com.sirika.pymager.api.ImageReference Maven / Gradle / Ivy

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/**
 * Copyright 2009 Sami Dalouche
 *
 * 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 com.sirika.pymager.api;

import static com.sirika.pymager.api.ImageId.imageId;
import com.google.common.base.Objects;
import com.google.common.base.Preconditions;

/**
 * Identifies the image that we want to retrieve.
 * 
 * The Image ID
 * The optional {@link ImageScale}
 * The optional {@link ImageFormat} (defaults to {@link ImageFormat#JPEG}
 * 
 * 
 * @author Sami Dalouche ([email protected])
 * 
 */
public class ImageReference {

    private ImageId id;
    private ImageScale rescaling;
    private ImageFormat imageFormat;

    private ImageReference(ImageId id) {
        this(id, null, null);
    }

    private ImageReference(ImageId id, ImageScale rescaling,
            ImageFormat imageFormat) {
        Preconditions.checkArgument(id != null, "ID cannnot be null");
        this.id = id;
        this.rescaling = rescaling;
        this.imageFormat = imageFormat;
    }

    public ImageReference getOriginalParentReference() {
        if (!isDerived()) {
            return this;
        }
        return new ImageReference(this.id);
    }

    public static ImageReference originalImage(String id) {
        return new ImageReference(imageId(id));
    }

    public static ImageReference originalImage(ImageId id) {
        return new ImageReference(id);
    }

    public ImageReference rescaledTo(ImageScale imageScale) {
        return new ImageReference(this.id, imageScale, ImageFormat.JPEG);
    }

    public boolean isConverted() {
        return this.imageFormat != null;
    }

    public ImageReference convertedTo(ImageFormat imageFormat) {
        Preconditions.checkArgument(this.rescaling != null, "Because of a limitation of the image service, converting to another format also requires rescaling the image");
        Preconditions.checkArgument(imageFormat != null, "imageFormat is required");
        return new ImageReference(this.id, this.rescaling, imageFormat);
    }

    public ImageId getId() {
        return id;
    }

    public ImageScale getRescaling() {
        return rescaling;
    }

    public boolean isDerived() {
        return rescaling != null;
    }

    public ImageFormat getImageFormat() {
        return imageFormat;
    }

    @Override
    public int hashCode() {
        return Objects.hashCode(id, imageFormat, rescaling);
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        ImageReference other = (ImageReference) obj;
        
        return Objects.equal(id, other.id) 
            && Objects.equal(imageFormat, other.imageFormat)
            && Objects.equal(rescaling, other.rescaling);
    }

    @Override
    public String toString() {
        return Objects.toStringHelper(this)
            .add("id", id)
            .add("imageScale", rescaling)
            .add("rescaling", rescaling)
            .toString();
    }
}