LicensesFragment.java

/*
 * VITacademics
 * Copyright (C) 2015  Aneesh Neelam <neelam.aneesh@gmail.com>
 * Copyright (C) 2015  Saurabh Joshi <saurabhjoshi94@outlook.com>
 * Copyright (C) 2015  Gaurav Agerwala <gauravagerwala@gmail.com>
 * Copyright (C) 2015  Karthik Balakrishnan <karthikb351@gmail.com>
 * Copyright (C) 2015  Pulkit Juneja <pulkit.16296@gmail.com>
 * Copyright (C) 2015  Hemant Jain <hemanham@gmail.com>
 * Copyright (C) 2015  Darshan Mehta <darshanmehta17@gmail.com>
 *
 * This file is part of VITacademics.
 *
 * VITacademics is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * VITacademics is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with VITacademics.  If not, see <http://www.gnu.org/licenses/>.
 */

package com.karthikb351.vitinfo2.fragment;

import android.annotation.SuppressLint;
import android.app.AlertDialog;
import android.app.Dialog;
import android.content.DialogInterface;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.DialogFragment;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.view.LayoutInflater;
import android.view.View;
import android.webkit.WebView;
import android.widget.ProgressBar;

import com.karthikb351.vitinfo2.R;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

/**
 * Created by Adam Speakman on 24/09/13.
 * http://speakman.net.nz
 */
public class LicensesFragment extends DialogFragment {

    private static final String FRAGMENT_TAG = LicensesFragment.class.getCanonicalName();
    private static final String KEY_SHOW_CLOSE_BUTTON = "keyShowCloseButton";

    private AsyncTask<Void, Void, String> mLicenseLoader;
    private WebView mWebView;
    private ProgressBar mIndeterminateProgress;

    /**
     * Creates a new instance of LicensesFragment with no Close button.
     *
     * @return A new licenses fragment.
     */
    public static LicensesFragment newInstance() {
        return new LicensesFragment();
    }

    /**
     * Creates a new instance of LicensesFragment with an optional Close button.
     *
     * @param showCloseButton Whether to show a Close button at the bottom of the dialog.
     * @return A new licenses fragment.
     */
    public static LicensesFragment newInstance(boolean showCloseButton) {
        LicensesFragment fragment = new LicensesFragment();

        Bundle bundle = new Bundle();
        bundle.putBoolean(KEY_SHOW_CLOSE_BUTTON, showCloseButton);
        fragment.setArguments(bundle);

        return fragment;
    }

    /**
     * Builds and displays a licenses fragment with no Close button. Requires
     * "/res/raw/licenses.html" and "/res/layout/licenses_fragment.xml" to be
     * present.
     *
     * @param fm A fragment manager instance used to display this LicensesFragment.
     */
    public static void displayLicensesFragment(FragmentManager fm) {
        FragmentTransaction ft = fm.beginTransaction();
        Fragment prev = fm.findFragmentByTag(FRAGMENT_TAG);
        if (prev != null) {
            ft.remove(prev);
        }
        ft.addToBackStack(null);

        // Create and show the dialog.
        DialogFragment newFragment = LicensesFragment.newInstance();
        newFragment.show(ft, FRAGMENT_TAG);
    }

    /**
     * Builds and displays a licenses fragment with or without a Close button.
     * Requires "/res/raw/licenses.html" and "/res/layout/licenses_fragment.xml"
     * to be present.
     *
     * @param fm              A fragment manager instance used to display this LicensesFragment.
     * @param showCloseButton Whether to show a Close button at the bottom of the dialog.
     */
    public static void displayLicensesFragment(FragmentManager fm, boolean showCloseButton) {
        FragmentTransaction ft = fm.beginTransaction();
        Fragment prev = fm.findFragmentByTag(FRAGMENT_TAG);
        if (prev != null) {
            ft.remove(prev);
        }
        ft.addToBackStack(null);

        // Create and show the dialog.
        DialogFragment newFragment = LicensesFragment.newInstance(showCloseButton);
        newFragment.show(ft, FRAGMENT_TAG);
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        loadLicenses();
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        if (mLicenseLoader != null) {
            mLicenseLoader.cancel(true);
        }
    }

    @SuppressLint("InflateParams")
    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        View content = LayoutInflater.from(getActivity()).inflate(R.layout.fragment_licenses, null);
        mWebView = (WebView) content.findViewById(R.id.licensesFragmentWebView);
        mIndeterminateProgress = (ProgressBar) content.findViewById(R.id.licensesFragmentIndeterminateProgress);

        boolean showCloseButton = false;
        Bundle arguments = getArguments();
        if (arguments != null) {
            showCloseButton = arguments.getBoolean(KEY_SHOW_CLOSE_BUTTON);
        }

        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
        builder.setTitle(getActivity().getString(R.string.fragment_licenses_title));
        builder.setView(content);
        if (showCloseButton) {
            builder.setNegativeButton(getActivity().getString(R.string.button_close_dialog),
                    new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int id) {
                            dialog.dismiss();
                        }
                    });
        }

        return builder.create();
    }

    private void loadLicenses() {
        // Load asynchronously in case of a very large file.
        mLicenseLoader = new AsyncTask<Void, Void, String>() {

            @Override
            protected String doInBackground(Void... params) {
                InputStream rawResource = getActivity().getResources().openRawResource(R.raw.licenses);
                BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(rawResource));

                String line;
                StringBuilder sb = new StringBuilder();

                try {
                    while ((line = bufferedReader.readLine()) != null) {
                        sb.append(line);
                        sb.append("\n");
                    }
                    bufferedReader.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }

                return sb.toString();
            }

            @Override
            protected void onPostExecute(String licensesBody) {
                super.onPostExecute(licensesBody);
                if (getActivity() == null || isCancelled()) {
                    return;
                }
                mIndeterminateProgress.setVisibility(View.INVISIBLE);
                mWebView.setVisibility(View.VISIBLE);
                mWebView.loadDataWithBaseURL(null, licensesBody, "text/html", "utf-8", null);
                mLicenseLoader = null;
            }

        }.execute();
    }
}