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package javafx.scene.input;

import java.util.Arrays;
import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;

import com.sun.javafx.util.WeakReferenceQueue;
import javafx.beans.NamedArg;


Data format identifier used as means
of identifying the data stored on a clipboard/dragboard.

Since:JavaFX 2.0
/**
 * Data format identifier used as means
 * of identifying the data stored on a clipboard/dragboard.
 * @since JavaFX 2.0
 */
public class DataFormat {

    
A static cache of all DataFormats created and currently in use. This is needed
by the underlying implementation, such that, given a mime type, we can determine
the associated DataFormat. The OS level is going to supply us with a mime type
(or other string based key), and we need to be able to map this back to the FX
DataFormat.

/**
     * A static cache of all DataFormats created and currently in use. This is needed
     * by the underlying implementation, such that, given a mime type, we can determine
     * the associated DataFormat. The OS level is going to supply us with a mime type
     * (or other string based key), and we need to be able to map this back to the FX
     * DataFormat.
     */
    private static final WeakReferenceQueue<DataFormat> DATA_FORMAT_LIST = new WeakReferenceQueue<DataFormat>();

    
Represents a plain text string.

/**
     * Represents a plain text string.
     */
    public static final DataFormat PLAIN_TEXT = new DataFormat("text/plain");

    
Represents an HTML formatted string.

/**
     * Represents an HTML formatted string.
     */
    public static final DataFormat HTML = new DataFormat("text/html");

    
Represents an RTF formatted string

/**
     * Represents an RTF formatted string
     */
    public static final DataFormat RTF = new DataFormat("text/rtf");

    
Represents a URL, encoded as a String

/**
     * Represents a URL, encoded as a String
     */
    public static final DataFormat URL = new DataFormat("text/uri-list");

    
A special platform specific image type, such as is commonly used
on the clipboard and interoperates widely with other applications.
For example, on Mac this might ultimately be a TIFF while on
Windows it might be a DIB (device independent bitmap).

/**
     * A special platform specific image type, such as is commonly used
     * on the clipboard and interoperates widely with other applications.
     * For example, on Mac this might ultimately be a TIFF while on
     * Windows it might be a DIB (device independent bitmap).
     */
    public static final DataFormat IMAGE = new DataFormat("application/x-java-rawimage");

    
Represents a List of Files.

/**
     * Represents a List of Files.
     */
    public static final DataFormat FILES = new DataFormat("application/x-java-file-list", "java.file-list");

    
Data format used internally, represents dragged image. Making this
a private field prevents user from creating this DataFormat and breaking
our drag view implementation.

/**
     * Data format used internally, represents dragged image. Making this
     * a private field prevents user from creating this DataFormat and breaking
     * our drag view implementation.
     */
    private static final DataFormat DRAG_IMAGE = new DataFormat("application/x-java-drag-image");

    
Data format used internally, represents offset in the dragged image.
Making this a private field prevents user from creating this DataFormat
and breaking our drag view implementation.

/**
     * Data format used internally, represents offset in the dragged image.
     * Making this a private field prevents user from creating this DataFormat
     * and breaking our drag view implementation.
     */
    private static final DataFormat DRAG_IMAGE_OFFSET = new DataFormat("application/x-java-drag-image-offset");

    
A set of identifiers, typically mime types, for this DataFormat.
In most cases this will be a single String.

/**
     * A set of identifiers, typically mime types, for this DataFormat.
     * In most cases this will be a single String.
     */
    private final Set<String> identifier;

    
Create a new DataFormat, specifying the set of ids that are associated with
this data format. Typically the ids are one or more mime types. For each
id, any data associated with this DataFormat will be registered on the
clipboard. For example, suppose I had the following:


    DataFormat fmt = new DataFormat("text/foo", "text/bar");
    Clipboard clipboard = Clipboard.getSystemClipboard();
    ClipboardContent content = new ClipboardContent();
    content.put(fmt, "Hello");
    clipboard.setContent(content);


With the above code, if I were to look on the clipboard, I'd find the String "Hello"
listed both for "text/foo" and "text/bar" on the clipboard.

 Note that the ids may be subject to platform restrictions in some cases. For instance, Swing requires a mime type so if an id is not of the "type/subtype" format it won't be possible to drag data of this type from/to JFXPanel. 


Params:
  • ids – The set of ids used to represent this DataFormat on the clipboard.
Throws:
/**
     * Create a new DataFormat, specifying the set of ids that are associated with
     * this data format. Typically the ids are one or more mime types. For each
     * id, any data associated with this DataFormat will be registered on the
     * clipboard. For example, suppose I had the following:
     * <pre>{@code
     *     DataFormat fmt = new DataFormat("text/foo", "text/bar");
     *     Clipboard clipboard = Clipboard.getSystemClipboard();
     *     ClipboardContent content = new ClipboardContent();
     *     content.put(fmt, "Hello");
     *     clipboard.setContent(content);
     * }</pre>
     *
     * With the above code, if I were to look on the clipboard, I'd find the String "Hello"
     * listed both for "text/foo" and "text/bar" on the clipboard.
     *
     * <p>
     * Note that the ids may be subject to platform restrictions in some cases.
     * For instance, Swing requires a mime type so if an {@code id} is not
     * of the "type/subtype" format it won't be possible
     * to drag data of this type from/to {@link javafx.embed.swing.JFXPanel}.
     * </p>
     * @param ids The set of ids used to represent this DataFormat on the clipboard.
     * @throws IllegalArgumentException if one of the given mime types is already
     *         assigned to another DataFormat.
     */
    public DataFormat(@NamedArg("ids") String... ids) {
        DATA_FORMAT_LIST.cleanup();
        if (ids != null) {
            for (String id : ids) {
                if (lookupMimeType(id) != null) {
                    throw new IllegalArgumentException("DataFormat '" + id +
                            "' already exists.");
                }
            }
            this.identifier = Collections.unmodifiableSet(new HashSet<String>(Arrays.asList(ids)));
        } else {
            this.identifier = Collections.<String>emptySet();
        }

        // Add to the statis data format list.
        DATA_FORMAT_LIST.add(this);
    }

    
Gets the unmodifiable set of identifiers for this DataFormat.

Returns:an unmodifiable set that is never null.
/**
     * Gets the unmodifiable set of identifiers for this DataFormat.
     * @return an unmodifiable set that is never null.
     */
    public final Set<String> getIdentifiers() {
        return identifier;
    }

    
Returns a string representation of this DataFormat object. 
Returns:a string representation of this DataFormat object.
/**
     * Returns a string representation of this {@code DataFormat} object.
     * @return a string representation of this {@code DataFormat} object.
     */
    @Override public String toString() {
        if (identifier.isEmpty()) {
            return "[]";
        } else if (identifier.size() == 1) {
            StringBuilder sb = new StringBuilder("[");
            sb.append(identifier.iterator().next());
            return (sb.append("]").toString());
        } else {
            StringBuilder b = new StringBuilder("[");
            Iterator<String> itr = identifier.iterator();
            while (itr.hasNext()) {
                b = b.append(itr.next());
                if (itr.hasNext()) {
                    b = b.append(", ");
                }
            }
            b = b.append("]");
            return b.toString();
        }
    }

    
Returns a hash code for this DataFormat object. 
Returns:a hash code for this DataFormat object.
/**
     * Returns a hash code for this {@code DataFormat} object.
     * @return a hash code for this {@code DataFormat} object.
     */
    @Override public int hashCode() {
        int hash = 7;

        for (String id : identifier) {
            hash = 31 * hash + id.hashCode();
        }

        return hash;
    }

    
Indicates whether some other object is "equal to" this one.

Params:
  • obj – the reference object with which to compare.
Returns:true if this object is equal to the obj argument; false otherwise.
/**
     * Indicates whether some other object is "equal to" this one.
     * @param obj the reference object with which to compare.
     * @return {@code true} if this object is equal to the {@code obj} argument; {@code false} otherwise.
     */
    @Override public boolean equals(Object obj) {
        if (obj == null || ! (obj instanceof DataFormat)) {
            return false;
        }

        DataFormat otherDataFormat = (DataFormat) obj;

        if (identifier.equals(otherDataFormat.identifier)) {
            return true;
        }

        return false;
    }

    
Looks for the DataFormat which has been previously created with
the given mime type as one of its ids.

Params:
  • mimeType – If null or the empty string, then null is returned.
Returns:The matching DataFormat
/**
     * Looks for the DataFormat which has been previously created with
     * the given mime type as one of its ids.
     * @param mimeType If null or the empty string, then null is returned.
     * @return The matching DataFormat
     */
    public static DataFormat lookupMimeType(String mimeType) {
        if (mimeType == null || mimeType.length() == 0) {
            return null;
        }

        Iterator itr = DATA_FORMAT_LIST.iterator();
        while (itr.hasNext()) {
            DataFormat dataFormat = (DataFormat) itr.next();
            if (dataFormat.getIdentifiers().contains(mimeType)) {
                return dataFormat;
            }
        }
        return null;
    }
}