dateaxis.java

关于jfreechart的电子说明书,一种说明图型使用的介绍

     *
     * @param g2  the graphics device.
     * @param state  the axis state.
     * @param dataArea  the area in which the plot should be drawn.
     * @param edge  the location of the axis.
     *
     * @return A list of ticks.
     */
    public List refreshTicks(Graphics2D g2,
                             AxisState state,
                             Rectangle2D dataArea,
                             RectangleEdge edge) {

        List result = null;
        if (RectangleEdge.isTopOrBottom(edge)) {
            result = refreshTicksHorizontal(g2, dataArea, edge);
        }
        else if (RectangleEdge.isLeftOrRight(edge)) {
            result = refreshTicksVertical(g2, dataArea, edge);
        }
        return result;

    }

    /**
     * Recalculates the ticks for the date axis.
     *
     * @param g2  the graphics device.
     * @param dataArea  the area in which the data is to be drawn.
     * @param edge  the location of the axis.
     *
     * @return A list of ticks.
     */
    protected List refreshTicksHorizontal(Graphics2D g2,
                                          Rectangle2D dataArea,
                                          RectangleEdge edge) {

        List result = new java.util.ArrayList();

        Font tickLabelFont = getTickLabelFont();
        g2.setFont(tickLabelFont);

        if (isAutoTickUnitSelection()) {
            selectAutoTickUnit(g2, dataArea, edge);
        }

        DateTickUnit unit = getTickUnit();
        Date tickDate = calculateLowestVisibleTickValue(unit);
        Date upperDate = getMaximumDate();
        // float lastX = Float.MIN_VALUE;
        while (tickDate.before(upperDate)) {

            if (!isHiddenValue(tickDate.getTime())) {
                // work out the value, label and position
                String tickLabel;
                DateFormat formatter = getDateFormatOverride();
                if (formatter != null) {
                    tickLabel = formatter.format(tickDate);
                }
                else {
                    tickLabel = this.tickUnit.dateToString(tickDate);
                }
                TextAnchor anchor = null;
                TextAnchor rotationAnchor = null;
                double angle = 0.0;
                if (isVerticalTickLabels()) {
                    anchor = TextAnchor.CENTER_RIGHT;
                    rotationAnchor = TextAnchor.CENTER_RIGHT;
                    if (edge == RectangleEdge.TOP) {
                        angle = Math.PI / 2.0;
                    }
                    else {
                        angle = -Math.PI / 2.0;
                    }
                }
                else {
                    if (edge == RectangleEdge.TOP) {
                        anchor = TextAnchor.BOTTOM_CENTER;
                        rotationAnchor = TextAnchor.BOTTOM_CENTER;
                    }
                    else {
                        anchor = TextAnchor.TOP_CENTER;
                        rotationAnchor = TextAnchor.TOP_CENTER;
                    }
                }

                Tick tick = new DateTick(
                    tickDate, tickLabel, anchor, rotationAnchor, angle
                );
                result.add(tick);
                tickDate = unit.addToDate(tickDate);
            }
            else {
                tickDate = unit.rollDate(tickDate);
                continue;
            }

            // could add a flag to make the following correction optional...
            switch (unit.getUnit()) {

                case (DateTickUnit.MILLISECOND) :
                case (DateTickUnit.SECOND) :
                case (DateTickUnit.MINUTE) :
                case (DateTickUnit.HOUR) :
                case (DateTickUnit.DAY) :
                    break;
                case (DateTickUnit.MONTH) :
                    tickDate = calculateDateForPosition(
                        new Month(tickDate), this.tickMarkPosition
                    );
                    break;
                case(DateTickUnit.YEAR) :
                    tickDate = calculateDateForPosition(
                        new Year(tickDate), this.tickMarkPosition
                    );
                    break;

                default: break;

            }

        }
        return result;

    }

    /**
     * Recalculates the ticks for the date axis.
     *
     * @param g2  the graphics device.
     * @param dataArea  the area in which the plot should be drawn.
     * @param edge  the location of the axis.
     *
     * @return A list of ticks.
     */
    protected List refreshTicksVertical(Graphics2D g2,
                                        Rectangle2D dataArea,
                                        RectangleEdge edge) {

        List result = new java.util.ArrayList();

        Font tickLabelFont = getTickLabelFont();
        g2.setFont(tickLabelFont);

        if (isAutoTickUnitSelection()) {
            selectAutoTickUnit(g2, dataArea, edge);
        }
        DateTickUnit unit = getTickUnit();
        Date tickDate = calculateLowestVisibleTickValue(unit);
        //Date upperDate = calculateHighestVisibleTickValue(unit);
        Date upperDate = getMaximumDate();
        while (tickDate.before(upperDate)) {

            if (!isHiddenValue(tickDate.getTime())) {
                // work out the value, label and position
                String tickLabel;
                DateFormat formatter = getDateFormatOverride();
                if (formatter != null) {
                    tickLabel = formatter.format(tickDate);
                }
                else {
                    tickLabel = this.tickUnit.dateToString(tickDate);
                }
                TextAnchor anchor = null;
                TextAnchor rotationAnchor = null;
                double angle = 0.0;
                if (isVerticalTickLabels()) {
                    anchor = TextAnchor.BOTTOM_CENTER;
                    rotationAnchor = TextAnchor.BOTTOM_CENTER;
                    if (edge == RectangleEdge.LEFT) {
                        angle = -Math.PI / 2.0;
                    }
                    else {
                        angle = Math.PI / 2.0;
                    }
                }
                else {
                    if (edge == RectangleEdge.LEFT) {
                        anchor = TextAnchor.CENTER_RIGHT;
                        rotationAnchor = TextAnchor.CENTER_RIGHT;
                    }
                    else {
                        anchor = TextAnchor.CENTER_LEFT;
                        rotationAnchor = TextAnchor.CENTER_LEFT;
                    }
                }

                Tick tick = new DateTick(
                    tickDate, tickLabel, anchor, rotationAnchor, angle
                );
                result.add(tick);
                tickDate = unit.addToDate(tickDate);
            }
            else {
                tickDate = unit.rollDate(tickDate);
            }
        }
        return result;
    }

    /**
     * Draws the axis on a Java 2D graphics device (such as the screen or a 
     * printer).
     *
     * @param g2  the graphics device (<code>null</code> not permitted).
     * @param cursor  the cursor location.
     * @param plotArea  the area within which the axes and data should be 
     *                  drawn (<code>null</code> not permitted).
     * @param dataArea  the area within which the data should be drawn 
     *                  (<code>null</code> not permitted).
     * @param edge  the location of the axis (<code>null</code> not permitted).
     * @param plotState  collects information about the plot 
     *                   (<code>null</code> permitted).
     *
     * @return The axis state (never <code>null</code>).
     */
    public AxisState draw(Graphics2D g2, 
                          double cursor,
                          Rectangle2D plotArea, 
                          Rectangle2D dataArea, 
                          RectangleEdge edge,
                          PlotRenderingInfo plotState) {

        // if the axis is not visible, don't draw it...
        if (!isVisible()) {
            AxisState state = new AxisState(cursor);
            // even though the axis is not visible, we need to refresh ticks in
            // case the grid is being drawn...
            List ticks = refreshTicks(g2, state, dataArea, edge);
            state.setTicks(ticks);
            return state;
        }

        // draw the tick marks and labels...
        AxisState state = drawTickMarksAndLabels(
            g2, cursor, plotArea, dataArea, edge
        );

        // draw the axis label (note that 'state' is passed in *and* 
        // returned)...
        state = drawLabel(getLabel(), g2, plotArea, dataArea, edge, state);

        return state;

    }

    /**
     * Zooms in on the current range.
     *
     * @param lowerPercent  the new lower bound.
     * @param upperPercent  the new upper bound.
     */
    public void zoomRange(double lowerPercent, double upperPercent) {
        double start = this.timeline.toTimelineValue(
            (long) getRange().getLowerBound()
        );
        double length = (this.timeline.toTimelineValue(
                (long) getRange().getUpperBound()) 
                - this.timeline.toTimelineValue(
                    (long) getRange().getLowerBound()
        ));
        Range adjusted = null;
        if (isInverted()) {
            adjusted = new DateRange(
                this.timeline.toMillisecond(
                    (long) (start + (length * (1 - upperPercent)))
                ),
                this.timeline.toMillisecond(
                    (long) (start + (length * (1 - lowerPercent)))
                )
            );
        }
        else {
            adjusted = new DateRange(this.timeline.toMillisecond(
                (long) (start + length * lowerPercent)),
                this.timeline.toMillisecond(
                    (long) (start + length * upperPercent)
                )
            );
        }
        setRange(adjusted);
    } 
    
    /**
     * Tests an object for equality with this instance.
     *
     * @param obj  the object to test.
     *
     * @return A boolean.
     */
    public boolean equals(Object obj) {
        if (obj == this) {
            return true;
        }
        if (!(obj instanceof DateAxis)) {
            return false;
        }
        DateAxis that = (DateAxis) obj;
        if (!ObjectUtilities.equal(this.tickUnit, that.tickUnit)) {
            return false;
        }
        if (!ObjectUtilities.equal(
            this.dateFormatOverride, that.dateFormatOverride)
        ) {
            return false;
        }
        if (!ObjectUtilities.equal(
            this.tickMarkPosition, that.tickMarkPosition
        )) {
            return false;
        }
        if (!ObjectUtilities.equal(this.timeline, that.timeline)) {
            return false;
        }
        return true;
    }

    /**
     * Returns a hash code for this object.
     * 
     * @return A hash code.
     */
    public int hashCode() {
        if (getLabel() != null) {
            return getLabel().hashCode();
        }
        else {
            return 0;
        }
    }

    /**
     * Returns a clone of the object.
     *
     * @return A clone.
     *
     * @throws CloneNotSupportedException if some component of the axis does 
     *         not support cloning.
     */
    public Object clone() throws CloneNotSupportedException {

        DateAxis clone = (DateAxis) super.clone();

        // 'dateTickUnit' is immutable : no need to clone
        if (this.dateFormatOverride != null) {
            clone.dateFormatOverride 
                = (DateFormat) this.dateFormatOverride.clone();
        }
        // 'tickMarkPosition' is immutable : no need to clone

        return clone;

    }
            
}