Media: use blurhash library

features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/timeline/components/blurhash/BlurHashAsyncImage.kt

@@ -0,0 +1,81 @@
+/*
+ * Copyright (c) 2023 New Vector Ltd
+ *
+ * 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.
+ */
+
+package io.element.android.features.messages.impl.timeline.components.blurhash
+
+import android.graphics.Bitmap
+import androidx.compose.foundation.Image
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.DisposableEffect
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.asImageBitmap
+import androidx.compose.ui.layout.ContentScale
+import coil.compose.SubcomposeAsyncImage
+import com.vanniktech.blurhash.BlurHash
+
+@Composable
+fun BlurHashAsyncImage(
+    model: Any?,
+    blurHash: String?,
+    modifier: Modifier = Modifier,
+    contentScale: ContentScale = ContentScale.Fit,
+    contentDescription: String? = null,
+) {
+    SubcomposeAsyncImage(
+        model = model,
+        modifier = modifier,
+        contentScale = contentScale,
+        contentDescription = contentDescription,
+        loading = {
+            BlurHashImage(
+                blurHash = blurHash,
+                contentScale = contentScale,
+                contentDescription = "Loading placeholder"
+            )
+        },
+    )
+}
+
+@Composable
+fun BlurHashImage(
+    blurHash: String?,
+    modifier: Modifier = Modifier,
+    contentDescription: String? = null,
+    contentScale: ContentScale = ContentScale.Fit,
+) {
+    if (blurHash == null) return
+    val bitmapState = remember {
+        mutableStateOf<Bitmap?>(null)
+    }
+    DisposableEffect(blurHash) {
+        // Build a small blurhash image so that it's fast
+        bitmapState.value = BlurHash.decode(blurHash, 10, 10)
+        onDispose {
+            bitmapState.value?.recycle()
+        }
+    }
+    bitmapState.value?.let { bitmap ->
+        Image(
+            modifier = modifier.fillMaxSize(),
+            bitmap = bitmap.asImageBitmap(),
+            contentScale = contentScale,
+            contentDescription = contentDescription
+        )
+    }
+}