/**
* Draws the Legend for the scatter plot
*
* @param g {@link Graphics}
*/
private void drawLegend(Graphics g) {
// set the color of the legend rectangle
g.setColor(LEGEND_BACKGROUND);
int lineHeight = g.getFontMetrics().getHeight() + 2; // height of a legend line
// draw the legend rectangle
g.fillRect(
getWidth() - legendWidth - LENGEND_PAD - (LEGEND_INSET * 2),
LENGEND_PAD,
legendWidth + (LEGEND_INSET * 2),
((data.size() + 2) * lineHeight) + (LEGEND_INSET * 2));
g.setColor(Colors.BLACK);
g.drawRect(
getWidth() - legendWidth - LENGEND_PAD - (LEGEND_INSET * 2),
LENGEND_PAD,
legendWidth + (LEGEND_INSET * 2),
((data.size() + 2) * lineHeight) + (LEGEND_INSET * 2));
// search the position where to start the text of the legend
Point p =
new Point(
getWidth() - legendWidth - LENGEND_PAD - LEGEND_INSET,
LENGEND_PAD + LEGEND_INSET + g.getFontMetrics().getHeight());
// draw the axis names
g.drawString(X_AXIS_PREFIX + xAxis.getName(), p.x, p.y); // draw X-Axis legend
g.drawString(Y_AXIS_PREFIX + yAxis.getName(), p.x, p.y + lineHeight); // draw Y-Axis legend
// draw graph name legend
for (int i = 0; i < data.size(); i++) {
Color graphColor = data.get(i).getColor();
String graphName = data.get(i).getName();
g.setColor(graphColor);
int yLine = p.y + ((i + 2) * lineHeight); // y position of the current line
g.drawLine(p.x, yLine - 5, p.x + 25, yLine - 5); // draw a line with the color of the graph
g.setColor(Colors.BLACK);
g.drawString(graphName, p.x + 30, yLine); // draw the name of the graph
}
}
/** @return the width of the legend text in pixels */
private int computeLegendWidth() {
FontMetrics fm = getFontMetrics(getFont());
int legendWidth = fm.stringWidth(X_AXIS_PREFIX + xAxis.getName());
legendWidth = Math.max(legendWidth, fm.stringWidth(Y_AXIS_PREFIX + yAxis.getName()));
for (ScatterPlotData currentPlot : data) {
if (data != null) {
legendWidth = Math.max(legendWidth, fm.stringWidth(currentPlot.getName()) + 30);
}
}
return legendWidth;
}
