我遇到了Window Builder示例的一些问题： https://developers.google.com/web-toolkit/tools/gwtdesigner/features/custom_composites
当我将代码复制到Eclipse时，代码中出现错误：
customComposite.setFirstFieldBackground(SWTResourceManager
.getColor(SWT.COLOR_YELLOW));
当我尝试在设计模式下展示表单时，代码中会出现另一个错误：
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，即使在自己的WindowBuilder的帮助文件中，我也说我的应用程序没有正确的设置/文件。
我会以不同的方式做什么？谢谢！
答案 0 :(得分：2)
当您使用设计视图设置颜色等内容时，SWTResourceManager是在插件中创建的类，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时，您将获得一个未找到类的异常。最简单的事情就是复制代码。删除设置颜色，在新插件的编辑器中设置颜色，并为该插件自动创建SWTResourceManager。第二个NPE不确定声音环境特定，但作为一个经验法则swt资源管理器是特定于捆绑。
答案 1 :(得分：1)
当您使用Eclipse向导（File＆gt; New＆gt; Other＆gt; WindowBuilder＆gt; SWTDesigner）创建新的WindowBuilder项目时，SWTResourceManager类通常在com.swtdesigner包中生成。
尝试使用此向导生成项目。
如果你还没有在这里生成这个类，那就是它的代码：
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();
}
}