Rewrite FeedColors with some tests

appcompose/build.gradle

@@ -72,6 +72,7 @@ dependencies {
     implementation composeBom
     androidTestImplementation composeBom
 
+    implementation 'androidx.palette:palette-ktx:1.0.0'
     implementation 'androidx.activity:activity-compose:1.7.2'
     implementation 'androidx.compose.material3:material3'
 

appcompose/src/androidTest/java/com/readrops/app/compose/FeedColorsTest.kt

@@ -0,0 +1,58 @@
+package com.readrops.app.compose
+
+import android.content.Context
+import androidx.test.core.app.ApplicationProvider
+import com.readrops.api.apiModule
+import com.readrops.api.utils.ApiUtils
+import com.readrops.app.compose.utils.FeedColors
+import kotlinx.coroutines.runBlocking
+import okhttp3.mockwebserver.MockResponse
+import okhttp3.mockwebserver.MockWebServer
+import okio.Buffer
+import org.junit.After
+import org.junit.Before
+import org.junit.Test
+import org.koin.dsl.module
+import org.koin.test.KoinTestRule
+import java.net.HttpURLConnection
+import kotlin.test.assertTrue
+
+class FeedColorsTest {
+
+    private val mockServer = MockWebServer()
+
+    @Before
+    fun before() {
+        val context = ApplicationProvider.getApplicationContext<Context>()
+
+        KoinTestRule.create {
+            modules(apiModule, module {
+                single { context }
+            })
+        }
+
+        mockServer.start()
+    }
+
+    @After
+    fun after() {
+        mockServer.shutdown()
+    }
+
+    @Test
+    fun getFeedColorTest() = runBlocking {
+        val stream = TestUtils.loadResource("favicon.ico")
+
+        mockServer.enqueue(
+            MockResponse()
+                .setResponseCode(HttpURLConnection.HTTP_OK)
+                .addHeader(ApiUtils.CONTENT_TYPE_HEADER, "image/jpeg")
+                .setBody(Buffer().readFrom(stream))
+        )
+
+        val url = mockServer.url("/rss").toString()
+        val color = FeedColors.getFeedColor(url)
+
+        assertTrue { color != 0 }
+    }
+}

appcompose/src/main/java/com/readrops/app/compose/ReadropsApp.kt

@@ -1,14 +1,18 @@
 package com.readrops.app.compose
 
 import android.app.Application
+import coil.ImageLoader
+import coil.ImageLoaderFactory
 import com.readrops.api.apiModule
 import com.readrops.db.dbModule
 import org.koin.android.ext.koin.androidContext
 import org.koin.android.ext.koin.androidLogger
+import org.koin.core.component.KoinComponent
+import org.koin.core.component.get
 import org.koin.core.context.startKoin
 import org.koin.core.logger.Level
 
-open class ReadropsApp : Application() {
+open class ReadropsApp : Application(), KoinComponent, ImageLoaderFactory {
 
     override fun onCreate() {
         super.onCreate()
@@ -20,4 +24,11 @@ open class ReadropsApp : Application() {
             modules(apiModule, dbModule, composeAppModule)
         }
     }
+
+    override fun newImageLoader(): ImageLoader {
+        return ImageLoader.Builder(this)
+            .okHttpClient { get() }
+            .crossfade(true)
+            .build()
+    }
 }

appcompose/src/main/java/com/readrops/app/compose/utils/FeedColors.kt

@@ -0,0 +1,48 @@
+package com.readrops.app.compose.utils
+
+import android.content.Context
+import android.graphics.drawable.BitmapDrawable
+import androidx.annotation.ColorInt
+import androidx.palette.graphics.Palette
+import coil.imageLoader
+import coil.request.ImageRequest
+import org.koin.core.component.KoinComponent
+import org.koin.core.component.get
+
+object FeedColors : KoinComponent {
+
+    suspend fun getFeedColor(feedUrl: String): Int {
+        val context = get<Context>() // TODO maybe call imageLoader directly ? may require some DI changes
+
+        val result = context.imageLoader
+            .execute(
+                ImageRequest.Builder(context)
+                    .data(feedUrl)
+                    .allowHardware(false)
+                    .build()
+            ).drawable as BitmapDrawable
+
+        val palette = Palette.from(result.bitmap).generate()
+
+        val dominantSwatch = palette.dominantSwatch
+        return if (dominantSwatch != null && !isColorTooBright(dominantSwatch.rgb)
+            && !isColorTooDark(dominantSwatch.rgb)) {
+            dominantSwatch.rgb
+        } else 0
+    }
+
+    private fun isColorTooBright(@ColorInt color: Int): Boolean {
+        return getColorLuma(color) > 210
+    }
+
+    private fun isColorTooDark(@ColorInt color: Int): Boolean {
+        return getColorLuma(color) < 40
+    }
+
+    private fun getColorLuma(@ColorInt color: Int): Double {
+        val r = color shr 16 and 0xff
+        val g = color shr 8 and 0xff
+        val b = color shr 0 and 0xff
+        return 0.2126 * r + 0.7152 * g + 0.0722 * b
+    }
+}