PackageManagerHelper.java

/*
 * Copyright (C) 2016 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.launcher3.util;

import android.app.AppOpsManager;
import android.content.Context;
import android.content.Intent;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageManager;
import android.content.pm.PackageManager.NameNotFoundException;
import android.content.pm.ResolveInfo;
import android.os.Build;
import android.text.TextUtils;

import com.android.launcher3.Utilities;

import java.util.ArrayList;

/**
 * Utility methods using package manager
 */
public class PackageManagerHelper {

    private static final int FLAG_SUSPENDED = 1<<30;
    private static final String LIVE_WALLPAPER_PICKER_PKG = "com.android.wallpaper.livepicker";

    /**
     * Returns true if the app can possibly be on the SDCard. This is just a workaround and doesn't
     * guarantee that the app is on SD card.
     */
    public static boolean isAppOnSdcard(PackageManager pm, String packageName) {
        return isAppEnabled(pm, packageName, PackageManager.GET_UNINSTALLED_PACKAGES);
    }

    public static boolean isAppEnabled(PackageManager pm, String packageName) {
        return isAppEnabled(pm, packageName, 0);
    }

    public static boolean isAppEnabled(PackageManager pm, String packageName, int flags) {
        try {
            ApplicationInfo info = pm.getApplicationInfo(packageName, flags);
            return info != null && info.enabled;
        } catch (PackageManager.NameNotFoundException e) {
            return false;
        }
    }

    public static boolean isAppSuspended(PackageManager pm, String packageName) {
        try {
            ApplicationInfo info = pm.getApplicationInfo(packageName, 0);
            return info != null && isAppSuspended(info);
        } catch (PackageManager.NameNotFoundException e) {
            return false;
        }
    }

    public static boolean isAppSuspended(ApplicationInfo info) {
        // The value of FLAG_SUSPENDED was reused by a hidden constant
        // ApplicationInfo.FLAG_PRIVILEGED prior to N, so only check for suspended flag on N
        // or later.
        if (Utilities.isNycOrAbove()) {
            return (info.flags & FLAG_SUSPENDED) != 0;
        } else {
            return false;
        }
    }

    /**
     * Returns the package for a wallpaper picker system app giving preference to a app which
     * is not as image picker.
     */
    public static String getWallpaperPickerPackage(PackageManager pm) {
        ArrayList<String> excludePackages = new ArrayList<>();
        // Exclude packages which contain an image picker
        for (ResolveInfo info : pm.queryIntentActivities(
                new Intent(Intent.ACTION_GET_CONTENT).setType("image/*"), 0)) {
            excludePackages.add(info.activityInfo.packageName);
        }
        excludePackages.add(LIVE_WALLPAPER_PICKER_PKG);

        for (ResolveInfo info : pm.queryIntentActivities(
                new Intent(Intent.ACTION_SET_WALLPAPER), 0)) {
            if (!excludePackages.contains(info.activityInfo.packageName) &&
                    (info.activityInfo.applicationInfo.flags & ApplicationInfo.FLAG_SYSTEM) != 0) {
                return info.activityInfo.packageName;
            }
        }
        return excludePackages.get(0);
    }

    /**
     * Returns true if {@param srcPackage} has the permission required to start the activity from
     * {@param intent}. If {@param srcPackage} is null, then the activity should not need
     * any permissions
     */
    public static boolean hasPermissionForActivity(Context context, Intent intent,
            String srcPackage) {
        PackageManager pm = context.getPackageManager();
        ResolveInfo target = pm.resolveActivity(intent, 0);
        if (target == null) {
            // Not a valid target
            return false;
        }
        if (TextUtils.isEmpty(target.activityInfo.permission)) {
            // No permission is needed
            return true;
        }
        if (TextUtils.isEmpty(srcPackage)) {
            // The activity requires some permission but there is no source.
            return false;
        }

        // Source does not have sufficient permissions.
        if(pm.checkPermission(target.activityInfo.permission, srcPackage) !=
                PackageManager.PERMISSION_GRANTED) {
            return false;
        }

        if (!Utilities.ATLEAST_MARSHMALLOW) {
            // These checks are sufficient for below M devices.
            return true;
        }

        // On M and above also check AppOpsManager for compatibility mode permissions.
        if (TextUtils.isEmpty(AppOpsManager.permissionToOp(target.activityInfo.permission))) {
            // There is no app-op for this permission, which could have been disabled.
            return true;
        }

        // There is no direct way to check if the app-op is allowed for a particular app. Since
        // app-op is only enabled for apps running in compatibility mode, simply block such apps.

        try {
            return pm.getApplicationInfo(srcPackage, 0).targetSdkVersion >= Build.VERSION_CODES.M;
        } catch (NameNotFoundException e) { }

        return false;
    }
}