问题
I have found SWTChart library and just wonder how it would be possible to select with the mouse a range e.g. 1 to 3 on the x-axis and I would get all y-axis values which belongs to the selected x values.
(source: swtchart.org)
package org.swtchart.examples;
import org.eclipse.swt.SWT;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;
import org.swtchart.Chart;
import org.swtchart.ILineSeries;
import org.swtchart.ISeries.SeriesType;
/**
* An example for area chart.
*/
public class AreaChartExample {
private static final double[] ySeries1 = { 0.1, 0.38, 0.71, 0.92, 1.0 };
private static final double[] ySeries2 = { 1.2, 3.53, 3.1, 0.1, 0.5 };
/**
* The main method.
*
* @param args
* the arguments
*/
public static void main(String[] args) {
Display display = new Display();
Shell shell = new Shell(display);
shell.setText("Area Chart");
shell.setSize(500, 400);
shell.setLayout(new FillLayout());
createChart(shell);
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
display.dispose();
}
/**
* create the chart.
*
* @param parent
* The parent composite
* @return The created chart
*/
static public Chart createChart(Composite parent) {
// create a chart
Chart chart = new Chart(parent, SWT.NONE);
// set titles
chart.getTitle().setText("Area Chart");
// create line series
ILineSeries lineSeries1 = (ILineSeries) chart.getSeriesSet()
.createSeries(SeriesType.LINE, "line series 1");
lineSeries1.setYSeries(ySeries1);
lineSeries1.setLineColor(Display.getDefault().getSystemColor(
SWT.COLOR_RED));
lineSeries1.enableArea(true);
ILineSeries lineSeries2 = (ILineSeries) chart.getSeriesSet()
.createSeries(SeriesType.LINE, "line series 2");
lineSeries2.setYSeries(ySeries2);
lineSeries2.enableArea(true);
// adjust the axis range
chart.getAxisSet().adjustRange();
return chart;
}
}
How is it possible to include a mouse event for selecting a range in the above example?
Thank you in advance.
回答1:
The following code should give you an idea on how to do this. Basically, you have to get the chartArea
of the chart
, add the listeners for SWT.MouseDown
and SWT.MouseUp
and remember the position of both events. To answer your comment: Yes, you can add a "highlight" functionality by using the SWT.Paint
listener.
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Shell;
import org.swtchart.Chart;
import org.swtchart.IAxis;
import org.swtchart.ILineSeries;
import org.swtchart.ISeries.SeriesType;
/**
* An example for area chart.
*/
public class AreaChartExample {
private static final double[] ySeries1 = { 0.1, 0.38, 0.71, 0.92, 1.0 };
private static final double[] ySeries2 = { 1.2, 3.53, 3.1, 0.1, 0.5 };
/* Used to remember location point of mouse down */
private static double startX;
private static double startY;
private static int startXPos;
private static int startYPos;
private static int currentX;
private static int currentY;
private static boolean drag = false;
/**
* The main method.
*
* @param args
* the arguments
*/
public static void main(String[] args) {
Display display = new Display();
Shell shell = new Shell(display);
shell.setText("Area Chart");
shell.setSize(500, 400);
shell.setLayout(new FillLayout());
createChart(shell);
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
display.dispose();
}
/**
* create the chart.
*
* @param parent
* The parent composite
* @return The created chart
*/
static public Chart createChart(Composite parent) {
// create a chart
final Chart chart = new Chart(parent, SWT.NONE);
// set titles
chart.getTitle().setText("Area Chart");
// create line series
ILineSeries lineSeries1 = (ILineSeries) chart.getSeriesSet()
.createSeries(SeriesType.LINE, "line series 1");
lineSeries1.setYSeries(ySeries1);
lineSeries1.setLineColor(Display.getDefault().getSystemColor(
SWT.COLOR_RED));
lineSeries1.enableArea(true);
ILineSeries lineSeries2 = (ILineSeries) chart.getSeriesSet()
.createSeries(SeriesType.LINE, "line series 2");
lineSeries2.setYSeries(ySeries2);
lineSeries2.enableArea(true);
// adjust the axis range
chart.getAxisSet().adjustRange();
/* Get the plot area and add the mouse listeners */
final Composite plotArea = chart.getPlotArea();
plotArea.addListener(SWT.MouseDown, new Listener() {
@Override
public void handleEvent(Event event) {
IAxis xAxis = chart.getAxisSet().getXAxis(0);
IAxis yAxis = chart.getAxisSet().getYAxis(0);
startX = xAxis.getDataCoordinate(event.x);
startY = yAxis.getDataCoordinate(event.y);
startXPos = event.x;
startYPos = event.y;
drag = true;
}
});
plotArea.addListener(SWT.MouseUp, new Listener() {
@Override
public void handleEvent(Event event) {
IAxis xAxis = chart.getAxisSet().getXAxis(0);
IAxis yAxis = chart.getAxisSet().getYAxis(0);
double endX = xAxis.getDataCoordinate(event.x);
double endY = yAxis.getDataCoordinate(event.y);
System.out.println(startX + " " + endX);
System.out.println(startY + " " + endY);
drag = false;
plotArea.redraw();
}
});
plotArea.addListener(SWT.MouseMove, new Listener() {
@Override
public void handleEvent(Event event) {
if(drag)
{
currentX = event.x;
currentY = event.y;
plotArea.redraw();
}
}
});
plotArea.addListener(SWT.Paint, new Listener() {
@Override
public void handleEvent(Event event) {
if(drag)
{
GC gc = event.gc;
gc.setBackground(Display.getDefault().getSystemColor(SWT.COLOR_RED));
gc.setAlpha(128);
int minX = Math.min(startXPos, currentX);
int minY = Math.min(startYPos, currentY);
int maxX = Math.max(startXPos, currentX);
int maxY = Math.max(startYPos, currentY);
int width = maxX - minX;
int height = maxY - minY;
gc.fillRectangle(minX, minY, width, height);
}
}
});
return chart;
}
}
来源:https://stackoverflow.com/questions/12419077/swtchart-mouse-event-handling