diff options
Diffstat (limited to 'java/src')
| -rw-r--r-- | java/src/com/android/intentresolver/widget/ScrollableImagePreviewView.kt | 98 |
1 files changed, 63 insertions, 35 deletions
diff --git a/java/src/com/android/intentresolver/widget/ScrollableImagePreviewView.kt b/java/src/com/android/intentresolver/widget/ScrollableImagePreviewView.kt index e760e6d0..1f5be601 100644 --- a/java/src/com/android/intentresolver/widget/ScrollableImagePreviewView.kt +++ b/java/src/com/android/intentresolver/widget/ScrollableImagePreviewView.kt @@ -28,6 +28,7 @@ import android.view.View import android.view.ViewGroup import android.widget.ImageView import android.widget.TextView +import androidx.annotation.VisibleForTesting import androidx.constraintlayout.widget.ConstraintLayout import androidx.recyclerview.widget.LinearLayoutManager import androidx.recyclerview.widget.RecyclerView @@ -45,8 +46,6 @@ import kotlinx.coroutines.flow.takeWhile import kotlinx.coroutines.joinAll import kotlinx.coroutines.launch import kotlinx.coroutines.plus -import java.util.ArrayDeque -import kotlin.math.roundToInt private const val TRANSITION_NAME = "screenshot_preview_image" private const val PLURALS_COUNT = "count" @@ -149,14 +148,17 @@ class ScrollableImagePreviewView : RecyclerView, ImagePreviewView { previewAdapter.reset(0, imageLoader) batchLoader?.cancel() batchLoader = BatchPreviewLoader( - previewAdapter, imageLoader, previews, otherItemCount, - ) { - onNoPreviewCallback?.run() - } - .apply { + onReset = { totalItemCount -> previewAdapter.reset(totalItemCount, imageLoader) }, + onUpdate = previewAdapter::addPreviews, + onCompletion = { + if (!previewAdapter.hasPreviews) { + onNoPreviewCallback?.run() + } + } + ).apply { if (isMeasured) { loadAspectRatios(getMaxWidth(), this@ScrollableImagePreviewView::updatePreviewSize) } @@ -409,14 +411,17 @@ class ScrollableImagePreviewView : RecyclerView, ImagePreviewView { } } - private class BatchPreviewLoader( - private val adapter: Adapter, + @VisibleForTesting + class BatchPreviewLoader( private val imageLoader: CachingImageLoader, previews: List<Preview>, otherItemCount: Int, - private val onNoPreviewCallback: (() -> Unit) + private val onReset: (Int) -> Unit, + private val onUpdate: (List<Preview>) -> Unit, + private val onCompletion: () -> Unit, ) { - private val pendingPreviews = ArrayDeque<Preview>(previews) + private val previews: List<Preview> = + if (previews is RandomAccess) previews else ArrayList(previews) private val totalItemCount = previews.size + otherItemCount private var scope: CoroutineScope? = MainScope() + Dispatchers.Main.immediate @@ -427,52 +432,75 @@ class ScrollableImagePreviewView : RecyclerView, ImagePreviewView { fun loadAspectRatios(maxWidth: Int, previewSizeUpdater: (Preview, Int, Int) -> Int) { val scope = this.scope ?: return - val updates = ArrayDeque<Preview>(pendingPreviews.size) + // -1 encodes that the preview has not been processed, + // 0 means failed, > 0 is a preview width + val previewWidths = IntArray(previews.size) { -1 } + var blockStart = 0 // inclusive + var blockEnd = 0 // exclusive + // replay 2 items to guarantee that we'd get at least one update val reportFlow = MutableSharedFlow<Any>(replay = 2) - var isFirstUpdate = true val updateEvent = Any() val completedEvent = Any() - // throttle adapter updates by waiting on the channel, the channel first notified - // when enough preview elements is loaded and then periodically with a delay + + // throttle adapter updates using flow; the flow first emits when enough preview + // elements is loaded to fill the viewport and then each time a subsequent block of + // previews is loaded scope.launch(Dispatchers.Main) { reportFlow .takeWhile { it !== completedEvent } .throttle(ADAPTER_UPDATE_INTERVAL_MS) .onCompletion { cause -> - if (cause == null && !adapter.hasPreviews) { - onNoPreviewCallback() + if (cause == null) { + onCompletion() } } .collect { - if (isFirstUpdate) { - isFirstUpdate = false - adapter.reset(totalItemCount, imageLoader) + if (blockStart == 0) { + onReset(totalItemCount) + } + val updates = ArrayList<Preview>(blockEnd - blockStart) + while (blockStart < blockEnd) { + if (previewWidths[blockStart] > 0) { + updates.add(previews[blockStart]) + } + blockStart++ } if (updates.isNotEmpty()) { - adapter.addPreviews(updates) - updates.clear() + onUpdate(updates) } } } scope.launch { - var loadedPreviewWidth = 0 + var blockWidth = 0 + var isFirstBlock = true + var nextIdx = 0 List<Job>(4) { launch { - while (pendingPreviews.isNotEmpty()) { - val preview = pendingPreviews.poll() ?: continue - val isVisible = loadedPreviewWidth < maxWidth - val bitmap = runCatching { + while (true) { + val i = nextIdx++ + if (i >= previews.size) break + val preview = previews[i] + + previewWidths[i] = runCatching { // TODO: decide on adding a timeout - imageLoader(preview.uri, isVisible) - }.getOrNull() ?: continue - val previewWidth = - previewSizeUpdater(preview, bitmap.width, bitmap.height) - updates.add(preview) - if (isVisible) { - loadedPreviewWidth += previewWidth - if (loadedPreviewWidth >= maxWidth) { + imageLoader(preview.uri, isFirstBlock)?.let { bitmap -> + previewSizeUpdater(preview, bitmap.width, bitmap.height) + } ?: 0 + }.getOrDefault(0) + + if (blockEnd != i) continue + while ( + blockEnd < previewWidths.size + && previewWidths[blockEnd] >= 0 + ) { + blockWidth += previewWidths[blockEnd] + blockEnd++ + } + if (isFirstBlock) { + if (blockWidth >= maxWidth) { + isFirstBlock = false // notify that the preview now can be displayed reportFlow.emit(updateEvent) } |