Add ImageLoader option for creating memory cache key using toString()…

… by default.

coil-core/src/androidMain/kotlin/coil3/RealImageLoader.android.kt

@@ -1,5 +1,7 @@
 package coil3
 
+import android.graphics.Bitmap
+import android.graphics.drawable.Drawable
 import android.os.Build.VERSION.SDK_INT
 import coil3.decode.BitmapFactoryDecoder
 import coil3.decode.ExifOrientationStrategy.Companion.RESPECT_ALL
@@ -11,6 +13,7 @@ import coil3.fetch.ContentUriFetcher
 import coil3.fetch.DrawableFetcher
 import coil3.fetch.ResourceUriFetcher
 import coil3.key.AndroidResourceUriKeyer
+import coil3.key.CacheDisabledKeyer
 import coil3.map.AndroidUriMapper
 import coil3.map.ResourceIntMapper
 import coil3.request.Disposable
@@ -79,6 +82,10 @@ internal actual fun ComponentRegistry.Builder.addAndroidComponents(
 
     // Keyers
     add(AndroidResourceUriKeyer())
+    if (options.defaultKeyerEnabled) {
+        add(CacheDisabledKeyer<Bitmap>())
+        add(CacheDisabledKeyer<Drawable>())
+    }
 
     // Fetchers
     add(AssetUriFetcher.Factory())

coil-core/src/commonMain/kotlin/coil3/RealImageLoader.kt

@@ -6,6 +6,7 @@ import coil3.fetch.DataUriFetcher
 import coil3.fetch.FileUriFetcher
 import coil3.intercept.EngineInterceptor
 import coil3.intercept.RealInterceptorChain
+import coil3.key.CacheEnabledKeyer
 import coil3.key.FileUriKeyer
 import coil3.key.UriKeyer
 import coil3.map.PathMapper
@@ -56,7 +57,7 @@ internal class RealImageLoader(
         .addAndroidComponents(options)
         .addJvmComponents(options)
         .addAppleComponents(options)
-        .addCommonComponents()
+        .addCommonComponents(options)
         .add(EngineInterceptor(this, systemCallbacks, requestService, options.logger))
         .build()
     private val shutdown = atomic(false)
@@ -288,18 +289,24 @@ internal expect fun ComponentRegistry.Builder.addAppleComponents(
     options: RealImageLoader.Options,
 ): ComponentRegistry.Builder
 
-internal fun ComponentRegistry.Builder.addCommonComponents(): ComponentRegistry.Builder {
-    return this
-        // Mappers
-        .add(StringMapper())
-        .add(PathMapper())
-        // Keyers
-        .add(FileUriKeyer())
-        .add(UriKeyer())
-        // Fetchers
-        .add(FileUriFetcher.Factory())
-        .add(ByteArrayFetcher.Factory())
-        .add(DataUriFetcher.Factory())
+internal fun ComponentRegistry.Builder.addCommonComponents(
+    options: RealImageLoader.Options,
+): ComponentRegistry.Builder = apply {
+    // Mappers
+    add(StringMapper())
+    add(PathMapper())
+
+    // Keyers
+    add(FileUriKeyer())
+    add(UriKeyer())
+    if (options.defaultKeyerEnabled) {
+        add(CacheEnabledKeyer())
+    }
+
+    // Fetchers
+    add(FileUriFetcher.Factory())
+    add(ByteArrayFetcher.Factory())
+    add(DataUriFetcher.Factory())
 }
 
 private const val TAG = "RealImageLoader"

coil-core/src/commonMain/kotlin/coil3/imageLoaders.kt

@@ -1,5 +1,7 @@
 package coil3
 
+import coil3.key.Keyer
+
 /**
  * Create a new [ImageLoader] without configuration.
  */
@@ -30,3 +32,19 @@ internal val RealImageLoader.Options.serviceLoaderEnabled: Boolean
 private val serviceLoaderEnabledKey = Extras.Key(default = true)
 
 // endregion
+
+/**
+ * Enables the default [Keyer]. This means that data types that don't have a registered [Keyer]
+ * will have a memory cache key created for them using [Any.toString].
+ *
+ * If disabled (the default), images will not be cached if they do not have a registered [Keyer]
+ * for the associated data type.
+ */
+fun ImageLoader.Builder.defaultKeyerEnabled(enable: Boolean) = apply {
+    extras[defaultKeyerEnabledKey] = enable
+}
+
+internal val RealImageLoader.Options.defaultKeyerEnabled: Boolean
+    get() = defaults.extras.getOrDefault(defaultKeyerEnabledKey)
+
+private val defaultKeyerEnabledKey = Extras.Key(default = false)

coil-core/src/commonMain/kotlin/coil3/key/AnyKeyer.kt

@@ -0,0 +1,21 @@
+package coil3.key
+
+import coil3.request.Options
+
+@Suppress("UNCHECKED_CAST")
+internal fun <T : Any> CacheEnabledKeyer(): Keyer<T> = CacheEnabledKeyer as Keyer<T>
+
+private object CacheEnabledKeyer : Keyer<Any> {
+    override fun key(data: Any, options: Options): String {
+        return data.toString()
+    }
+}
+
+@Suppress("UNCHECKED_CAST")
+internal fun <T : Any> CacheDisabledKeyer(): Keyer<T> = CacheDisabledKeyer as Keyer<T>
+
+private object CacheDisabledKeyer : Keyer<Any> {
+    override fun key(data: Any, options: Options): String? {
+        return null
+    }
+}