org.openmrs.module.pmtct.web.view.chart.AbstractChartView.java Source code

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Here is the source code for org.openmrs.module.pmtct.web.view.chart.AbstractChartView.java

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/**
 * The contents of this file are subject to the OpenMRS Public License
 * Version 1.0 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://license.openmrs.org
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
 * License for the specific language governing rights and limitations
 * under the License.
 *
 * Copyright (C) OpenMRS, LLC.  All Rights Reserved.
 */
package org.openmrs.module.pmtct.web.view.chart;

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Font;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.jfree.chart.ChartUtilities;
import org.jfree.chart.JFreeChart;
import org.springframework.web.servlet.view.AbstractView;

/**
 * Base class for views that render usage data as a comma separated values
 */
public abstract class AbstractChartView extends AbstractView {

    protected static final Log log = LogFactory.getLog(AbstractChartView.class);

    private static Font font = new Font("Verdana", Font.PLAIN, 12);
    private static Color bkColor = new Color(240, 240, 250);

    /**
     * @see org.springframework.web.servlet.view.AbstractView
     */
    @Override
    @SuppressWarnings("unchecked")
    protected void renderMergedOutputModel(Map model, HttpServletRequest request, HttpServletResponse response)
            throws Exception {
        // Respond as a PNG image
        response.setContentType("image/png");

        // Disable caching
        response.setHeader("Pragma", "No-cache");
        response.setDateHeader("Expires", 0);
        response.setHeader("Cache-Control", "no-cache");

        int width = 400;
        int height = 300;

        JFreeChart chart = createChart(model, request);
        chart.setBackgroundPaint(Color.WHITE);
        chart.getPlot().setOutlineStroke(new BasicStroke(0));
        chart.getPlot().setOutlinePaint(getBackgroundColor());
        chart.getPlot().setBackgroundPaint(getBackgroundColor());
        chart.getPlot().setNoDataMessage("No data available");

        ChartUtilities.writeChartAsPNG(response.getOutputStream(), chart, width, height);
    }

    /**
     * Generates a JFreeChart
     * @param model the model
     * @param request the servlet request
     * @return the chart object
     */
    protected abstract JFreeChart createChart(Map<String, Object> model, HttpServletRequest request);

    /**
     * Gets the font for chart rendering
     */
    protected Font getFont() {
        return font;
    }

    /**
     * Gets the plot background color
     */
    protected Color getBackgroundColor() {
        return bkColor;
    }
}