Improve splash screen adaptive icon support

app/ui/src/main/java/de/mm20/launcher2/ui/component/FakeSplashScreen.kt

@@ -3,6 +3,8 @@ package de.mm20.launcher2.ui.component
 import android.content.Context
 import android.content.pm.PackageManager
 import android.content.res.Resources
+import android.graphics.drawable.AdaptiveIconDrawable
+import android.graphics.drawable.ColorDrawable
 import android.graphics.drawable.Drawable
 import android.util.TypedValue
 import androidx.compose.animation.animateColorAsState
@@ -33,6 +35,9 @@ import de.mm20.launcher2.search.SavableSearchable
 import de.mm20.launcher2.search.data.LauncherApp
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
+import kotlin.math.abs
+import kotlin.math.pow
+import kotlin.math.sqrt
 
 @Composable
 fun FakeSplashScreen(
@@ -92,7 +97,12 @@ fun rememberSplashScreenData(searchable: SavableSearchable?): SplashScreenData {
     val context = LocalContext.current
     val defaultBackgroundColor = MaterialTheme.colorScheme.background
     val state = remember {
-        mutableStateOf(SplashScreenData(backgroundColor = defaultBackgroundColor, iconSize = 288.dp))
+        mutableStateOf(
+            SplashScreenData(
+                backgroundColor = defaultBackgroundColor,
+                iconSize = 288.dp
+            )
+        )
     }
 
     LaunchedEffect(searchable) {
@@ -184,7 +194,7 @@ fun rememberSplashScreenData(searchable: SavableSearchable?): SplashScreenData {
 
                 var iconSize = 288.dp
 
-                var iconBackground = if (typedValue.isColor && typedValue.data != 0) {
+                val iconBackground = if (typedValue.isColor && typedValue.data != 0) {
                     iconSize = 240.dp
                     Color(typedValue.data)
                 } else {
@@ -193,7 +203,19 @@ fun rememberSplashScreenData(searchable: SavableSearchable?): SplashScreenData {
 
                 if (icon == null) {
                     icon = activityInfo.loadIcon(context.packageManager)
-                    iconSize = 160.dp
+                    iconSize = 240.dp
+                }
+
+                if (icon is AdaptiveIconDrawable) {
+                    val bg = icon.background
+                    if (bg is ColorDrawable && backgroundColor != null && iconBackground == null &&
+                        isRgbSimilarInHsv(bg.color, backgroundColor)
+                    ) {
+                        icon = icon.foreground
+                        iconSize = 288.dp
+                    } else {
+                        iconSize = 160.dp
+                    }
                 }
 
                 state.value = SplashScreenData(
@@ -211,4 +233,51 @@ fun rememberSplashScreenData(searchable: SavableSearchable?): SplashScreenData {
 }
 
 internal val TypedValue.isColor
-    get() = type in TypedValue.TYPE_FIRST_COLOR_INT..TypedValue.TYPE_LAST_COLOR_INT
+    get() = type in TypedValue.TYPE_FIRST_COLOR_INT..TypedValue.TYPE_LAST_COLOR_INT
+
+
+/*
+ * From: https://android.googlesource.com/platform/frameworks/base/+/f05f9b960832b6272b6740721c0a4bbd1ce632c1/libs/WindowManager/Shell/src/com/android/wm/shell/startingsurface/SplashscreenContentDrawer.java#550
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+internal fun isRgbSimilarInHsv(a: Int, b: Int): Boolean {
+    if (a == b) {
+        return true
+    }
+    val lumA: Float = android.graphics.Color.luminance(a)
+    val lumB: Float = android.graphics.Color.luminance(b)
+    val contrastRatio =
+        if (lumA > lumB) (lumA + 0.05f) / (lumB + 0.05f) else (lumB + 0.05f) / (lumA + 0.05f)
+    if (contrastRatio < 2) {
+        return true
+    }
+    val aHsv = FloatArray(3)
+    val bHsv = FloatArray(3)
+    android.graphics.Color.colorToHSV(a, aHsv)
+    android.graphics.Color.colorToHSV(b, bHsv)
+    // Minimum degree of the hue between two colors, the result range is 0-180.
+    var minAngle = abs(aHsv[0] - bHsv[0]).toInt()
+    minAngle = (minAngle + 180) % 360 - 180
+
+    // Calculate the difference between two colors based on the HSV dimensions.
+    val normalizeH = minAngle / 180f
+    val squareH = normalizeH.toDouble().pow(2.0)
+    val squareS = (aHsv[1] - bHsv[1]).toDouble().pow(2.0)
+    val squareV = (aHsv[2] - bHsv[2]).toDouble().pow(2.0)
+    val square = squareH + squareS + squareV
+    val mean = square / 3
+    val root = sqrt(mean)
+    return root < 0.1
+}