OptAnimationLoader.java

package cn.pedant.SweetAlert;

import android.content.Context;
import android.content.res.Resources;
import android.content.res.XmlResourceParser;
import android.util.AttributeSet;
import android.util.Xml;
import android.view.animation.*;
import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;

import java.io.IOException;

public class OptAnimationLoader {

    public static Animation loadAnimation(Context context, int id)
            throws Resources.NotFoundException {

        XmlResourceParser parser = null;
        try {
            parser = context.getResources().getAnimation(id);
            return createAnimationFromXml(context, parser);
        } catch (XmlPullParserException ex) {
            Resources.NotFoundException rnf = new Resources.NotFoundException("Can't load animation resource ID #0x" +
                    Integer.toHexString(id));
            rnf.initCause(ex);
            throw rnf;
        } catch (IOException ex) {
            Resources.NotFoundException rnf = new Resources.NotFoundException("Can't load animation resource ID #0x" +
                    Integer.toHexString(id));
            rnf.initCause(ex);
            throw rnf;
        } finally {
            if (parser != null) parser.close();
        }
    }

    private static Animation createAnimationFromXml(Context c, XmlPullParser parser)
            throws XmlPullParserException, IOException {

        return createAnimationFromXml(c, parser, null, Xml.asAttributeSet(parser));
    }

    private static Animation createAnimationFromXml(Context c, XmlPullParser parser,
                                                    AnimationSet parent, AttributeSet attrs) throws XmlPullParserException, IOException {

        Animation anim = null;

        // Make sure we are on a start tag.
        int type;
        int depth = parser.getDepth();

        while (((type=parser.next()) != XmlPullParser.END_TAG || parser.getDepth() > depth)
                && type != XmlPullParser.END_DOCUMENT) {

            if (type != XmlPullParser.START_TAG) {
                continue;
            }

            String  name = parser.getName();

            if (name.equals("set")) {
                anim = new AnimationSet(c, attrs);
                createAnimationFromXml(c, parser, (AnimationSet)anim, attrs);
            } else if (name.equals("alpha")) {
                anim = new AlphaAnimation(c, attrs);
            } else if (name.equals("scale")) {
                anim = new ScaleAnimation(c, attrs);
            }  else if (name.equals("rotate")) {
                anim = new RotateAnimation(c, attrs);
            }  else if (name.equals("translate")) {
                anim = new TranslateAnimation(c, attrs);
            } else {
                try {
                    anim = (Animation) Class.forName(name).getConstructor(Context.class, AttributeSet.class).newInstance(c, attrs);
                } catch (Exception te) {
                    throw new RuntimeException("Unknown animation name: " + parser.getName() + " error:" + te.getMessage());
                }
            }

            if (parent != null) {
                parent.addAnimation(anim);
            }
        }

        return anim;

    }
}