valueaxismrtg.java

jrobin,使用纯java实现的RRD数据库,使用RRD数据库来统计数据.

/* ============================================================
 * JRobin : Pure java implementation of RRDTool's functionality
 * ============================================================
 *
 * Project Info:  http://www.jrobin.org
 * Project Lead:  Sasa Markovic ([e-mail])
 *
 * Developers:    Sasa Markovic ([e-mail])
 *
 *
 * (C) Copyright 2003-2005, by Sasa Markovic.
 *
 * This library is free software; you can redistribute it and/or modify it under the terms
 * of the GNU Lesser General Public License as published by the Free Software Foundation;
 * either version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along with this
 * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 * Boston, MA 02111-1307, USA.
 */
package org.jrobin.graph;

import org.jrobin.core.Util;

import java.awt.*;

class ValueAxisMrtg implements RrdGraphConstants {
	private ImageParameters im;
	private ImageWorker worker;
	private RrdGraphDef gdef;

	ValueAxisMrtg(RrdGraph rrdGraph) {
		this.im = rrdGraph.im;
		this.gdef = rrdGraph.gdef;
		this.worker = rrdGraph.worker;
		im.unit = gdef.unit;
	}

	boolean draw() {
		Font font = gdef.smallFont;
		Paint mGridColor = gdef.colors[COLOR_MGRID];
		Paint fontColor = gdef.colors[COLOR_FONT];
		int labelOffset = (int) (worker.getFontAscent(font) / 2);

		if (Double.isNaN((im.maxval - im.minval) / im.magfact)) {
			return false;
		}

		int xLeft = im.xorigin;
		int xRight = im.xorigin + im.xsize;
		String labfmt;
		if (im.scaledstep / im.magfact * Math.max(Math.abs(im.quadrant), Math.abs(4 - im.quadrant)) <= 1.0) {
			labfmt = "%5.2f";
		}
		else {
			labfmt = Util.sprintf("%%4.%df", 1 - ((im.scaledstep / im.magfact > 10.0 || Math.ceil(im.scaledstep / im.magfact) == im.scaledstep / im.magfact) ? 1 : 0));
		}
		if (im.symbol != ' ' || im.unit != null) {
			labfmt += " ";
		}
		if (im.symbol != ' ') {
			labfmt += im.symbol;
		}
		if (im.unit != null) {
			labfmt += im.unit;
		}
		for (int i = 0; i <= 4; i++) {
			int y = im.yorigin - im.ysize * i / 4;
			if (y >= im.yorigin - im.ysize && y <= im.yorigin) {
				String graph_label = Util.sprintf(labfmt, im.scaledstep / im.magfact * (i - im.quadrant));
				int length = (int) (worker.getStringWidth(graph_label, font));
				worker.drawString(graph_label, xLeft - length - PADDING_VLABEL, y + labelOffset, font, fontColor);
				worker.drawLine(xLeft - 2, y, xLeft + 2, y, mGridColor, TICK_STROKE);
				worker.drawLine(xRight - 2, y, xRight + 2, y, mGridColor, TICK_STROKE);
				worker.drawLine(xLeft, y, xRight, y, mGridColor, GRID_STROKE);
			}
		}
		return true;
	}

}