MockImageLoader.java

package ru.ltst.u2020mvp.data.api.mock;

import android.app.Application;
import android.content.res.AssetManager;
import android.graphics.BitmapFactory;

import javax.inject.Inject;

import ru.ltst.u2020mvp.ApplicationScope;
import ru.ltst.u2020mvp.data.api.model.response.Image;

@ApplicationScope
public final class MockImageLoader {
    private final AssetManager assetManager;

    @Inject
    MockImageLoader(Application application) {
        assetManager = application.getAssets();
    }

    /**
     * A filename like {@code abc123.jpg} inside the {@code mock/images/} asset folder.
     */
    private ImageBuilder newImage(String filename) {
        String path = "mock/images/" + filename;

        int width;
        int height;
        try {
            BitmapFactory.Options options = new BitmapFactory.Options();
            options.inJustDecodeBounds = true;

            BitmapFactory.decodeStream(assetManager.open(path), null, options);

            width = options.outWidth;
            height = options.outHeight;
        } catch (Exception e) {
            throw new RuntimeException("Unable to load " + filename, e);
        }

        String id = filename.substring(0, filename.lastIndexOf('.'));
        String link = "mock:///" + path;
        return new ImageBuilder(id, link, id /* default title == id */, id /* default description == id */,
                width, height);
    }

    public Image newImage(MockImage mockImage) {
        return newImage(mockImage.image)
                .title(mockImage.title)
                .views(mockImage.views)
                .build();
    }

    public static class ImageBuilder {
        private final String id;
        private final String link;
        private final int width;
        private final int height;
        private String title;
        private String description;
        private long datetime = System.currentTimeMillis();
        private int views;
        private boolean isAlbum;

        private ImageBuilder(String id, String link, String title, String description, int width, int height) {
            this.id = id;
            this.link = link;
            this.title = title;
            this.description = description;
            this.width = width;
            this.height = height;
        }

        public ImageBuilder title(String title) {
            this.title = title;
            return this;
        }

        public ImageBuilder description(String description) {
            this.description = description;
            return this;
        }

        public ImageBuilder datetime(int datetime) {
            this.datetime = datetime;
            return this;
        }

        public ImageBuilder views(int views) {
            this.views = views;
            return this;
        }

        public ImageBuilder isAlbum(boolean isAlbum) {
            this.isAlbum = isAlbum;
            return this;
        }

        public Image build() {
            return new Image(id, link, title, description, width, height, datetime, views, isAlbum);
        }
    }
}