Removed gif parsing and changed encoded loop count to be available on…

…ly on SDK 28 or higher

coil-gif/src/main/java/coil3/gif/AnimatedImageDecoder.kt

@@ -16,8 +16,7 @@ import coil3.decode.Decoder
 import coil3.decode.ImageSource
 import coil3.decode.toImageDecoderSourceOrNull
 import coil3.fetch.SourceFetchResult
-import coil3.gif.MovieDrawable.Companion.GIF_LOOP_COUNT
-import coil3.gif.MovieDrawable.Companion.REPEAT_INFINITE
+import coil3.gif.MovieDrawable.Companion.ENCODED_LOOP_COUNT
 import coil3.gif.internal.animatable2CallbackOf
 import coil3.gif.internal.asPostProcessor
 import coil3.gif.internal.maybeWrapImageSourceToRewriteFrameDelay
@@ -57,21 +56,10 @@ class AnimatedImageDecoder(
     override suspend fun decode(): DecodeResult {
         var isSampled = false
 
-        val loopCount = if (options.repeatCount == GIF_LOOP_COUNT) {
-            extractLoopCountFromGif(source.source().peek()) ?: REPEAT_INFINITE
-        } else {
-            options.repeatCount
-        }
-
         val drawable = runInterruptible {
-            maybeWrapImageSourceToRewriteFrameDelay(
-                source,
-                enforceMinimumFrameDelay,
-            ).use { source ->
+            maybeWrapImageSourceToRewriteFrameDelay(source, enforceMinimumFrameDelay).use { source ->
                 val imageSource = source.toImageDecoderSourceOrNull(options, animated = true)
-                    ?: ImageDecoder.createSource(
-                        source.source().use { it.squashToDirectByteBuffer() },
-                    )
+                    ?: ImageDecoder.createSource(source.source().use { it.squashToDirectByteBuffer() })
                 imageSource.decodeDrawable { info, _ ->
                     // Configure the output image's size.
                     val (srcWidth, srcHeight) = info.size
@@ -102,13 +90,14 @@ class AnimatedImageDecoder(
                             setTargetSize(targetWidth, targetHeight)
                         }
                     }
+
                     // Configure any other attributes.
                     configureImageDecoderProperties()
                 }
             }
         }
         return DecodeResult(
-            image = wrapDrawable(drawable, loopCount).asImage(),
+            image = wrapDrawable(drawable).asImage(),
             isSampled = isSampled,
         )
     }
@@ -130,12 +119,14 @@ class AnimatedImageDecoder(
         postProcessor = options.animatedTransformation?.asPostProcessor()
     }
 
-    private suspend fun wrapDrawable(baseDrawable: Drawable, loopCount: Int): Drawable {
+    private suspend fun wrapDrawable(baseDrawable: Drawable): Drawable {
         if (baseDrawable !is AnimatedImageDrawable) {
             return baseDrawable
         }
 
-        baseDrawable.repeatCount = loopCount
+        if (options.repeatCount != ENCODED_LOOP_COUNT) {
+            baseDrawable.repeatCount = options.repeatCount
+        }
 
         // Set the start and end animation callbacks if any one is supplied through the request.
         val onStart = options.animationStartCallback

coil-gif/src/main/java/coil3/gif/GifDecoder.kt

@@ -34,13 +34,6 @@ class GifDecoder(
 ) : Decoder {
 
     override suspend fun decode() = runInterruptible {
-        val loopCount = if (options.repeatCount == MovieDrawable.GIF_LOOP_COUNT) {
-            source.source().peek().let { extractLoopCountFromGif(it) }
-                ?: MovieDrawable.REPEAT_INFINITE
-        } else {
-            options.repeatCount
-        }
-
         val source = maybeWrapImageSourceToRewriteFrameDelay(source, enforceMinimumFrameDelay)
         val movie: Movie? = source.use { Movie.decodeStream(it.source().inputStream()) }
 
@@ -56,8 +49,9 @@ class GifDecoder(
             scale = options.scale,
         )
 
-        drawable.setRepeatCount(loopCount)
+        drawable.setRepeatCount(options.repeatCount)
 
+        // Set the start and end animation callbacks if any one is supplied through the request.
         val onStart = options.animationStartCallback
         val onEnd = options.animationEndCallback
         if (onStart != null || onEnd != null) {

coil-gif/src/main/java/coil3/gif/MovieDrawable.kt

@@ -14,7 +14,9 @@ import android.graphics.PorterDuff
 import android.graphics.Rect
 import android.graphics.drawable.AnimatedImageDrawable
 import android.graphics.drawable.Drawable
+import android.os.Build.VERSION.SDK_INT
 import android.os.SystemClock
+import androidx.annotation.RequiresApi
 import androidx.core.graphics.createBitmap
 import androidx.core.graphics.withSave
 import androidx.vectordrawable.graphics.drawable.Animatable2Compat
@@ -151,7 +153,11 @@ class MovieDrawable @JvmOverloads constructor(
      * Default: [REPEAT_INFINITE]
      */
     fun setRepeatCount(repeatCount: Int) {
-        require(repeatCount >= GIF_LOOP_COUNT) { "Invalid repeatCount: $repeatCount" }
+        if (SDK_INT >= 28) {
+            require(repeatCount >= ENCODED_LOOP_COUNT) { "Invalid repeatCount: $repeatCount" }
+        } else {
+            require(repeatCount >= REPEAT_INFINITE) { "Invalid repeatCount: $repeatCount" }
+        }
         this.repeatCount = repeatCount
     }
 
@@ -193,8 +199,7 @@ class MovieDrawable @JvmOverloads constructor(
     @Suppress("DEPRECATION")
     override fun getOpacity(): Int {
         return if (paint.alpha == 255 &&
-            (pixelOpacity == OPAQUE || (pixelOpacity == UNCHANGED && movie.isOpaque))
-        ) {
+            (pixelOpacity == OPAQUE || (pixelOpacity == UNCHANGED && movie.isOpaque))) {
             PixelFormat.OPAQUE
         } else {
             PixelFormat.TRANSLUCENT
@@ -286,11 +291,8 @@ class MovieDrawable @JvmOverloads constructor(
         /** Pass this to [setRepeatCount] to repeat infinitely. */
         const val REPEAT_INFINITE = -1
 
-        /**
-         * Pass this to [setRepeatCount] to repeat according to GIF's LoopCount metadata.
-         *
-         * If the metadata is not available, it will default to infinite repetition.
-         */
-        const val GIF_LOOP_COUNT = -2
+        /** Pass this to [setRepeatCount] to repeat according to encoded LoopCount metadata. */
+        @RequiresApi(28)
+        const val ENCODED_LOOP_COUNT = -2
     }
 }

coil-gif/src/main/java/coil3/gif/decodeUtils.kt

@@ -63,63 +63,3 @@ fun DecodeUtils.isAnimatedHeif(source: BufferedSource): Boolean {
             source.rangeEquals(8, HEIF_HEADER_HEVC) ||
             source.rangeEquals(8, HEIF_HEADER_HEVX))
 }
-
-internal fun extractLoopCountFromGif(source: BufferedSource): Int? {
-    return try {
-        parseLoopCount(source)
-    } catch (e: Exception) {
-        null
-    }
-}
-
-private fun parseLoopCount(source: BufferedSource): Int? {
-    val headerBytes = ByteArray(6)
-    if (source.read(headerBytes) != 6) return null
-
-    val screenDescriptorBytes = ByteArray(7)
-    if (source.read(screenDescriptorBytes) != 7) return null
-
-    if ((screenDescriptorBytes[4] and 0b10000000.toByte()) != 0.toByte()) {
-        val colorTableSize = 3 * (1 shl ((screenDescriptorBytes[4].toInt() and 0b00000111) + 1))
-        source.skip(colorTableSize.toLong())
-    }
-
-    // Handle Application Extension Block
-    while (!source.exhausted()) {
-        val blockType = source.readByte().toInt() and 0xFF
-        if (blockType == 0x21) { // Extension Introducer
-            val label = source.readByte().toInt() and 0xFF
-            if (label == 0xFF) { // Application Extension
-                val blockSize = source.readByte().toInt() and 0xFF
-                val appIdentifier = source.readUtf8(8)
-                val appAuthCode = source.readUtf8(3)
-
-                if (appIdentifier == "NETSCAPE" && appAuthCode == "2.0") {
-                    val dataBlockSize = source.readByte().toInt() and 0xFF
-                    val loopCountIndicator = source.readByte().toInt() and 0xFF
-
-                    // Read low and high bytes for loop count
-                    val loopCountLow = source.readByte().toInt() and 0xFF
-                    val loopCountHigh = source.readByte().toInt() and 0xFF
-                    val loopCount = (loopCountHigh shl 8) or loopCountLow
-                    val blockTerminator = source.readByte().toInt() and 0xFF
-                    return if (loopCount == 0) null else loopCount
-                } else {
-                    skipExtensionBlock(source) // Skip if not NETSCAPE
-                }
-            } else {
-                skipExtensionBlock(source) // Skip other extension blocks
-            }
-        }
-    }
-    return null
-}
-
-// Extension Blocks always terminate with a zero
-private fun skipExtensionBlock(source: BufferedSource) {
-    while (true) {
-        val size = source.readByte().toInt() and 0xFF
-        if (size == 0) break
-        source.skip(size.toLong())
-    }
-}

coil-gif/src/main/java/coil3/gif/imageRequests.kt

@@ -6,7 +6,7 @@ import android.graphics.drawable.Drawable
 import coil3.Extras
 import coil3.annotation.ExperimentalCoilApi
 import coil3.getExtra
-import coil3.gif.MovieDrawable.Companion.GIF_LOOP_COUNT
+import coil3.gif.MovieDrawable.Companion.ENCODED_LOOP_COUNT
 import coil3.gif.MovieDrawable.Companion.REPEAT_INFINITE
 import coil3.request.ImageRequest
 import coil3.request.Options
@@ -18,7 +18,7 @@ import coil3.request.Options
  * @see AnimatedImageDrawable.setRepeatCount
  */
 fun ImageRequest.Builder.repeatCount(repeatCount: Int) = apply {
-    require(repeatCount >= GIF_LOOP_COUNT) { "Invalid repeatCount: $repeatCount" }
+    require(repeatCount >= ENCODED_LOOP_COUNT) { "Invalid repeatCount: $repeatCount" }
     extras[repeatCountKey] = repeatCount
 }