[DocsUI Peek] Initial Peek overlay and view manager

Define the initial Peek fragment, with its associated layout.

If Peek is enabled, the PeekViewManager, instantiated when DocsUI is
launched, loads the PeekFragment (with its inflated view) in its
hidden container.

Flag: com.android.documentsui.flags.use_material3
Flag: com.android.documentsui.flags.use_peek_preview_ro
Test: DocumentsUIGoogleTests:com.android.documentsui.peek.PeekUiTest
Test: DocumentsUIGoogleTests:c.a.d.files.ActionHandlerTest#testShowPeek
Bug: 382163291
Bug: 382163274
Change-Id: I7fdd1afd856803091425b8257b69206746530989

6 files changed, 135 insertions, 5 deletions

diff --git a/src/com/android/documentsui/BaseActivity.java b/src/com/android/documentsui/BaseActivity.java
index 0b5d96da9..ab40eca3f 100644
--- a/src/com/android/documentsui/BaseActivity.java
+++ b/src/com/android/documentsui/BaseActivity.java
@@ -20,6 +20,7 @@ import static com.android.documentsui.base.Shared.EXTRA_BENCHMARK;
 import static com.android.documentsui.base.SharedMinimal.DEBUG;
 import static com.android.documentsui.base.State.MODE_GRID;
 import static com.android.documentsui.util.FlagUtils.isUseMaterial3FlagEnabled;
+import static com.android.documentsui.util.FlagUtils.isUsePeekPreviewFlagEnabled;
 
 import android.content.Context;
 import android.content.Intent;
@@ -65,6 +66,7 @@ import com.android.documentsui.base.UserId;
 import com.android.documentsui.dirlist.AnimationView;
 import com.android.documentsui.dirlist.AppsRowManager;
 import com.android.documentsui.dirlist.DirectoryFragment;
+import com.android.documentsui.peek.PeekViewManager;
 import com.android.documentsui.prefs.LocalPreferences;
 import com.android.documentsui.prefs.PreferencesMonitor;
 import com.android.documentsui.queries.CommandInterceptor;
@@ -96,6 +98,7 @@ public abstract class BaseActivity
 
     protected SearchViewManager mSearchManager;
     protected AppsRowManager mAppsRowManager;
+    protected @Nullable PeekViewManager mPeekViewManager;
     protected UserIdManager mUserIdManager;
     protected UserManagerState mUserManagerState;
     protected State mState;
@@ -414,6 +417,11 @@ public abstract class BaseActivity
         // Base classes must update result in their onCreate.
         setResult(AppCompatActivity.RESULT_CANCELED);
         updateRecentsSetting();
+
+        if (isUsePeekPreviewFlagEnabled()) {
+            mPeekViewManager = new PeekViewManager(this);
+            mPeekViewManager.initFragment(getSupportFragmentManager());
+        }
     }
 
     private NavigationViewManager getNavigationViewManager(Breadcrumb breadcrumb,
diff --git a/src/com/android/documentsui/files/ActionHandler.java b/src/com/android/documentsui/files/ActionHandler.java
index 86f7a1a14..cbe02dc25 100644
--- a/src/com/android/documentsui/files/ActionHandler.java
+++ b/src/com/android/documentsui/files/ActionHandler.java
@@ -71,6 +71,7 @@ import com.android.documentsui.clipping.DocumentClipper;
 import com.android.documentsui.clipping.UrisSupplier;
 import com.android.documentsui.dirlist.AnimationView;
 import com.android.documentsui.inspector.InspectorActivity;
+import com.android.documentsui.peek.PeekViewManager;
 import com.android.documentsui.queries.SearchViewManager;
 import com.android.documentsui.roots.ProvidersAccess;
 import com.android.documentsui.services.FileOperation;
@@ -101,6 +102,7 @@ public class ActionHandler<T extends FragmentActivity & AbstractActionHandler.Co
     private final ClipStore mClipStore;
     private final DragAndDropManager mDragAndDropManager;
     private final Runnable mCloseSelectionBar;
+    private final @Nullable PeekViewManager mPeekViewManager;
 
     ActionHandler(
             T activity,
@@ -114,6 +116,7 @@ public class ActionHandler<T extends FragmentActivity & AbstractActionHandler.Co
             DocumentClipper clipper,
             ClipStore clipStore,
             DragAndDropManager dragAndDropManager,
+            @Nullable PeekViewManager peekViewManager,
             Injector injector) {
 
         super(activity, state, providers, docs, searchMgr, executors, injector);
@@ -125,6 +128,7 @@ public class ActionHandler<T extends FragmentActivity & AbstractActionHandler.Co
         mClipper = clipper;
         mClipStore = clipStore;
         mDragAndDropManager = dragAndDropManager;
+        mPeekViewManager = peekViewManager;
     }
 
     @Override
@@ -609,14 +613,16 @@ public class ActionHandler<T extends FragmentActivity & AbstractActionHandler.Co
         mActivity.startActivity(intent);
     }
 
-    private void showPeek() {
-        Log.d(TAG, "Peek not implemented");
+    private void showPeek(DocumentInfo doc) {
+        if (mPeekViewManager != null) {
+            mPeekViewManager.peekDocument(doc);
+        }
     }
 
     @Override
     public void showPreview(DocumentInfo doc) {
-        if (isUseMaterial3FlagEnabled() && isUsePeekPreviewFlagEnabled()) {
-            showPeek();
+        if (isUsePeekPreviewFlagEnabled()) {
+            showPeek(doc);
         } else {
             showInspector(doc);
         }
diff --git a/src/com/android/documentsui/files/FilesActivity.java b/src/com/android/documentsui/files/FilesActivity.java
index 50e266d38..6328a031a 100644
--- a/src/com/android/documentsui/files/FilesActivity.java
+++ b/src/com/android/documentsui/files/FilesActivity.java
@@ -163,6 +163,7 @@ public class FilesActivity extends BaseActivity implements AbstractActionHandler
                         clipper,
                         DocumentsApplication.getClipStore(this),
                         DocumentsApplication.getDragAndDropManager(this),
+                        mPeekViewManager,
                         mInjector);
 
         mInjector.searchManager = mSearchManager;
diff --git a/src/com/android/documentsui/peek/PeekFragment.kt b/src/com/android/documentsui/peek/PeekFragment.kt
new file mode 100644
index 000000000..50ee64efc
--- /dev/null
+++ b/src/com/android/documentsui/peek/PeekFragment.kt
@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2025 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.documentsui.peek
+
+import android.os.Bundle
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import androidx.fragment.app.Fragment
+
+import com.android.documentsui.R
+
+class PeekFragment : Fragment() {
+    override fun onCreateView(
+        inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?
+    ): View? {
+        return inflater.inflate(R.layout.peek_layout, container, /* attachToRoot= */ false)
+    }
+}
diff --git a/src/com/android/documentsui/peek/PeekViewManager.kt b/src/com/android/documentsui/peek/PeekViewManager.kt
new file mode 100644
index 000000000..9bbeba3bf
--- /dev/null
+++ b/src/com/android/documentsui/peek/PeekViewManager.kt
@@ -0,0 +1,83 @@
+/*
+ * Copyright (C) 2025 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.documentsui.peek
+
+import android.app.Activity
+import android.os.Bundle
+import android.util.Log
+import android.view.View
+import android.widget.FrameLayout
+import androidx.annotation.IdRes
+import androidx.fragment.app.FragmentManager
+import com.android.documentsui.R
+import androidx.fragment.app.FragmentTransaction
+import com.android.documentsui.base.DocumentInfo
+import com.android.documentsui.util.FlagUtils.Companion.isUsePeekPreviewFlagEnabled
+
+/**
+ * Manager that controls the Peek UI.
+ */
+open class PeekViewManager(
+    private val mActivity: Activity
+) {
+    companion object {
+        const val TAG = "PeekViewManager"
+    }
+
+    private var mPeekFragment: PeekFragment? = null
+
+    open fun initFragment(
+        fm: FragmentManager
+    ) {
+        if (!isUsePeekPreviewFlagEnabled()) {
+            Log.e(TAG, "Attempting to create PeekViewManager while Peek disabled")
+            return
+        }
+
+        if (getOverlayContainer() == null) {
+            Log.e(TAG, "Unable to find Peek container")
+            return
+        }
+
+        // Load the Peek fragment into its container.
+        val peekFragment = PeekFragment()
+        mPeekFragment = peekFragment
+        val ft: FragmentTransaction = fm.beginTransaction()
+        ft.replace(getOverlayId(), peekFragment)
+        ft.commitAllowingStateLoss()
+    }
+
+    open fun peekDocument(doc: DocumentInfo) {
+        if (mPeekFragment == null) {
+            Log.e(TAG, "Peek fragment not initialized")
+            return
+        }
+        show()
+    }
+
+    @IdRes
+    private fun getOverlayId(): Int {
+        return R.id.peek_overlay
+    }
+
+    private fun getOverlayContainer(): FrameLayout? {
+        return mActivity.findViewById(getOverlayId())
+    }
+
+    private fun show() {
+        getOverlayContainer()?.visibility = View.VISIBLE
+    }
+}
\ No newline at end of file
diff --git a/src/com/android/documentsui/util/FlagUtils.kt b/src/com/android/documentsui/util/FlagUtils.kt
index eee51be89..191a1f8d7 100644
--- a/src/com/android/documentsui/util/FlagUtils.kt
+++ b/src/com/android/documentsui/util/FlagUtils.kt
@@ -56,7 +56,7 @@ class FlagUtils {
 
         @JvmStatic
         fun isUsePeekPreviewFlagEnabled(): Boolean {
-            return Flags.usePeekPreviewRo()
+            return Flags.usePeekPreviewRo() && isUseMaterial3FlagEnabled()
         }
     }
 }