src/com/android/documentsui/files/QuickViewIntentBuilder.java - platform/packages/apps/DocumentsUI - Git at Google

 /*
  * Copyright (C) 2015 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.files;

 import static com.android.documentsui.base.DocumentInfo.getCursorInt;
 import static com.android.documentsui.base.DocumentInfo.getCursorString;
 import static com.android.documentsui.base.Shared.MAX_DOCS_IN_INTENT;
 import static com.android.documentsui.base.SharedMinimal.DEBUG;

 import android.content.ClipData;
 import android.content.ClipDescription;
 import android.content.Context;
 import android.content.Intent;
 import android.content.QuickViewConstants;
 import android.content.pm.PackageManager;
 import android.content.res.Resources;
 import android.database.Cursor;
 import android.net.Uri;
 import android.provider.DocumentsContract;
 import android.provider.DocumentsContract.Document;
 import android.text.TextUtils;
 import android.util.Log;
 import android.util.Range;

 import androidx.annotation.Nullable;

 import com.android.documentsui.Model;
 import com.android.documentsui.R;
 import com.android.documentsui.base.DebugFlags;
 import com.android.documentsui.base.DocumentInfo;
 import com.android.documentsui.base.UserId;
 import com.android.documentsui.roots.RootCursorWrapper;

 import java.util.ArrayList;
 import java.util.List;

 /**
  * Provides support for gather a list of quick-viewable files into a quick view intent.
  */
 public final class QuickViewIntentBuilder {

     // trusted quick view package can be set via system property on debug builds.
     // Unfortunately when the value is set, it interferes with testing (supercedes
     // any value set in the resource system).
     // For that reason when trusted quick view package is set to this magic value
     // we won't honor the system property.
     public static final String IGNORE_DEBUG_PROP = "*disabled*";
     private static final String TAG = "QuickViewIntentBuilder";

     private static final String[] IN_ARCHIVE_FEATURES = {};
     private static final String[] FULL_FEATURES = {
             QuickViewConstants.FEATURE_VIEW,
             QuickViewConstants.FEATURE_EDIT,
             QuickViewConstants.FEATURE_DELETE,
             QuickViewConstants.FEATURE_SEND,
             QuickViewConstants.FEATURE_DOWNLOAD,
             QuickViewConstants.FEATURE_PRINT
     };
     private static final String[] PICKER_FEATURES = {
             QuickViewConstants.FEATURE_VIEW
     };

     private final DocumentInfo mDocument;
     private final Model mModel;

     private final PackageManager mPackageMgr;
     private final Resources mResources;

     private final boolean mFromPicker;

     public QuickViewIntentBuilder(
             Context context,
             Resources resources,
             DocumentInfo doc,
             Model model,
             boolean fromPicker) {

         assert(context != null);
         assert(resources != null);
         assert(doc != null);
         assert(model != null);

         mPackageMgr = doc.userId.getPackageManager(context);
         mResources = resources;
         mDocument = doc;
         mModel = model;
         mFromPicker = fromPicker;
     }

     /**
      * Builds the intent for quick viewing. Short circuits building if a handler cannot
      * be resolved; in this case {@code null} is returned.
      */
     @Nullable public Intent build() {
         if (DEBUG) {
             Log.d(TAG, "Preparing intent for doc:" + mDocument.documentId);
         }

         String trustedPkg = getQuickViewPackage();

         if (!TextUtils.isEmpty(trustedPkg)) {
             Intent intent = new Intent(Intent.ACTION_QUICK_VIEW);
             intent.setDataAndType(mDocument.getDocumentUri(), mDocument.mimeType);
             intent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION
                     | Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
             intent.setPackage(trustedPkg);
             if (hasRegisteredHandler(intent)) {
                 includeQuickViewFeaturesFlag(intent, mDocument, mFromPicker);

                 final ArrayList<Uri> uris = new ArrayList<>();
                 final int documentLocation = collectViewableUris(uris);
                 final Range<Integer> range = computeSiblingsRange(uris, documentLocation);

                 ClipData clipData = null;
                 ClipData.Item item;
                 Uri uri;
                 for (int i = range.getLower(); i <= range.getUpper(); i++) {
                     uri = uris.get(i);
                     item = new ClipData.Item(uri);
                     if (DEBUG) {
                         Log.d(TAG, "Including file: " + uri);
                     }
                     if (clipData == null) {
                         clipData = new ClipData(
                                 "URIs", new String[] { ClipDescription.MIMETYPE_TEXT_URILIST },
                                 item);
                     } else {
                         clipData.addItem(item);
                     }
                 }

                 // The documentLocation variable contains an index in "uris". However,
                 // ClipData contains a slice of "uris", so we need to shift the location
                 // so it points to the same Uri.
                 intent.putExtra(Intent.EXTRA_INDEX, documentLocation - range.getLower());
                 intent.setClipData(clipData);

                 return intent;
             } else {
                 Log.e(TAG, "Can't resolve trusted quick view package: " + trustedPkg);
             }
         }

         return null;
     }

     private String getQuickViewPackage() {
         String resValue = mResources.getString(R.string.trusted_quick_viewer_package);

         // Allow automated tests to hard-disable quick viewing.
         if (IGNORE_DEBUG_PROP.equals(resValue)) {
             return "";
         }

         // Allow users of debug devices to override default quick viewer
         // for the purposes of testing.
         if (DEBUG) {
             String quickViewer = DebugFlags.getQuickViewer();
             if (quickViewer != null) {
                 return quickViewer;
             }
         }
         return resValue;
     }

     private int collectViewableUris(ArrayList<Uri> uris) {
         final String[] siblingIds = mModel.getModelIds();
         uris.ensureCapacity(siblingIds.length);

         int documentLocation = 0;
         Cursor cursor;
         String mimeType;
         String id;
         String authority;
         UserId userId;
         Uri uri;
         boolean hasNonMatchingDocumentUser = false;

         // Cursor's are not guaranteed to be immutable. Hence, traverse it only once.
         for (int i = 0; i < siblingIds.length; i++) {
             cursor = mModel.getItem(siblingIds[i]);

             if (cursor == null) {
                 if (DEBUG) {
                     Log.d(TAG,
                         "Unable to obtain cursor for sibling document, modelId: "
                             + siblingIds[i]);
                 }
                 continue;
             }

             mimeType = getCursorString(cursor, Document.COLUMN_MIME_TYPE);
             if (Document.MIME_TYPE_DIR.equals(mimeType)) {
                 if (DEBUG) {
                     Log.d(TAG,
                         "Skipping directory, not supported by quick view. modelId: "
                             + siblingIds[i]);
                 }
                 continue;
             }

             userId = UserId.of(getCursorInt(cursor, RootCursorWrapper.COLUMN_USER_ID));
             if (!userId.equals(mDocument.userId)) {
                 // If there is any document in the model does not have the same user as
                 // mDocument, we will not add any siblings and the user for security reason.
                 // Although the quick view package is trusted, the trusted quick view package may
                 // not notice it is a cross-profile uri and may allow other app to handle this uri.
                 if (DEBUG) {
                     Log.d(TAG,
                             "Skipping document from the other user. modelId: "
                                     + siblingIds[i]);
                 }
                 hasNonMatchingDocumentUser = true;
                 continue;
             }

             id = getCursorString(cursor, Document.COLUMN_DOCUMENT_ID);
             authority = getCursorString(cursor, RootCursorWrapper.COLUMN_AUTHORITY);
             if (UserId.CURRENT_USER.equals(userId)) {
                 uri = DocumentsContract.buildDocumentUri(authority, id);
             } else {
                 uri = userId.buildDocumentUriAsUser(authority, id);
             }

             if (id.equals(mDocument.documentId)) {
                 uris.add(uri);
                 documentLocation = uris.size() - 1;  // Position in "uris", not in the model.
                 if (DEBUG) {
                     Log.d(TAG, "Found starting point for QV. " + documentLocation);
                 }
             } else if (!hasNonMatchingDocumentUser) {
                 uris.add(uri);
             }
         }

         if (!uris.isEmpty() && hasNonMatchingDocumentUser) {
             if (DEBUG) {
                 Log.d(TAG,
                         "Remove all other uris except the document uri");
             }
             Uri documentUri = uris.get(documentLocation);
             uris.clear();
             uris.add(documentUri);
             return 0; // index of the item in a singleton list is 0.
         }

         return documentLocation;
     }

     private boolean hasRegisteredHandler(Intent intent) {
         // Try to resolve the intent. If a matching app isn't installed, it won't resolve.
         return intent.resolveActivity(mPackageMgr) != null;
     }

     private static void includeQuickViewFeaturesFlag(Intent intent, DocumentInfo doc,
             boolean fromPicker) {
         intent.putExtra(
                 Intent.EXTRA_QUICK_VIEW_FEATURES,
                 doc.isInArchive() ? IN_ARCHIVE_FEATURES
                         : fromPicker ? PICKER_FEATURES : FULL_FEATURES);
     }

     private static Range<Integer> computeSiblingsRange(List<Uri> uris, int documentLocation) {
         // Restrict number of siblings to avoid hitting the IPC limit.
         // TODO: Remove this restriction once ClipData can hold an arbitrary number of
         // items.
         int firstSibling;
         int lastSibling;
         if (documentLocation < uris.size() / 2) {
             firstSibling = Math.max(0, documentLocation - MAX_DOCS_IN_INTENT / 2);
             lastSibling = Math.min(uris.size() - 1, firstSibling + MAX_DOCS_IN_INTENT - 1);
         } else {
             lastSibling = Math.min(uris.size() - 1, documentLocation + MAX_DOCS_IN_INTENT / 2);
             firstSibling = Math.max(0, lastSibling - MAX_DOCS_IN_INTENT + 1);
         }

         if (DEBUG) {
             Log.d(TAG, "Copmuted siblings from index: " + firstSibling
                 + " to: " + lastSibling);
         }

         return new Range(firstSibling, lastSibling);
     }
 }
	/*
	* Copyright (C) 2015 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.files;

	import static com.android.documentsui.base.DocumentInfo.getCursorInt;
	import static com.android.documentsui.base.DocumentInfo.getCursorString;
	import static com.android.documentsui.base.Shared.MAX_DOCS_IN_INTENT;
	import static com.android.documentsui.base.SharedMinimal.DEBUG;

	import android.content.ClipData;
	import android.content.ClipDescription;
	import android.content.Context;
	import android.content.Intent;
	import android.content.QuickViewConstants;
	import android.content.pm.PackageManager;
	import android.content.res.Resources;
	import android.database.Cursor;
	import android.net.Uri;
	import android.provider.DocumentsContract;
	import android.provider.DocumentsContract.Document;
	import android.text.TextUtils;
	import android.util.Log;
	import android.util.Range;

	import androidx.annotation.Nullable;

	import com.android.documentsui.Model;
	import com.android.documentsui.R;
	import com.android.documentsui.base.DebugFlags;
	import com.android.documentsui.base.DocumentInfo;
	import com.android.documentsui.base.UserId;
	import com.android.documentsui.roots.RootCursorWrapper;

	import java.util.ArrayList;
	import java.util.List;

	/**
	* Provides support for gather a list of quick-viewable files into a quick view intent.
	*/
	public final class QuickViewIntentBuilder {

	// trusted quick view package can be set via system property on debug builds.
	// Unfortunately when the value is set, it interferes with testing (supercedes
	// any value set in the resource system).
	// For that reason when trusted quick view package is set to this magic value
	// we won't honor the system property.
	public static final String IGNORE_DEBUG_PROP = "disabled";
	private static final String TAG = "QuickViewIntentBuilder";

	private static final String[] IN_ARCHIVE_FEATURES = {};
	private static final String[] FULL_FEATURES = {
	QuickViewConstants.FEATURE_VIEW,
	QuickViewConstants.FEATURE_EDIT,
	QuickViewConstants.FEATURE_DELETE,
	QuickViewConstants.FEATURE_SEND,
	QuickViewConstants.FEATURE_DOWNLOAD,
	QuickViewConstants.FEATURE_PRINT
	};
	private static final String[] PICKER_FEATURES = {
	QuickViewConstants.FEATURE_VIEW
	};

	private final DocumentInfo mDocument;
	private final Model mModel;

	private final PackageManager mPackageMgr;
	private final Resources mResources;

	private final boolean mFromPicker;

	public QuickViewIntentBuilder(
	Context context,
	Resources resources,
	DocumentInfo doc,
	Model model,
	boolean fromPicker) {

	assert(context != null);
	assert(resources != null);
	assert(doc != null);
	assert(model != null);

	mPackageMgr = doc.userId.getPackageManager(context);
	mResources = resources;
	mDocument = doc;
	mModel = model;
	mFromPicker = fromPicker;
	}

	/**
	* Builds the intent for quick viewing. Short circuits building if a handler cannot
	* be resolved; in this case {@code null} is returned.
	*/
	@Nullable public Intent build() {
	if (DEBUG) {
	Log.d(TAG, "Preparing intent for doc:" + mDocument.documentId);
	}

	String trustedPkg = getQuickViewPackage();

	if (!TextUtils.isEmpty(trustedPkg)) {
	Intent intent = new Intent(Intent.ACTION_QUICK_VIEW);
	intent.setDataAndType(mDocument.getDocumentUri(), mDocument.mimeType);
	intent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION
	\| Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
	intent.setPackage(trustedPkg);
	if (hasRegisteredHandler(intent)) {
	includeQuickViewFeaturesFlag(intent, mDocument, mFromPicker);

	final ArrayList<Uri> uris = new ArrayList<>();
	final int documentLocation = collectViewableUris(uris);
	final Range<Integer> range = computeSiblingsRange(uris, documentLocation);

	ClipData clipData = null;
	ClipData.Item item;
	Uri uri;
	for (int i = range.getLower(); i <= range.getUpper(); i++) {
	uri = uris.get(i);
	item = new ClipData.Item(uri);
	if (DEBUG) {
	Log.d(TAG, "Including file: " + uri);
	}
	if (clipData == null) {
	clipData = new ClipData(
	"URIs", new String[] { ClipDescription.MIMETYPE_TEXT_URILIST },
	item);
	} else {
	clipData.addItem(item);
	}
	}

	// The documentLocation variable contains an index in "uris". However,
	// ClipData contains a slice of "uris", so we need to shift the location
	// so it points to the same Uri.
	intent.putExtra(Intent.EXTRA_INDEX, documentLocation - range.getLower());
	intent.setClipData(clipData);

	return intent;
	} else {
	Log.e(TAG, "Can't resolve trusted quick view package: " + trustedPkg);
	}
	}

	return null;
	}

	private String getQuickViewPackage() {
	String resValue = mResources.getString(R.string.trusted_quick_viewer_package);

	// Allow automated tests to hard-disable quick viewing.
	if (IGNORE_DEBUG_PROP.equals(resValue)) {
	return "";
	}

	// Allow users of debug devices to override default quick viewer
	// for the purposes of testing.
	if (DEBUG) {
	String quickViewer = DebugFlags.getQuickViewer();
	if (quickViewer != null) {
	return quickViewer;
	}
	}
	return resValue;
	}

	private int collectViewableUris(ArrayList<Uri> uris) {
	final String[] siblingIds = mModel.getModelIds();
	uris.ensureCapacity(siblingIds.length);

	int documentLocation = 0;
	Cursor cursor;
	String mimeType;
	String id;
	String authority;
	UserId userId;
	Uri uri;
	boolean hasNonMatchingDocumentUser = false;

	// Cursor's are not guaranteed to be immutable. Hence, traverse it only once.
	for (int i = 0; i < siblingIds.length; i++) {
	cursor = mModel.getItem(siblingIds[i]);

	if (cursor == null) {
	if (DEBUG) {
	Log.d(TAG,
	"Unable to obtain cursor for sibling document, modelId: "
	+ siblingIds[i]);
	}
	continue;
	}

	mimeType = getCursorString(cursor, Document.COLUMN_MIME_TYPE);
	if (Document.MIME_TYPE_DIR.equals(mimeType)) {
	if (DEBUG) {
	Log.d(TAG,
	"Skipping directory, not supported by quick view. modelId: "
	+ siblingIds[i]);
	}
	continue;
	}

	userId = UserId.of(getCursorInt(cursor, RootCursorWrapper.COLUMN_USER_ID));
	if (!userId.equals(mDocument.userId)) {
	// If there is any document in the model does not have the same user as
	// mDocument, we will not add any siblings and the user for security reason.
	// Although the quick view package is trusted, the trusted quick view package may
	// not notice it is a cross-profile uri and may allow other app to handle this uri.
	if (DEBUG) {
	Log.d(TAG,
	"Skipping document from the other user. modelId: "
	+ siblingIds[i]);
	}
	hasNonMatchingDocumentUser = true;
	continue;
	}

	id = getCursorString(cursor, Document.COLUMN_DOCUMENT_ID);
	authority = getCursorString(cursor, RootCursorWrapper.COLUMN_AUTHORITY);
	if (UserId.CURRENT_USER.equals(userId)) {
	uri = DocumentsContract.buildDocumentUri(authority, id);
	} else {
	uri = userId.buildDocumentUriAsUser(authority, id);
	}

	if (id.equals(mDocument.documentId)) {
	uris.add(uri);
	documentLocation = uris.size() - 1; // Position in "uris", not in the model.
	if (DEBUG) {
	Log.d(TAG, "Found starting point for QV. " + documentLocation);
	}
	} else if (!hasNonMatchingDocumentUser) {
	uris.add(uri);
	}
	}

	if (!uris.isEmpty() && hasNonMatchingDocumentUser) {
	if (DEBUG) {
	Log.d(TAG,
	"Remove all other uris except the document uri");
	}
	Uri documentUri = uris.get(documentLocation);
	uris.clear();
	uris.add(documentUri);
	return 0; // index of the item in a singleton list is 0.
	}

	return documentLocation;
	}

	private boolean hasRegisteredHandler(Intent intent) {
	// Try to resolve the intent. If a matching app isn't installed, it won't resolve.
	return intent.resolveActivity(mPackageMgr) != null;
	}

	private static void includeQuickViewFeaturesFlag(Intent intent, DocumentInfo doc,
	boolean fromPicker) {
	intent.putExtra(
	Intent.EXTRA_QUICK_VIEW_FEATURES,
	doc.isInArchive() ? IN_ARCHIVE_FEATURES
	: fromPicker ? PICKER_FEATURES : FULL_FEATURES);
	}

	private static Range<Integer> computeSiblingsRange(List<Uri> uris, int documentLocation) {
	// Restrict number of siblings to avoid hitting the IPC limit.
	// TODO: Remove this restriction once ClipData can hold an arbitrary number of
	// items.
	int firstSibling;
	int lastSibling;
	if (documentLocation < uris.size() / 2) {
	firstSibling = Math.max(0, documentLocation - MAX_DOCS_IN_INTENT / 2);
	lastSibling = Math.min(uris.size() - 1, firstSibling + MAX_DOCS_IN_INTENT - 1);
	} else {
	lastSibling = Math.min(uris.size() - 1, documentLocation + MAX_DOCS_IN_INTENT / 2);
	firstSibling = Math.max(0, lastSibling - MAX_DOCS_IN_INTENT + 1);
	}

	if (DEBUG) {
	Log.d(TAG, "Copmuted siblings from index: " + firstSibling
	+ " to: " + lastSibling);
	}

	return new Range(firstSibling, lastSibling);
	}
	}