meterplot.java

java图形利器

                    Polygon arrow = new Polygon();
                    if ((valueAngle > 135 && valueAngle < 225)
                        || (valueAngle < 45 && valueAngle > -45)) {

                        double valueP3 = (meterMiddleY 
                                - DEFAULT_CIRCLE_SIZE / 4);
                        double valueP4 = (meterMiddleY 
                                + DEFAULT_CIRCLE_SIZE / 4);
                        arrow.addPoint((int) meterMiddleX, (int) valueP3);
                        arrow.addPoint((int) meterMiddleX, (int) valueP4);
 
                    }
                    else {
                        arrow.addPoint((int) (meterMiddleX 
                                - DEFAULT_CIRCLE_SIZE / 4), (int) meterMiddleY);
                        arrow.addPoint((int) (meterMiddleX 
                                + DEFAULT_CIRCLE_SIZE / 4), (int) meterMiddleY);
                    }
                    arrow.addPoint((int) valueP1, (int) valueP2);
                    g2.fill(arrow);

                    Ellipse2D circle = new Ellipse2D.Double(meterMiddleX 
                            - DEFAULT_CIRCLE_SIZE / 2, meterMiddleY 
                            - DEFAULT_CIRCLE_SIZE / 2, DEFAULT_CIRCLE_SIZE, 
                            DEFAULT_CIRCLE_SIZE);
                    g2.fill(circle);
                }
            }
                
            g2.setClip(savedClip);
            g2.setComposite(originalComposite);

        }
        if (this.drawBorder) {
            drawOutline(g2, area);
        }

    }

    /**
     * Draws the arc to represent an interval.
     *
     * @param g2  the graphics device.
     * @param meterArea  the drawing area.
     * @param interval  the interval.
     */
    protected void drawArcForInterval(Graphics2D g2, Rectangle2D meterArea, 
                                      MeterInterval interval) {

        double minValue = interval.getRange().getLowerBound();
        double maxValue = interval.getRange().getUpperBound();
        Paint outlinePaint = interval.getOutlinePaint();
        Stroke outlineStroke = interval.getOutlineStroke();
        Paint backgroundPaint = interval.getBackgroundPaint();
 
        if (backgroundPaint != null) {
            fillArc(g2, meterArea, minValue, maxValue, backgroundPaint, false);
        }
        if (outlinePaint != null) {
            if (outlineStroke != null) {
                drawArc(g2, meterArea, minValue, maxValue, outlinePaint, 
                        outlineStroke);
            }
            drawTick(g2, meterArea, minValue, true);
            drawTick(g2, meterArea, maxValue, true);
        }
    }

    /**
     * Draws an arc.
     *
     * @param g2  the graphics device.
     * @param area  the plot area.
     * @param minValue  the minimum value.
     * @param maxValue  the maximum value.
     * @param paint  the paint.
     * @param stroke  the stroke.
     */
    protected void drawArc(Graphics2D g2, Rectangle2D area, double minValue, 
                           double maxValue, Paint paint, Stroke stroke) {

        double startAngle = valueToAngle(maxValue);
        double endAngle = valueToAngle(minValue);
        double extent = endAngle - startAngle;

        double x = area.getX();
        double y = area.getY();
        double w = area.getWidth();
        double h = area.getHeight();
        g2.setPaint(paint);
        g2.setStroke(stroke);

        if (paint != null && stroke != null) {
            Arc2D.Double arc = new Arc2D.Double(x, y, w, h, startAngle, 
                    extent, Arc2D.OPEN);
            g2.setPaint(paint); 
            g2.setStroke(stroke);
            g2.draw(arc);
        }

    }

    /**
     * Fills an arc on the dial between the given values.
     *
     * @param g2  the graphics device.
     * @param area  the plot area.
     * @param minValue  the minimum data value.
     * @param maxValue  the maximum data value.
     * @param paint  the background paint (<code>null</code> not permitted).
     * @param dial  a flag that indicates whether the arc represents the whole 
     *              dial.
     */
    protected void fillArc(Graphics2D g2, Rectangle2D area, 
                           double minValue, double maxValue, Paint paint,
                           boolean dial) {
        if (paint == null) {
            throw new IllegalArgumentException("Null 'paint' argument");
        }
        double startAngle = valueToAngle(maxValue);
        double endAngle = valueToAngle(minValue);
        double extent = endAngle - startAngle;

        double x = area.getX();
        double y = area.getY();
        double w = area.getWidth();
        double h = area.getHeight();
        int joinType = Arc2D.OPEN;
        if (this.shape == DialShape.PIE) {
            joinType = Arc2D.PIE;
        }
        else if (this.shape == DialShape.CHORD) {
            if (dial && this.meterAngle > 180) {
                joinType = Arc2D.CHORD;
            }
            else {
                joinType = Arc2D.PIE;
            }
        }
        else if (this.shape == DialShape.CIRCLE) {
            joinType = Arc2D.PIE;
            if (dial) {
                extent = 360;
            }
        }
        else {
            throw new IllegalStateException("DialShape not recognised.");
        }

        g2.setPaint(paint);
        Arc2D.Double arc = new Arc2D.Double(x, y, w, h, startAngle, extent, 
                joinType);
        g2.fill(arc);
    }
    
    /**
     * Translates a data value to an angle on the dial.
     *
     * @param value  the value.
     *
     * @return The angle on the dial.
     */
    public double valueToAngle(double value) {
        value = value - this.range.getLowerBound();
        double baseAngle = 180 + ((this.meterAngle - 180) / 2);
        return baseAngle - ((value / this.range.getLength()) * this.meterAngle);
    }

    /**
     * Draws the ticks that subdivide the overall range.
     *
     * @param g2  the graphics device.
     * @param meterArea  the meter area.
     * @param minValue  the minimum value.
     * @param maxValue  the maximum value.
     */
    protected void drawTicks(Graphics2D g2, Rectangle2D meterArea, 
                             double minValue, double maxValue) {
        for (double v = minValue; v <= maxValue; v += this.tickSize) {
            drawTick(g2, meterArea, v);
        }
    }

    /**
     * Draws a tick.
     *
     * @param g2  the graphics device.
     * @param meterArea  the meter area.
     * @param value  the value.
     */
    protected void drawTick(Graphics2D g2, Rectangle2D meterArea, 
            double value) {
        drawTick(g2, meterArea, value, false);
    }

    /**
     * Draws a tick on the dial.
     *
     * @param g2  the graphics device.
     * @param meterArea  the meter area.
     * @param value  the tick value.
     * @param label  a flag that controls whether or not a value label is drawn.
     */
    protected void drawTick(Graphics2D g2, Rectangle2D meterArea,
                            double value, boolean label) {

        double valueAngle = valueToAngle(value);

        double meterMiddleX = meterArea.getCenterX();
        double meterMiddleY = meterArea.getCenterY();

        g2.setPaint(this.tickPaint);
        g2.setStroke(new BasicStroke(2.0f));

        double valueP2X = 0;
        double valueP2Y = 0;

        double radius = (meterArea.getWidth() / 2) + DEFAULT_BORDER_SIZE;
        double radius1 = radius - 15;

        double valueP1X = meterMiddleX 
                + (radius * Math.cos(Math.PI * (valueAngle / 180)));
        double valueP1Y = meterMiddleY 
                - (radius * Math.sin(Math.PI * (valueAngle / 180)));

        valueP2X = meterMiddleX 
                + (radius1 * Math.cos(Math.PI * (valueAngle / 180)));
        valueP2Y = meterMiddleY 
                - (radius1 * Math.sin(Math.PI * (valueAngle / 180)));

        Line2D.Double line = new Line2D.Double(valueP1X, valueP1Y, valueP2X, 
                valueP2Y);
        g2.draw(line);

        if (this.tickLabelsVisible && label) {

            String tickLabel =  this.tickLabelFormat.format(value);
            g2.setFont(this.tickLabelFont);
            g2.setPaint(this.tickLabelPaint);

            FontMetrics fm = g2.getFontMetrics();
            Rectangle2D tickLabelBounds 
                = TextUtilities.getTextBounds(tickLabel, g2, fm);

            double x = valueP2X;
            double y = valueP2Y;
            if (valueAngle == 90 || valueAngle == 270) {
                x = x - tickLabelBounds.getWidth() / 2;
            }
            else if (valueAngle < 90 || valueAngle > 270) {
                x = x - tickLabelBounds.getWidth();
            }
            if ((valueAngle > 135 && valueAngle < 225) 
                    || valueAngle > 315 || valueAngle < 45) {
                y = y - tickLabelBounds.getHeight() / 2;
            }
            else {
                y = y + tickLabelBounds.getHeight() / 2;
            }
            g2.drawString(tickLabel, (float) x, (float) y);
        }
    }
    
    /**
     * Draws the value label just below the center of the dial.
     * 
     * @param g2  the graphics device.
     * @param area  the plot area.
     */
    protected void drawValueLabel(Graphics2D g2, Rectangle2D area) {
        g2.setFont(this.valueFont);
        g2.setPaint(this.valuePaint);
        String valueStr = "No value";
        if (this.dataset != null) {
            Number n = this.dataset.getValue();
            if (n != null) {
                valueStr = this.tickLabelFormat.format(n.doubleValue()) + " " 
                         + this.units;
            }
        }
        float x = (float) area.getCenterX();
        float y = (float) area.getCenterY() + DEFAULT_CIRCLE_SIZE;
        TextUtilities.drawAlignedString(valueStr, g2, x, y, 
                TextAnchor.TOP_CENTER);
    }

    /**
     * Returns a short string describing the type of plot.
     *
     * @return A string describing the type of plot.
     */
    public String getPlotType() {
        return localizationResources.getString("Meter_Plot");
    }

    /**
     * A zoom method that does nothing.  Plots are required to support the 
     * zoom operation.  In the case of a meter plot, it doesn't make sense to 
     * zoom in or out, so the method is empty.
     *
     * @param percent   The zoom percentage.
     */
    public void zoom(double percent) {
        // intentionally blank
    }
    
    /**
     * Tests the plot for equality with an arbitrary object.  Note that the 
     * dataset is ignored for the purposes of testing equality.
     * 
     * @param obj  the object (<code>null</code> permitted).
     * 
     * @return A boolean.
     */
    public boolean equals(Object obj) {
        if (obj == this) {
            return true;
        }   
        if (!(obj instanceof MeterPlot)) {
            return false;   
        }
        if (!super.equals(obj)) {
            return false;
        }
        MeterPlot that = (MeterPlot) obj;
        if (!ObjectUtilities.equal(this.units, that.units)) {
            return false;   
        }
        if (!ObjectUtilities.equal(this.range, that.range)) {
            return false;
        }
        if (!ObjectUtilities.equal(this.intervals, that.intervals)) {
            return false;   
        }
        if (!PaintUtilities.equal(this.dialOutlinePaint, 
                that.dialOutlinePaint)) {
            return false;   
        }
        if (this.shape != that.shape) {
            return false;   
        }
        if (!PaintUtilities.equal(this.dialBackgroundPaint, 
                that.dialBackgroundPaint)) {
            return false;   
        }
        if (!PaintUtilities.equal(this.needlePaint, that.needlePaint)) {
            return false;   
        }
        if (!ObjectUtilities.equal(this.valueFont, that.valueFont)) {
            return false;   
        }
        if (!PaintUtilities.equal(this.valuePaint, that.valuePaint)) {
            return false;   
        }
        if (!PaintUtilities.equal(this.tickPaint, that.tickPaint)) {
            return false;
        }
        if (this.tickSize != that.tickSize) {
            return false;
        }
        if (this.tickLabelsVisible != that.tickLabelsVisible) {
            return false;   
        }
        if (!ObjectUtilities.equal(this.tickLabelFont, that.tickLabelFont)) {
            return false;   
        }
        if (!PaintUtilities.equal(this.tickLabelPaint, that.tickLabelPaint)) {
            return false;
        }
        if (!ObjectUtilities.equal(this.tickLabelFormat, 
                that.tickLabelFormat)) {
            return false;   
        }
        if (this.drawBorder != that.drawBorder) {
            return false;   
        }
        if (this.meterAngle != that.meterAngle) {
            return false;   
        }
        return true;      
    }
    
    /**
     * Provides serialization support.
     *
     * @param stream  the output stream.
     *
     * @throws IOException  if there is an I/O error.
     */
    private void writeObject(ObjectOutputStream stream) throws IOException {
        stream.defaultWriteObject();
        SerialUtilities.writePaint(this.dialBackgroundPaint, stream);
        SerialUtilities.writePaint(this.needlePaint, stream);
        SerialUtilities.writePaint(this.valuePaint, stream);
        SerialUtilities.writePaint(this.tickPaint, stream);
        SerialUtilities.writePaint(this.tickLabelPaint, stream);
    }
    
    /**
     * Provides serialization support.
     *
     * @param stream  the input stream.
     *
     * @throws IOException  if there is an I/O error.
     * @throws ClassNotFoundException  if there is a classpath problem.
     */
    private void readObject(ObjectInputStream stream) 
        throws IOException, ClassNotFoundException {
        stream.defaultReadObject();
        this.dialBackgroundPaint = SerialUtilities.readPaint(stream);
        this.needlePaint = SerialUtilities.readPaint(stream);
        this.valuePaint = SerialUtilities.readPaint(stream);
        this.tickPaint = SerialUtilities.readPaint(stream);
        this.tickLabelPaint = SerialUtilities.readPaint(stream);
        if (this.dataset != null) {
            this.dataset.addChangeListener(this);
        }
    }

    /** 
     * Returns an independent copy (clone) of the plot.  The dataset is NOT 
     * cloned - both the original and the clone will have a reference to the
     * same dataset.
     * 
     * @return A clone.
     * 
     * @throws CloneNotSupportedException if some component of the plot cannot
     *         be cloned.
     */
    public Object clone() throws CloneNotSupportedException {
        MeterPlot clone = (MeterPlot) super.clone();
        clone.tickLabelFormat = (NumberFormat) this.tickLabelFormat.clone();
        // the following relies on the fact that the intervals are immutable
        clone.intervals = new java.util.ArrayList(this.intervals);
        if (clone.dataset != null) {
            clone.dataset.addChangeListener(clone); 
        }
        return clone;
    }

}