library/src/main/java/com/bumptech/glide/load/engine/prefill/PreFillType.java

package com.bumptech.glide.load.engine.prefill;

import android.graphics.Bitmap;

/**
 * A container for a set of options used to pre-fill a {@link com.bumptech.glide.load.engine.bitmap_recycle.BitmapPool}
 * with {@link Bitmap Bitmaps} of a single size and configuration.
 */
public final class PreFillType {
    // Visible for testing.
    static final Bitmap.Config DEFAULT_CONFIG = Bitmap.Config.RGB_565;
    private final int width;
    private final int height;
    private final Bitmap.Config config;
    private final int weight;

    /**
     * Constructor for a single type of {@link android.graphics.Bitmap}.
     *
     * @param width The width in pixels of the {@link android.graphics.Bitmap Bitmaps} to
     *              pre-fill.
     * @param height The height in pixels of the {@link android.graphics.Bitmap Bitmaps} to
     *               pre-fill.
     * @param config The {@link android.graphics.Bitmap.Config} of the {@link android.graphics.Bitmap Bitmaps} to
     *               pre-fill.
     * @param weight An integer indicating how to balance pre-filling this size and configuration of
     * {@link android.graphics.Bitmap} against any other sizes/configurations that may be being pre-filled.
     */
    PreFillType(int width, int height, Bitmap.Config config, int weight) {
        if (config == null) {
            throw new NullPointerException("Config must not be null");
        }

        this.width = width;
        this.height = height;
        this.config = config;
        this.weight = weight;
    }

    /**
     * Returns the width in pixels of the {@link android.graphics.Bitmap Bitmaps}.
     */
    int getWidth() {
        return width;
    }

    /**
     * Returns the height in pixels of the {@link android.graphics.Bitmap Bitmaps}.
     */
    int getHeight() {
        return height;
    }

    /**
     * Returns the {@link android.graphics.Bitmap.Config} of the {@link android.graphics.Bitmap Bitmaps}.
     */
    Bitmap.Config getConfig() {
        return config;
    }

    /**
     * Returns the weight of the {@link android.graphics.Bitmap Bitmaps} of this type.
     */
    int getWeight() {
        return weight;
    }

    @Override
    public boolean equals(Object o) {
        if (o instanceof PreFillType) {
            PreFillType other = (PreFillType) o;
            return height == other.height
                    && width == other.width
                    && weight == other.weight
                    && config == other.config;
        }
        return false;
    }

    @Override
    public int hashCode() {
        int result = width;
        result = 31 * result + height;
        result = 31 * result + config.hashCode();
        result = 31 * result + weight;
        return result;
    }

    @Override
    public String toString() {
        return "PreFillSize{"
                + "width=" + width
                + ", height=" + height
                + ", config=" + config
                + ", weight=" + weight
                + '}';
    }

    /**
     * Builder for {@link PreFillType}.
     */
    public static class Builder {
        private final int width;
        private final int height;

        private Bitmap.Config config;
        private int weight = 1;

        /**
         * Constructor for a builder that uses the given size as the width and height of the Bitmaps to prefill.
         * @param size The width and height in pixels of the Bitmaps to prefill.
         */
        public Builder(int size) {
            this(size, size);
        }

        /**
         * Constructor for a builder that uses the given dimensions as the dimensions of the Bitmaps to prefill.
         * @param width The width in pixels of the Bitmaps to prefill.
         * @param height The height in pixels of the Bitmaps to prefill.
         */
        public Builder(int width, int height) {
            if (width <= 0) {
                throw new IllegalArgumentException("Width must be > 0");
            }
            if (height <= 0) {
                throw new IllegalArgumentException("Height must be > 0");
            }
            this.width = width;
            this.height = height;
        }

        /**
         * Sets the {@link android.graphics.Bitmap.Config} for the Bitmaps to pre-fill.
         * @param config The config to use, or null to use Glide's default.
         * @return This builder.
         */
        public Builder setConfig(Bitmap.Config config) {
            this.config = config;
            return this;
        }

        /**
         * Returns the current {@link android.graphics.Bitmap.Config}.
         */
        Bitmap.Config getConfig() {
            return config;
        }

        /**
         * Sets the weight to use to balance how many Bitmaps of this type are prefilled relative to the other requested
         * types.
         * @param weight An integer indicating how to balance pre-filling this size and configuration of
         * {@link android.graphics.Bitmap} against any other sizes/configurations that may be being pre-filled.
         * @return This builder.
         */
        public Builder setWeight(int weight) {
            if (weight <= 0) {
                throw new IllegalArgumentException("Weight must be > 0");
            }
            this.weight = weight;
            return this;
        }

        /**
         * Returns a new {@link PreFillType}.
         */
        PreFillType build() {
            return new PreFillType(width, height, config, weight);
        }
    }
}