rgb.java

Tapestry的一个练习例子

package com.ttdev.customercomp;

import org.apache.tapestry.BaseComponent;
import org.apache.tapestry.IMarkupWriter;
import org.apache.tapestry.IRequestCycle;
import org.apache.tapestry.annotations.Parameter;

public abstract class RGB extends BaseComponent {
	public abstract int getRed();

	public abstract void setRed(int red);

	public abstract int getGreen();

	public abstract void setGreen(int green);

	public abstract int getBlue();

	public abstract void setBlue(int blue);

	@Parameter(required = true)
	public abstract int getColor();

	public abstract void setColor(int color);

	public String getBackgroundColorAssignment() {
		return "background-color: rgb(" + getRed() + "," + getGreen() + ","
				+ getBlue() + ")";
	}

	protected void renderComponent(IMarkupWriter writer, IRequestCycle cycle) {
		if (!cycle.isRewinding()) {
			setRed(getColor() >> 16);
			setGreen((getColor() >> 8) & 0xff);
			setBlue(getColor() & 0xff);
		}
		super.renderComponent(writer, cycle);
		if (cycle.isRewinding()) {
			setColor((getRed() << 16) | (getGreen() << 8) | getBlue());
		}
	}
}