src/com/android/car/settings/applications/ApplicationDetailsFragment.java

/*
 * Copyright (C) 2018 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.car.settings.applications;

import android.app.Activity;
import android.app.ActivityManager;
import android.app.admin.DevicePolicyManager;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.net.Uri;
import android.os.Bundle;
import android.os.UserHandle;
import android.view.View;
import android.widget.Button;

import androidx.annotation.LayoutRes;
import androidx.annotation.XmlRes;

import com.android.car.settings.R;
import com.android.car.settings.common.Logger;
import com.android.car.settings.common.SettingsFragment;
import com.android.settingslib.Utils;
import com.android.settingslib.applications.ApplicationsState;

import java.text.MessageFormat;

/**
 * Shows details about an application and action associated with that application,
 * like uninstall, forceStop.
 */
public class ApplicationDetailsFragment extends SettingsFragment {
    private static final Logger LOG = new Logger(ApplicationDetailsFragment.class);
    public static final String EXTRA_PACKAGE_NAME = "extra_package_name";

    private String mPackageName;
    private PackageInfo mPackageInfo;

    private Button mDisableToggle;
    private Button mForceStopButton;
    private DevicePolicyManager mDpm;

    /** Creates an instance of this fragment, passing packageName as an argument. */
    public static ApplicationDetailsFragment getInstance(String packageName) {
        ApplicationDetailsFragment applicationDetailFragment = new ApplicationDetailsFragment();
        Bundle bundle = new Bundle();
        bundle.putString(EXTRA_PACKAGE_NAME, packageName);
        applicationDetailFragment.setArguments(bundle);
        return applicationDetailFragment;
    }

    @Override
    @XmlRes
    protected int getPreferenceScreenResId() {
        return R.xml.application_details_fragment;
    }

    @Override
    @LayoutRes
    protected int getActionBarLayoutId() {
        return R.layout.action_bar_with_button;
    }

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);

        // These should be loaded before onCreate() so that the controller operates as expected.
        mPackageName = getArguments().getString(EXTRA_PACKAGE_NAME);
        mPackageInfo = getPackageInfo();
        ApplicationsState applicationsState =
                ApplicationsState.getInstance(getActivity().getApplication());
        ApplicationsState.AppEntry appEntry =
                applicationsState.getEntry(mPackageName, UserHandle.myUserId());

        use(ApplicationPreferenceController.class,
                R.string.pk_application_details_app)
                        .setAppEntry(appEntry).setAppState(applicationsState);
        use(PermissionsPreferenceController.class,
                R.string.pk_application_details_permissions).setPackageName(mPackageName);
        use(VersionPreferenceController.class,
                R.string.pk_application_details_version).setPackageInfo(mPackageInfo);
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        if (mPackageName == null) {
            LOG.w("No application info set.");
            return;
        }

        mDisableToggle = (Button) getActivity().findViewById(R.id.action_button1);
        mForceStopButton = (Button) getActivity().findViewById(R.id.action_button2);
        mForceStopButton.setText(R.string.force_stop);
        mForceStopButton.setVisibility(View.VISIBLE);

        mDpm = (DevicePolicyManager) getContext().getSystemService(Context.DEVICE_POLICY_SERVICE);
        updateForceStopButton();
        mForceStopButton.setOnClickListener(
                v -> forceStopPackage(mPackageName));
    }

    @Override
    public void onStart() {
        super.onStart();
        updateForceStopButton();
        updateDisableable();
    }

    // fetch the latest ApplicationInfo instead of caching it so it reflects the current state.
    private ApplicationInfo getAppInfo() {
        try {
            return getContext().getPackageManager().getApplicationInfo(mPackageName, 0 /* flag */);
        } catch (PackageManager.NameNotFoundException e) {
            LOG.e("incorrect packagename: " + mPackageName, e);
            throw new IllegalArgumentException(e);
        }
    }

    private PackageInfo getPackageInfo() {
        try {
            return getContext().getPackageManager().getPackageInfo(mPackageName, 0 /* flag */);
        } catch (PackageManager.NameNotFoundException e) {
            LOG.e("incorrect packagename: " + mPackageName, e);
            throw new IllegalArgumentException(e);
        }
    }

    private void updateDisableable() {
        boolean disableable = false;
        boolean disabled = false;
        // Try to prevent the user from bricking their phone
        // by not allowing disabling of apps in the system.
        if (Utils.isSystemPackage(
                getResources(), getContext().getPackageManager(), mPackageInfo)) {
            // Disable button for core system applications.
            mDisableToggle.setText(R.string.disable_text);
            disabled = false;
        } else if (getAppInfo().enabled && !isDisabledUntilUsed()) {
            mDisableToggle.setText(R.string.disable_text);
            disableable = true;
            disabled = false;
        } else {
            mDisableToggle.setText(R.string.enable_text);
            disableable = true;
            disabled = true;
        }
        mDisableToggle.setEnabled(disableable);
        final int enableState = disabled
                ? PackageManager.COMPONENT_ENABLED_STATE_DEFAULT
                : PackageManager.COMPONENT_ENABLED_STATE_DISABLED_USER;
        mDisableToggle.setOnClickListener(v -> {
            getContext().getPackageManager().setApplicationEnabledSetting(
                    mPackageName,
                    enableState,
                    0);
            updateDisableable();
        });
    }

    private boolean isDisabledUntilUsed() {
        return getAppInfo().enabledSetting
                == PackageManager.COMPONENT_ENABLED_STATE_DISABLED_UNTIL_USED;
    }

    private void forceStopPackage(String pkgName) {
        ActivityManager am = (ActivityManager) getContext().getSystemService(
                Context.ACTIVITY_SERVICE);
        LOG.d("Stopping package " + pkgName);
        am.forceStopPackage(pkgName);
        updateForceStopButton();
    }

    // enable or disable the force stop button:
    // - disabled if it's a device admin
    // - if the application is stopped unexplicitly, enabled the button
    // - if there's a reason for the system to restart the application, that indicates the app
    //   can be force stopped.
    private void updateForceStopButton() {
        if (mDpm.packageHasActiveAdmins(mPackageName)) {
            // User can't force stop device admin.
            LOG.d("Disabling button, user can't force stop device admin");
            mForceStopButton.setEnabled(false);
        } else if ((getAppInfo().flags & ApplicationInfo.FLAG_STOPPED) == 0) {
            // If the app isn't explicitly stopped, then always show the
            // force stop button.
            LOG.w("App is not explicitly stopped");
            mForceStopButton.setEnabled(true);
        } else {
            Intent intent = new Intent(Intent.ACTION_QUERY_PACKAGE_RESTART,
                    Uri.fromParts("package", mPackageName, null));
            intent.putExtra(Intent.EXTRA_PACKAGES, new String[]{
                    mPackageName
            });
            LOG.d("Sending broadcast to query restart for " + mPackageName);
            getActivity().sendOrderedBroadcastAsUser(intent, UserHandle.CURRENT, null,
                    mCheckKillProcessesReceiver, null, Activity.RESULT_CANCELED, null, null);
        }
    }

    private final BroadcastReceiver mCheckKillProcessesReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            final boolean enabled = getResultCode() != Activity.RESULT_CANCELED;
            LOG.d(MessageFormat.format("Got broadcast response: Restart status for {0} {1}",
                    mPackageName, enabled));
            mForceStopButton.setEnabled(enabled);
        }
    };
}