dateaxis.java

提供JFreechart图表功能, 提供JFreechart图表功能,提供JFreechart图表功能

     * Returns the first "standard" date (based on the specified field and 
     * units).
     *
     * @param date  the reference date.
     * @param unit  the date tick unit.
     *
     * @return The next "standard" date.
     */
    protected Date nextStandardDate(Date date, DateTickUnit unit) {
        Date previous = previousStandardDate(date, unit);
        Calendar calendar = Calendar.getInstance(this.timeZone);
        calendar.setTime(previous);
        calendar.add(unit.getCalendarField(), unit.getCount());
        return calendar.getTime();
    }

    /**
     * Returns a collection of standard date tick units that uses the default 
     * time zone.  This collection will be used by default, but you are free 
     * to create your own collection if you want to (see the 
     * {@link ValueAxis#setStandardTickUnits(TickUnitSource)} method inherited 
     * from the {@link ValueAxis} class).
     *
     * @return A collection of standard date tick units.
     */
    public static TickUnitSource createStandardDateTickUnits() {
        return createStandardDateTickUnits(TimeZone.getDefault());
    }

    /**
     * Returns a collection of standard date tick units.  This collection will 
     * be used by default, but you are free to create your own collection if 
     * you want to (see the 
     * {@link ValueAxis#setStandardTickUnits(TickUnitSource)} method inherited 
     * from the {@link ValueAxis} class).
     *
     * @param zone  the time zone (<code>null</code> not permitted).
     * 
     * @return A collection of standard date tick units.
     */
    public static TickUnitSource createStandardDateTickUnits(TimeZone zone) {

        if (zone == null) {
            throw new IllegalArgumentException("Null 'zone' argument.");
        }
        TickUnits units = new TickUnits();

        // date formatters
        DateFormat f1 = new SimpleDateFormat("HH:mm:ss.SSS");
        DateFormat f2 = new SimpleDateFormat("HH:mm:ss");
        DateFormat f3 = new SimpleDateFormat("HH:mm");
        DateFormat f4 = new SimpleDateFormat("d-MMM, HH:mm");
        DateFormat f5 = new SimpleDateFormat("d-MMM");
        DateFormat f6 = new SimpleDateFormat("MMM-yyyy");
        DateFormat f7 = new SimpleDateFormat("yyyy");
        
        f1.setTimeZone(zone);
        f2.setTimeZone(zone);
        f3.setTimeZone(zone);
        f4.setTimeZone(zone);
        f5.setTimeZone(zone);
        f6.setTimeZone(zone);
        f7.setTimeZone(zone);
        
        // milliseconds
        units.add(new DateTickUnit(DateTickUnit.MILLISECOND, 1, f1));
        units.add(new DateTickUnit(DateTickUnit.MILLISECOND, 5, 
                DateTickUnit.MILLISECOND, 1, f1));
        units.add(new DateTickUnit(DateTickUnit.MILLISECOND, 10, 
                DateTickUnit.MILLISECOND, 1, f1));
        units.add(new DateTickUnit(DateTickUnit.MILLISECOND, 25, 
                DateTickUnit.MILLISECOND, 5, f1));
        units.add(new DateTickUnit(DateTickUnit.MILLISECOND, 50, 
                DateTickUnit.MILLISECOND, 10, f1));
        units.add(new DateTickUnit(DateTickUnit.MILLISECOND, 100, 
                DateTickUnit.MILLISECOND, 10, f1));
        units.add(new DateTickUnit(DateTickUnit.MILLISECOND, 250, 
                DateTickUnit.MILLISECOND, 10, f1));
        units.add(new DateTickUnit(DateTickUnit.MILLISECOND, 500, 
                DateTickUnit.MILLISECOND, 50, f1));

        // seconds
        units.add(new DateTickUnit(DateTickUnit.SECOND, 1, 
                DateTickUnit.MILLISECOND, 50, f2));
        units.add(new DateTickUnit(DateTickUnit.SECOND, 5, 
                DateTickUnit.SECOND, 1, f2));
        units.add(new DateTickUnit(DateTickUnit.SECOND, 10, 
                DateTickUnit.SECOND, 1, f2));
        units.add(new DateTickUnit(DateTickUnit.SECOND, 30, 
                DateTickUnit.SECOND, 5, f2));

        // minutes
        units.add(new DateTickUnit(DateTickUnit.MINUTE, 1, 
                DateTickUnit.SECOND, 5, f3));
        units.add(new DateTickUnit(DateTickUnit.MINUTE, 2, 
                DateTickUnit.SECOND, 10, f3));
        units.add(new DateTickUnit(DateTickUnit.MINUTE, 5, 
                DateTickUnit.MINUTE, 1, f3));
        units.add(new DateTickUnit(DateTickUnit.MINUTE, 10, 
                DateTickUnit.MINUTE, 1, f3));
        units.add(new DateTickUnit(DateTickUnit.MINUTE, 15, 
                DateTickUnit.MINUTE, 5, f3));
        units.add(new DateTickUnit(DateTickUnit.MINUTE, 20, 
                DateTickUnit.MINUTE, 5, f3));
        units.add(new DateTickUnit(DateTickUnit.MINUTE, 30, 
                DateTickUnit.MINUTE, 5, f3));

        // hours
        units.add(new DateTickUnit(DateTickUnit.HOUR, 1, 
                DateTickUnit.MINUTE, 5, f3));
        units.add(new DateTickUnit(DateTickUnit.HOUR, 2, 
                DateTickUnit.MINUTE, 10, f3));
        units.add(new DateTickUnit(DateTickUnit.HOUR, 4, 
                DateTickUnit.MINUTE, 30, f3));
        units.add(new DateTickUnit(DateTickUnit.HOUR, 6, 
                DateTickUnit.HOUR, 1, f3));
        units.add(new DateTickUnit(DateTickUnit.HOUR, 12, 
                DateTickUnit.HOUR, 1, f4));

        // days
        units.add(new DateTickUnit(DateTickUnit.DAY, 1, 
                DateTickUnit.HOUR, 1, f5));
        units.add(new DateTickUnit(DateTickUnit.DAY, 2, 
                DateTickUnit.HOUR, 1, f5));
        units.add(new DateTickUnit(DateTickUnit.DAY, 7, 
                DateTickUnit.DAY, 1, f5));
        units.add(new DateTickUnit(DateTickUnit.DAY, 15, 
                DateTickUnit.DAY, 1, f5));

        // months
        units.add(new DateTickUnit(DateTickUnit.MONTH, 1, 
                DateTickUnit.DAY, 1, f6));
        units.add(new DateTickUnit(DateTickUnit.MONTH, 2, 
                DateTickUnit.DAY, 1, f6));
        units.add(new DateTickUnit(DateTickUnit.MONTH, 3, 
                DateTickUnit.MONTH, 1, f6));
        units.add(new DateTickUnit(DateTickUnit.MONTH, 4,  
                DateTickUnit.MONTH, 1, f6));
        units.add(new DateTickUnit(DateTickUnit.MONTH, 6,  
                DateTickUnit.MONTH, 1, f6));

        // years
        units.add(new DateTickUnit(DateTickUnit.YEAR, 1,  
                DateTickUnit.MONTH, 1, f7));
        units.add(new DateTickUnit(DateTickUnit.YEAR, 2,  
                DateTickUnit.MONTH, 3, f7));
        units.add(new DateTickUnit(DateTickUnit.YEAR, 5,  
                DateTickUnit.YEAR, 1, f7));
        units.add(new DateTickUnit(DateTickUnit.YEAR, 10,  
                DateTickUnit.YEAR, 1, f7));
        units.add(new DateTickUnit(DateTickUnit.YEAR, 25, 
                DateTickUnit.YEAR, 5, f7));
        units.add(new DateTickUnit(DateTickUnit.YEAR, 50, 
                DateTickUnit.YEAR, 10, f7));
        units.add(new DateTickUnit(DateTickUnit.YEAR, 100, 
                DateTickUnit.YEAR, 20, f7));

        return units;

    }

    /**
     * Rescales the axis to ensure that all data is visible.
     */
    protected void autoAdjustRange() {

        Plot plot = getPlot();

        if (plot == null) {
            return;  // no plot, no data
        }

        if (plot instanceof ValueAxisPlot) {
            ValueAxisPlot vap = (ValueAxisPlot) plot;

            Range r = vap.getDataRange(this);
            if (r == null) {
                if (this.timeline instanceof SegmentedTimeline) { 
                    //Timeline hasn't method getStartTime()
                    r = new DateRange((
                            (SegmentedTimeline) this.timeline).getStartTime(),
                            ((SegmentedTimeline) this.timeline).getStartTime() 
                            + 1);
                } 
                else {
                    r = new DateRange();
                }
            }

            long upper = this.timeline.toTimelineValue(
                    (long) r.getUpperBound());
            long lower;
            long fixedAutoRange = (long) getFixedAutoRange();
            if (fixedAutoRange > 0.0) {
                lower = upper - fixedAutoRange;
            }
            else {
                lower = this.timeline.toTimelineValue((long) r.getLowerBound());
                double range = upper - lower;
                long minRange = (long) getAutoRangeMinimumSize();
                if (range < minRange) {
                    long expand = (long) (minRange - range) / 2;
                    upper = upper + expand;
                    lower = lower - expand;
                }
                upper = upper + (long) (range * getUpperMargin());
                lower = lower - (long) (range * getLowerMargin());
            }

            upper = this.timeline.toMillisecond(upper);
            lower = this.timeline.toMillisecond(lower);
            DateRange dr = new DateRange(new Date(lower), new Date(upper));
            setRange(dr, false, false);
        }

    }

    /**
     * Selects an appropriate tick value for the axis.  The strategy is to
     * display as many ticks as possible (selected from an array of 'standard'
     * tick units) without the labels overlapping.
     *
     * @param g2  the graphics device.
     * @param dataArea  the area defined by the axes.
     * @param edge  the axis location.
     */
    protected void selectAutoTickUnit(Graphics2D g2, 
                                      Rectangle2D dataArea,
                                      RectangleEdge edge) {

        if (RectangleEdge.isTopOrBottom(edge)) {
            selectHorizontalAutoTickUnit(g2, dataArea, edge);
        }
        else if (RectangleEdge.isLeftOrRight(edge)) {
            selectVerticalAutoTickUnit(g2, dataArea, edge);
        }

    }

    /**
     * Selects an appropriate tick size for the axis.  The strategy is to
     * display as many ticks as possible (selected from a collection of 
     * 'standard' tick units) without the labels overlapping.
     *
     * @param g2  the graphics device.
     * @param dataArea  the area defined by the axes.
     * @param edge  the axis location.
     */
    protected void selectHorizontalAutoTickUnit(Graphics2D g2, 
                                                Rectangle2D dataArea, 
                                                RectangleEdge edge) {

        long shift = 0;
        if (this.timeline instanceof SegmentedTimeline) {
            shift = ((SegmentedTimeline) this.timeline).getStartTime();
        }
        double zero = valueToJava2D(shift + 0.0, dataArea, edge);
        double tickLabelWidth 
            = estimateMaximumTickLabelWidth(g2, getTickUnit());

        // start with the current tick unit...
        TickUnitSource tickUnits = getStandardTickUnits();
        TickUnit unit1 = tickUnits.getCeilingTickUnit(getTickUnit());
        double x1 = valueToJava2D(shift + unit1.getSize(), dataArea, edge);
        double unit1Width = Math.abs(x1 - zero);

        // then extrapolate...
        double guess = (tickLabelWidth / unit1Width) * unit1.getSize();
        DateTickUnit unit2 = (DateTickUnit) tickUnits.getCeilingTickUnit(guess);
        double x2 = valueToJava2D(shift + unit2.getSize(), dataArea, edge);
        double unit2Width = Math.abs(x2 - zero);
        tickLabelWidth = estimateMaximumTickLabelWidth(g2, unit2);
        if (tickLabelWidth > unit2Width) {
            unit2 = (DateTickUnit) tickUnits.getLargerTickUnit(unit2);
        }
        setTickUnit(unit2, false, false);
    }
    
    /**
     * Selects an appropriate tick size for the axis.  The strategy is to
     * display as many ticks as possible (selected from a collection of 
     * 'standard' tick units) without the labels overlapping.
     *
     * @param g2  the graphics device.
     * @param dataArea  the area in which the plot should be drawn.
     * @param edge  the axis location.
     */
    protected void selectVerticalAutoTickUnit(Graphics2D g2,
                                              Rectangle2D dataArea,
                                              RectangleEdge edge) {

        // start with the current tick unit...
        TickUnitSource tickUnits = getStandardTickUnits();
        double zero = valueToJava2D(0.0, dataArea, edge);

        // start with a unit that is at least 1/10th of the axis length
        double estimate1 = getRange().getLength() / 10.0;
        DateTickUnit candidate1 
            = (DateTickUnit) tickUnits.getCeilingTickUnit(estimate1);
        double labelHeight1 = estimateMaximumTickLabelHeight(g2, candidate1);
        double y1 = valueToJava2D(candidate1.getSize(), dataArea, edge);
        double candidate1UnitHeight = Math.abs(y1 - zero);

        // now extrapolate based on label height and unit height...
        double estimate2 
            = (labelHeight1 / candidate1UnitHeight) * candidate1.getSize();
        DateTickUnit candidate2 
            = (DateTickUnit) tickUnits.getCeilingTickUnit(estimate2);
        double labelHeight2 = estimateMaximumTickLabelHeight(g2, candidate2);
        double y2 = valueToJava2D(candidate2.getSize(), dataArea, edge);
        double unit2Height = Math.abs(y2 - zero);

       // make final selection...
       DateTickUnit finalUnit;
       if (labelHeight2 < unit2Height) {
           finalUnit = candidate2;
       }
       else {
           finalUnit = (DateTickUnit) tickUnits.getLargerTickUnit(candidate2);
       }
       setTickUnit(finalUnit, false, false);

    }

    /**
     * Estimates the maximum width of the tick labels, assuming the specified 
     * tick unit is used.
     * <P>
     * Rather than computing the string bounds of every tick on the axis, we
     * just look at two values: the lower bound and the upper bound for the 
     * axis.  These two values will usually be representative.
     *
     * @param g2  the graphics device.
     * @param unit  the tick unit to use for calculation.
     *
     * @return The estimated maximum width of the tick labels.
     */
    private double estimateMaximumTickLabelWidth(Graphics2D g2, 
                                                 DateTickUnit unit) {

        RectangleInsets tickLabelInsets = getTickLabelInsets();
        double result = tickLabelInsets.getLeft() + tickLabelInsets.getRight();

        Font tickLabelFont = getTickLabelFont();