Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
/*
 * Copyright (C) 2015 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.
 */

import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;

import android.text.TextUtils;
import java.util.List;

public class Main {
    /**
     * Start an intent. If it is possible for this app to handle the intent, force this app's
     * activity to handle the intent. Sometimes it is impossible to know whether this app
     * can handle an intent while coding since the code is used inside both Dialer and Contacts.
     * This method is particularly useful in such circumstances.
     *
     * On a Nexus 5 with a small number of apps, this method consistently added 3-16ms of delay
     * in order to talk to the package manager.
     */
    public static void startActivityInAppIfPossible(Context context, Intent intent) {
        final Intent appIntent = getIntentInAppIfExists(context, intent);
        if (appIntent != null) {
            context.startActivity(appIntent);
        } else {
            context.startActivity(intent);
        }
    }

    /**
     * Returns a copy of {@param intent} with a class name set, if a class inside this app
     * has a corresponding intent filter.
     */
    private static Intent getIntentInAppIfExists(Context context, Intent intent) {
        try {
            final Intent intentCopy = new Intent(intent);
            // Force this intentCopy to open inside the current app.
            intentCopy.setPackage(context.getPackageName());
            final List<ResolveInfo> list = context.getPackageManager().queryIntentActivities(intentCopy,
                    PackageManager.MATCH_DEFAULT_ONLY);
            if (list != null && list.size() != 0) {
                // Now that we know the intentCopy will work inside the current app, we
                // can return this intent non-null.
                if (list.get(0).activityInfo != null && !TextUtils.isEmpty(list.get(0).activityInfo.name)) {
                    // Now that we know the class name, we may as well attach it to intentCopy
                    // to prevent the package manager from needing to find it again inside
                    // startActivity(). This is only needed for efficiency.
                    intentCopy.setClassName(context.getPackageName(), list.get(0).activityInfo.name);
                }
                return intentCopy;
            }
            return null;
        } catch (Exception e) {
            // Don't let the package manager crash our app. If the package manager can't resolve the
            // intent here, then we can still call startActivity without calling setClass() first.
            return null;
        }
    }
}