/*******************************************************************************
 * Copyright (c) 2000, 2006 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 * Port to the D programming language:
 *     Frank Benoit <benoit@tionex.de>
 *******************************************************************************/
module dwtx.jface.resource.FileImageDescriptor;

import dwtx.jface.resource.ImageDescriptor;

// import java.io.BufferedInputStream;
// import java.io.FileInputStream;
// import java.io.FileNotFoundException;
// import java.io.IOException;
// import java.io.InputStream;

import dwt.DWT;
import dwt.DWTException;
import dwt.graphics.ImageData;

import dwt.dwthelper.utils;
import dwt.dwthelper.InputStream;
import dwt.dwthelper.FileInputStream;
import dwt.dwthelper.BufferedInputStream;

/**
 * An image descriptor that loads its image information
 * from a file.
 */
class FileImageDescriptor : ImageDescriptor {

    /**
     * The class whose resource directory contain the file,
     * or <code>null</code> if none.
     */
    private ClassInfo location;

    /**
     * The name of the file.
     */
    private String name;

    /**
     * Creates a new file image descriptor.
     * The file has the given file name and is located
     * in the given class's resource directory. If the given
     * class is <code>null</code>, the file name must be absolute.
     * <p>
     * Note that the file is not accessed until its
     * <code>getImageDate</code> method is called.
     * </p>
     *
     * @param clazz class for resource directory, or
     *   <code>null</code>
     * @param filename the name of the file
     */
    this(ClassInfo clazz, String filename) {
        this.location = clazz;
        this.name = filename;
    }

    /* (non-Javadoc)
     * Method declared on Object.
     */
    public bool equals(Object o) {
        if (!( cast(FileImageDescriptor)o )) {
            return false;
        }
        FileImageDescriptor other = cast(FileImageDescriptor) o;
        if (location !is null) {
            if ( location.name != other.location.name ) {
                return false;
            }
        } else {
            if (other.location !is null) {
                return false;
            }
        }
        return name == other.name;
    }

    /* (non-Javadoc)
     * Method declared on ImageDesciptor.
     * Returns null if the image data cannot be read.
     */
    public ImageData getImageData() {
        InputStream in_ = getStream();
        ImageData result = null;
        if (in_ !is null) {
            try {
                result = new ImageData(in_);
            } catch (DWTException e) {
                if (e.code !is DWT.ERROR_INVALID_IMAGE) {
                    throw e;
                // fall through otherwise
                }
            } finally {
                in_.close();
            }
        }
        return result;
    }

    /**
     * Returns a stream on the image contents.  Returns
     * null if a stream could not be opened.
     *
     * @return the buffered stream on the file or <code>null</code>
     * if the file cannot be found
     */
    private InputStream getStream() {
        InputStream is_ = null;

        if (location !is null) {
            is_ = ClassInfoGetResourceAsStream( location, name);

        } else {
            try {
                is_ = new FileInputStream(name);
            } catch (/+FileNotFoundException+/ IOException e) {
                return null;
            }
        }
        if (is_ is null) {
            return null;
        } else {
            return new BufferedInputStream(is_);
        }
    }

    /* (non-Javadoc)
     * Method declared on Object.
     */
    public override hash_t toHash() {
        int code = dwt.dwthelper.utils.toHash(name);
        if (location !is null) {
            code += location.toHash();
        }
        return code;
    }

    /* (non-Javadoc)
     * Method declared on Object.
     */
    /**
     * The <code>FileImageDescriptor</code> implementation of this <code>Object</code> method
     * returns a string representation of this object which is suitable only for debugging.
     */
    public override String toString() {
        return "FileImageDescriptor(location=" ~ location.toString() ~ ", name=" ~ name ~ ")";//$NON-NLS-3$//$NON-NLS-2$//$NON-NLS-1$
    }
}