Allow toggling of final shareousel item

When no items selected the UI will:
* change the chooser headline;
* make the custom action row invisible;
* make all targets disabled and all target icons greyscale.

Fix: 349468879
Test: atest IntentResolver-tests-unit
Test: manual functionality testing
Flag: com.android.intentresolver.unselect_final_item

Change-Id: I53b9c908943b1f1003cb0131a6dec8abc26ec782

11 files changed, 125 insertions, 43 deletions

diff --git a/java/res/values/strings.xml b/java/res/values/strings.xml
index c026ee59..4f77d248 100644
--- a/java/res/values/strings.xml
+++ b/java/res/values/strings.xml
@@ -162,6 +162,9 @@
         }
     </string>
 
+    <!-- Title atop a sharing UI indicating that a selection needs to be made for sharing -->
+    <string name="select_items_to_share">Select items to share</string>
+
     <!-- Title atop a sharing UI indicating that some number of images are being shared
          along with text [CHAR_LIMIT=50] -->
     <string name="sharing_images_with_text">{count, plural,
diff --git a/java/src/com/android/intentresolver/ChooserActivity.java b/java/src/com/android/intentresolver/ChooserActivity.java
index 51d8785f..8871ce3f 100644
--- a/java/src/com/android/intentresolver/ChooserActivity.java
+++ b/java/src/com/android/intentresolver/ChooserActivity.java
@@ -25,6 +25,7 @@ import static androidx.lifecycle.LifecycleKt.getCoroutineScope;
 import static com.android.intentresolver.ChooserActionFactory.EDIT_SOURCE;
 import static com.android.intentresolver.Flags.shareouselUpdateExcludeComponentsExtra;
 import static com.android.intentresolver.Flags.fixShortcutsFlashing;
+import static com.android.intentresolver.Flags.unselectFinalItem;
 import static com.android.intentresolver.ext.CreationExtrasExtKt.addDefaultArgs;
 import static com.android.intentresolver.profiles.MultiProfilePagerAdapter.PROFILE_PERSONAL;
 import static com.android.intentresolver.profiles.MultiProfilePagerAdapter.PROFILE_WORK;
@@ -351,6 +352,9 @@ public class ChooserActivity extends Hilt_ChooserActivity implements
         if (mChooserServiceFeatureFlags.chooserPayloadToggling()) {
             mChooserHelper.setOnChooserRequestChanged(this::onChooserRequestChanged);
             mChooserHelper.setOnPendingSelection(this::onPendingSelection);
+            if (unselectFinalItem()) {
+                mChooserHelper.setOnHasSelections(this::onHasSelections);
+            }
         }
     }
     private int mInitialProfile = -1;
@@ -705,7 +709,6 @@ public class ChooserActivity extends Hilt_ChooserActivity implements
     }
 
     private void onChooserRequestChanged(ChooserRequest chooserRequest) {
-        // intentional reference comparison
         if (mRequest == chooserRequest) {
             return;
         }
@@ -724,6 +727,10 @@ public class ChooserActivity extends Hilt_ChooserActivity implements
         setTabsViewEnabled(false);
     }
 
+    private void onHasSelections(boolean hasSelections) {
+        mChooserMultiProfilePagerAdapter.setTargetsEnabled(hasSelections);
+    }
+
     private void onAppTargetsLoaded(ResolverListAdapter listAdapter) {
         Log.d(TAG, "onAppTargetsLoaded("
                 + "listAdapter.userHandle=" + listAdapter.getUserHandle() + ")");
diff --git a/java/src/com/android/intentresolver/ChooserHelper.kt b/java/src/com/android/intentresolver/ChooserHelper.kt
index 312911a6..7d382bfc 100644
--- a/java/src/com/android/intentresolver/ChooserHelper.kt
+++ b/java/src/com/android/intentresolver/ChooserHelper.kt
@@ -27,9 +27,12 @@ import androidx.lifecycle.Lifecycle
 import androidx.lifecycle.LifecycleOwner
 import androidx.lifecycle.lifecycleScope
 import androidx.lifecycle.repeatOnLifecycle
+import com.android.intentresolver.Flags.unselectFinalItem
 import com.android.intentresolver.annotation.JavaInterop
+import com.android.intentresolver.contentpreview.ContentPreviewType.CONTENT_PREVIEW_PAYLOAD_SELECTION
 import com.android.intentresolver.contentpreview.payloadtoggle.data.repository.ActivityResultRepository
 import com.android.intentresolver.contentpreview.payloadtoggle.data.repository.PendingSelectionCallbackRepository
+import com.android.intentresolver.contentpreview.payloadtoggle.data.repository.PreviewSelectionsRepository
 import com.android.intentresolver.data.model.ChooserRequest
 import com.android.intentresolver.platform.GlobalSettings
 import com.android.intentresolver.ui.viewmodel.ChooserViewModel
@@ -39,6 +42,8 @@ import com.android.intentresolver.validation.log
 import dagger.hilt.android.scopes.ActivityScoped
 import java.util.function.Consumer
 import javax.inject.Inject
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.distinctUntilChanged
 import kotlinx.coroutines.flow.filter
@@ -46,6 +51,7 @@ import kotlinx.coroutines.flow.filterNotNull
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.onEach
+import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.launch
 
 private const val TAG: String = "ChooserHelper"
@@ -86,6 +92,7 @@ constructor(
     hostActivity: Activity,
     private val activityResultRepo: ActivityResultRepository,
     private val pendingSelectionCallbackRepo: PendingSelectionCallbackRepository,
+    private val selectionsRepo: PreviewSelectionsRepository,
     private val globalSettings: GlobalSettings,
 ) : DefaultLifecycleObserver {
     // This is guaranteed by Hilt, since only a ComponentActivity is injectable.
@@ -98,6 +105,7 @@ constructor(
     var onChooserRequestChanged: Consumer<ChooserRequest> = Consumer {}
     /** Invoked when there are a new change to payload selection */
     var onPendingSelection: Runnable = Runnable {}
+    var onHasSelections: Consumer<Boolean> = Consumer {}
 
     init {
         activity.lifecycle.addObserver(this)
@@ -144,22 +152,40 @@ constructor(
         }
 
         activity.lifecycleScope.launch {
-            val hasPendingCallbackFlow =
+            val hasPendingIntentFlow =
                 pendingSelectionCallbackRepo.pendingTargetIntent
                     .map { it != null }
                     .distinctUntilChanged()
-                    .onEach { hasPendingCallback ->
-                        if (hasPendingCallback) {
+                    .onEach { hasPendingIntent ->
+                        if (hasPendingIntent) {
                             onPendingSelection.run()
                         }
                     }
             activity.lifecycle.repeatOnLifecycle(Lifecycle.State.STARTED) {
-                viewModel.request
-                    .combine(hasPendingCallbackFlow) { request, hasPendingCallback ->
-                        request to hasPendingCallback
+                val hasSelectionFlow =
+                    if (
+                        unselectFinalItem() &&
+                            viewModel.previewDataProvider.previewType ==
+                                CONTENT_PREVIEW_PAYLOAD_SELECTION
+                    ) {
+                        selectionsRepo.selections
+                            .map { it.isNotEmpty() }
+                            .distinctUntilChanged()
+                            .stateIn(scope = this)
+                            .also { flow -> launch { flow.collect { onHasSelections.accept(it) } } }
+                    } else {
+                        MutableStateFlow(true).asStateFlow()
                     }
+                val requestControlFlow =
+                    hasSelectionFlow
+                        .combine(hasPendingIntentFlow) { hasSelections, hasPendingIntent ->
+                            hasSelections && !hasPendingIntent
+                        }
+                        .distinctUntilChanged()
+                viewModel.request
+                    .combine(requestControlFlow) { request, isReady -> request to isReady }
                     // only take ChooserRequest if there are no pending callbacks
-                    .filter { !it.second }
+                    .filter { it.second }
                     .map { it.first }
                     .distinctUntilChanged(areEquivalent = { old, new -> old === new })
                     .collect { onChooserRequestChanged.accept(it) }
diff --git a/java/src/com/android/intentresolver/ChooserListAdapter.java b/java/src/com/android/intentresolver/ChooserListAdapter.java
index 26e2feeb..016eb714 100644
--- a/java/src/com/android/intentresolver/ChooserListAdapter.java
+++ b/java/src/com/android/intentresolver/ChooserListAdapter.java
@@ -18,7 +18,6 @@ package com.android.intentresolver;
 
 import static com.android.intentresolver.ChooserActivity.TARGET_TYPE_SHORTCUTS_FROM_PREDICTION_SERVICE;
 import static com.android.intentresolver.ChooserActivity.TARGET_TYPE_SHORTCUTS_FROM_SHORTCUT_MANAGER;
-import static com.android.intentresolver.util.graphics.SuspendedMatrixColorFilter.getSuspendedColorMatrix;
 
 import android.app.ActivityManager;
 import android.app.prediction.AppTarget;
@@ -439,10 +438,7 @@ public class ChooserListAdapter extends ResolverListAdapter {
             }
         }
 
-        holder.bindIcon(info);
-        if (info.hasDisplayIcon() && !mTargetsEnabled) {
-            holder.icon.setColorFilter(getSuspendedColorMatrix());
-        }
+        holder.bindIcon(info, mTargetsEnabled);
         if (mAnimateItems && info.hasDisplayIcon()) {
             mAnimationTracker.animateIcon(holder.icon, info);
         }
diff --git a/java/src/com/android/intentresolver/ResolverListAdapter.java b/java/src/com/android/intentresolver/ResolverListAdapter.java
index 7ca1c724..fc5514b6 100644
--- a/java/src/com/android/intentresolver/ResolverListAdapter.java
+++ b/java/src/com/android/intentresolver/ResolverListAdapter.java
@@ -16,6 +16,7 @@
 
 package com.android.intentresolver;
 
+import static com.android.intentresolver.Flags.unselectFinalItem;
 import static com.android.intentresolver.util.graphics.SuspendedMatrixColorFilter.getSuspendedColorMatrix;
 
 import android.content.Context;
@@ -973,13 +974,26 @@ public class ResolverListAdapter extends BaseAdapter {
         /**
          * Bind view holder to a TargetInfo.
          */
-        public void bindIcon(TargetInfo info) {
+        public final void bindIcon(TargetInfo info) {
+            bindIcon(info, true);
+        }
+
+        /**
+         * Bind view holder to a TargetInfo.
+         */
+        public void bindIcon(TargetInfo info, boolean isEnabled) {
             Drawable displayIcon = info.getDisplayIconHolder().getDisplayIcon();
             icon.setImageDrawable(displayIcon);
-            if (info.isSuspended()) {
+            if (info.isSuspended() || !isEnabled) {
                 icon.setColorFilter(getSuspendedColorMatrix());
             } else {
                 icon.setColorFilter(null);
+                if (unselectFinalItem() && displayIcon != null) {
+                    // For some reason, ImageView.setColorFilter() not always propagate the call
+                    // to the drawable and the icon remains grayscale when rebound; reset the filter
+                    // explicitly.
+                    displayIcon.setColorFilter(null);
+                }
             }
         }
     }
diff --git a/java/src/com/android/intentresolver/contentpreview/HeadlineGenerator.kt b/java/src/com/android/intentresolver/contentpreview/HeadlineGenerator.kt
index 21308341..059ee083 100644
--- a/java/src/com/android/intentresolver/contentpreview/HeadlineGenerator.kt
+++ b/java/src/com/android/intentresolver/contentpreview/HeadlineGenerator.kt
@@ -36,4 +36,6 @@ interface HeadlineGenerator {
     fun getVideosHeadline(count: Int): String
 
     fun getFilesHeadline(count: Int): String
+
+    fun getNotItemsSelectedHeadline(): String
 }
diff --git a/java/src/com/android/intentresolver/contentpreview/HeadlineGeneratorImpl.kt b/java/src/com/android/intentresolver/contentpreview/HeadlineGeneratorImpl.kt
index e92d9bc6..822d3097 100644
--- a/java/src/com/android/intentresolver/contentpreview/HeadlineGeneratorImpl.kt
+++ b/java/src/com/android/intentresolver/contentpreview/HeadlineGeneratorImpl.kt
@@ -93,6 +93,9 @@ constructor(
         return getPluralString(R.string.sharing_files, count)
     }
 
+    override fun getNotItemsSelectedHeadline(): String =
+        context.getString(R.string.select_items_to_share)
+
     private fun getPluralString(@StringRes templateResource: Int, count: Int): String {
         return PluralsMessageFormatter.format(
             context.resources,
diff --git a/java/src/com/android/intentresolver/contentpreview/payloadtoggle/data/repository/PreviewSelectionsRepository.kt b/java/src/com/android/intentresolver/contentpreview/payloadtoggle/data/repository/PreviewSelectionsRepository.kt
index 81c56d1e..0688ce02 100644
--- a/java/src/com/android/intentresolver/contentpreview/payloadtoggle/data/repository/PreviewSelectionsRepository.kt
+++ b/java/src/com/android/intentresolver/contentpreview/payloadtoggle/data/repository/PreviewSelectionsRepository.kt
@@ -18,12 +18,12 @@ package com.android.intentresolver.contentpreview.payloadtoggle.data.repository
 
 import android.net.Uri
 import com.android.intentresolver.contentpreview.payloadtoggle.shared.model.PreviewModel
-import dagger.hilt.android.scopes.ViewModelScoped
+import dagger.hilt.android.scopes.ActivityRetainedScoped
 import javax.inject.Inject
 import kotlinx.coroutines.flow.MutableStateFlow
 
 /** Stores set of selected previews. */
-@ViewModelScoped
+@ActivityRetainedScoped
 class PreviewSelectionsRepository @Inject constructor() {
     val selections = MutableStateFlow(emptyMap<Uri, PreviewModel>())
 }
diff --git a/java/src/com/android/intentresolver/contentpreview/payloadtoggle/domain/interactor/SelectionInteractor.kt b/java/src/com/android/intentresolver/contentpreview/payloadtoggle/domain/interactor/SelectionInteractor.kt
index 97d9fa66..2d02e4fd 100644
--- a/java/src/com/android/intentresolver/contentpreview/payloadtoggle/domain/interactor/SelectionInteractor.kt
+++ b/java/src/com/android/intentresolver/contentpreview/payloadtoggle/domain/interactor/SelectionInteractor.kt
@@ -17,6 +17,7 @@
 package com.android.intentresolver.contentpreview.payloadtoggle.domain.interactor
 
 import android.net.Uri
+import com.android.intentresolver.Flags.unselectFinalItem
 import com.android.intentresolver.contentpreview.MimeTypeClassifier
 import com.android.intentresolver.contentpreview.payloadtoggle.data.repository.PreviewSelectionsRepository
 import com.android.intentresolver.contentpreview.payloadtoggle.domain.intent.TargetIntentModifier
@@ -60,8 +61,12 @@ constructor(
     }
 
     fun unselect(model: PreviewModel) {
-        if (selectionsRepo.selections.value.size > 1) {
-            updateChooserRequest(selectionsRepo.selections.updateAndGet { it - model.uri }.values)
+        if (selectionsRepo.selections.value.size > 1 || unselectFinalItem()) {
+            selectionsRepo.selections
+                .updateAndGet { it - model.uri }
+                .values
+                .takeIf { it.isNotEmpty() }
+                ?.let { updateChooserRequest(it) }
         }
     }
 
diff --git a/java/src/com/android/intentresolver/contentpreview/payloadtoggle/ui/composable/ShareouselComposable.kt b/java/src/com/android/intentresolver/contentpreview/payloadtoggle/ui/composable/ShareouselComposable.kt
index 93ac90db..f8cf243d 100644
--- a/java/src/com/android/intentresolver/contentpreview/payloadtoggle/ui/composable/ShareouselComposable.kt
+++ b/java/src/com/android/intentresolver/contentpreview/payloadtoggle/ui/composable/ShareouselComposable.kt
@@ -64,6 +64,7 @@ import androidx.compose.ui.semantics.contentDescription
 import androidx.compose.ui.semantics.semantics
 import androidx.compose.ui.unit.dp
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import com.android.intentresolver.Flags.unselectFinalItem
 import com.android.intentresolver.R
 import com.android.intentresolver.contentpreview.payloadtoggle.domain.model.ValueUpdate
 import com.android.intentresolver.contentpreview.payloadtoggle.domain.model.getOrDefault
@@ -73,6 +74,7 @@ import com.android.intentresolver.contentpreview.payloadtoggle.ui.viewmodel.Shar
 import com.android.intentresolver.contentpreview.payloadtoggle.ui.viewmodel.ShareouselViewModel
 import kotlin.math.abs
 import kotlin.math.min
+import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.launch
 
 @Composable
@@ -286,30 +288,46 @@ private fun ActionCarousel(viewModel: ShareouselViewModel) {
     val actions by viewModel.actions.collectAsStateWithLifecycle(initialValue = emptyList())
     if (actions.isNotEmpty()) {
         Spacer(Modifier.height(16.dp))
-        LazyRow(
-            horizontalArrangement = Arrangement.spacedBy(4.dp),
-            modifier = Modifier.height(32.dp),
-        ) {
-            itemsIndexed(actions) { idx, actionViewModel ->
-                if (idx == 0) {
-                    Spacer(Modifier.width(dimensionResource(R.dimen.chooser_edge_margin_normal)))
-                }
-                ShareouselAction(
-                    label = actionViewModel.label,
-                    onClick = { actionViewModel.onClicked() },
-                ) {
-                    actionViewModel.icon?.let {
-                        Image(
-                            icon = it,
-                            modifier = Modifier.size(16.dp),
-                            colorFilter = ColorFilter.tint(LocalContentColor.current)
+        val visibilityFlow =
+            if (unselectFinalItem()) {
+                viewModel.hasSelectedItems
+            } else {
+                MutableStateFlow(true)
+            }
+        val visibility by visibilityFlow.collectAsStateWithLifecycle(true)
+        val height = 32.dp
+        if (visibility) {
+            LazyRow(
+                horizontalArrangement = Arrangement.spacedBy(4.dp),
+                modifier = Modifier.height(height),
+            ) {
+                itemsIndexed(actions) { idx, actionViewModel ->
+                    if (idx == 0) {
+                        Spacer(
+                            Modifier.width(dimensionResource(R.dimen.chooser_edge_margin_normal))
+                        )
+                    }
+                    ShareouselAction(
+                        label = actionViewModel.label,
+                        onClick = { actionViewModel.onClicked() },
+                    ) {
+                        actionViewModel.icon?.let {
+                            Image(
+                                icon = it,
+                                modifier = Modifier.size(16.dp),
+                                colorFilter = ColorFilter.tint(LocalContentColor.current)
+                            )
+                        }
+                    }
+                    if (idx == actions.size - 1) {
+                        Spacer(
+                            Modifier.width(dimensionResource(R.dimen.chooser_edge_margin_normal))
                         )
                     }
-                }
-                if (idx == actions.size - 1) {
-                    Spacer(Modifier.width(dimensionResource(R.dimen.chooser_edge_margin_normal)))
                 }
             }
+        } else {
+            Spacer(modifier = Modifier.height(height))
         }
     }
 }
diff --git a/java/src/com/android/intentresolver/contentpreview/payloadtoggle/ui/viewmodel/ShareouselViewModel.kt b/java/src/com/android/intentresolver/contentpreview/payloadtoggle/ui/viewmodel/ShareouselViewModel.kt
index 6f8be1ff..9762794e 100644
--- a/java/src/com/android/intentresolver/contentpreview/payloadtoggle/ui/viewmodel/ShareouselViewModel.kt
+++ b/java/src/com/android/intentresolver/contentpreview/payloadtoggle/ui/viewmodel/ShareouselViewModel.kt
@@ -17,6 +17,7 @@ package com.android.intentresolver.contentpreview.payloadtoggle.ui.viewmodel
 
 import android.util.Size
 import com.android.intentresolver.Flags
+import com.android.intentresolver.Flags.unselectFinalItem
 import com.android.intentresolver.contentpreview.CachingImagePreviewImageLoader
 import com.android.intentresolver.contentpreview.HeadlineGenerator
 import com.android.intentresolver.contentpreview.ImageLoader
@@ -58,6 +59,8 @@ data class ShareouselViewModel(
     val previews: Flow<PreviewsModel?>,
     /** List of action chips presented underneath Shareousel. */
     val actions: Flow<List<ActionChipViewModel>>,
+    /** Indicates whether there are any selected items */
+    val hasSelectedItems: Flow<Boolean>,
     /** Creates a [ShareouselPreviewViewModel] for a [PreviewModel] present in [previews]. */
     val preview:
         (
@@ -104,10 +107,14 @@ object ShareouselViewModelModule {
                 selectionInteractor.aggregateContentType.zip(selectionInteractor.amountSelected) {
                     contentType,
                     numItems ->
-                    when (contentType) {
-                        ContentType.Other -> headlineGenerator.getFilesHeadline(numItems)
-                        ContentType.Image -> headlineGenerator.getImagesHeadline(numItems)
-                        ContentType.Video -> headlineGenerator.getVideosHeadline(numItems)
+                    if (unselectFinalItem() && numItems == 0) {
+                        headlineGenerator.getNotItemsSelectedHeadline()
+                    } else {
+                        when (contentType) {
+                            ContentType.Other -> headlineGenerator.getFilesHeadline(numItems)
+                            ContentType.Image -> headlineGenerator.getImagesHeadline(numItems)
+                            ContentType.Video -> headlineGenerator.getVideosHeadline(numItems)
+                        }
                     }
                 },
             metadataText = chooserRequestInteractor.metadataText,
@@ -128,6 +135,7 @@ object ShareouselViewModelModule {
                         }
                     }
                 },
+            hasSelectedItems = selectionInteractor.selections.map { it.isNotEmpty() },
             preview = { key, previewHeight, index, previewScope ->
                 keySet.value?.maybeLoad(index)
                 val previewInteractor = interactor.preview(key)