jFreeChart1.0.14を使用しています。横長のグラフがありますDateAxis。そして、2つの後続のティック内に収まるように、ティックラベルを中央に配置しようとしています。
JFreeChartは、一般的なケースで次のように目盛りラベルを揃えます。
----+------------+------------+----
Mon Tue Wed
しかし、私はこのように目盛りラベルを揃えたいと思います：
----+------------+------------+------------+----
Mon Tue Wed
画像の目盛りラベルは、元の画像を編集してグラフィックエディタで手動で位置合わせされます。jFreeChartライブラリの出力ではありません。
DateAxisのAPIを介してそれを行う方法はありますか？どんな助けでもありがたいです...:)
助けやアイデアをありがとう。本座（スポラック）
だれも私にトリックを助けてくれなかったので、私はDateAxisをオーバーライドして、目盛りラベルの配置でAxisを取得しようとしました。私はそれを' AlignedDateAxis'と名付けました。DateAxis目盛りラベルのレンダリングに使用されるメソッドのみを拡張およびオーバーライドします。目盛りラベルは、目盛りの下にラベルを配置する標準的な方法と、間隔の中央にラベルを中央揃えする必要な方法の2つの方法でレンダリングできます。
JFreeChartsライブラリについてよく知らないので、いくつかのクラスとメソッドを理解するのは簡単ではありませんでした。私はそれがすべての一般的なケースでうまくいくことを願っています。私のクラスには母国語でのみjavadocとコメントが含まれているため、ここに完全に投稿することはしません。
package x.y.z;
import java.awt.Graphics2D;
import java.awt.Shape;
import java.awt.geom.Line2D;
import java.awt.geom.Rectangle2D;
import java.util.Date;
import java.util.List;
import org.jfree.chart.axis.AxisState;
import org.jfree.chart.axis.DateAxis;
import org.jfree.chart.axis.DateTick;
import org.jfree.chart.axis.DateTickUnit;
import org.jfree.chart.axis.TickType;
import org.jfree.chart.axis.ValueTick;
import org.jfree.text.TextUtilities;
import org.jfree.ui.RectangleEdge;
/**
* Extension of DateAxis for jFreeChart graphs that can render tick labels in two ways:
* 1) labels under ticks (common way, same as DateAxis)
* 2) labels in the middle of interval (new feature)
* @author Honza Spurny, Czech Republic
* @version 1.0
*/
public class AlignedDateAxis extends DateAxis {
/**
* Tick labels alignment setting.
*/
private TickLabelPosition tickLabelPosition = TickLabelPosition.DEFAULT_VALUE;
/**
* Value for interface Serializable.
*/
static private final long serialVersionUID = 1;
// ***********************
// *** Enums ***
// ***********************
/**
* Tick label alignment modes.
*/
public enum TickLabelPosition {
/**
* Tick label is rendered under/next by own tick.
* (common rendering same as in DateAxis)
*/
INTERVAL_START,
/**
* Tick label is placed in the middle of interval
* (between two subsequent ticks)
*/
INTERVAL_MIDDLE;
static public final TickLabelPosition DEFAULT_VALUE = INTERVAL_START;
}
// ******************************
// *** Constructors ***
// ******************************
/**
* Default constructor.
*/
public AlignedDateAxis() {
super();
}
/**
* Constructor.
* @param tickLabelPos tick label alignment mode setting for this axis.
*/
public AlignedDateAxis(TickLabelPosition tickLabelPos) {
this();
this.setTickLabelPosition(tickLabelPos);
}
// *********************************
// *** GET/SET methods ***
// *********************************
public TickLabelPosition getTickLabelPosition() {
return this.tickLabelPosition;
}
public void setTickLabelPosition(TickLabelPosition value) {
this.tickLabelPosition = value;
}
// *******************************************************
// *** Overrided methods for label rendering ***
// *******************************************************
/**
* Auxiliary method to calculate tick label position of given tick.
* @param tick tick we need calculate label position for (DateTick is expected)
* @param cursor the cursor
* @param dataArea area to draw the ticks and labels in
* @param edge edge of dataArea
* @return Returns coordinates [x,y] where label should be placed.
*/
@Override
protected float[] calculateAnchorPoint(ValueTick tick, double cursor, Rectangle2D dataArea, RectangleEdge edge) {
float[] resultAnchor = super.calculateAnchorPoint(tick, cursor, dataArea, edge);
// Time of tick
Date tickDate = (tick instanceof DateTick) ?
((DateTick) tick).getDate() :
new Date((long)tick.getValue());
// Tick label shift.
// (for INTERVAL_START it is 0, for INTERVAL_MIDDLE it is calculated)
double labelShift;
switch (this.getTickLabelPosition()) {
case INTERVAL_MIDDLE:
// Getting next tick value...
DateTickUnit unit = this.getTickUnit();
Date nextTickDate = unit.addToDate(tickDate, this.getTimeZone());
double nextTickVal = this.valueToJava2D(nextTickDate.getTime(), dataArea, edge);
// Shifting label in between ticks...
labelShift = (nextTickVal - resultAnchor[0]) / 2;
break;
case INTERVAL_START:
default:
labelShift = 0;
break;
}
// Edge defines which coordinate is shifted.
if (RectangleEdge.isTopOrBottom(edge)) {
resultAnchor[0] += labelShift;
} else if (RectangleEdge.isLeftOrRight(edge)) {
resultAnchor[1] += labelShift;
}
return resultAnchor;
}
/**
* Renders this axis with ticks and labels.
* @param g2 graphics to draw the axis in.
* @param cursor the cursor
* @param plotArea area to draw the chart in
* @param dataArea area to draw this axis in
* @param edge edge of dataArea
* @return Returns state of axis.
*/
@Override
protected AxisState drawTickMarksAndLabels(Graphics2D g2, double cursor, Rectangle2D plotArea, Rectangle2D dataArea, RectangleEdge edge) {
AxisState state = new AxisState(cursor);
if (this.isAxisLineVisible()) this.drawAxisLine(g2, cursor, dataArea, edge);
List<DateTick> ticks = this.refreshTicks(g2, state, dataArea, edge);
state.setTicks(ticks);
g2.setFont(this.getTickLabelFont());
for (DateTick tick: ticks) {
if (this.isTickLabelsVisible()) {
g2.setPaint(this.getTickLabelPaint());
float anchorPoint[] = this.calculateAnchorPoint(tick, cursor, dataArea, edge);
// TextUtilities.drawRotatedString(tick.getText(), g2, anchorPoint[0], anchorPoint[1], tick.getTextAnchor(), tick.getAngle(), tick.getRotationAnchor());
// Commented code above is original code from DateAxis.
// ---[Override]---
// Position of tick label is shifted so it can point outside the dataArea.
// We have to check whether the tick label on this position is drawable into the given area.
Shape labelBounds = TextUtilities.calculateRotatedStringBounds(tick.getText(), g2, anchorPoint[0], anchorPoint[1], tick.getTextAnchor(), tick.getAngle(), tick.getRotationAnchor());
double labelEdge = (RectangleEdge.isTopOrBottom(edge)) ? (labelBounds.getBounds2D().getMaxX()) : (labelBounds.getBounds2D().getMaxY());
double dataAreaBound = (RectangleEdge.isTopOrBottom(edge)) ? (dataArea.getMaxX()) : (dataArea.getMaxY());
// Magic constant 5: tick label can be rendered although it exceeds area edge for max. 5px
// (it still looks good - visualy tested :-)
if ((labelEdge - 5) <= dataAreaBound) {
TextUtilities.drawRotatedString(tick.getText(), g2, anchorPoint[0], anchorPoint[1], tick.getTextAnchor(), tick.getAngle(), tick.getRotationAnchor());
}
// ---[/Override]---
}
if ( (this.isTickMarksVisible() && tick.getTickType().equals(TickType.MAJOR)) || (this.isMinorTickMarksVisible() && tick.getTickType().equals(TickType.MINOR)) ) {
double ol = tick.getTickType().equals(TickType.MINOR) ? this.getMinorTickMarkOutsideLength() : this.getTickMarkOutsideLength();
double il = tick.getTickType().equals(TickType.MINOR) ? this.getMinorTickMarkInsideLength() : this.getTickMarkInsideLength();
float tickVal = (float)this.valueToJava2D(tick.getValue(), dataArea, edge);
Line2D mark = null;
g2.setStroke(this.getTickMarkStroke());
g2.setPaint(this.getTickMarkPaint());
if(edge == RectangleEdge.LEFT) {
mark = new Line2D.Double(cursor - ol, tickVal, cursor + il, tickVal);
} else if(edge == RectangleEdge.RIGHT) {
mark = new Line2D.Double(cursor + ol, tickVal, cursor - il, tickVal);
} else if(edge == RectangleEdge.TOP) {
mark = new Line2D.Double(tickVal, cursor - ol, tickVal, cursor + il);
} else if(edge == RectangleEdge.BOTTOM) {
mark = new Line2D.Double(tickVal, cursor + ol, tickVal, cursor - il);
}
g2.draw(mark);
}
}
if (this. isTickLabelsVisible()) {
double used = 0.0;
if (edge == RectangleEdge.LEFT) {
used += this.findMaximumTickLabelWidth(ticks, g2, plotArea, this.isVerticalTickLabels());
state.cursorLeft(used);
} else if (edge == RectangleEdge.RIGHT) {
used = this.findMaximumTickLabelWidth(ticks, g2, plotArea, this.isVerticalTickLabels());
state.cursorRight(used);
} else if (edge == RectangleEdge.TOP) {
used = this.findMaximumTickLabelHeight(ticks, g2, plotArea, this.isVerticalTickLabels());
state.cursorUp(used);
} else if (edge == RectangleEdge.BOTTOM) {
used = this.findMaximumTickLabelHeight(ticks, g2, plotArea, this.isVerticalTickLabels());
state.cursorDown(used);
}
}
return state;
}
}
このaxis-class（AlignedDateAxis）は私にとっては問題なく機能し、プロジェクトで使用しています。
本座（スポラック）