tabris - 保存画布图像

Question

我使用 clientcanvas 来编辑我用 tabris 创建的应用程序中的图片。到目前为止它工作得很好，但是我遇到了将编辑后的图片保存为新图像的问题。有没有人有这方面的经验？

Answer 1

您需要将 swt ImageData 转换为 awt BufferedImage 并保存。用于此的实用程序可能如下所示：

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.awt.image.ColorModel;
import java.awt.image.IndexColorModel;
import java.awt.image.WritableRaster;

import org.eclipse.swt.graphics.ImageData;
import org.eclipse.swt.graphics.PaletteData;
import org.eclipse.swt.graphics.RGB;

public class ImageUtil {

  public static BufferedImage convertToAWT( ImageData data ) {
    BufferedImage imageToDraw = bgToAWT( data, data.width, data.height );
    BufferedImage result = new BufferedImage( data.width, data.height, BufferedImage.TYPE_INT_RGB );
    drawWhiteBackground( result );
    Graphics graphics = result.getGraphics();
    graphics.drawImage( imageToDraw, 0, 0, null );
    graphics.dispose();
    return result;
  }

  /*
   * See
   * http://m4tx.pl/en/2013/01/01/java-swt-to-awt-and-vice-versa-image-conversion
   * -with-transparency-support/
   */
  public static BufferedImage bgToAWT( ImageData data, int width, int height ) {
    BufferedImage result = null;
    ColorModel colorModel = null;
    PaletteData palette = data.palette;
    if( palette.isDirect ) {
      BufferedImage bufferedImage = new BufferedImage( width, height, BufferedImage.TYPE_INT_ARGB );
      for( int y = 0; y < data.height; y++ ) {
        for( int x = 0; x < data.width; x++ ) {
          int pixel = data.getPixel( x, y );
          RGB rgb = palette.getRGB( pixel );
          bufferedImage.setRGB( x, y, data.getAlpha( x, y ) << 24
                                      | rgb.red << 16
                                      | rgb.green << 8
                                      | rgb.blue );
        }
      }
      result = bufferedImage;
    } else {
      RGB[] rgbs = palette.getRGBs();
      byte[] red = new byte[ rgbs.length ];
      byte[] green = new byte[ rgbs.length ];
      byte[] blue = new byte[ rgbs.length ];
      for( int i = 0; i < rgbs.length; i++ ) {
        RGB rgb = rgbs[ i ];
        red[ i ] = ( byte )rgb.red;
        green[ i ] = ( byte )rgb.green;
        blue[ i ] = ( byte )rgb.blue;
      }
      if( data.transparentPixel != -1 ) {
        colorModel = new IndexColorModel( data.depth,
                                          rgbs.length,
                                          red,
                                          green,
                                          blue,
                                          data.transparentPixel );
      } else {
        colorModel = new IndexColorModel( data.depth, rgbs.length, red, green, blue );
      }
      BufferedImage bufferedImage = new BufferedImage( colorModel,
                                                       colorModel.createCompatibleWritableRaster( width,
                                                                                                  height ),
                                                       false,
                                                       null );
      WritableRaster raster = bufferedImage.getRaster();
      int[] pixelArray = new int[ 1 ];
      for( int y = 0; y < data.height; y++ ) {
        for( int x = 0; x < data.width; x++ ) {
          int pixel = data.getPixel( x, y );
          pixelArray[ 0 ] = pixel;
          raster.setPixel( x, y, pixelArray );
        }
      }
      result = bufferedImage;
    }
    return result;
  }

  private static void drawWhiteBackground( BufferedImage bufferedImage ) {
    Graphics2D graphics = bufferedImage.createGraphics();
    graphics.setColor( new Color( 255, 255, 255 ) );
    graphics.fillRect( 0, 0, bufferedImage.getWidth(), bufferedImage.getHeight() );
  }
}