XmlChangelogUtils.java

package xyz.klinker.blur.addons.utils;

import android.content.Context;
import android.content.res.XmlResourceParser;
import android.text.Html;
import android.text.Spanned;
import xyz.klinker.blur.R;
import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class XmlChangelogUtils {

    private static final String TAG = "XmlChangelogUtils";
    private static final String ns = null;

    public static Spanned[] parse(Context context) {
        try {
            XmlResourceParser parser = context.getResources().getXml(R.xml.changelog);
            parser.next();
            parser.nextTag();
            return readChangelog(parser);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    private static Spanned[] readChangelog(XmlPullParser parser) throws XmlPullParserException, IOException {
        List items = new ArrayList();

        parser.require(XmlPullParser.START_TAG, ns, "changelog");
        while (parser.next() != XmlPullParser.END_TAG) {
            if (parser.getEventType() != XmlPullParser.START_TAG) {
                continue;
            }
            String name = parser.getName();
            if ("version".equals(name)) {
                items.add(readVersion(parser));
            } else {
                skip(parser);
            }
        }

        return (Spanned[]) items.toArray(new Spanned[items.size()]);
    }

    private static Spanned readVersion(XmlPullParser parser) throws XmlPullParserException, IOException {
        StringBuilder versionInfo = new StringBuilder();
        parser.require(XmlPullParser.START_TAG, ns, "version");
        versionInfo.append(readVersionNumber(parser));

        while (parser.next() != XmlPullParser.END_TAG) {
            if (parser.getEventType() != XmlPullParser.START_TAG) {
                continue;
            }

            String name = parser.getName();
            if ("text".equals(name)) {
                versionInfo.append(readVersionText(parser));
            } else {
                skip(parser);
            }
        }

        return Html.fromHtml(versionInfo.toString());
    }

    private static String readVersionNumber(XmlPullParser parser) throws XmlPullParserException, IOException {
        parser.require(XmlPullParser.START_TAG, ns, "version");
        String versionNumber = parser.getAttributeValue(null, "name");
        String description = parser.getAttributeValue(null, "description");
        String version = "<b><u>Version " + versionNumber + ":</b></u>";
        if (description != null) {
            version += " " + description;
        }
        version += "<br/><br/>";
        return version;
    }

    private static String readVersionText(XmlPullParser parser) throws XmlPullParserException, IOException {
        parser.require(XmlPullParser.START_TAG, ns, "text");
        String text = "\t• " + readText(parser) + "<br/>";
        parser.require(XmlPullParser.END_TAG, ns, "text");
        return text;
    }

    private static String readText(XmlPullParser parser) throws XmlPullParserException, IOException {
        String result = "";
        if (parser.next() == XmlPullParser.TEXT) {
            result = parser.getText();
            parser.nextTag();
        }
        return result;
    }

    private static void skip(XmlPullParser parser) throws XmlPullParserException, IOException {
        if (parser.getEventType() != XmlPullParser.START_TAG) {
            throw new IllegalStateException();
        }
        int depth = 1;
        while (depth != 0) {
            switch (parser.next()) {
                case XmlPullParser.END_TAG:
                    depth--;
                    break;
                case XmlPullParser.START_TAG:
                    depth++;
                    break;
            }
        }
    }
}