MainActivity.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.example.android.implicitintents;

import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    /**
     * This method is called when the Open Website button is clicked. It will open the website
     * specified by the URL represented by the variable urlAsString using implicit Intents.
     *
     * @param v Button that was clicked.
     */
    public void onClickOpenWebpageButton(View v) {
        // COMPLETED (5) Create a String that contains a URL ( make sure it starts with http:// or https:// )
        String urlAsString = "http://www.udacity.com";

        // COMPLETED (6) Replace the Toast with a call to openWebPage, passing in the URL String from the previous step
        openWebPage(urlAsString);
    }

    /**
     * This method is called when the Open Location in Map button is clicked. It will open the
     * a map to the location represented by the variable addressString using implicit Intents.
     *
     * @param v Button that was clicked.
     */
    public void onClickOpenAddressButton(View v) {
        Toast.makeText(this, "TODO: Open a map when this button is clicked", Toast.LENGTH_SHORT).show();
    }

    /**
     * This method is called when the Share Text Content button is clicked. It will simply share
     * the text contained within the String textThatYouWantToShare.
     *
     * @param v Button that was clicked.
     */
    public void onClickShareTextButton(View v) {
        Toast.makeText(this, "TODO: Share text when this is clicked", Toast.LENGTH_LONG).show();
    }

    /**
     * This is where you will create and fire off your own implicit Intent. Yours will be very
     * similar to what I've done above. You can view a list of implicit Intents on the Common
     * Intents page from the developer documentation.
     *
     * @see <http://developer.android.com/guide/components/intents-common.html/>
     *
     * @param v Button that was clicked.
     */
    public void createYourOwn(View v) {
        Toast.makeText(this,
                "TODO: Create Your Own Implicit Intent",
                Toast.LENGTH_SHORT)
                .show();
    }

    // COMPLETED (1) Create a method called openWebPage that accepts a String as a parameter
    /**
     * This method fires off an implicit Intent to open a webpage.
     *
     * @param url Url of webpage to open. Should start with http:// or https:// as that is the
     *            scheme of the URI expected with this Intent according to the Common Intents page
     */
    private void openWebPage(String url) {
        // COMPLETED (2) Use Uri.parse to parse the String into a Uri
        /*
         * We wanted to demonstrate the Uri.parse method because its usage occurs frequently. You
         * could have just as easily passed in a Uri as the parameter of this method.
         */
        Uri webpage = Uri.parse(url);

        // COMPLETED (3) Create an Intent with Intent.ACTION_VIEW and the webpage Uri as parameters
        /*
         * Here, we create the Intent with the action of ACTION_VIEW. This action allows the user
         * to view particular content. In this case, our webpage URL.
         */
        Intent intent = new Intent(Intent.ACTION_VIEW, webpage);

        // COMPLETED (4) Verify that this Intent can be launched and then call startActivity
        /*
         * This is a check we perform with every implicit Intent that we launch. In some cases,
         * the device where this code is running might not have an Activity to perform the action
         * with the data we've specified. Without this check, in those cases your app would crash.
         */
        if (intent.resolveActivity(getPackageManager()) != null) {
            startActivity(intent);
        }
    }

}