com.alternatecomputing.jschnizzle.ui.ImagePanel.java Source code

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Here is the source code for com.alternatecomputing.jschnizzle.ui.ImagePanel.java

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/*
 * Copyright 2010 Alternate Computing Solutions Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.alternatecomputing.jschnizzle.ui;

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.Image;
import java.awt.event.MouseListener;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;

import javax.swing.ImageIcon;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JSlider;
import javax.swing.SwingConstants;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;

import org.apache.batik.transcoder.TranscoderException;
import org.apache.batik.transcoder.TranscoderInput;
import org.apache.batik.transcoder.image.PNGTranscoder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.alternatecomputing.jschnizzle.model.Diagram;
import com.alternatecomputing.jschnizzle.renderer.util.BufferedImageTranscoder;
import com.jgoodies.forms.layout.CellConstraints;
import com.jgoodies.forms.layout.FormLayout;

public class ImagePanel extends JPanel {
    private static final long serialVersionUID = 8899749112300691634L;
    private static final Logger LOGGER = LoggerFactory.getLogger(ImagePanel.class);
    private Diagram diagram;
    private JPanel diagramPanel;
    private JSlider scaleSlider;
    private static final int INTERVALS = 10;

    public ImagePanel() {
        super();
        this.setLayout(new FormLayout("fill:min:grow, pref, 4dlu, pref, 4dlu", "fill:min:grow, 4dlu, pref, 4dlu"));
        CellConstraints cc = new CellConstraints();
        this.diagramPanel = new JPanel();
        this.diagramPanel.setLayout(new BorderLayout());
        this.diagramPanel.setBackground(Color.WHITE);
        JScrollPane jScrollPane = new JScrollPane(diagramPanel);
        add(jScrollPane, cc.xywh(1, 1, 5, 1));
        add(new JLabel("Scale:"), cc.xy(2, 3));
        scaleSlider = createScaleSlider(this);
        add(scaleSlider, cc.xy(4, 3));
    }

    private JSlider createScaleSlider(final Component panel) {
        final JSlider slider = new JSlider(SwingConstants.HORIZONTAL, 0, INTERVALS, INTERVALS / 2);
        slider.setMajorTickSpacing(2);
        slider.setMinorTickSpacing(1);
        slider.setSnapToTicks(true);
        slider.addChangeListener(new ChangeListener() {

            public void stateChanged(ChangeEvent e) {
                if (diagram != null) {
                    if (slider.getValue() == INTERVALS / 2) {
                        setDiagram(diagram); // use original at full size
                    } else {
                        if (slider.getValueIsAdjusting()) {
                            resizeImage(slider, Image.SCALE_FAST);
                        } else {
                            resizeFromSVG(slider);
                        }
                    }
                    panel.validate();
                }
            }
        });
        return slider;
    }

    public void setDiagram(Diagram diagram) {
        if (diagramPanel.getComponentCount() != 0) {
            diagramPanel.removeAll();
        }
        this.diagram = diagram;
        scaleSlider.setValue(INTERVALS / 2);
        if (diagram != null) {
            BufferedImage image = (BufferedImage) diagram.nonBeanImage();
            if (image != null) {
                int width = image.getWidth();
                int height = image.getHeight();
                diagramPanel.setPreferredSize(new Dimension(width, height)); // reset size to remove sticky scrollbars
                if (diagram != null) {
                    diagramPanel.add(new JLabel(new ImageIcon(diagram.nonBeanImage())), BorderLayout.CENTER);
                }
            }
        }
        diagramPanel.validate();
        diagramPanel.repaint();
    }

    private void resizeImage(final JSlider slider, int hints) {
        BufferedImage image = (BufferedImage) diagram.nonBeanImage();
        float width = image.getWidth() * slider.getValue() / INTERVALS * 2;
        float height = image.getHeight() * slider.getValue() / INTERVALS * 2;
        JLabel scaledComponent = new JLabel(
                new ImageIcon(image.getScaledInstance(Math.max(1, (int) width), Math.max(1, (int) height), hints)));
        synchronized (diagramPanel) {
            diagramPanel.setPreferredSize(new Dimension((int) width, (int) height));
            if (diagramPanel.getComponentCount() != 0) {
                diagramPanel.removeAll();
            }
            diagramPanel.add(scaledComponent, BorderLayout.CENTER);
        }
    }

    private void resizeFromSVG(JSlider slider) {
        BufferedImage image = (BufferedImage) diagram.nonBeanImage();
        float width = image.getWidth() * slider.getValue() / INTERVALS * 2;
        float height = image.getHeight() * slider.getValue() / INTERVALS * 2;
        byte[] svgBytes = diagram.getEncodedImage().getBytes();
        TranscoderInput input = new TranscoderInput(new ByteArrayInputStream(svgBytes));
        BufferedImageTranscoder imageTranscoder = new BufferedImageTranscoder();
        imageTranscoder.addTranscodingHint(PNGTranscoder.KEY_WIDTH, width);
        imageTranscoder.addTranscodingHint(PNGTranscoder.KEY_HEIGHT, height);
        try {
            imageTranscoder.transcode(input, null);
            BufferedImage bufferedImage = imageTranscoder.getBufferedImage();
            JLabel scaledComponent = new JLabel(new ImageIcon(bufferedImage));
            synchronized (diagramPanel) {
                diagramPanel.setPreferredSize(new Dimension((int) width, (int) height));
                if (diagramPanel.getComponentCount() != 0) {
                    diagramPanel.removeAll();
                }
                diagramPanel.add(scaledComponent, BorderLayout.CENTER);
            }
        } catch (TranscoderException e) {
            LOGGER.error("Error resizing SVG image", e);
        }
    }

    public Diagram getDiagram() {
        return diagram;
    }

    public synchronized void addDiagramPanelMouseListener(MouseListener l) {
        super.addMouseListener(l);
        diagramPanel.addMouseListener(l);
    }

}