Set clipboard to transparent image

问题

I am creating a program that needs to copy an image to clipboard. The problem is that the image has a transparent background and, whenever I copy it, the image comes out with a black background instead of transparent. I tried lots of things since 2 days ago but none worked. The class imageSelection is based on http://www.java2s.com/Tutorial/Java/0120__Development/SettinganimageontheclipboardwithacustomTransferableobjecttoholdtheimage.htm

package Package1;

import java.awt.Image;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.Transferable;
import java.awt.datatransfer.UnsupportedFlavorException;
import java.io.IOException;

/** Transferable image */
public class imageSelection implements Transferable {
    private Image image;

    /** Creates a "transferable image" */
    public imageSelection(Image image) {
        this.image = image;
    }


    public DataFlavor[] getTransferDataFlavors() {
        DataFlavor[] transferData = new DataFlavor[] { DataFlavor.imageFlavor }; // <--- Works but gives me a black background instead of transparent

        /* I tried this (based on https://stackoverflow.com/questions/15977001/clipboard-copy-from-outlook-always-has-black-background-set-when-retrieved-as-im) but wasn't able to achieve any good result with it.

        DataFlavor transferData = null;
        try {
            transferData = new DataFlavor(Image.class, null); // <---- How to get an object of the type DataFlavor[] from this ( DataFlavor("image/x-emf") is of the type DataFlavor, not DataFlavor[] )
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            error.displayError(e.getStackTrace(), "Error creating DataFlavor (mime type: image/x-emf)");
        } 

        return new DataFlavor[] { transferData }
        */

        return transferData;
    }

    public boolean isDataFlavorSupported(DataFlavor flavor) {
        return DataFlavor.imageFlavor.equals(flavor);
    }


    public Object getTransferData(DataFlavor flavor) throws UnsupportedFlavorException, IOException {
        if (!DataFlavor.imageFlavor.equals(flavor)) {
            throw new UnsupportedFlavorException(flavor);
        }
        return image;
    }
}

Call:

imageSelection imgSel = new imageSelection(new ImageIcon(emojiLocation).getImage());
Toolkit.getDefaultToolkit().getSystemClipboard().setContents(imgSel, null);

Thanks

I am testing the contents by pasting it into Discord (chat app and it does support transparency, I made sure of that). I am using jdk1.8.0_131. I am using Windows 10 64bits fully updated. If needed, full source code here: https://github.com/KingOffNothing/EmojiMenu-for-discord/tree/master/src/Package1 What the program does is change the clipboard to a selected image and then a program written in AHK will simulate the key press ctrl+v that pastes the image.

回答1:

I was not able to exactly fix the transparency issue but was able to do a workaround (change transparent pixels to match the background's color)

private static BufferedImage fixTransparency(BufferedImage image) {
        int width = image.getWidth();
        int height = image.getHeight();
        Color discordChatColor = new Color(54,57,62, 255);

        for (int xx = 0; xx < width; xx++) {
            for (int yy = 0; yy < height; yy++) {
                Color originalColor = new Color(image.getRGB(xx, yy), true);
                if (originalColor.getAlpha() == 0) {
                    image.setRGB(xx, yy, discordChatColor.getRGB());
                }
            }
        }
        return image;
    }

来源：https://stackoverflow.com/questions/44444487/set-clipboard-to-transparent-image

标签

java

image

clipboard

transparent

transferable