android/print/PrintDocumentInfo.java

/*
 * Copyright (C) 2013 The Android Open Source Project
 *
 * 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 android.print;

import android.annotation.IntDef;
import android.annotation.IntRange;
import android.annotation.NonNull;
import android.os.Parcel;
import android.os.Parcelable;
import android.text.TextUtils;
import com.android.internal.util.Preconditions;

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;

/**
 * This class encapsulates information about a document for printing
 * purposes. This meta-data is used by the platform and print services,
 * components that interact with printers. For example, this class
 * contains the number of pages contained in the document it describes and
 * this number of pages is shown to the user allowing him/her to select
 * the range to print. Also a print service may optimize the printing
 * process based on the content type, such as document or photo.
 * <p>
 * Instances of this class are created by the printing application and
 * passed to the {@link PrintDocumentAdapter.LayoutResultCallback#onLayoutFinished(
 * PrintDocumentInfo, boolean) PrintDocumentAdapter.LayoutResultCallback.onLayoutFinished(
 * PrintDocumentInfo, boolean)} callback after successfully laying out the
 * content which is performed in {@link PrintDocumentAdapter#onLayout(PrintAttributes,
 * PrintAttributes, android.os.CancellationSignal, PrintDocumentAdapter.LayoutResultCallback,
 * android.os.Bundle) PrintDocumentAdapter.onLayout(PrintAttributes,
 * PrintAttributes, android.os.CancellationSignal,
 * PrintDocumentAdapter.LayoutResultCallback, android.os.Bundle)}.
 * </p>
 * <p>
 * An example usage looks like this:
 * <pre>
 *
 * . . .
 *
 * public void onLayout(PrintAttributes oldAttributes, PrintAttributes newAttributes,
 *         CancellationSignal cancellationSignal, LayoutResultCallback callback,
 *         Bundle metadata) {
 *
 *        // Assume the app defined a LayoutResult class which contains
 *        // the layout result data and that the content is a document.
 *        LayoutResult result = doSomeLayoutWork();
 *
 *        PrintDocumentInfo info = new PrintDocumentInfo
 *                .Builder("printed_file.pdf")
 *                .setContentType(PrintDocumentInfo.CONTENT_TYPE_DOCUMENT)
 *                .setPageCount(result.getPageCount())
 *                .build();
 *
 *       callback.onLayoutFinished(info, result.getContentChanged());
 *   }
 *
 *   . . .
 *
 * </pre>
 * </p>
 */
public final class PrintDocumentInfo implements Parcelable {

    /**
     * Constant for unknown page count.
     */
    public static final int PAGE_COUNT_UNKNOWN = -1;

    /** @hide */
    @Retention(RetentionPolicy.SOURCE)
    @IntDef(prefix = { "CONTENT_TYPE_" }, value = {
            CONTENT_TYPE_UNKNOWN,
            CONTENT_TYPE_DOCUMENT,
            CONTENT_TYPE_PHOTO
    })
    public @interface ContentType {
    }

    /**
     * Content type: unknown.
     */
    public static final int CONTENT_TYPE_UNKNOWN = -1;

    /**
     * Content type: document.
     * <p>
     * A print service may use normal paper to print the content instead
     * of dedicated photo paper. Also it may use a lower quality printing
     * process as the content is not as sensitive to print quality variation
     * as a photo is.
     * </p>
     */
    public static final int CONTENT_TYPE_DOCUMENT = 0;

    /**
     * Content type: photo.
     * <p>
     * A print service may use dedicated photo paper to print the content
     * instead of normal paper. Also it may use a higher quality printing
     * process as the content is more sensitive to print quality variation
     * than a document.
     * </p>
     */
    public static final int CONTENT_TYPE_PHOTO = 1;

    private @NonNull String mName;
    private @IntRange(from = -1) int mPageCount;
    private int mContentType;
    private long mDataSize;

    /**
     * Creates a new instance.
     */
    private PrintDocumentInfo() {
        /* do nothing */
    }

    /**
     * Creates a new instance.
     *
     * @param prototype from which to clone.
     */
    private PrintDocumentInfo(@NonNull PrintDocumentInfo prototype) {
        mName = prototype.mName;
        mPageCount = prototype.mPageCount;
        mContentType = prototype.mContentType;
        mDataSize = prototype.mDataSize;
    }

    /**
     * Creates a new instance.
     *
     * @param parcel Data from which to initialize.
     */
    private PrintDocumentInfo(Parcel parcel) {
        mName = Preconditions.checkStringNotEmpty(parcel.readString());
        mPageCount = parcel.readInt();
        Preconditions.checkArgument(mPageCount == PAGE_COUNT_UNKNOWN || mPageCount > 0);
        mContentType = parcel.readInt();
        mDataSize = Preconditions.checkArgumentNonnegative(parcel.readLong());
    }

    /**
     * Gets the document name. This name may be shown to
     * the user.
     *
     * @return The document name.
     */
    public @NonNull String getName() {
        return mName;
    }

    /**
     * Gets the total number of pages.
     *
     * @return The number of pages.
     *
     * @see #PAGE_COUNT_UNKNOWN
     */
    public @IntRange(from = -1) int getPageCount() {
        return mPageCount;
    }

    /**
     * Gets the content type.
     *
     * @return The content type.
     *
     * @see #CONTENT_TYPE_UNKNOWN
     * @see #CONTENT_TYPE_DOCUMENT
     * @see #CONTENT_TYPE_PHOTO
     */
    public int getContentType() {
        return mContentType;
    }

    /**
     * Gets the document data size in bytes.
     *
     * @return The data size.
     */
    public @IntRange(from = 0) long getDataSize() {
        return mDataSize;
    }

    /**
     * Sets the document data size in bytes.
     *
     * @param dataSize The data size.
     *
     * @hide
     */
    public void setDataSize(@IntRange(from = 0) long dataSize) {
        mDataSize = dataSize;
    }

    @Override
    public int describeContents() {
        return 0;
    }

    @Override
    public void writeToParcel(Parcel parcel, int flags) {
        parcel.writeString(mName);
        parcel.writeInt(mPageCount);
        parcel.writeInt(mContentType);
        parcel.writeLong(mDataSize);
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((mName != null) ? mName.hashCode() : 0);
        result = prime * result + mContentType;
        result = prime * result + mPageCount;
        result = prime * result + (int) mDataSize;
        result = prime * result + (int) (mDataSize >> 32);
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj == null) {
            return false;
        }
        if (getClass() != obj.getClass()) {
            return false;
        }
        PrintDocumentInfo other = (PrintDocumentInfo) obj;
        if (!TextUtils.equals(mName, other.mName)) {
            return false;
        }
        if (mContentType != other.mContentType) {
            return false;
        }
        if (mPageCount != other.mPageCount) {
            return false;
        }
        if (mDataSize != other.mDataSize) {
            return false;
        }
        return true;
    }

    @Override
    public String toString() {
        StringBuilder builder = new StringBuilder();
        builder.append("PrintDocumentInfo{");
        builder.append("name=").append(mName);
        builder.append(", pageCount=").append(mPageCount);
        builder.append(", contentType=").append(contentTypeToString(mContentType));
        builder.append(", dataSize=").append(mDataSize);
        builder.append("}");
        return builder.toString();
    }

    private String contentTypeToString(int contentType) {
        switch (contentType) {
            case CONTENT_TYPE_DOCUMENT: {
                return "CONTENT_TYPE_DOCUMENT";
            }
            case CONTENT_TYPE_PHOTO: {
                return "CONTENT_TYPE_PHOTO";
            }
            default: {
                return "CONTENT_TYPE_UNKNOWN";
            }
        }
    }

    /**
     * Builder for creating a {@link PrintDocumentInfo}.
     */
    public static final class Builder {
        private final PrintDocumentInfo mPrototype;

        /**
         * Constructor.
         * 
         * <p>
         * The values of the relevant properties are initialized with defaults.
         * Please refer to the documentation of the individual setters for
         * information about the default values.
         * </p>
         *
         * @param name The document name which may be shown to the user and
         * is the file name if the content it describes is saved as a PDF.
         * Cannot be empty. 
         */
        public Builder(@NonNull String name) {
            if (TextUtils.isEmpty(name)) {
                throw new IllegalArgumentException("name cannot be empty");
            }
            mPrototype = new PrintDocumentInfo();
            mPrototype.mName = name;
        }

        /**
         * Sets the total number of pages.
         * <p>
         * <strong>Default: </strong> {@link #PAGE_COUNT_UNKNOWN}
         * </p>
         *
         * @param pageCount The number of pages. Must be greater than or equal to zero or
         *            {@link PrintDocumentInfo#PAGE_COUNT_UNKNOWN}.
         * @return This builder.
         */
        public @NonNull Builder setPageCount(@IntRange(from = -1) int pageCount) {
            if (pageCount < 0 && pageCount != PAGE_COUNT_UNKNOWN) {
                throw new IllegalArgumentException("pageCount"
                        + " must be greater than or equal to zero or"
                        + " DocumentInfo#PAGE_COUNT_UNKNOWN");
            }
            mPrototype.mPageCount = pageCount;
            return this;
        }

        /**
         * Sets the content type.
         * <p>
         * <strong>Default: </strong> {@link #CONTENT_TYPE_DOCUMENT}
         * </p>
         *
         * @param type The content type.
         * @return This builder.
         * @see #CONTENT_TYPE_UNKNOWN
         * @see #CONTENT_TYPE_DOCUMENT
         * @see #CONTENT_TYPE_PHOTO
         */
        public @NonNull Builder setContentType(@ContentType int type) {
            mPrototype.mContentType = type;
            return this;
        }

        /**
         * Creates a new {@link PrintDocumentInfo} instance.
         *
         * @return The new instance.
         */
        public @NonNull PrintDocumentInfo build() {
            // Zero pages is the same as unknown as in this case
            // we will have to ask for all pages and look a the
            // wiritten PDF file for the page count.
            if (mPrototype.mPageCount == 0) {
                mPrototype.mPageCount = PAGE_COUNT_UNKNOWN;
            }
            return new PrintDocumentInfo(mPrototype);
        }
    }

    public static final @android.annotation.NonNull Parcelable.Creator<PrintDocumentInfo> CREATOR =
            new Creator<PrintDocumentInfo>() {
        @Override
        public PrintDocumentInfo createFromParcel(Parcel parcel) {
            return new PrintDocumentInfo(parcel);
        }

        @Override
        public PrintDocumentInfo[] newArray(int size) {
            return new PrintDocumentInfo[size];
        }
    };
}