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我在使用 Window Builder 示例时遇到了一些问题: https ://developers.google.com/web-toolkit/tools/gwtdesigner/features/custom_composites

当我将代码复制到我的 Eclipse 时,代码中出现错误:

    customComposite.setFirstFieldBackground(SWTResourceManager
            .getColor(SWT.COLOR_YELLOW));

Eclipse 告诉我没有 SWTResourceManager。

当我尝试在设计模式下展示表单时,代码中出现另一个错误:

    final Label thirdFieldLabel = new Label(customComposite.getComposite(),
            SWT.NONE);
    thirdFieldLabel.setText("Third Field");

错误:org.eclipse.wb.internal.core.utils.exception.DesignerException:2005(Null 作为父参数。)。

考虑到这个例子在 Web 中很常见,甚至在自己的 WindowBuilder 的帮助文件中,我想我的应用程序没有正确的设置/文件。

我会做些什么不同的事情?谢谢!

4

2 回答 2

2

发生的事情是 SWTResourceManager 是一个在插件中创建的类,当您使用设计视图设置颜色等内容时,它特定于您的插件。因此,当您将代码复制到另一个引用该类的插件中时,您将得到一个找不到类的异常。最简单的方法就是复制代码。删除设置的颜色,在新插件的编辑器中设置颜色,然后将为该插件自动创建 SWTResourceManager。第二个 NPE 不确定听起来特定于环境,但根据经验,swt 资源管理器是特定于捆绑包的。

于 2012-11-20T17:05:23.467 回答
1

当您使用 Eclipse 向导(文件 > 新建 > 其他 > WindowBuilder> SWTDesigner)创建新的 WindowBuilder 项目时,通常会在 com.swtdesigner 包中生成 SWTResourceManager 类。

尝试使用此向导生成您的项目。

如果您仍然没有生成此类,这里是它的代码:

package com.swtdesigner;

import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Map;

import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.Cursor;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.FontData;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.ImageData;
import org.eclipse.swt.graphics.RGB;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.widgets.Display;

/**
 * Utility class for managing OS resources associated with SWT controls such as colors, fonts, images, etc.
 * <p>
 * !!! IMPORTANT !!! Application code must explicitly invoke the <code>dispose()</code> method to release the
* operating system resources managed by cached objects when those objects and OS resources are no longer
* needed (e.g. on application shutdown)
* <p>
* This class may be freely distributed as part of any application or plugin.
* <p>
* @author scheglov_ke
* @author Dan Rubel
*/
public class SWTResourceManager {
   ////////////////////////////////////////////////////////////////////////////
   //
   // Color
   //
   ////////////////////////////////////////////////////////////////////////////
   private static Map<RGB, Color> m_colorMap = new HashMap<RGB, Color>();

  /**
   * Returns the system {@link Color} matching the specific ID.
   * 
   * @param systemColorID
   *            the ID value for the color
   * @return the system {@link Color} matching the specific ID
   */
  public static Color getColor(int systemColorID) {
     Display display = Display.getCurrent();
     return display.getSystemColor(systemColorID);
  }

  /**
   * Returns a {@link Color} given its red, green and blue component values.
   * 
   * @param r
   *            the red component of the color
   * @param g
   *            the green component of the color
   * @param b
   *            the blue component of the color
   * @return the {@link Color} matching the given red, green and blue component values
   */
  public static Color getColor(int r, int g, int b) {
     return getColor(new RGB(r, g, b));
  }

  /**
   * Returns a {@link Color} given its RGB value.
   * 
   * @param rgb
   *            the {@link RGB} value of the color
   * @return the {@link Color} matching the RGB value
   */
  public static Color getColor(RGB rgb) {
     Color color = m_colorMap.get(rgb);
     if (color == null) {
        Display display = Display.getCurrent();
        color = new Color(display, rgb);
        m_colorMap.put(rgb, color);
     }
     return color;
  }

  /**
   * Dispose of all the cached {@link Color}'s.
   */
  public static void disposeColors() {
     for (Color color : m_colorMap.values()) {
        color.dispose();
     }
     m_colorMap.clear();
  }

  ////////////////////////////////////////////////////////////////////////////
  //
  // Image
  //
  ////////////////////////////////////////////////////////////////////////////
  /**
   * Maps image paths to images.
   */
  private static Map<String, Image> m_imageMap = new HashMap<String, Image>();

  /**
   * Returns an {@link Image} encoded by the specified {@link InputStream}.
   * 
   * @param stream
   *            the {@link InputStream} encoding the image data
   * @return the {@link Image} encoded by the specified input stream
   */
  protected static Image getImage(InputStream stream) throws IOException {
     try {
        Display display = Display.getCurrent();
        ImageData data = new ImageData(stream);
        if (data.transparentPixel > 0) {
           return new Image(display, data, data.getTransparencyMask());
        }
        return new Image(display, data);
     } finally {
        stream.close();
     }
  }

  /**
   * Returns an {@link Image} stored in the file at the specified path.
   * 
   * @param path
   *            the path to the image file
   * @return the {@link Image} stored in the file at the specified path
   */
  public static Image getImage(String path) {
     Image image = m_imageMap.get(path);
     if (image == null) {
        try {
           image = getImage(new FileInputStream(path));
           m_imageMap.put(path, image);
        } catch (Exception e) {
           image = getMissingImage();
           m_imageMap.put(path, image);
        }
     }
     return image;
  }

  /**
   * Returns an {@link Image} stored in the file at the specified path relative to the specified class.
   * 
   * @param clazz
   *            the {@link Class} relative to which to find the image
   * @param path
   *            the path to the image file, if starts with <code>'/'</code>
   * @return the {@link Image} stored in the file at the specified path
   */
  public static Image getImage(Class<?> clazz, String path) {
     String key = clazz.getName() + '|' + path;
     Image image = m_imageMap.get(key);
     if (image == null) {
        try {
           image = getImage(clazz.getResourceAsStream(path));
           m_imageMap.put(key, image);
        } catch (Exception e) {
           image = getMissingImage();
           m_imageMap.put(key, image);
        }
     }
     return image;
  }

  private static final int MISSING_IMAGE_SIZE = 10;

  /**
   * @return the small {@link Image} that can be used as placeholder for missing image.
   */
  private static Image getMissingImage() {
     Image image = new Image(Display.getCurrent(), MISSING_IMAGE_SIZE, MISSING_IMAGE_SIZE);
     //
     GC gc = new GC(image);
     gc.setBackground(getColor(SWT.COLOR_RED));
     gc.fillRectangle(0, 0, MISSING_IMAGE_SIZE, MISSING_IMAGE_SIZE);
     gc.dispose();
     //
     return image;
  }

  /**
   * Style constant for placing decorator image in top left corner of base image.
   */
  public static final int TOP_LEFT = 1;

  /**
   * Style constant for placing decorator image in top right corner of base image.
   */
  public static final int TOP_RIGHT = 2;

  /**
   * Style constant for placing decorator image in bottom left corner of base image.
   */
  public static final int BOTTOM_LEFT = 3;

  /**
   * Style constant for placing decorator image in bottom right corner of base image.
   */
  public static final int BOTTOM_RIGHT = 4;

  /**
   * Internal value.
   */
  protected static final int LAST_CORNER_KEY = 5;

  /**
   * Maps images to decorated images.
   */
  @SuppressWarnings("unchecked")
  private static Map<Image, Map<Image, Image>>[] m_decoratedImageMap = new Map[LAST_CORNER_KEY];

  /**
   * Returns an {@link Image} composed of a base image decorated by another image.
   * 
   * @param baseImage
   *            the base {@link Image} that should be decorated
   * @param decorator
   *            the {@link Image} to decorate the base image
   * @return {@link Image} The resulting decorated image
   */
  public static Image decorateImage(Image baseImage, Image decorator) {
     return decorateImage(baseImage, decorator, BOTTOM_RIGHT);
  }

  /**
   * Returns an {@link Image} composed of a base image decorated by another image.
   * 
   * @param baseImage
   *            the base {@link Image} that should be decorated
   * @param decorator
   *            the {@link Image} to decorate the base image
   * @param corner
   *            the corner to place decorator image
   * @return the resulting decorated {@link Image}
   */
  public static Image decorateImage(final Image baseImage, final Image decorator, final int corner) {
     if (corner <= 0 || corner >= LAST_CORNER_KEY) {
        throw new IllegalArgumentException("Wrong decorate corner");
     }
     Map<Image, Map<Image, Image>> cornerDecoratedImageMap = m_decoratedImageMap[corner];
     if (cornerDecoratedImageMap == null) {
        cornerDecoratedImageMap = new HashMap<Image, Map<Image, Image>>();
        m_decoratedImageMap[corner] = cornerDecoratedImageMap;
     }
     Map<Image, Image> decoratedMap = cornerDecoratedImageMap.get(baseImage);
     if (decoratedMap == null) {
        decoratedMap = new HashMap<Image, Image>();
        cornerDecoratedImageMap.put(baseImage, decoratedMap);
     }
     //
     Image result = decoratedMap.get(decorator);
     if (result == null) {
        Rectangle bib = baseImage.getBounds();
        Rectangle dib = decorator.getBounds();
        //
        result = new Image(Display.getCurrent(), bib.width, bib.height);
        //
        GC gc = new GC(result);
        gc.drawImage(baseImage, 0, 0);
        if (corner == TOP_LEFT) {
           gc.drawImage(decorator, 0, 0);
        } else if (corner == TOP_RIGHT) {
           gc.drawImage(decorator, bib.width - dib.width, 0);
        } else if (corner == BOTTOM_LEFT) {
           gc.drawImage(decorator, 0, bib.height - dib.height);
        } else if (corner == BOTTOM_RIGHT) {
           gc.drawImage(decorator, bib.width - dib.width, bib.height - dib.height);
        }
        gc.dispose();
        //
        decoratedMap.put(decorator, result);
     }
     return result;
  }

  /**
   * Dispose all of the cached {@link Image}'s.
   */
  public static void disposeImages() {
     // dispose loaded images
     {
        for (Image image : m_imageMap.values()) {
           image.dispose();
        }
        m_imageMap.clear();
     }
     // dispose decorated images
     for (int i = 0; i < m_decoratedImageMap.length; i++) {
        Map<Image, Map<Image, Image>> cornerDecoratedImageMap = m_decoratedImageMap[i];
        if (cornerDecoratedImageMap != null) {
           for (Map<Image, Image> decoratedMap : cornerDecoratedImageMap.values()) {
              for (Image image : decoratedMap.values()) {
                 image.dispose();
              }
              decoratedMap.clear();
           }
           cornerDecoratedImageMap.clear();
        }
     }
  }

  ////////////////////////////////////////////////////////////////////////////
  //
  // Font
  //
  ////////////////////////////////////////////////////////////////////////////
  /**
   * Maps font names to fonts.
   */
  private static Map<String, Font> m_fontMap = new HashMap<String, Font>();

  /**
   * Maps fonts to their bold versions.
   */
  private static Map<Font, Font> m_fontToBoldFontMap = new HashMap<Font, Font>();

  /**
   * Returns a {@link Font} based on its name, height and style.
   * 
   * @param name
   *            the name of the font
   * @param height
   *            the height of the font
   * @param style
   *            the style of the font
   * @return {@link Font} The font matching the name, height and style
   */
  public static Font getFont(String name, int height, int style) {
     return getFont(name, height, style, false, false);
  }

  /**
   * Returns a {@link Font} based on its name, height and style. Windows-specific strikeout and underline
   * flags are also supported.
   * 
   * @param name
   *            the name of the font
   * @param size
   *            the size of the font
   * @param style
   *            the style of the font
   * @param strikeout
   *            the strikeout flag (warning: Windows only)
   * @param underline
   *            the underline flag (warning: Windows only)
   * @return {@link Font} The font matching the name, height, style, strikeout and underline
   */
  public static Font getFont(String name, int size, int style, boolean strikeout, boolean underline) {
     String fontName = name + '|' + size + '|' + style + '|' + strikeout + '|' + underline;
     Font font = m_fontMap.get(fontName);
     if (font == null) {
        FontData fontData = new FontData(name, size, style);
        if (strikeout || underline) {
           try {
              Class<?> logFontClass = Class.forName("org.eclipse.swt.internal.win32.LOGFONT"); //$NON-NLS-1$
              Object logFont = FontData.class.getField("data").get(fontData); //$NON-NLS-1$
              if (logFont != null && logFontClass != null) {
                 if (strikeout) {
                    logFontClass.getField("lfStrikeOut").set(logFont, Byte.valueOf((byte) 1)); //$NON-NLS-1$
                 }
                 if (underline) {
                    logFontClass.getField("lfUnderline").set(logFont, Byte.valueOf((byte) 1)); //$NON-NLS-1$
                 }
              }
           } catch (Throwable e) {
              System.err
                    .println("Unable to set underline or strikeout" + " (probably on a non-Windows platform). " + e); //$NON-NLS-1$ //$NON-NLS-2$
           }
        }
        font = new Font(Display.getCurrent(), fontData);
        m_fontMap.put(fontName, font);
     }
     return font;
  }

  /**
   * Returns a bold version of the given {@link Font}.
   * 
   * @param baseFont
   *            the {@link Font} for which a bold version is desired
   * @return the bold version of the given {@link Font}
   */
  public static Font getBoldFont(Font baseFont) {
     Font font = m_fontToBoldFontMap.get(baseFont);
     if (font == null) {
        FontData fontDatas[] = baseFont.getFontData();
        FontData data = fontDatas[0];
        font = new Font(Display.getCurrent(), data.getName(), data.getHeight(), SWT.BOLD);
        m_fontToBoldFontMap.put(baseFont, font);
     }
     return font;
  }

  /**
   * Dispose all of the cached {@link Font}'s.
   */
  public static void disposeFonts() {
     // clear fonts
     for (Font font : m_fontMap.values()) {
        font.dispose();
     }
     m_fontMap.clear();
     // clear bold fonts
     for (Font font : m_fontToBoldFontMap.values()) {
        font.dispose();
     }
     m_fontToBoldFontMap.clear();
  }

  ////////////////////////////////////////////////////////////////////////////
  //
  // Cursor
  //
  ////////////////////////////////////////////////////////////////////////////
  /**
   * Maps IDs to cursors.
   */
  private static Map<Integer, Cursor> m_idToCursorMap = new HashMap<Integer, Cursor>();

  /**
   * Returns the system cursor matching the specific ID.
   * 
   * @param id
   *            int The ID value for the cursor
   * @return Cursor The system cursor matching the specific ID
   */
  public static Cursor getCursor(int id) {
     Integer key = Integer.valueOf(id);
     Cursor cursor = m_idToCursorMap.get(key);
     if (cursor == null) {
        cursor = new Cursor(Display.getDefault(), id);
        m_idToCursorMap.put(key, cursor);
     }
     return cursor;
  }

  /**
   * Dispose all of the cached cursors.
   */
  public static void disposeCursors() {
     for (Cursor cursor : m_idToCursorMap.values()) {
        cursor.dispose();
     }
     m_idToCursorMap.clear();
  }

  ////////////////////////////////////////////////////////////////////////////
  //
  // General
  //
  ////////////////////////////////////////////////////////////////////////////
  /**
   * Dispose of cached objects and their underlying OS resources. This should only be called when the cached
   * objects are no longer needed (e.g. on application shutdown).
   */
  public static void dispose() {
     disposeColors();
     disposeImages();
     disposeFonts();
     disposeCursors();
  }
}
于 2012-11-20T17:04:19.427 回答