/*
 * Copyright (C) 2012 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.internal.view;

import android.content.Context;
import android.content.pm.PackageManager;
import android.content.res.Configuration;
import android.database.ContentObserver;
import android.graphics.Point;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Handler;
import android.os.RemoteException;
import android.os.UserHandle;
import android.provider.Settings;
import android.util.Log;
import android.view.Display;
import android.view.IWindowManager;
import android.view.Surface;
import android.view.WindowManagerGlobal;

import com.android.internal.R;

Provides helper functions for configuring the display rotation policy.
/**
 * Provides helper functions for configuring the display rotation policy.
 */
public final class RotationPolicy {
    private static final String TAG = "RotationPolicy";
    private static final int CURRENT_ROTATION = -1;

    public static final int NATURAL_ROTATION = Surface.ROTATION_0;

    private RotationPolicy() {
    }

    
Gets whether the device supports rotation. In general such a
device has an accelerometer and has the portrait and landscape
features.
Params:
context – Context for accessing system resources.
Returns:
Whether the device supports rotation./**
     * Gets whether the device supports rotation. In general such a
     * device has an accelerometer and has the portrait and landscape
     * features.
     *
     * @param context Context for accessing system resources.
     * @return Whether the device supports rotation.
     */
    public static boolean isRotationSupported(Context context) {
        PackageManager pm = context.getPackageManager();
        return pm.hasSystemFeature(PackageManager.FEATURE_SENSOR_ACCELEROMETER)
                && pm.hasSystemFeature(PackageManager.FEATURE_SCREEN_PORTRAIT)
                && pm.hasSystemFeature(PackageManager.FEATURE_SCREEN_LANDSCAPE)
                && context.getResources().getBoolean(
                        com.android.internal.R.bool.config_supportAutoRotation);
    }

    
Returns the orientation that will be used when locking the orientation from system UI with setRotationLock. If the device only supports locking to its natural orientation, this will be either Configuration.ORIENTATION_PORTRAIT or Configuration.ORIENTATION_LANDSCAPE, otherwise Configuration.ORIENTATION_UNDEFINED if any orientation is lockable. /**
     * Returns the orientation that will be used when locking the orientation from system UI
     * with {@link #setRotationLock}.
     *
     * If the device only supports locking to its natural orientation, this will be either
     * Configuration.ORIENTATION_PORTRAIT or Configuration.ORIENTATION_LANDSCAPE,
     * otherwise Configuration.ORIENTATION_UNDEFINED if any orientation is lockable.
     */
    public static int getRotationLockOrientation(Context context) {
        if (!areAllRotationsAllowed(context)) {
            final Point size = new Point();
            final IWindowManager wm = WindowManagerGlobal.getWindowManagerService();
            try {
                wm.getInitialDisplaySize(Display.DEFAULT_DISPLAY, size);
                return size.x < size.y ?
                        Configuration.ORIENTATION_PORTRAIT : Configuration.ORIENTATION_LANDSCAPE;
            } catch (RemoteException e) {
                Log.w(TAG, "Unable to get the display size");
            }
        }
        return Configuration.ORIENTATION_UNDEFINED;
    }

    
Returns true if the rotation-lock toggle should be shown in system UI.
/**
     * Returns true if the rotation-lock toggle should be shown in system UI.
     */
    public static boolean isRotationLockToggleVisible(Context context) {
        return isRotationSupported(context) &&
                Settings.System.getIntForUser(context.getContentResolver(),
                        Settings.System.HIDE_ROTATION_LOCK_TOGGLE_FOR_ACCESSIBILITY, 0,
                        UserHandle.USER_CURRENT) == 0;
    }

    
Returns true if rotation lock is enabled.
/**
     * Returns true if rotation lock is enabled.
     */
    public static boolean isRotationLocked(Context context) {
        return Settings.System.getIntForUser(context.getContentResolver(),
                Settings.System.ACCELEROMETER_ROTATION, 0, UserHandle.USER_CURRENT) == 0;
    }

    
Enables or disables rotation lock from the system UI toggle.
/**
     * Enables or disables rotation lock from the system UI toggle.
     */
    public static void setRotationLock(Context context, final boolean enabled) {
        final int rotation = areAllRotationsAllowed(context) ? CURRENT_ROTATION : NATURAL_ROTATION;
        setRotationLockAtAngle(context, enabled, rotation);
    }

    
Enables or disables rotation lock at a specific rotation from system UI.
/**
     * Enables or disables rotation lock at a specific rotation from system UI.
     */
    public static void setRotationLockAtAngle(Context context, final boolean enabled,
            final int rotation) {
        Settings.System.putIntForUser(context.getContentResolver(),
                Settings.System.HIDE_ROTATION_LOCK_TOGGLE_FOR_ACCESSIBILITY, 0,
                UserHandle.USER_CURRENT);

        setRotationLock(enabled, rotation);
    }

    
Enables or disables natural rotation lock from Accessibility settings.
If rotation is locked for accessibility, the system UI toggle is hidden to avoid confusion.
/**
     * Enables or disables natural rotation lock from Accessibility settings.
     *
     * If rotation is locked for accessibility, the system UI toggle is hidden to avoid confusion.
     */
    public static void setRotationLockForAccessibility(Context context, final boolean enabled) {
        Settings.System.putIntForUser(context.getContentResolver(),
                Settings.System.HIDE_ROTATION_LOCK_TOGGLE_FOR_ACCESSIBILITY, enabled ? 1 : 0,
                        UserHandle.USER_CURRENT);

        setRotationLock(enabled, NATURAL_ROTATION);
    }

    private static boolean areAllRotationsAllowed(Context context) {
        return context.getResources().getBoolean(R.bool.config_allowAllRotations);
    }

    private static void setRotationLock(final boolean enabled, final int rotation) {
        AsyncTask.execute(new Runnable() {
            @Override
            public void run() {
                try {
                    IWindowManager wm = WindowManagerGlobal.getWindowManagerService();
                    if (enabled) {
                        wm.freezeRotation(rotation);
                    } else {
                        wm.thawRotation();
                    }
                } catch (RemoteException exc) {
                    Log.w(TAG, "Unable to save auto-rotate setting");
                }
            }
        });
    }

    
Registers a listener for rotation policy changes affecting the caller's user
/**
     * Registers a listener for rotation policy changes affecting the caller's user
     */
    public static void registerRotationPolicyListener(Context context,
            RotationPolicyListener listener) {
        registerRotationPolicyListener(context, listener, UserHandle.getCallingUserId());
    }

    
Registers a listener for rotation policy changes affecting a specific user,
or USER_ALL for all users.
/**
     * Registers a listener for rotation policy changes affecting a specific user,
     * or USER_ALL for all users.
     */
    public static void registerRotationPolicyListener(Context context,
            RotationPolicyListener listener, int userHandle) {
        context.getContentResolver().registerContentObserver(Settings.System.getUriFor(
                Settings.System.ACCELEROMETER_ROTATION),
                false, listener.mObserver, userHandle);
        context.getContentResolver().registerContentObserver(Settings.System.getUriFor(
                Settings.System.HIDE_ROTATION_LOCK_TOGGLE_FOR_ACCESSIBILITY),
                false, listener.mObserver, userHandle);
    }

    
Unregisters a listener for rotation policy changes.
/**
     * Unregisters a listener for rotation policy changes.
     */
    public static void unregisterRotationPolicyListener(Context context,
            RotationPolicyListener listener) {
        context.getContentResolver().unregisterContentObserver(listener.mObserver);
    }

    
Listener that is invoked whenever a change occurs that might affect the rotation policy.
/**
     * Listener that is invoked whenever a change occurs that might affect the rotation policy.
     */
    public static abstract class RotationPolicyListener {
        final ContentObserver mObserver = new ContentObserver(new Handler()) {
            @Override
            public void onChange(boolean selfChange, Uri uri) {
                RotationPolicyListener.this.onChange();
            }
        };

        public abstract void onChange();
    }
}