/**
* high-level method for drawing a chart axis line plus labeled tic marks. introduces a dependancy
* on AWT because it takes a Graphics parameter. perhaps this method belongs in some higher-level
* class but i added it here since it's highly related with the tic lable generation code.
*
* @author Melinda Green
* @param axis is one of Axis.X_AXIS or Axis.Y_AXIS.
* @param maxTics is the maximum number of labeled tics to draw. note: the actual number drawn may
* be less.
* @param lowVal is the smallest value tic mark that may be drawn. note: the lowest valued tic
* label may be greater than this limit.
* @param highVal is the largest value tic mark that may be drawn. note: the highest valued tic
* label may be less than this limit.
* @param screenStart is the coordinate in the low valued direction.
* @param screenEnd is the coordinate in the high valued direction.
* @param offset is the coordinate in the direction perpendicular to the specified direction.
* @param logScale is true if a log scale axis is to be drawn, false for a linear scale.
* @param screenHeight is needed to flip Y coordinates.
* @param g is the AWT Graphics object to draw into. note: all drawing will be done in the current
* color of the given Graphics object.
*/
public static void drawAxis(
int axis,
int maxTics,
int ticLength,
float lowVal,
float highVal,
int screenStart,
int screenEnd,
int screenOffset,
boolean logScale,
int screenHeight,
Graphics g) {
if (logScale && (lowVal == 0 || highVal == 0))
throw new IllegalArgumentException("Axis.drawAxis: zero range value not allowed in log axes");
if (axis == X_AXIS) // horizontal baseline
g.drawLine(screenStart, screenHeight - screenOffset, screenEnd, screenHeight - screenOffset);
else
// vertical baseline
g.drawLine(screenOffset, screenStart, screenOffset, screenEnd);
Vector tics = Axis.computeTicks(lowVal, highVal, maxTics, logScale); // nice
// round
// numbers
// for
// tic
// labels
int last_label_end = axis == X_AXIS ? -88888 : 88888;
String dbgstr = "tics: ";
for (Enumeration e = tics.elements(); e.hasMoreElements(); ) {
String ticstr = (String) e.nextElement();
if (DEBUG) dbgstr += ticstr + ", ";
float ticval = Float.parseFloat(ticstr);
int tic_coord = screenStart;
Dimension str_size = stringSize(ticstr, g);
tic_coord +=
plotValue(ticval, lowVal, highVal, screenStart, screenEnd, logScale, screenHeight);
if (axis == X_AXIS) { // horizontal axis == vertical tics
g.drawLine(
tic_coord,
screenHeight - screenOffset,
tic_coord,
screenHeight - screenOffset + ticLength);
if (tic_coord - str_size.width / 2 > last_label_end) {
g.drawString(
ticstr,
tic_coord - str_size.width / 2,
screenHeight - screenOffset + str_size.height + 5);
last_label_end = tic_coord + str_size.width / 2 + str_size.height / 2;
}
} else { // vertical axis == horizontal tics
tic_coord = screenHeight - tic_coord; // flips Y coordinates
g.drawLine(screenOffset - ticLength, tic_coord, screenOffset, tic_coord);
if (tic_coord - str_size.height / 3 < last_label_end) {
g.drawString(
ticstr,
screenOffset - ticLength - str_size.width - 5,
tic_coord + str_size.height / 3);
last_label_end = tic_coord - str_size.height;
}
}
}
if (DEBUG) System.out.println(dbgstr);
} // end drawAxis
