Core java 2 第二卷上的实例,我这里只处理一个 titlePosition 属性。首先,新建一个 bean。package testApp;
import java.awt.*;
import java.awt.font.FontRenderContext;
import java.awt.geom.Rectangle2D;
import java.beans.IndexedPropertyChangeEvent;
import java.beans.PropertyChangeListener;
import javax.swing.JComponent;
/**
* A bean to draw a bar chart.
* @version 1.31 2007-10-03
* @author Cay Horstmann
*/
public class ChartBean extends JComponent
{
public ChartBean()
{
setPreferredSize(new Dimension(XPREFSIZE, YPREFSIZE));
}
@Override
public void paintComponent(Graphics g)
{
Graphics2D g2 = (Graphics2D) g; if (values == null || values.length == 0) return;
double minValue = 0;
double maxValue = 0;
for (int i = 0; i < values.length; i++)
{
if (minValue > getValues(i)) minValue = getValues(i);
if (maxValue < getValues(i)) maxValue = getValues(i);
}
if (maxValue == minValue) return; Rectangle2D bounds = getBounds();
double clientWidth = bounds.getWidth();
double clientHeight = bounds.getHeight();
double barWidth = (clientWidth - 2 * INSETS) / values.length; g2.setPaint(inverse ? color : Color.white);
g2.fill(new Rectangle2D.Double(0, 0, clientWidth, clientHeight));
g2.setPaint(Color.black); Font titleFont = new Font("SansSerif", Font.BOLD, 20);
FontRenderContext context = g2.getFontRenderContext();
Rectangle2D titleBounds = titleFont.getStringBounds(title, context); double titleWidth = titleBounds.getWidth();
double y = -titleBounds.getY();
double x = 0;
if (titlePosition == Position.CENTER) x += (clientWidth - titleWidth) / 2;
else if (titlePosition == Position.RIGHT) x += clientWidth - titleWidth; g2.setFont(titleFont);
g2.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING,
RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
g2.drawString(title, (float) x, (float) y);
double top = titleBounds.getHeight();
double scale = (clientHeight - top - 2 * INSETS) / (maxValue - minValue);
y = clientHeight;
for (int i = 0; i < values.length; i++)
{
double x1 = INSETS + i * barWidth + 1;
double y1 = INSETS + top;
double value = getValues(i);
double height = value * scale;
if (value >= 0) y1 += (maxValue - value) * scale;
else
{
y1 += (int) (maxValue * scale);
height = -height;
}
g2.setPaint(inverse ? Color.white : color);
Rectangle2D bar = new Rectangle2D.Double(x1, y1, barWidth - 2, height);
g2.fill(bar);
g2.setPaint(Color.black);
g2.draw(bar);
}
} /**
* Sets the title property.
* @param t the new chart title.
*/
public void setTitle(String t)
{
title = t;
} /**
* Gets the title property.
* @return the chart title.
*/
public String getTitle()
{
return title;
} /**
* Sets the indexed values property.
* @param newValue the values to display in the chart.
*/
public void setValues(double[] newValue)
{
double[] oldValue = values;
firePropertyChange("values", oldValue, newValue);
values = newValue;
} /**
* Gets the indexed values property.
* @return the values to display in the chart.
*/
public double[] getValues()
{
return values;
} /**
* Sets the indexed values property.
* @param i the index of the value to set
* @param value the new value for that index
*/
public void setValues(int i, double value)
{
if (0 <= i && i < values.length)
{
double oldValue = values[i];
values[i] = value;
for (PropertyChangeListener listener : getPropertyChangeListeners())
listener.propertyChange(new IndexedPropertyChangeEvent(this, "values", oldValue,
value, i));
}
} /**
* Gets the indexed values property.
* @param i the index of the value to get
* @return the value for that index
*/
public double getValues(int i)
{
if (0 <= i && i < values.length) return values[i];
return 0;
} /**
* Sets the inverse property.
* @param b true if the display is inverted (white bars on colored background)
*/
public void setInverse(boolean b)
{
inverse = b;
} /**
* Gets the inverse property.
* @return true if the display is inverted
*/
public boolean isInverse()
{
return inverse;
} /**
* Sets the titlePosition property.
* @param p LEFT, CENTER, or RIGHT
*/
public void setTitlePosition(Position p)
{
titlePosition = p;
} /**
* Gets the titlePosition property.
* @return LEFT, CENTER, or RIGHT
*/
public Position getTitlePosition()
{
return titlePosition;
} /**
* Sets the graphColor property.
* @param c the color to use for the graph
*/
public void setGraphColor(Color c)
{
color = c;
} /**
* Gets the graphColor property.
* @param c the color to use for the graph
*/
public Color getGraphColor()
{
return color;
}
public enum Position { LEFT, CENTER, RIGHT }; private static final int XPREFSIZE = 300;
private static final int YPREFSIZE = 300; private static final int INSETS = 10; private double[] values = { 1,2,3};
private String title = "Title";
private Position titlePosition = Position.CENTER;
private boolean inverse;
private Color color = Color.red;
}然后,在同一个包下新建一个 beanInfo 文件。
package testApp;
import java.beans.IntrospectionException;
import java.beans.PropertyDescriptor;
import java.beans.SimpleBeanInfo;
public class ChartBeanBeanInfo extends SimpleBeanInfo
{
public ChartBeanBeanInfo()
{
try
{
PropertyDescriptor titlePositionDescriptor =
new PropertyDescriptor("titlePosition", ChartBean.class);
titlePositionDescriptor.setPropertyEditorClass(TitlePositonEditor.class);
propertyDescriptors = new PropertyDescriptor[]
{
titlePositionDescriptor
};
}
catch (IntrospectionException e)
{
}
}
@Override
public PropertyDescriptor[] getPropertyDescriptors()
{
return propertyDescriptors;
}
private PropertyDescriptor[] propertyDescriptors;
}再创建一个属性编辑器文件。
package testApp;
import java.beans.PropertyEditorSupport;
import java.util.Arrays;
class TitlePositonEditor extends PropertyEditorSupport
{
@Override
public String[] getTags()
{
return tags;
}
@Override
public String getAsText()
{
int index=((ChartBean.Position)getValue()).ordinal();
return tags[index];
}
@Override
public void setAsText(String s)
{
int index=Arrays.asList(tags).indexOf(s);
if(index>=0)
setValue(ChartBean.Position.values()[index]);
} @Override
public String getJavaInitializationString()
{
return ChartBean.Position.class.getName().replace('$', '.')+getValue();
}
private String[] tags={"Left","Center","Right"};
}
然后,无论我用 cmd 的 jar 命令创建 ChartBean.jar 还是用 NetBeans 的添加到面板功能,生成的 Bean 都和预期的不同。在属性里面,titlePosition 应该显示 属性编辑器 TitlePositonEditor 里面的字符串数组里面的值 Left,Center,Right,这里显示的情况是 LEFT,CENTER,RIGHT,NULL四个选项,和只有一个ChartBean文件的效果一样。
我知道我没有把这3个文件关联起来,请指教一下,创建这三个文件后,怎么操作才可以把他们关联起来。
最好有详细步骤,看到预期效果。我是新手。谢谢。
import java.awt.*;
import java.awt.font.FontRenderContext;
import java.awt.geom.Rectangle2D;
import java.beans.IndexedPropertyChangeEvent;
import java.beans.PropertyChangeListener;
import javax.swing.JComponent;
/**
* A bean to draw a bar chart.
* @version 1.31 2007-10-03
* @author Cay Horstmann
*/
public class ChartBean extends JComponent
{
public ChartBean()
{
setPreferredSize(new Dimension(XPREFSIZE, YPREFSIZE));
}
@Override
public void paintComponent(Graphics g)
{
Graphics2D g2 = (Graphics2D) g; if (values == null || values.length == 0) return;
double minValue = 0;
double maxValue = 0;
for (int i = 0; i < values.length; i++)
{
if (minValue > getValues(i)) minValue = getValues(i);
if (maxValue < getValues(i)) maxValue = getValues(i);
}
if (maxValue == minValue) return; Rectangle2D bounds = getBounds();
double clientWidth = bounds.getWidth();
double clientHeight = bounds.getHeight();
double barWidth = (clientWidth - 2 * INSETS) / values.length; g2.setPaint(inverse ? color : Color.white);
g2.fill(new Rectangle2D.Double(0, 0, clientWidth, clientHeight));
g2.setPaint(Color.black); Font titleFont = new Font("SansSerif", Font.BOLD, 20);
FontRenderContext context = g2.getFontRenderContext();
Rectangle2D titleBounds = titleFont.getStringBounds(title, context); double titleWidth = titleBounds.getWidth();
double y = -titleBounds.getY();
double x = 0;
if (titlePosition == Position.CENTER) x += (clientWidth - titleWidth) / 2;
else if (titlePosition == Position.RIGHT) x += clientWidth - titleWidth; g2.setFont(titleFont);
g2.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING,
RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
g2.drawString(title, (float) x, (float) y);
double top = titleBounds.getHeight();
double scale = (clientHeight - top - 2 * INSETS) / (maxValue - minValue);
y = clientHeight;
for (int i = 0; i < values.length; i++)
{
double x1 = INSETS + i * barWidth + 1;
double y1 = INSETS + top;
double value = getValues(i);
double height = value * scale;
if (value >= 0) y1 += (maxValue - value) * scale;
else
{
y1 += (int) (maxValue * scale);
height = -height;
}
g2.setPaint(inverse ? Color.white : color);
Rectangle2D bar = new Rectangle2D.Double(x1, y1, barWidth - 2, height);
g2.fill(bar);
g2.setPaint(Color.black);
g2.draw(bar);
}
} /**
* Sets the title property.
* @param t the new chart title.
*/
public void setTitle(String t)
{
title = t;
} /**
* Gets the title property.
* @return the chart title.
*/
public String getTitle()
{
return title;
} /**
* Sets the indexed values property.
* @param newValue the values to display in the chart.
*/
public void setValues(double[] newValue)
{
double[] oldValue = values;
firePropertyChange("values", oldValue, newValue);
values = newValue;
} /**
* Gets the indexed values property.
* @return the values to display in the chart.
*/
public double[] getValues()
{
return values;
} /**
* Sets the indexed values property.
* @param i the index of the value to set
* @param value the new value for that index
*/
public void setValues(int i, double value)
{
if (0 <= i && i < values.length)
{
double oldValue = values[i];
values[i] = value;
for (PropertyChangeListener listener : getPropertyChangeListeners())
listener.propertyChange(new IndexedPropertyChangeEvent(this, "values", oldValue,
value, i));
}
} /**
* Gets the indexed values property.
* @param i the index of the value to get
* @return the value for that index
*/
public double getValues(int i)
{
if (0 <= i && i < values.length) return values[i];
return 0;
} /**
* Sets the inverse property.
* @param b true if the display is inverted (white bars on colored background)
*/
public void setInverse(boolean b)
{
inverse = b;
} /**
* Gets the inverse property.
* @return true if the display is inverted
*/
public boolean isInverse()
{
return inverse;
} /**
* Sets the titlePosition property.
* @param p LEFT, CENTER, or RIGHT
*/
public void setTitlePosition(Position p)
{
titlePosition = p;
} /**
* Gets the titlePosition property.
* @return LEFT, CENTER, or RIGHT
*/
public Position getTitlePosition()
{
return titlePosition;
} /**
* Sets the graphColor property.
* @param c the color to use for the graph
*/
public void setGraphColor(Color c)
{
color = c;
} /**
* Gets the graphColor property.
* @param c the color to use for the graph
*/
public Color getGraphColor()
{
return color;
}
public enum Position { LEFT, CENTER, RIGHT }; private static final int XPREFSIZE = 300;
private static final int YPREFSIZE = 300; private static final int INSETS = 10; private double[] values = { 1,2,3};
private String title = "Title";
private Position titlePosition = Position.CENTER;
private boolean inverse;
private Color color = Color.red;
}然后,在同一个包下新建一个 beanInfo 文件。
package testApp;
import java.beans.IntrospectionException;
import java.beans.PropertyDescriptor;
import java.beans.SimpleBeanInfo;
public class ChartBeanBeanInfo extends SimpleBeanInfo
{
public ChartBeanBeanInfo()
{
try
{
PropertyDescriptor titlePositionDescriptor =
new PropertyDescriptor("titlePosition", ChartBean.class);
titlePositionDescriptor.setPropertyEditorClass(TitlePositonEditor.class);
propertyDescriptors = new PropertyDescriptor[]
{
titlePositionDescriptor
};
}
catch (IntrospectionException e)
{
}
}
@Override
public PropertyDescriptor[] getPropertyDescriptors()
{
return propertyDescriptors;
}
private PropertyDescriptor[] propertyDescriptors;
}再创建一个属性编辑器文件。
package testApp;
import java.beans.PropertyEditorSupport;
import java.util.Arrays;
class TitlePositonEditor extends PropertyEditorSupport
{
@Override
public String[] getTags()
{
return tags;
}
@Override
public String getAsText()
{
int index=((ChartBean.Position)getValue()).ordinal();
return tags[index];
}
@Override
public void setAsText(String s)
{
int index=Arrays.asList(tags).indexOf(s);
if(index>=0)
setValue(ChartBean.Position.values()[index]);
} @Override
public String getJavaInitializationString()
{
return ChartBean.Position.class.getName().replace('$', '.')+getValue();
}
private String[] tags={"Left","Center","Right"};
}
然后,无论我用 cmd 的 jar 命令创建 ChartBean.jar 还是用 NetBeans 的添加到面板功能,生成的 Bean 都和预期的不同。在属性里面,titlePosition 应该显示 属性编辑器 TitlePositonEditor 里面的字符串数组里面的值 Left,Center,Right,这里显示的情况是 LEFT,CENTER,RIGHT,NULL四个选项,和只有一个ChartBean文件的效果一样。
我知道我没有把这3个文件关联起来,请指教一下,创建这三个文件后,怎么操作才可以把他们关联起来。
最好有详细步骤,看到预期效果。我是新手。谢谢。
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