edu.rowan.app.carousel.CarouselView.java Source code

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Here is the source code for edu.rowan.app.carousel.CarouselView.java

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/**
 * Copyright 2013 Tom Renn
 *
 * 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 edu.rowan.app.carousel;

import android.content.Context;
import android.content.res.Resources;
import android.graphics.Color;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.View;
import android.view.ViewGroup;

/**
 * 
 * Please note: This View controls its own height because the way ViewPager works (http://stackoverflow.com/a/8532550/121654)
 * @author tomrenn
 *
 */
public class CarouselView extends ViewPager implements CarouselListener {
    private CarouselFetch fetcher;
    private CarouselAdapter adapter;
    private int numFeatures;
    private int featuresLoaded;
    private static final int CAROUSEL_WIDTH = 528;
    private static final int CAROUSEL_HEIGHT = 220;

    public CarouselView(Context context) {
        super(context);
        numFeatures = 0;
        featuresLoaded = 0;
        this.setBackgroundColor(Color.BLACK);
        Resources r = context.getResources();
        int width = r.getDisplayMetrics().widthPixels;
        float ratio = (float) width / CAROUSEL_WIDTH;
        int height = 0;
        height = (int) (ratio * CAROUSEL_HEIGHT + 0.5);
        this.setLayoutParams(new ViewGroup.LayoutParams(LayoutParams.FILL_PARENT, height));
        //      Log.d("Rowan Prototype", "Height of viewpager is " + height);
        //      System.out.println("Height of ViewPager is " + height);

        adapter = new CarouselAdapter();
        this.setAdapter(adapter);

        fetcher = new CarouselFetch(this, context);
        fetcher.execute();
    }

    public String getCurrentFeatureLink() {
        return adapter.getFeatureAt(getCurrentItem()).getURL();
    }

    /**
     * Receive the list of fetched features
     */
    @Override
    public void receiveFeatures(CarouselFeature[] features) {
        if (features != null) {
            numFeatures = features.length;
            adapter.updateFeatures(features);

            for (CarouselFeature feature : features)
                feature.loadImage();
        }
    }

    /**
     * Feature is fully loaded (Image downloaded or loaded from cache)
     * Once all features are loaded, CarouselView is updated
     */
    @Override
    public void doneLoading(final CarouselFeature feature) {
        featuresLoaded++;

        // update features when they have all loaded
        if (featuresLoaded == numFeatures) {
            adapter.notifyDataSetChanged();
        }
    }

    /***************************************************
     * CarouselAdapter
     * Handles the data for the CarouselView Pager
     */
    private class CarouselAdapter extends PagerAdapter {
        private CarouselView carouselPager;
        private CarouselFeature[] features;

        public CarouselAdapter() {
            final CarouselFeature defaultFeature = new CarouselFeature(CarouselView.this.getContext());
            carouselPager = CarouselView.this;
            features = new CarouselFeature[] { defaultFeature };
        }

        public void updateFeatures(CarouselFeature[] newFeatures) {
            features = newFeatures;
        }

        public CarouselFeature getFeatureAt(int index) {
            return features[index];
        }

        @Override
        public Object instantiateItem(ViewGroup container, int position) {
            View view = features[position].getView();
            container.addView(view);
            return view;
        }

        @Override
        public void destroyItem(ViewGroup container, int position, Object object) {
            container.removeView((View) object);
        }

        @Override
        public int getCount() {
            return features.length;
        }

        /**
         * Overrode this method in order to force the default view to get removed when adapter.notifyDataSetChanged() is called
         */
        @Override
        public int getItemPosition(Object object) {
            Object tag = ((View) object).getTag();
            if (tag != null && tag.equals(CarouselFeature.DEFAULT_FEATURE_TAG)) {
                System.out.println("REMOVING DEFAULT VIEW");
                return POSITION_NONE;
            } else
                return super.getItemPosition(object);
        }

        @Override
        public boolean isViewFromObject(View view, Object object) {
            return view == object;
        }

    }

}