Add gif support to network requests

picasso-sample/src/main/java/com/example/picasso/Data.kt

@@ -18,6 +18,7 @@ package com.example.picasso
 internal object Data {
   private const val BASE = "https://i.imgur.com/"
   private const val EXT = ".jpg"
+  private const val GIF_EXT = ".gif"
 
   @JvmField
   val URLS = arrayOf(
@@ -32,6 +33,6 @@ internal object Data {
     BASE + "Q54zMKT" + EXT, BASE + "9t6hLbm" + EXT, BASE + "F8n3Ic6" + EXT,
     BASE + "P5ZRSvT" + EXT, BASE + "jbemFzr" + EXT, BASE + "8B7haIK" + EXT,
     BASE + "aSeTYQr" + EXT, BASE + "OKvWoTh" + EXT, BASE + "zD3gT4Z" + EXT,
-    BASE + "z77CaIt" + EXT
+    BASE + "z77CaIt" + EXT, BASE + "B3wgCmW" + GIF_EXT
   )
 }

picasso/src/main/java/com/squareup/picasso3/BitmapUtils.kt

@@ -21,10 +21,14 @@ import android.content.res.Resources
 import android.graphics.Bitmap
 import android.graphics.BitmapFactory
 import android.graphics.ImageDecoder
+import android.graphics.Movie
+import android.graphics.drawable.BitmapDrawable
+import android.graphics.drawable.Drawable
 import android.os.Build.VERSION
 import android.util.TypedValue
 import androidx.annotation.DrawableRes
 import androidx.annotation.RequiresApi
+import com.squareup.picasso3.Utils.isGifFile
 import okio.Buffer
 import okio.BufferedSource
 import okio.ForwardingSource
@@ -186,6 +190,45 @@ internal object BitmapUtils {
     }
   }
 
+  /**
+   * Decode a byte stream into a Drawable. This method will take into account additional information
+   * about the supplied request in order to do the decoding efficiently.
+   */
+  fun decodeDrawableStream(source: Source, request: Request): Drawable {
+    val exceptionCatchingSource = ExceptionCatchingSource(source)
+    val bufferedSource = exceptionCatchingSource.buffer()
+    val drawable = if (VERSION.SDK_INT >= 28) {
+      val imageSource = ImageDecoder.createSource(ByteBuffer.wrap(bufferedSource.readByteArray()))
+      decodeDrawableSourceP(imageSource, request)
+    } else {
+      if (isGifFile(bufferedSource)) {
+        val movie = Movie.decodeStream(bufferedSource.inputStream())
+        MovieDrawable(movie)
+      } else {
+        BitmapDrawable(decodeStreamPreP(request, bufferedSource))
+      }
+    }
+    exceptionCatchingSource.throwIfCaught()
+    return drawable
+  }
+
+  @RequiresApi(28)
+  fun decodeDrawableSourceP(imageSource: ImageDecoder.Source, request: Request): Drawable {
+    return ImageDecoder.decodeDrawable(imageSource) { imageDecoder, imageInfo, source ->
+      if (request.hasSize()) {
+        val size = imageInfo.size
+        val width = size.width
+        val height = size.height
+        val targetWidth = request.targetWidth
+        val targetHeight = request.targetHeight
+        if (shouldResize(request.onlyScaleDown, width, height, targetWidth, targetHeight)) {
+          val ratio = ratio(targetWidth, targetHeight, width, height, request)
+          imageDecoder.setTargetSize(width / ratio, height / ratio)
+        }
+      }
+    }
+  }
+
   private fun ratio(
     requestWidth: Int,
     requestHeight: Int,

picasso/src/main/java/com/squareup/picasso3/MovieDrawable.kt

@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2022 Square, Inc.
+ *
+ * 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 com.squareup.picasso3
+
+import android.graphics.Canvas
+import android.graphics.ColorFilter
+import android.graphics.Movie
+import android.graphics.Paint
+import android.graphics.PixelFormat
+import android.graphics.drawable.Animatable
+import android.graphics.drawable.Drawable
+import android.os.SystemClock
+
+internal class MovieDrawable(private val movie: Movie) : Drawable(), Animatable {
+
+  private var paint = Paint(Paint.ANTI_ALIAS_FLAG)
+  private var start = 0
+
+  override fun draw(canvas: Canvas) {
+    if (start > 0) {
+      movie.setTime(((SystemClock.uptimeMillis() - start).toInt()) % movie.duration())
+      invalidateSelf()
+    }
+
+    movie.draw(canvas, 0f, 0f, paint)
+  }
+
+  override fun setAlpha(alpha: Int) {
+    paint.alpha = alpha
+  }
+
+  override fun setColorFilter(colorFilter: ColorFilter?) {
+    paint.colorFilter = colorFilter
+  }
+
+  override fun getOpacity(): Int {
+    return PixelFormat.OPAQUE
+  }
+
+  override fun getIntrinsicWidth(): Int {
+    return movie.width()
+  }
+
+  override fun getIntrinsicHeight(): Int {
+    return movie.height()
+  }
+
+  override fun start() {
+    start = SystemClock.uptimeMillis().toInt()
+    invalidateSelf()
+  }
+
+  override fun stop() {
+    start = 0
+  }
+
+  override fun isRunning() = start != 0
+}

picasso/src/main/java/com/squareup/picasso3/NetworkRequestHandler.kt

@@ -16,12 +16,14 @@
 package com.squareup.picasso3
 
 import android.net.NetworkInfo
+import com.squareup.picasso3.BitmapUtils.decodeDrawableStream
 import com.squareup.picasso3.BitmapUtils.decodeStream
 import com.squareup.picasso3.NetworkPolicy.Companion.isOfflineOnly
 import com.squareup.picasso3.NetworkPolicy.Companion.shouldReadFromDiskCache
 import com.squareup.picasso3.NetworkPolicy.Companion.shouldWriteToDiskCache
 import com.squareup.picasso3.Picasso.LoadedFrom.DISK
 import com.squareup.picasso3.Picasso.LoadedFrom.NETWORK
+import com.squareup.picasso3.Utils.isGifFile
 import okhttp3.CacheControl
 import okhttp3.Call
 import okhttp3.Response
@@ -67,8 +69,15 @@ internal class NetworkRequestHandler(
             picasso.downloadFinished(body.contentLength())
           }
           try {
-            val bitmap = decodeStream(body!!.source(), request)
-            callback.onSuccess(Result.Bitmap(bitmap, loadedFrom))
+            val bufferedSource = body!!.source()
+            val result = if (isGifFile(bufferedSource)) {
+              val drawable = decodeDrawableStream(bufferedSource, request)
+              Result.Drawable(drawable, loadedFrom)
+            } else {
+              val bitmap = decodeStream(bufferedSource, request)
+              Result.Bitmap(bitmap, loadedFrom)
+            }
+            callback.onSuccess(result)
           } catch (e: IOException) {
             body!!.close()
             callback.onError(e)

picasso/src/main/java/com/squareup/picasso3/Utils.kt

@@ -82,6 +82,8 @@ internal object Utils {
   */
   private val WEBP_FILE_HEADER_RIFF: ByteString = "RIFF".encodeUtf8()
   private val WEBP_FILE_HEADER_WEBP: ByteString = "WEBP".encodeUtf8()
+  private val GIF_FILE_HEADER_87A: ByteString = "GIF87a".encodeUtf8()
+  private val GIF_FILE_HEADER_89A: ByteString = "GIF89a".encodeUtf8()
 
   fun <T> checkNotNull(value: T?, message: String?): T {
     if (value == null) {
@@ -178,6 +180,11 @@ internal object Utils {
       source.rangeEquals(8, WEBP_FILE_HEADER_WEBP)
   }
 
+  fun isGifFile(source: BufferedSource): Boolean {
+    return source.rangeEquals(0, GIF_FILE_HEADER_87A) ||
+      source.rangeEquals(0, GIF_FILE_HEADER_89A)
+  }
+
   fun getResourceId(resources: Resources, data: Request): Int {
     if (data.resourceId != 0 || data.uri == null) {
       return data.resourceId

picasso/src/test/java/com/squareup/picasso3/UtilsTest.kt

@@ -21,6 +21,7 @@ import com.squareup.picasso3.TestUtils.RESOURCE_ID_URI
 import com.squareup.picasso3.TestUtils.RESOURCE_TYPE_URI
 import com.squareup.picasso3.TestUtils.URI_1
 import com.squareup.picasso3.TestUtils.mockPackageResourceContext
+import com.squareup.picasso3.Utils.isGifFile
 import com.squareup.picasso3.Utils.isWebPFile
 import okio.Buffer
 import org.junit.Test
@@ -61,6 +62,11 @@ class UtilsTest {
     assertThat(isWebPFile(Buffer().writeUtf8("RIFFxxWEBP"))).isFalse()
   }
 
+  @Test fun detectGifFile() {
+    assertThat(isGifFile(Buffer().writeUtf8("GIF87a"))).isTrue()
+    assertThat(isGifFile(Buffer().writeUtf8("GIF89a"))).isTrue()
+  }
+
   @Test fun ensureBuilderIsCleared() {
     Request.Builder(RESOURCE_ID_URI).build()
     assertThat(Utils.MAIN_THREAD_KEY_BUILDER.length).isEqualTo(0)