/**
* Sets the data set that the graph displays. Depending on the log mode, the line will represents
* the values of the <sup>10</sup>log() of the values.
*
* @param d the data set.
* @see #getDataSet
*/
public void setDataSet(GraphDataSet d) {
if (dataSet != null) {
dataSet.removePropertyChangeListener(this);
}
dataSet = d;
if (dataSet != null) {
dataSet.addPropertyChangeListener(this);
}
}
/**
* Returns the minimum size.
*
* @return the dimensions of the minimum size
*/
public Dimension getMinimumSize() {
int w, h;
int cap = 100;
if (dataSet != null) {
cap = dataSet.getCapacity();
}
w = cap * 1 + 2;
h = (int) (numYTicks * 2) + 2;
return new Dimension(w, h);
}
/**
* Returns the preferred size.
*
* @return the dimensions of the preferred size
*/
public Dimension getPreferredSize() {
int w, h;
int cap = 100;
if (dataSet != null) {
cap = dataSet.getCapacity();
}
w = cap * 2 + 5;
h = (int) (numYTicks * 5) + 5;
return new Dimension(w, h);
}
/**
* This method will draw the line.
*
* @param gc the graphics
* @see #setLog
*/
void paintLine(Graphics g) {
double dvalue;
int[] values = dataSet.getValues();
// first decide the x scale factor;
if ((dataSet == null) || (dataSet.getSize() < 1)) {
return; // nothing to draw
}
// the maximum number of values we are every going to get
int capacity = dataSet.getCapacity();
// the available number of values at the moment
int nr = dataSet.getSize();
Rectangle space = g.getClipBounds();
// pixel width of x values
int width = space.width;
int xscale = (int) (width / capacity);
if (xscale < 1) {
xscale = 1;
}
width = xscale * capacity;
if (width > space.width) {
width = space.width;
}
// pixel width of y values
float yscale = (space.height) / (float) (dmax - dmin);
// offset into array
int xstart = 0;
if (width < (nr * xscale)) {
// we are lacking space
xstart = nr - (int) (width / xscale);
}
// if needed reallocate some space
int totx = nr - xstart + 1;
if (xline.length < totx) {
xline = new int[totx + 100];
yline = new int[totx + 100];
}
// now workout where to put the first point so that
// the last one ends up on the right hand edge
int x = width - (int) ((nr - xstart - 1) * xscale);
if (x < 0) {
x = 0; // can't be negative
System.out.println("negative start point in graph.");
}
int y;
int ox = x;
x += xscale;
dvalue = values[xstart];
if (doLog) {
dvalue = log10(values[xstart]);
}
xstart++;
int oy = space.height - (int) ((dvalue - dmin) * yscale);
int pt = 0;
for (int i = xstart; i < nr; i++) {
dvalue = values[i];
if (doLog) {
dvalue = log10(values[i]);
}
y = space.height - (int) ((dvalue - dmin) * yscale);
xline[pt] = x;
yline[pt] = y;
pt++;
ox = x;
oy = y;
x += xscale;
}
g.drawPolyline(xline, yline, pt);
}