content: /*
   * Copyright (C) 2017 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 android.app.slice;
  
  import static android.app.slice.Slice.SUBTYPE_COLOR;
  
  import android.annotation.NonNull;
  import android.app.PendingIntent;
  import android.content.ComponentName;
  import android.content.ContentProvider;
  import android.content.ContentResolver;
  import android.content.ContentValues;
  import android.content.Context;
  import android.content.Intent;
  import android.content.IntentFilter;
  import android.content.pm.PackageManager;
  import android.content.pm.PackageManager.NameNotFoundException;
  import android.content.pm.ProviderInfo;
  import android.database.ContentObserver;
  import android.database.Cursor;
  import android.graphics.drawable.Icon;
  import android.net.Uri;
  import android.os.Binder;
  import android.os.Bundle;
  import android.os.CancellationSignal;
  import android.os.Handler;
  import android.os.Process;
  import android.os.StrictMode;
  import android.os.StrictMode.ThreadPolicy;
  import android.util.ArraySet;
  import android.util.Log;
  import android.util.TypedValue;
  import android.view.ContextThemeWrapper;
  
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.List;
  import java.util.Set;
  
  /**
   * A SliceProvider allows an app to provide content to be displayed in system spaces. This content
   * is templated and can contain actions, and the behavior of how it is surfaced is specific to the
   * system surface.
   * <p>
   * Slices are not currently live content. They are bound once and shown to the user. If the content
   * changes due to a callback from user interaction, then
   * {@link ContentResolver#notifyChange(Uri, ContentObserver)} should be used to notify the system.
   * </p>
   * <p>
   * The provider needs to be declared in the manifest to provide the authority for the app. The
   * authority for most slices is expected to match the package of the application.
   * </p>
   *
   * <pre class="prettyprint">
   * {@literal
   * <provider
   *     android:name="com.example.mypkg.MySliceProvider"
   *     android:authorities="com.example.mypkg" />}
   * </pre>
   * <p>
   * Slices can be identified by a Uri or by an Intent. To link an Intent with a slice, the provider
   * must have an {@link IntentFilter} matching the slice intent. When a slice is being requested via
   * an intent, {@link #onMapIntentToUri(Intent)} can be called and is expected to return an
   * appropriate Uri representing the slice.
   *
   * <pre class="prettyprint">
   * {@literal
   * <provider
   *     android:name="com.example.mypkg.MySliceProvider"
   *     android:authorities="com.example.mypkg">
   *     <intent-filter>
   *         <action android:name="com.example.mypkg.intent.action.MY_SLICE_INTENT" />
   *         <category android:name="android.app.slice.category.SLICE" />
   *     </intent-filter>
   * </provider>}
   * </pre>
   *
   * @see Slice
   */
  public abstract class SliceProvider extends ContentProvider {
      /**
       * This is the Android platform's MIME type for a URI
       * containing a slice implemented through {@link SliceProvider}.
       */
      public static final String SLICE_TYPE = "vnd.android.slice";
  
      private static final String TAG = "SliceProvider";
      /**
       * @hide
       */
      public static final String EXTRA_BIND_URI = "slice_uri";
      /**
       * @hide
       */
      public static final String EXTRA_SUPPORTED_SPECS = "supported_specs";
      /**
       * @hide
       */
      public static final String METHOD_SLICE = "bind_slice";
      /**
       * @hide
       */
      public static final String METHOD_MAP_INTENT = "map_slice";
      /**
       * @hide
       */
      public static final String METHOD_MAP_ONLY_INTENT = "map_only";
      /**
       * @hide
       */
      public static final String METHOD_PIN = "pin";
      /**
       * @hide
       */
      public static final String METHOD_UNPIN = "unpin";
      /**
       * @hide
       */
      public static final String METHOD_GET_DESCENDANTS = "get_descendants";
      /**
       * @hide
       */
      public static final String METHOD_GET_PERMISSIONS = "get_permissions";
      /**
       * @hide
       */
      public static final String EXTRA_INTENT = "slice_intent";
      /**
       * @hide
       */
      public static final String EXTRA_SLICE = "slice";
      /**
       * @hide
       */
      public static final String EXTRA_SLICE_DESCENDANTS = "slice_descendants";
      /**
       * @hide
       */
      public static final String EXTRA_PKG = "pkg";
      /**
       * @hide
       */
      public static final String EXTRA_PROVIDER_PKG = "provider_pkg";
      /**
       * @hide
       */
      public static final String EXTRA_RESULT = "result";
  
      private static final boolean DEBUG = false;
  
      private static final long SLICE_BIND_ANR = 2000;
      private final String[] mAutoGrantPermissions;
  
      private String mCallback;
      private SliceManager mSliceManager;
  
      /**
       * A version of constructing a SliceProvider that allows autogranting slice permissions
       * to apps that hold specific platform permissions.
       * <p>
       * When an app tries to bind a slice from this provider that it does not have access to,
       * This provider will check if the caller holds permissions to any of the autoGrantPermissions
       * specified, if they do they will be granted persisted uri access to all slices of this
       * provider.
       *
       * @param autoGrantPermissions List of permissions that holders are auto-granted access
       *                             to slices.
       */
      public SliceProvider(@NonNull String... autoGrantPermissions) {
          mAutoGrantPermissions = autoGrantPermissions;
      }
  
      public SliceProvider() {
          mAutoGrantPermissions = new String[0];
      }
  
      @Override
      public void attachInfo(Context context, ProviderInfo info) {
          super.attachInfo(context, info);
          mSliceManager = context.getSystemService(SliceManager.class);
      }
  
      /**
       * Implemented to create a slice.
       * <p>
       * onBindSlice should return as quickly as possible so that the UI tied
       * to this slice can be responsive. No network or other IO will be allowed
       * during onBindSlice. Any loading that needs to be done should happen
       * in the background with a call to {@link ContentResolver#notifyChange(Uri, ContentObserver)}
       * when the app is ready to provide the complete data in onBindSlice.
       * <p>
       * The slice returned should have a spec that is compatible with one of
       * the supported specs.
       *
       * @param sliceUri Uri to bind.
       * @param supportedSpecs List of supported specs.
       * @see Slice
       * @see Slice#HINT_PARTIAL
       */
      public Slice onBindSlice(Uri sliceUri, Set<SliceSpec> supportedSpecs) {
          return onBindSlice(sliceUri, new ArrayList<>(supportedSpecs));
      }
  
      /**
       * @deprecated TO BE REMOVED
       * @removed
       */
      @Deprecated
      public Slice onBindSlice(Uri sliceUri, List<SliceSpec> supportedSpecs) {
          return null;
      }
  
      /**
       * Called to inform an app that a slice has been pinned.
       * <p>
       * Pinning is a way that slice hosts use to notify apps of which slices
       * they care about updates for. When a slice is pinned the content is
       * expected to be relatively fresh and kept up to date.
       * <p>
       * Being pinned does not provide any escalated privileges for the slice
       * provider. So apps should do things such as turn on syncing or schedule
       * a job in response to a onSlicePinned.
       * <p>
       * Pinned state is not persisted through a reboot, and apps can expect a
       * new call to onSlicePinned for any slices that should remain pinned
       * after a reboot occurs.
       *
       * @param sliceUri The uri of the slice being unpinned.
       * @see #onSliceUnpinned(Uri)
       */
      public void onSlicePinned(Uri sliceUri) {
      }
  
      /**
       * Called to inform an app that a slices is no longer pinned.
       * <p>
       * This means that no other apps on the device care about updates to this
       * slice anymore and therefore it is not important to be updated. Any syncs
       * or jobs related to this slice should be cancelled.
       * @see #onSlicePinned(Uri)
       */
      public void onSliceUnpinned(Uri sliceUri) {
      }
  
      /**
       * Obtains a list of slices that are descendants of the specified Uri.
       * <p>
       * Implementing this is optional for a SliceProvider, but does provide a good
       * discovery mechanism for finding slice Uris.
       *
       * @param uri The uri to look for descendants under.
       * @return All slices within the space.
       * @see SliceManager#getSliceDescendants(Uri)
       */
      public @NonNull Collection<Uri> onGetSliceDescendants(@NonNull Uri uri) {
          return Collections.emptyList();
      }
  
      /**
       * This method must be overridden if an {@link IntentFilter} is specified on the SliceProvider.
       * In that case, this method can be called and is expected to return a non-null Uri representing
       * a slice. Otherwise this will throw {@link UnsupportedOperationException}.
       *
       * Any intent filter added to a slice provider should also contain
       * {@link SliceManager#CATEGORY_SLICE}, because otherwise it will not be detected by
       * {@link SliceManager#mapIntentToUri(Intent)}.
       *
       * @return Uri representing the slice associated with the provided intent.
       * @see Slice
       * @see SliceManager#mapIntentToUri(Intent)
       */
      public @NonNull Uri onMapIntentToUri(Intent intent) {
          throw new UnsupportedOperationException(
                  "This provider has not implemented intent to uri mapping");
      }
  
      /**
       * Called when an app requests a slice it does not have write permission
       * to the uri for.
       * <p>
       * The return value will be the action on a slice that prompts the user that
       * the calling app wants to show slices from this app. The default implementation
       * launches a dialog that allows the user to grant access to this slice. Apps
       * that do not want to allow this user grant, can override this and instead
       * launch their own dialog with different behavior.
       *
       * @param sliceUri the Uri of the slice attempting to be bound.
       * @see #getCallingPackage()
       */
      public @NonNull PendingIntent onCreatePermissionRequest(Uri sliceUri) {
          return createPermissionIntent(getContext(), sliceUri, getCallingPackage());
      }
  
      @Override
      public final int update(Uri uri, ContentValues values, String selection,
              String[] selectionArgs) {
          if (DEBUG) Log.d(TAG, "update " + uri);
          return 0;
      }
  
      @Override
      public final int delete(Uri uri, String selection, String[] selectionArgs) {
          if (DEBUG) Log.d(TAG, "delete " + uri);
          return 0;
      }
  
      @Override
      public final Cursor query(Uri uri, String[] projection, String selection,
              String[] selectionArgs, String sortOrder) {
          if (DEBUG) Log.d(TAG, "query " + uri);
          return null;
      }
  
      @Override
      public final Cursor query(Uri uri, String[] projection, String selection, String[]
              selectionArgs, String sortOrder, CancellationSignal cancellationSignal) {
          if (DEBUG) Log.d(TAG, "query " + uri);
          return null;
      }
  
      @Override
      public final Cursor query(Uri uri, String[] projection, Bundle queryArgs,
              CancellationSignal cancellationSignal) {
          if (DEBUG) Log.d(TAG, "query " + uri);
          return null;
      }
  
      @Override
      public final Uri insert(Uri uri, ContentValues values) {
          if (DEBUG) Log.d(TAG, "insert " + uri);
          return null;
      }
  
      @Override
      public final String getType(Uri uri) {
          if (DEBUG) Log.d(TAG, "getType " + uri);
          return SLICE_TYPE;
      }
  
      @Override
      public Bundle call(String method, String arg, Bundle extras) {
          if (method.equals(METHOD_SLICE)) {
              Uri uri = getUriWithoutUserId(validateIncomingUriOrNull(
                      extras.getParcelable(EXTRA_BIND_URI)));
              List<SliceSpec> supportedSpecs = extras.getParcelableArrayList(EXTRA_SUPPORTED_SPECS);
  
              String callingPackage = getCallingPackage();
              int callingUid = Binder.getCallingUid();
              int callingPid = Binder.getCallingPid();
  
              Slice s = handleBindSlice(uri, supportedSpecs, callingPackage, callingUid, callingPid);
              Bundle b = new Bundle();
              b.putParcelable(EXTRA_SLICE, s);
              return b;
          } else if (method.equals(METHOD_MAP_INTENT)) {
              Intent intent = extras.getParcelable(EXTRA_INTENT);
              if (intent == null) return null;
              Uri uri = validateIncomingUriOrNull(onMapIntentToUri(intent));
              List<SliceSpec> supportedSpecs = extras.getParcelableArrayList(EXTRA_SUPPORTED_SPECS);
              Bundle b = new Bundle();
              if (uri != null) {
                  Slice s = handleBindSlice(uri, supportedSpecs, getCallingPackage(),
                          Binder.getCallingUid(), Binder.getCallingPid());
                  b.putParcelable(EXTRA_SLICE, s);
              } else {
                  b.putParcelable(EXTRA_SLICE, null);
              }
              return b;
          } else if (method.equals(METHOD_MAP_ONLY_INTENT)) {
              Intent intent = extras.getParcelable(EXTRA_INTENT);
              if (intent == null) return null;
              Uri uri = validateIncomingUriOrNull(onMapIntentToUri(intent));
              Bundle b = new Bundle();
              b.putParcelable(EXTRA_SLICE, uri);
              return b;
          } else if (method.equals(METHOD_PIN)) {
              Uri uri = getUriWithoutUserId(validateIncomingUriOrNull(
                      extras.getParcelable(EXTRA_BIND_URI)));
              if (Binder.getCallingUid() != Process.SYSTEM_UID) {
                  throw new SecurityException("Only the system can pin/unpin slices");
              }
              handlePinSlice(uri);
          } else if (method.equals(METHOD_UNPIN)) {
              Uri uri = getUriWithoutUserId(validateIncomingUriOrNull(
                      extras.getParcelable(EXTRA_BIND_URI)));
              if (Binder.getCallingUid() != Process.SYSTEM_UID) {
                  throw new SecurityException("Only the system can pin/unpin slices");
              }
              handleUnpinSlice(uri);
          } else if (method.equals(METHOD_GET_DESCENDANTS)) {
              Uri uri = getUriWithoutUserId(
                      validateIncomingUriOrNull(extras.getParcelable(EXTRA_BIND_URI)));
              Bundle b = new Bundle();
              b.putParcelableArrayList(EXTRA_SLICE_DESCENDANTS,
                      new ArrayList<>(handleGetDescendants(uri)));
              return b;
          } else if (method.equals(METHOD_GET_PERMISSIONS)) {
              if (Binder.getCallingUid() != Process.SYSTEM_UID) {
                  throw new SecurityException("Only the system can get permissions");
              }
              Bundle b = new Bundle();
              b.putStringArray(EXTRA_RESULT, mAutoGrantPermissions);
              return b;
          }
          return super.call(method, arg, extras);
      }
  
      private Uri validateIncomingUriOrNull(Uri uri) {
          return uri == null ? null : validateIncomingUri(uri);
      }
  
      private Collection<Uri> handleGetDescendants(Uri uri) {
          mCallback = "onGetSliceDescendants";
          return onGetSliceDescendants(uri);
      }
  
      private void handlePinSlice(Uri sliceUri) {
          mCallback = "onSlicePinned";
          Handler.getMain().postDelayed(mAnr, SLICE_BIND_ANR);
          try {
              onSlicePinned(sliceUri);
          } finally {
              Handler.getMain().removeCallbacks(mAnr);
          }
      }
  
      private void handleUnpinSlice(Uri sliceUri) {
          mCallback = "onSliceUnpinned";
          Handler.getMain().postDelayed(mAnr, SLICE_BIND_ANR);
          try {
              onSliceUnpinned(sliceUri);
          } finally {
              Handler.getMain().removeCallbacks(mAnr);
          }
      }
  
      private Slice handleBindSlice(Uri sliceUri, List<SliceSpec> supportedSpecs,
              String callingPkg, int callingUid, int callingPid) {
          // This can be removed once Slice#bindSlice is removed and everyone is using
          // SliceManager#bindSlice.
          String pkg = callingPkg != null ? callingPkg
                  : getContext().getPackageManager().getNameForUid(callingUid);
          try {
              mSliceManager.enforceSlicePermission(sliceUri, pkg,
                      callingPid, callingUid, mAutoGrantPermissions);
          } catch (SecurityException e) {
              return createPermissionSlice(getContext(), sliceUri, pkg);
          }
          mCallback = "onBindSlice";
          Handler.getMain().postDelayed(mAnr, SLICE_BIND_ANR);
          try {
              return onBindSliceStrict(sliceUri, supportedSpecs);
          } finally {
              Handler.getMain().removeCallbacks(mAnr);
          }
      }
  
      /**
       * @hide
       */
      public Slice createPermissionSlice(Context context, Uri sliceUri,
              String callingPackage) {
          PendingIntent action;
          mCallback = "onCreatePermissionRequest";
          Handler.getMain().postDelayed(mAnr, SLICE_BIND_ANR);
          try {
              action = onCreatePermissionRequest(sliceUri);
          } finally {
              Handler.getMain().removeCallbacks(mAnr);
          }
          Slice.Builder parent = new Slice.Builder(sliceUri);
          Slice.Builder childAction = new Slice.Builder(parent)
                  .addIcon(Icon.createWithResource(context,
                          com.android.internal.R.drawable.ic_permission), null,
                          Collections.emptyList())
                  .addHints(Arrays.asList(Slice.HINT_TITLE, Slice.HINT_SHORTCUT))
                  .addAction(action, new Slice.Builder(parent).build(), null);
  
          TypedValue tv = new TypedValue();
          new ContextThemeWrapper(context, android.R.style.Theme_DeviceDefault_Light)
                  .getTheme().resolveAttribute(android.R.attr.colorAccent, tv, true);
          int deviceDefaultAccent = tv.data;
  
          parent.addSubSlice(new Slice.Builder(sliceUri.buildUpon().appendPath("permission").build())
                  .addIcon(Icon.createWithResource(context,
                          com.android.internal.R.drawable.ic_arrow_forward), null,
                          Collections.emptyList())
                  .addText(getPermissionString(context, callingPackage), null,
                          Collections.emptyList())
                  .addInt(deviceDefaultAccent, SUBTYPE_COLOR,
                          Collections.emptyList())
                  .addSubSlice(childAction.build(), null)
                  .build(), null);
          return parent.addHints(Arrays.asList(Slice.HINT_PERMISSION_REQUEST)).build();
      }
  
      /**
       * @hide
       */
      public static PendingIntent createPermissionIntent(Context context, Uri sliceUri,
              String callingPackage) {
          Intent intent = new Intent(SliceManager.ACTION_REQUEST_SLICE_PERMISSION);
          intent.setComponent(new ComponentName("com.android.systemui",
                  "com.android.systemui.SlicePermissionActivity"));
          intent.putExtra(EXTRA_BIND_URI, sliceUri);
          intent.putExtra(EXTRA_PKG, callingPackage);
          intent.putExtra(EXTRA_PROVIDER_PKG, context.getPackageName());
          // Unique pending intent.
          intent.setData(sliceUri.buildUpon().appendQueryParameter("package", callingPackage)
                  .build());
  
          return PendingIntent.getActivity(context, 0, intent, 0);
      }
  
      /**
       * @hide
       */
      public static CharSequence getPermissionString(Context context, String callingPackage) {
          PackageManager pm = context.getPackageManager();
          try {
              return context.getString(
                      com.android.internal.R.string.slices_permission_request,
                      pm.getApplicationInfo(callingPackage, 0).loadLabel(pm),
                      context.getApplicationInfo().loadLabel(pm));
          } catch (NameNotFoundException e) {
              // This shouldn't be possible since the caller is verified.
              throw new RuntimeException("Unknown calling app", e);
          }
      }
  
      private Slice onBindSliceStrict(Uri sliceUri, List<SliceSpec> supportedSpecs) {
          ThreadPolicy oldPolicy = StrictMode.getThreadPolicy();
          try {
              StrictMode.setThreadPolicy(new StrictMode.ThreadPolicy.Builder()
                      .detectAll()
                      .penaltyDeath()
                      .build());
              return onBindSlice(sliceUri, new ArraySet<>(supportedSpecs));
          } finally {
              StrictMode.setThreadPolicy(oldPolicy);
          }
      }
  
      private final Runnable mAnr = () -> {
          Process.sendSignal(Process.myPid(), Process.SIGNAL_QUIT);
          Log.wtf(TAG, "Timed out while handling slice callback " + mCallback);
      };
  }
  