Introduce EmptyStateUiHelper (& initial tests)

Based on prototype work in ag/24516421, this CL introduces a new
component to handle the empty-state UI implementation details that had
previously been implemented in `MultiProfilePagerAdapter`, since those
details significantly clutter the implementation of that adapter's
other responsibilities.

As in ag/24516421 patchset #4, this just sets up the boilerplate and
kicks off with some "low-hanging-fruit" operations. Follow-up CLs will
continue migrating these responsibilities as in ag/24516421 (except
with more incremental testing).

Bug: 302311217
Test: IntentResolverUnitTests, CtsSharesheetDeviceTest
Change-Id: Ie9bb7f4e97836321521c3cf13c77cafc97b1a461

2 files changed, 73 insertions, 28 deletions

diff --git a/java/src/com/android/intentresolver/MultiProfilePagerAdapter.java b/java/src/com/android/intentresolver/MultiProfilePagerAdapter.java
index 2c98d89f..8c640dd3 100644
--- a/java/src/com/android/intentresolver/MultiProfilePagerAdapter.java
+++ b/java/src/com/android/intentresolver/MultiProfilePagerAdapter.java
@@ -29,6 +29,7 @@ import androidx.viewpager.widget.ViewPager;
 
 import com.android.intentresolver.emptystate.EmptyState;
 import com.android.intentresolver.emptystate.EmptyStateProvider;
+import com.android.intentresolver.emptystate.EmptyStateUiHelper;
 import com.android.internal.annotations.VisibleForTesting;
 
 import com.google.common.collect.ImmutableList;
@@ -424,7 +425,7 @@ public class MultiProfilePagerAdapter<
             clickListener = v -> emptyState.getButtonClickListener().onClick(() -> {
                 ProfileDescriptor<PageViewT, SinglePageAdapterT> descriptor = getItem(
                         userHandleToPageIndex(listAdapter.getUserHandle()));
-                MultiProfilePagerAdapter.this.showSpinner(descriptor.getEmptyStateView());
+                descriptor.mEmptyStateUi.showSpinner();
             });
         }
 
@@ -451,9 +452,9 @@ public class MultiProfilePagerAdapter<
                 userHandleToPageIndex(activeListAdapter.getUserHandle()));
         descriptor.mRootView.findViewById(
                 com.android.internal.R.id.resolver_list).setVisibility(View.GONE);
+        descriptor.mEmptyStateUi.resetViewVisibilities();
+
         ViewGroup emptyStateView = descriptor.getEmptyStateView();
-        resetViewVisibilitiesForEmptyState(emptyStateView);
-        emptyStateView.setVisibility(View.VISIBLE);
 
         View container = emptyStateView.findViewById(
                 com.android.internal.R.id.resolver_empty_state_container);
@@ -504,36 +505,12 @@ public class MultiProfilePagerAdapter<
                     paddingBottom));
     }
 
-    private void showSpinner(View emptyStateView) {
-        emptyStateView.findViewById(com.android.internal.R.id.resolver_empty_state_title)
-                .setVisibility(View.INVISIBLE);
-        emptyStateView.findViewById(com.android.internal.R.id.resolver_empty_state_button)
-                .setVisibility(View.INVISIBLE);
-        emptyStateView.findViewById(com.android.internal.R.id.resolver_empty_state_progress)
-                .setVisibility(View.VISIBLE);
-        emptyStateView.findViewById(com.android.internal.R.id.empty).setVisibility(View.GONE);
-    }
-
-    private void resetViewVisibilitiesForEmptyState(View emptyStateView) {
-        emptyStateView.findViewById(com.android.internal.R.id.resolver_empty_state_title)
-                .setVisibility(View.VISIBLE);
-        emptyStateView.findViewById(com.android.internal.R.id.resolver_empty_state_subtitle)
-                .setVisibility(View.VISIBLE);
-        emptyStateView.findViewById(com.android.internal.R.id.resolver_empty_state_button)
-                .setVisibility(View.INVISIBLE);
-        emptyStateView.findViewById(com.android.internal.R.id.resolver_empty_state_progress)
-                .setVisibility(View.GONE);
-        emptyStateView.findViewById(com.android.internal.R.id.empty).setVisibility(View.GONE);
-    }
-
     protected void showListView(ListAdapterT activeListAdapter) {
         ProfileDescriptor<PageViewT, SinglePageAdapterT> descriptor = getItem(
                 userHandleToPageIndex(activeListAdapter.getUserHandle()));
         descriptor.mRootView.findViewById(
                 com.android.internal.R.id.resolver_list).setVisibility(View.VISIBLE);
-        View emptyStateView = descriptor.mRootView.findViewById(
-                com.android.internal.R.id.resolver_empty_state);
-        emptyStateView.setVisibility(View.GONE);
+        descriptor.mEmptyStateUi.hide();
     }
 
     public boolean shouldShowEmptyStateScreen(ListAdapterT listAdapter) {
@@ -547,6 +524,10 @@ public class MultiProfilePagerAdapter<
     // should be the owner of all per-profile data (especially now that the API is generic)?
     private static class ProfileDescriptor<PageViewT, SinglePageAdapterT> {
         final ViewGroup mRootView;
+        final EmptyStateUiHelper mEmptyStateUi;
+
+        // TODO: post-refactoring, we may not need to retain these ivars directly (since they may
+        // be encapsulated within the `EmptyStateUiHelper`?).
         private final ViewGroup mEmptyStateView;
 
         private final SinglePageAdapterT mAdapter;
@@ -557,6 +538,7 @@ public class MultiProfilePagerAdapter<
             mAdapter = adapter;
             mEmptyStateView = rootView.findViewById(com.android.internal.R.id.resolver_empty_state);
             mView = (PageViewT) rootView.findViewById(com.android.internal.R.id.resolver_list);
+            mEmptyStateUi = new EmptyStateUiHelper(rootView);
         }
 
         protected ViewGroup getEmptyStateView() {
diff --git a/java/src/com/android/intentresolver/emptystate/EmptyStateUiHelper.java b/java/src/com/android/intentresolver/emptystate/EmptyStateUiHelper.java
new file mode 100644
index 00000000..d7ef8c75
--- /dev/null
+++ b/java/src/com/android/intentresolver/emptystate/EmptyStateUiHelper.java
@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * 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.android.intentresolver.emptystate;
+
+import android.view.View;
+import android.view.ViewGroup;
+
+/**
+ * Helper for building `MultiProfilePagerAdapter` tab UIs for profile tabs that are "blocked" by
+ * some empty-state status.
+ */
+public class EmptyStateUiHelper {
+    private final View mEmptyStateView;
+
+    public EmptyStateUiHelper(ViewGroup rootView) {
+        mEmptyStateView =
+                rootView.requireViewById(com.android.internal.R.id.resolver_empty_state);
+    }
+
+    public void resetViewVisibilities() {
+        mEmptyStateView.requireViewById(com.android.internal.R.id.resolver_empty_state_title)
+                .setVisibility(View.VISIBLE);
+        mEmptyStateView.requireViewById(com.android.internal.R.id.resolver_empty_state_subtitle)
+                .setVisibility(View.VISIBLE);
+        mEmptyStateView.requireViewById(com.android.internal.R.id.resolver_empty_state_button)
+                .setVisibility(View.INVISIBLE);
+        mEmptyStateView.requireViewById(com.android.internal.R.id.resolver_empty_state_progress)
+                .setVisibility(View.GONE);
+        mEmptyStateView.requireViewById(com.android.internal.R.id.empty)
+                .setVisibility(View.GONE);
+        mEmptyStateView.setVisibility(View.VISIBLE);
+    }
+
+    public void showSpinner() {
+        mEmptyStateView.requireViewById(com.android.internal.R.id.resolver_empty_state_title)
+                .setVisibility(View.INVISIBLE);
+        // TODO: subtitle?
+        mEmptyStateView.requireViewById(com.android.internal.R.id.resolver_empty_state_button)
+                .setVisibility(View.INVISIBLE);
+        mEmptyStateView.requireViewById(com.android.internal.R.id.resolver_empty_state_progress)
+                .setVisibility(View.VISIBLE);
+        mEmptyStateView.requireViewById(com.android.internal.R.id.empty)
+                .setVisibility(View.GONE);
+    }
+
+    public void hide() {
+        mEmptyStateView.setVisibility(View.GONE);
+    }
+}
+