawable: Drawable, backgroundColor: Int) : this(
+        image = drawable.toBitmap(),
+        backgroundColor = backgroundColor,
+    )
+
+    suspend fun getContrastColorIfNeeded(isDarkTheme: Boolean): Color {
+        return if (isLowContrast()) {
+            if (isDarkTheme) Color.White else Color.Black
+        } else {
+            Color.Transparent
+        }
+    }
+
+    suspend fun isLowContrast(): Boolean {
+        val palette = generatePaletteAsync(bitmap = image)
+        val color = palette.getDominantColor(backgroundColor)
+        val contrast = ColorUtils.calculateContrast(color, backgroundColor)
+        return contrast <= LOW_CONTRAST_RATIO
+    }
+
+    private suspend fun generatePaletteAsync(bitmap: Bitmap): Palette = withContext(Dispatchers.Default) {
+        return@withContext Palette.Builder(bitmap).generate()
+    }
+
+    private companion object {
+        // https://www.w3.org/TR/2008/REC-WCAG20-20081211/#contrast-ratiodef
+        private const val LOW_CONTRAST_RATIO = 1.5f
+    }
+}