com.github.shareme.blackandroids.greenandroid.easpermissions.EasyPermissions.java Source code

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/*
 * Copyright Google Inc. All Rights Reserved.
 * Modifications Copyright(C) 2016 Fred Grott(GrottWorkShop)
 *
 * 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.github.shareme.blackandroids.greenandroid.easpermissions;

import android.annotation.TargetApi;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.pm.PackageManager;
import android.os.Build;
import android.support.annotation.StringRes;
import android.support.v4.app.ActivityCompat;
import android.support.v4.app.Fragment;
import android.support.v4.content.ContextCompat;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import timber.log.Timber;

/**
 * Created by fgrott on 9/23/2016.
 */

public class EasyPermissions {

    private static final String TAG = "EasyPermissions";

    public interface PermissionCallbacks extends ActivityCompat.OnRequestPermissionsResultCallback {

        void onPermissionsGranted(int requestCode, List<String> perms);

        void onPermissionsDenied(int requestCode, List<String> perms);

    }

    /**
     * Check if the calling context has a set of permissions.
     *
     * @param context the calling context.
     * @param perms   one ore more permissions, such as {@code android.Manifest.permission.CAMERA}.
     * @return true if all permissions are already granted, false if at least one permission
     * is not yet granted.
     */
    public static boolean hasPermissions(Context context, String... perms) {
        // Always return true for SDK < M, let the system deal with the permissions
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M) {
            Timber.w(TAG, "hasPermissions: API version < M, returning true by default");
            return true;
        }

        for (String perm : perms) {
            boolean hasPerm = (ContextCompat.checkSelfPermission(context,
                    perm) == PackageManager.PERMISSION_GRANTED);
            if (!hasPerm) {
                return false;
            }
        }

        return true;
    }

    /**
     * Request a set of permissions, showing rationale if the system requests it.
     *
     * @param object      Activity or Fragment requesting permissions. Should implement
     *                    {@link ActivityCompat.OnRequestPermissionsResultCallback}
     *                    or
     *                    {android.support.v13.app.FragmentCompat.OnRequestPermissionsResultCallback}
     * @param rationale   a message explaining why the application needs this set of permissions, will
     *                    be displayed if the user rejects the request the first time.
     * @param requestCode request code to track this request, must be < 256.
     * @param perms       a set of permissions to be requested.
     */
    public static void requestPermissions(final Object object, String rationale, final int requestCode,
            final String... perms) {
        requestPermissions(object, rationale, android.R.string.ok, android.R.string.cancel, requestCode, perms);
    }

    /**
     * Request a set of permissions, showing rationale if the system requests it.
     *
     * @param object         Activity or Fragment requesting permissions. Should implement
     *                       {@link ActivityCompat.OnRequestPermissionsResultCallback}
     *                       or
     *                       {android.support.v13.app.FragmentCompat.OnRequestPermissionsResultCallback}
     * @param rationale      a message explaining why the application needs this set of permissions, will
     *                       be displayed if the user rejects the request the first time.
     * @param positiveButton custom text for positive button
     * @param negativeButton custom text for negative button
     * @param requestCode    request code to track this request, must be < 256.
     * @param perms          a set of permissions to be requested.
     */
    public static void requestPermissions(final Object object, String rationale, @StringRes int positiveButton,
            @StringRes int negativeButton, final int requestCode, final String... perms) {

        checkCallingObjectSuitability(object);

        boolean shouldShowRationale = false;
        for (String perm : perms) {
            shouldShowRationale = shouldShowRationale || shouldShowRequestPermissionRationale(object, perm);
        }

        if (shouldShowRationale) {
            Activity activity = getActivity(object);
            if (null == activity) {
                return;
            }

            AlertDialog dialog = new AlertDialog.Builder(activity).setMessage(rationale)
                    .setPositiveButton(positiveButton, new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            executePermissionsRequest(object, perms, requestCode);
                        }
                    }).setNegativeButton(negativeButton, new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            // act as if the permissions were denied
                            if (object instanceof PermissionCallbacks) {
                                ((PermissionCallbacks) object).onPermissionsDenied(requestCode,
                                        Arrays.asList(perms));
                            }
                        }
                    }).create();
            dialog.show();
        } else {
            executePermissionsRequest(object, perms, requestCode);
        }
    }

    /**
     * Check if at least one permission in the list of denied permissions has been permanently
     * denied (user clicked "Never ask again").
     * @param object Activity or Fragment requesting permissions.
     * @param deniedPermissions list of denied permissions, usually from
     *        {@link PermissionCallbacks#onPermissionsDenied(int, List)}
     * @return {@code true} if at least one permission in the list was permanently denied.
     */
    public static boolean somePermissionPermanentlyDenied(Object object, List<String> deniedPermissions) {
        for (String deniedPermission : deniedPermissions) {
            if (permissionPermanentlyDenied(object, deniedPermission)) {
                return true;
            }
        }

        return false;
    }

    /**
     * Check if a permission has been permanently denied (user clicked "Never ask again").
     * @param object Activity or Fragment requesting permissions.
     * @param deniedPermission denied permission.
     * @return {@code true} if the permissions has been permanently denied.
     */
    public static boolean permissionPermanentlyDenied(Object object, String deniedPermission) {
        return !shouldShowRequestPermissionRationale(object, deniedPermission);
    }

    /**
     * Handle the result of a permission request, should be called from the calling Activity's
     * {@link ActivityCompat.OnRequestPermissionsResultCallback#onRequestPermissionsResult(int, String[], int[])}
     * method.
     * <p>
     * If any permissions were granted or denied, the {@code object} will receive the appropriate
     * callbacks through {@link PermissionCallbacks} and methods annotated with
     * {@link AfterPermissionGranted} will be run if appropriate.
     *
     * @param requestCode  requestCode argument to permission result callback.
     * @param permissions  permissions argument to permission result callback.
     * @param grantResults grantResults argument to permission result callback.
     * @param receivers    an array of objects that have a method annotated with {@link AfterPermissionGranted}
     *                     or implement {@link PermissionCallbacks}.
     */
    public static void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults,
            Object... receivers) {

        // Make a collection of granted and denied permissions from the request.
        ArrayList<String> granted = new ArrayList<>();
        ArrayList<String> denied = new ArrayList<>();
        for (int i = 0; i < permissions.length; i++) {
            String perm = permissions[i];
            if (grantResults[i] == PackageManager.PERMISSION_GRANTED) {
                granted.add(perm);
            } else {
                denied.add(perm);
            }
        }

        // iterate through all receivers
        for (Object object : receivers) {
            // Report granted permissions, if any.
            if (!granted.isEmpty()) {
                if (object instanceof PermissionCallbacks) {
                    ((PermissionCallbacks) object).onPermissionsGranted(requestCode, granted);
                }
            }

            // Report denied permissions, if any.
            if (!denied.isEmpty()) {
                if (object instanceof PermissionCallbacks) {
                    ((PermissionCallbacks) object).onPermissionsDenied(requestCode, denied);
                }
            }

            // If 100% successful, call annotated methods
            if (!granted.isEmpty() && denied.isEmpty()) {
                runAnnotatedMethods(object, requestCode);
            }
        }

    }

    @TargetApi(23)
    private static boolean shouldShowRequestPermissionRationale(Object object, String perm) {
        if (object instanceof Activity) {
            return ActivityCompat.shouldShowRequestPermissionRationale((Activity) object, perm);
        } else if (object instanceof Fragment) {
            return ((Fragment) object).shouldShowRequestPermissionRationale(perm);
        } else if (object instanceof android.app.Fragment) {
            return ((android.app.Fragment) object).shouldShowRequestPermissionRationale(perm);
        } else {
            return false;
        }
    }

    @TargetApi(23)
    private static void executePermissionsRequest(Object object, String[] perms, int requestCode) {
        checkCallingObjectSuitability(object);

        if (object instanceof Activity) {
            ActivityCompat.requestPermissions((Activity) object, perms, requestCode);
        } else if (object instanceof Fragment) {
            ((Fragment) object).requestPermissions(perms, requestCode);
        } else if (object instanceof android.app.Fragment) {
            ((android.app.Fragment) object).requestPermissions(perms, requestCode);
        }
    }

    @TargetApi(11)
    private static Activity getActivity(Object object) {
        if (object instanceof Activity) {
            return ((Activity) object);
        } else if (object instanceof Fragment) {
            return ((Fragment) object).getActivity();
        } else if (object instanceof android.app.Fragment) {
            return ((android.app.Fragment) object).getActivity();
        } else {
            return null;
        }
    }

    private static void runAnnotatedMethods(Object object, int requestCode) {
        Class clazz = object.getClass();
        if (isUsingAndroidAnnotations(object)) {
            clazz = clazz.getSuperclass();
        }
        for (Method method : clazz.getDeclaredMethods()) {
            if (method.isAnnotationPresent(AfterPermissionGranted.class)) {
                // Check for annotated methods with matching request code.
                AfterPermissionGranted ann = method.getAnnotation(AfterPermissionGranted.class);
                if (ann.value() == requestCode) {
                    // Method must be void so that we can invoke it
                    if (method.getParameterTypes().length > 0) {
                        throw new RuntimeException("Cannot execute non-void method " + method.getName());
                    }

                    try {
                        // Make method accessible if private
                        if (!method.isAccessible()) {
                            method.setAccessible(true);
                        }
                        method.invoke(object);
                    } catch (IllegalAccessException e) {
                        Timber.e(TAG, "runDefaultMethod:IllegalAccessException", e);
                    } catch (InvocationTargetException e) {
                        Timber.e(TAG, "runDefaultMethod:InvocationTargetException", e);
                    }
                }
            }
        }
    }

    private static void checkCallingObjectSuitability(Object object) {
        // Make sure Object is an Activity or Fragment
        boolean isActivity = object instanceof Activity;
        boolean isSupportFragment = object instanceof Fragment;
        boolean isAppFragment = object instanceof android.app.Fragment;
        boolean isMinSdkM = Build.VERSION.SDK_INT >= Build.VERSION_CODES.M;

        if (!(isSupportFragment || isActivity || (isAppFragment && isMinSdkM))) {
            if (isAppFragment) {
                throw new IllegalArgumentException(
                        "Target SDK needs to be greater than 23 if caller is android.app.Fragment");
            } else {
                throw new IllegalArgumentException("Caller must be an Activity or a Fragment.");
            }
        }
    }

    private static boolean isUsingAndroidAnnotations(Object object) {
        if (!object.getClass().getSimpleName().endsWith("_")) {
            return false;
        }

        try {
            Class clazz = Class.forName("org.androidannotations.api.view.HasViews");
            return clazz.isInstance(object);
        } catch (ClassNotFoundException e) {
            return false;
        }
    }

}