Support streamable stories.

app/src/main/java/org/thoughtcrime/securesms/stories/viewer/page/StoryViewerPageFragment.kt

@@ -98,6 +98,7 @@ import org.thoughtcrime.securesms.util.DateUtils
 import org.thoughtcrime.securesms.util.LinkUtil
 import org.thoughtcrime.securesms.util.LongClickCopySpan
 import org.thoughtcrime.securesms.util.LongClickMovementMethod
+import org.thoughtcrime.securesms.util.MediaUtil
 import org.thoughtcrime.securesms.util.Projection
 import org.thoughtcrime.securesms.util.ViewUtil
 import org.thoughtcrime.securesms.util.fragments.requireListener
@@ -850,7 +851,7 @@ class StoryViewerPageFragment :
 
   private fun markViewedIfAble() {
     val post = viewModel.getPost() ?: return
-    if (post.content.transferState == AttachmentTable.TRANSFER_PROGRESS_DONE) {
+    if (post.content.transferState == AttachmentTable.TRANSFER_PROGRESS_DONE || post.content.transferState == AttachmentTable.TRANSFER_PROGRESS_STARTED) {
       if (isResumed) {
         viewModel.markViewed(post)
       }
@@ -895,6 +896,7 @@ class StoryViewerPageFragment :
 
     when (post.content.transferState) {
       AttachmentTable.TRANSFER_PROGRESS_DONE -> {
+        Log.d(TAG, "Story content download is done.")
         storySlate.moveToState(StorySlateView.State.HIDDEN, post.id)
         viewModel.setIsDisplayingSlate(false)
         markViewedIfAble()
@@ -908,10 +910,18 @@ class StoryViewerPageFragment :
       }
 
       AttachmentTable.TRANSFER_PROGRESS_STARTED -> {
-        Log.d(TAG, "Story content download is in progress.")
-        storySlate.moveToState(StorySlateView.State.LOADING, post.id)
-        sharedViewModel.setContentIsReady()
-        viewModel.setIsDisplayingSlate(true)
+        val isStreamable = post.content is StoryPost.Content.AttachmentContent && MediaUtil.isInstantVideoSupported(post.content.attachment)
+        if (isStreamable) {
+          Log.d(TAG, "Story content is streamable while download is in progress.")
+          storySlate.moveToState(StorySlateView.State.HIDDEN, post.id)
+          viewModel.setIsDisplayingSlate(false)
+          markViewedIfAble()
+        } else {
+          Log.d(TAG, "Story content download is in progress.")
+          storySlate.moveToState(StorySlateView.State.LOADING, post.id)
+          sharedViewModel.setContentIsReady()
+          viewModel.setIsDisplayingSlate(true)
+        }
       }
 
       AttachmentTable.TRANSFER_PROGRESS_FAILED -> {

app/src/main/java/org/thoughtcrime/securesms/util/MediaUtil.java

@@ -554,10 +554,13 @@ public class MediaUtil {
   }
 
   public static boolean isInstantVideoSupported(Slide slide) {
-    final Attachment attachment                        = slide.asAttachment();
-    final boolean    isIncremental                     = attachment.getIncrementalDigest() != null;
-    final boolean    hasIncrementalMacChunkSizeDefined = attachment.incrementalMacChunkSize > 0;
-    final boolean    contentTypeSupported              = isVideoType(slide.getContentType());
+    return isInstantVideoSupported(slide.asAttachment());
+  }
+
+  public static boolean isInstantVideoSupported(Attachment attachment) {
+    final boolean isIncremental                     = attachment.getIncrementalDigest() != null;
+    final boolean hasIncrementalMacChunkSizeDefined = attachment.incrementalMacChunkSize > 0;
+    final boolean contentTypeSupported              = isVideoType(attachment.contentType);
     return isIncremental && contentTypeSupported && hasIncrementalMacChunkSizeDefined;
   }
 

app/src/main/res/layout/story_video_player.xml

@@ -17,4 +17,13 @@
         app:shutter_background_color="@color/core_black"
         app:surface_type="texture_view" />
 
+    <ProgressBar
+        android:id="@+id/progress_bar"
+        android:layout_width="48dp"
+        android:layout_height="48dp"
+        android:layout_gravity="center"
+        style="?android:attr/progressBarStyleLarge"
+        android:indeterminateTint="@color/signal_colorOnSurfaceVariant"
+        android:indeterminate="true" />
+
 </FrameLayout>

app/src/test/java/org/thoughtcrime/securesms/components/transfercontrols/TransferControlsTest.kt

@@ -35,7 +35,7 @@ class TransferControlsTest {
   @Before
   fun setUp() {
     mockkStatic(MediaUtil::class)
-    every { MediaUtil.isInstantVideoSupported(any()) } returns false
+    every { MediaUtil.isInstantVideoSupported(any() as Attachment) } returns false
   }
 
   @After
@@ -185,7 +185,7 @@ class TransferControlsTest {
 
   @Test
   fun `gallery pending playable is corner without item count`() {
-    every { MediaUtil.isInstantVideoSupported(any()) } returns true
+    every { MediaUtil.isInstantVideoSupported(any() as Attachment) } returns true
     val state = stateOf(listOf(slide(AttachmentTable.TRANSFER_PROGRESS_PENDING), slide(AttachmentTable.TRANSFER_PROGRESS_PENDING)))
     val render = TransferControls.deriveRenderState(state) as TransferControlsRenderState.Pending
     assertEquals(TransferControls.Placement.CORNER, render.placement)

lib/libsignal-service/src/main/java/org/whispersystems/signalservice/api/crypto/BetterCipherInputStream.kt

@@ -58,6 +58,27 @@ class BetterCipherInputStream(
 
   override fun markSupported(): Boolean = false
 
+  /**
+   * Since AES/CBC decryption is sequential, we can't just skip bytes on the underlying ciphertext stream
+   * so we must process every preceding ciphertext block to keep its internal chaining state correct.
+   */
+  @Throws(IOException::class)
+  override fun skip(byteCount: Long): Long {
+    var totalSkipped = 0L
+    val buffer = ByteArray(4096)
+
+    while (totalSkipped < byteCount) {
+      val toRead = min(buffer.size.toLong(), byteCount - totalSkipped).toInt()
+      val read = read(buffer, 0, toRead)
+      if (read == -1) {
+        break
+      }
+      totalSkipped += read
+    }
+
+    return totalSkipped
+  }
+
   @Throws(IOException::class)
   private fun readIncremental(outputBuffer: ByteArray, originalOffset: Int, originalLength: Int): Int {
     var offset = originalOffset