From 77166f4474525ec7273690bea83d56266c6d3b6b Mon Sep 17 00:00:00 2001
From: Tim Molter <tim@knowm.org>
Date: Thu, 1 Oct 2015 12:46:44 +0200
Subject: [PATCH] "smart" tick spacing hint generation to provent tick label
crowding and overlap
---
.../xeiam/xchart/internal/chartpart/Axis.java | 4 ++
.../xchart/internal/chartpart/AxisTick.java | 17 ++++---
.../chartpart/AxisTickCalculator.java | 38 ++++++++++++++
.../chartpart/AxisTickDateCalculator.java | 50 ++++++++++++-------
4 files changed, 83 insertions(+), 26 deletions(-)
diff --git a/xchart/src/main/java/com/xeiam/xchart/internal/chartpart/Axis.java b/xchart/src/main/java/com/xeiam/xchart/internal/chartpart/Axis.java
index 1deb8df4..1cdfa436 100644
--- a/xchart/src/main/java/com/xeiam/xchart/internal/chartpart/Axis.java
+++ b/xchart/src/main/java/com/xeiam/xchart/internal/chartpart/Axis.java
@@ -270,6 +270,8 @@ public class Axis implements ChartPart {
if (getChartPainter().getStyleManager().isXAxisTicksVisible()) {
// get some real tick labels
+ // System.out.println("XAxisHeightHint");
+ // System.out.println("workingSpace: " + workingSpace);
AxisTickCalculator axisTickCalculator = axisTick.getAxisTickCalculator(workingSpace);
String sampleLabel = " ";
// find the longest String in all the labels
@@ -279,11 +281,13 @@ public class Axis implements ChartPart {
}
}
+ // get the height of the label including rotation
TextLayout textLayout = new TextLayout(sampleLabel, getChartPainter().getStyleManager().getAxisTickLabelsFont(), new FontRenderContext(null, true, false));
AffineTransform rot = getChartPainter().getStyleManager().getXAxisLabelRotation() == 0 ? null : AffineTransform.getRotateInstance(-1 * Math.toRadians(getChartPainter().getStyleManager()
.getXAxisLabelRotation()));
Shape shape = textLayout.getOutline(rot);
Rectangle2D rectangle = shape.getBounds();
+
axisTickLabelsHeight = rectangle.getHeight() + getChartPainter().getStyleManager().getAxisTickPadding() + getChartPainter().getStyleManager().getAxisTickMarkLength();
}
return titleHeight + axisTickLabelsHeight;
diff --git a/xchart/src/main/java/com/xeiam/xchart/internal/chartpart/AxisTick.java b/xchart/src/main/java/com/xeiam/xchart/internal/chartpart/AxisTick.java
index ec0f3236..6331a8fd 100644
--- a/xchart/src/main/java/com/xeiam/xchart/internal/chartpart/AxisTick.java
+++ b/xchart/src/main/java/com/xeiam/xchart/internal/chartpart/AxisTick.java
@@ -74,6 +74,8 @@ public class AxisTick implements ChartPart {
// System.out.println("workingspace= " + workingSpace);
}
+ System.out.println("AxisTick: " + axis.getDirection());
+ // System.out.println("workingSpace: " + workingSpace);
axisTickCalculator = getAxisTickCalculator(workingSpace);
if (axis.getDirection() == Axis.Direction.Y && getChartPainter().getStyleManager().isYAxisTicksVisible()) {
@@ -83,15 +85,15 @@ public class AxisTick implements ChartPart {
bounds = new Rectangle2D.Double(
- axisTickLabels.getBounds().getX(),
+ axisTickLabels.getBounds().getX(),
- axisTickLabels.getBounds().getY(),
+ axisTickLabels.getBounds().getY(),
- axisTickLabels.getBounds().getWidth() + getChartPainter().getStyleManager().getAxisTickPadding() + axisTickMarks.getBounds().getWidth(),
+ axisTickLabels.getBounds().getWidth() + getChartPainter().getStyleManager().getAxisTickPadding() + axisTickMarks.getBounds().getWidth(),
- axisTickMarks.getBounds().getHeight()
+ axisTickMarks.getBounds().getHeight()
- );
+ );
// g.setColor(Color.red);
// g.draw(bounds);
@@ -102,9 +104,8 @@ public class AxisTick implements ChartPart {
axisTickLabels.paint(g);
axisTickMarks.paint(g);
- bounds =
- new Rectangle2D.Double(axisTickMarks.getBounds().getX(), axisTickMarks.getBounds().getY(), axisTickLabels.getBounds().getWidth(), axisTickMarks.getBounds().getHeight()
- + getChartPainter().getStyleManager().getAxisTickPadding() + axisTickLabels.getBounds().getHeight());
+ bounds = new Rectangle2D.Double(axisTickMarks.getBounds().getX(), axisTickMarks.getBounds().getY(), axisTickLabels.getBounds().getWidth(), axisTickMarks.getBounds().getHeight()
+ + getChartPainter().getStyleManager().getAxisTickPadding() + axisTickLabels.getBounds().getHeight());
// g.setColor(Color.red);
// g.draw(bounds);
diff --git a/xchart/src/main/java/com/xeiam/xchart/internal/chartpart/AxisTickCalculator.java b/xchart/src/main/java/com/xeiam/xchart/internal/chartpart/AxisTickCalculator.java
index ad5f53bd..8f5d5723 100644
--- a/xchart/src/main/java/com/xeiam/xchart/internal/chartpart/AxisTickCalculator.java
+++ b/xchart/src/main/java/com/xeiam/xchart/internal/chartpart/AxisTickCalculator.java
@@ -15,6 +15,11 @@
*/
package com.xeiam.xchart.internal.chartpart;
+import java.awt.Shape;
+import java.awt.font.FontRenderContext;
+import java.awt.font.TextLayout;
+import java.awt.geom.AffineTransform;
+import java.awt.geom.Rectangle2D;
import java.util.LinkedList;
import java.util.List;
@@ -116,4 +121,37 @@ public abstract class AxisTickCalculator {
return tickLabels;
}
+ /**
+ * Given the generated tickLabels, will they fit side-by-side without overlapping each other and looking bad? Sometimes the given tickSpacingHint is simply too small.
+ *
+ * @param tickLabels
+ * @param tickSpacingHint
+ * @return
+ */
+ boolean willLabelsFitInTickSpaceHint(List<String> tickLabels, int tickSpacingHint) {
+
+ // Assume that for Y-Axis the ticks will all fit based on their tickSpace hint because the text is usually horizontal and "short". This more applies to the X-Axis.
+ if (this.axisDirection == Direction.Y) {
+ return true;
+ }
+
+ String sampleLabel = " ";
+ // find the longest String in all the labels
+ for (int i = 0; i < tickLabels.size(); i++) {
+ if (tickLabels.get(i) != null && tickLabels.get(i).length() > sampleLabel.length()) {
+ sampleLabel = tickLabels.get(i);
+ }
+ }
+
+ TextLayout textLayout = new TextLayout(sampleLabel, styleManager.getAxisTickLabelsFont(), new FontRenderContext(null, true, false));
+ AffineTransform rot = styleManager.getXAxisLabelRotation() == 0 ? null : AffineTransform.getRotateInstance(-1 * Math.toRadians(styleManager.getXAxisLabelRotation()));
+ Shape shape = textLayout.getOutline(rot);
+ Rectangle2D rectangle = shape.getBounds();
+ double largestLabelWidth = rectangle.getWidth();
+ // System.out.println("largestLabelWidth: " + largestLabelWidth);
+ // System.out.println("tickSpacingHint: " + tickSpacingHint);
+
+ return (largestLabelWidth * 1.8 < tickSpacingHint);
+
+ }
}
diff --git a/xchart/src/main/java/com/xeiam/xchart/internal/chartpart/AxisTickDateCalculator.java b/xchart/src/main/java/com/xeiam/xchart/internal/chartpart/AxisTickDateCalculator.java
index 40b6d956..fbc7f021 100644
--- a/xchart/src/main/java/com/xeiam/xchart/internal/chartpart/AxisTickDateCalculator.java
+++ b/xchart/src/main/java/com/xeiam/xchart/internal/chartpart/AxisTickDateCalculator.java
@@ -55,28 +55,42 @@ public class AxisTickDateCalculator extends AxisTickCalculator {
// the span of the data
long span = (long) Math.abs(maxValue - minValue); // in data space
- long gridStepHint = (long) (span / tickSpace * styleManager.getXAxisTickMarkSpacingHint());
-
- long timeUnit = dateFormatter.getTimeUnit(gridStepHint);
- double gridStep = 0.0;
- int[] steps = dateFormatter.getValidTickStepsMap().get(timeUnit);
- for (int i = 0; i < steps.length - 1; i++) {
- if (gridStepHint < (timeUnit * steps[i] + timeUnit * steps[i + 1]) / 2.0) {
- gridStep = timeUnit * steps[i];
- break;
+ // Can tickSpacingHint be intelligently calculated by looking at the label data?
+ // YES. Generate the labels first, see if they "look" OK and reiterate with an increased tickSpacingHint
+ // TODO apply this to other Axis types including bar charts
+ // TODO only do this for the X-Axis
+ int tickSpacingHint = styleManager.getXAxisTickMarkSpacingHint() - 10;
+ do {
+
+ System.out.println("calulating ticks...");
+ tickLabels.clear();
+ tickLocations.clear();
+ tickSpacingHint += 10;
+ long gridStepHint = (long) (span / tickSpace * tickSpacingHint);
+
+ long timeUnit = dateFormatter.getTimeUnit(gridStepHint);
+ double gridStep = 0.0;
+ int[] steps = dateFormatter.getValidTickStepsMap().get(timeUnit);
+ for (int i = 0; i < steps.length - 1; i++) {
+ if (gridStepHint < (timeUnit * steps[i] + timeUnit * steps[i + 1]) / 2.0) {
+ gridStep = timeUnit * steps[i];
+ break;
+ }
}
- }
- double firstPosition = getFirstPosition(gridStep);
+ // System.out.println("gridStep: " + gridStep);
- // generate all tickLabels and tickLocations from the first to last position
- for (double value = firstPosition; value <= maxValue + 2 * gridStep; value = value + gridStep) {
+ double firstPosition = getFirstPosition(gridStep);
- tickLabels.add(dateFormatter.formatDate(value, timeUnit));
- // here we convert tickPosition finally to plot space, i.e. pixels
- double tickLabelPosition = margin + ((value - minValue) / (maxValue - minValue) * tickSpace);
- tickLocations.add(tickLabelPosition);
- }
+ // generate all tickLabels and tickLocations from the first to last position
+ for (double value = firstPosition; value <= maxValue + 2 * gridStep; value = value + gridStep) {
+
+ tickLabels.add(dateFormatter.formatDate(value, timeUnit));
+ // here we convert tickPosition finally to plot space, i.e. pixels
+ double tickLabelPosition = margin + ((value - minValue) / (maxValue - minValue) * tickSpace);
+ tickLocations.add(tickLabelPosition);
+ }
+ } while (!willLabelsFitInTickSpaceHint(tickLabels, tickSpacingHint));
}
}
--
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