Drag drop some changes

Test: atest ItemDragListenerTest, DragHostTest, DragAndDropManagerTests

Bug: 155134389

Change-Id: Ib6d91798743544b669a4efbf2f292c6ee95faca5

7 files changed, 83 insertions, 23 deletions

diff --git a/res/values/strings.xml b/res/values/strings.xml
index feb767355..a7e26cd9c 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -534,4 +534,8 @@
 
     <!-- Accessibility label to indicate the subject(e.g. file/folder) is from work profile -->
     <string name="a11y_work">Work</string>
+
+    <!-- Snackbar shown when users drag and drop files from another app
+    to DocumentsUI. [CHAR_LIMIT=100] -->
+    <string name="drag_from_another_app">Drag from another app not allowed.</string>
 </resources>
diff --git a/src/com/android/documentsui/DragAndDropManager.java b/src/com/android/documentsui/DragAndDropManager.java
index d49b6894f..bed8764ae 100644
--- a/src/com/android/documentsui/DragAndDropManager.java
+++ b/src/com/android/documentsui/DragAndDropManager.java
@@ -16,18 +16,19 @@
 
 package com.android.documentsui;
 
-import androidx.annotation.IntDef;
-import androidx.annotation.Nullable;
 import android.content.ClipData;
 import android.content.Context;
 import android.graphics.drawable.Drawable;
 import android.net.Uri;
 import android.provider.DocumentsContract;
-import androidx.annotation.VisibleForTesting;
 import android.view.DragEvent;
 import android.view.KeyEvent;
 import android.view.View;
 
+import androidx.annotation.IntDef;
+import androidx.annotation.Nullable;
+import androidx.annotation.VisibleForTesting;
+
 import com.android.documentsui.MenuManager.SelectionDetails;
 import com.android.documentsui.base.DocumentInfo;
 import com.android.documentsui.base.DocumentStack;
@@ -119,6 +120,12 @@ public interface DragAndDropManager {
     void resetState(View v);
 
     /**
+     * Checks whether the drag was initiated from FilesApp.
+     * @return true if initiated from Files app.
+     */
+    boolean isDragFromSameApp();
+
+    /**
      * Drops items onto the a root.
      *
      * @param clipData the clip data that contains sources information.
@@ -165,6 +172,7 @@ public interface DragAndDropManager {
         private final Drawable mDefaultShadowIcon;
 
         private @State int mState = STATE_UNKNOWN;
+        private boolean mDragInitiated = false;
 
         // Key events info. This is used to derive state when user drags items into a view to derive
         // type of file operations.
@@ -233,6 +241,7 @@ public interface DragAndDropManager {
                 IconHelper iconHelper,
                 @Nullable DocumentInfo parent) {
 
+            mDragInitiated = true;
             mView = v;
             mInvalidDest = invalidDest;
             mMustBeCopied = !selectionDetails.canDelete();
@@ -355,6 +364,11 @@ public interface DragAndDropManager {
             updateState(STATE_UNKNOWN);
         }
 
+        @Override
+        public boolean isDragFromSameApp() {
+            return mDragInitiated;
+        }
+
         private void updateState(@State int state) {
             mState = state;
 
@@ -461,6 +475,7 @@ public interface DragAndDropManager {
             mDestDoc = null;
             mDestRoot = null;
             mMustBeCopied = false;
+            mDragInitiated = false;
         }
 
         private @OpType int calculateOpType(ClipData clipData, RootInfo destRoot) {
diff --git a/src/com/android/documentsui/ItemDragListener.java b/src/com/android/documentsui/ItemDragListener.java
index 530b55099..284fd55de 100644
--- a/src/com/android/documentsui/ItemDragListener.java
+++ b/src/com/android/documentsui/ItemDragListener.java
@@ -23,9 +23,10 @@ import android.view.DragEvent;
 import android.view.View;
 import android.view.View.OnDragListener;
 
-import com.android.documentsui.ItemDragListener.DragHost;
 import androidx.annotation.VisibleForTesting;
 
+import com.android.documentsui.ItemDragListener.DragHost;
+
 import java.util.Timer;
 import java.util.TimerTask;
 
@@ -63,13 +64,9 @@ public class ItemDragListener<H extends DragHost> implements OnDragListener {
 
     @Override
     public boolean onDrag(final View v, DragEvent event) {
-        if (!mDragHost.canHandleDragEvent(v)) {
-            return false;
-        }
-
         switch (event.getAction()) {
             case DragEvent.ACTION_DRAG_STARTED:
-                return true;
+                return mDragHost.canHandleDragEvent(v);
             case DragEvent.ACTION_DRAG_ENTERED:
                 handleEnteredEvent(v, event);
                 return true;
diff --git a/src/com/android/documentsui/dirlist/DragHost.java b/src/com/android/documentsui/dirlist/DragHost.java
index b08637b2b..0222ecb3e 100644
--- a/src/com/android/documentsui/dirlist/DragHost.java
+++ b/src/com/android/documentsui/dirlist/DragHost.java
@@ -30,12 +30,15 @@ import com.android.documentsui.AbstractActionHandler;
 import com.android.documentsui.AbstractDragHost;
 import com.android.documentsui.ActionHandler;
 import com.android.documentsui.DragAndDropManager;
+import com.android.documentsui.R;
 import com.android.documentsui.base.DocumentInfo;
 import com.android.documentsui.base.DocumentStack;
 import com.android.documentsui.base.Lookup;
 import com.android.documentsui.base.State;
 import com.android.documentsui.ui.DialogController;
 
+import com.google.android.material.snackbar.Snackbar;
+
 import java.util.function.Predicate;
 
 /**
@@ -105,6 +108,16 @@ class DragHost<T extends Activity & AbstractActionHandler.CommonAddons> extends
         mDragAndDropManager.updateState(v, mState.stack.getRoot(), mDestinationLookup.lookup(v));
     }
 
+    @Override
+    public boolean canHandleDragEvent(View v) {
+        if (!mDragAndDropManager.isDragFromSameApp()) {
+            Snackbar.make(
+                    v, R.string.drag_from_another_app, Snackbar.LENGTH_SHORT).show();
+            return false;
+        }
+        return true;
+    }
+
     boolean canSpringOpen(View v) {
         DocumentInfo doc = mDestinationLookup.lookup(v);
         return (doc != null) && mDragAndDropManager.canSpringOpen(mState.stack.getRoot(), doc);
diff --git a/tests/common/com/android/documentsui/testing/TestDragAndDropManager.java b/tests/common/com/android/documentsui/testing/TestDragAndDropManager.java
index 95f416508..7d76f53d9 100644
--- a/tests/common/com/android/documentsui/testing/TestDragAndDropManager.java
+++ b/tests/common/com/android/documentsui/testing/TestDragAndDropManager.java
@@ -16,16 +16,16 @@
 
 package com.android.documentsui.testing;
 
-import androidx.annotation.Nullable;
 import android.content.ClipData;
 import android.net.Uri;
 import android.util.Pair;
 import android.view.KeyEvent;
 import android.view.View;
 
+import androidx.annotation.Nullable;
+
 import com.android.documentsui.ActionHandler;
 import com.android.documentsui.DragAndDropManager;
-import com.android.documentsui.MenuManager;
 import com.android.documentsui.MenuManager.SelectionDetails;
 import com.android.documentsui.base.DocumentInfo;
 import com.android.documentsui.base.DocumentStack;
@@ -69,6 +69,11 @@ public class TestDragAndDropManager implements DragAndDropManager {
     public void resetState(View v) {}
 
     @Override
+    public boolean isDragFromSameApp() {
+        return true;
+    }
+
+    @Override
     public boolean drop(ClipData clipData, Object localState, RootInfo root, ActionHandler actions,
             FileOperations.Callback callback) {
         return dropOnRootHandler.accept(Pair.create(clipData, root));
diff --git a/tests/unit/com/android/documentsui/DragAndDropManagerTests.java b/tests/unit/com/android/documentsui/DragAndDropManagerTests.java
index 3c30bf391..d7a701f75 100644
--- a/tests/unit/com/android/documentsui/DragAndDropManagerTests.java
+++ b/tests/unit/com/android/documentsui/DragAndDropManagerTests.java
@@ -398,6 +398,44 @@ public class DragAndDropManagerTests {
     }
 
     @Test
+    public void testIsDragFromSameApp_afterStartDrag() {
+        mManager.startDrag(
+                mStartDragView,
+                Arrays.asList(TestEnv.FILE_APK, TestEnv.FILE_JPG),
+                TestProvidersAccess.DOWNLOADS,
+                Arrays.asList(TestEnv.FOLDER_0.derivedUri, TestEnv.FILE_APK.derivedUri,
+                        TestEnv.FILE_JPG.derivedUri),
+                mDetails,
+                mIconHelper,
+                TestEnv.FOLDER_0);
+
+        assertTrue(mManager.isDragFromSameApp());
+    }
+
+    @Test
+    public void testIsDragFromSameApp_beforeStartDrag() {
+        assertFalse(mManager.isDragFromSameApp());
+    }
+
+    @Test
+    public void testIsDragFromSameApp_afterStartDrag_afterDragEnded() {
+        mManager.startDrag(
+                mStartDragView,
+                Arrays.asList(TestEnv.FILE_APK, TestEnv.FILE_JPG),
+                TestProvidersAccess.DOWNLOADS,
+                Arrays.asList(TestEnv.FOLDER_0.derivedUri, TestEnv.FILE_APK.derivedUri,
+                        TestEnv.FILE_JPG.derivedUri),
+                mDetails,
+                mIconHelper,
+                TestEnv.FOLDER_0);
+        assertTrue(mManager.isDragFromSameApp());
+
+        mManager.dragEnded();
+        assertFalse(mManager.isDragFromSameApp());
+    }
+
+
+    @Test
     public void testUpdateState_UpdatesToCopy_SameRoot_RightCtrlPressed() {
         mManager.startDrag(
                 mStartDragView,
diff --git a/tests/unit/com/android/documentsui/ItemDragListenerTest.java b/tests/unit/com/android/documentsui/ItemDragListenerTest.java
index 94a867ac6..7407577e2 100644
--- a/tests/unit/com/android/documentsui/ItemDragListenerTest.java
+++ b/tests/unit/com/android/documentsui/ItemDragListenerTest.java
@@ -161,18 +161,6 @@ public class ItemDragListenerTest {
     }
 
     @Test
-    public void testDoNotHandleDragEvent() {
-        mTestDragHost.mLastEnteredView = null;
-
-        mTestDragHost.mCanHandleDragEvent = false;
-        final boolean handled = triggerDragEvent(DragEvent.ACTION_DRAG_ENTERED);
-        mTestDragHost.mCanHandleDragEvent = true;
-
-        assertFalse(handled);
-        assertNull(mTestDragHost.mLastEnteredView);
-    }
-
-    @Test
     public void testNoDropWithoutClipData() {
         triggerDragEvent(DragEvent.ACTION_DRAG_ENTERED);