/**
* ************************************************************************************ Initialize
* the canvas, and render all the vertical lines of the parallel coordinates
*
* @param g - the graphic2D object
* ************************************************************************************
*/
public void initializeCanvas(Graphics2D g) {
// set the color gradients using the selected column default is the first column i.e. 0)
this.setLineColors();
int x = init_x, y = init_y, miny = init_miny, maxy = init_maxy;
// set background of the canvas to white
g.setBackground(new Color(255, 240, 240));
g.clearRect(0, 0, CANVAS_WIDTH, CANVAS_HEIGHT);
g.setStroke(new BasicStroke(0.3f)); // set the thickness of the stroke
// render all vertical lines
for (int i = 0; i < colCount; i++) {
g.setColor(vertLinesColor); // set the color
// render vertical lines line_height pixels high
g.drawLine(x, miny, x, maxy);
// draw small horizontal lines to mark the dimensions of the data on the vertical lines
g.drawLine(x - 3, y, x + 3, y);
g.drawLine(x - 3, y + line_height, x + 3, y + line_height);
// render 2 vertical lines on the sides of the main vertical lines to form boxes around them.
g.setColor(new Color(170, 150, 140, 100));
g.drawLine(x - 2, miny, x - 2, maxy);
g.drawLine(x + 2, miny, x + 2, maxy);
/** ************ Printing the Headings ************************ */
// set color used to print the headings
g.setColor(new Color(0, 0, 0));
AffineTransform orig = g.getTransform(); // get the current transform
double rotateRadian = 0, offset = 0, labelX, halfRotAngle = 0;
rotateRadian = (headerAngle) * Math.PI / 180; // radians = degrees * pi/180
halfRotAngle = (headerAngle / 2.0) * Math.PI / 180;
// compute the offset
offset =
2
* Math.sin((halfRotAngle))
* (x - 10); // 2 * SOH to find the base of the isocelles triangle found
labelX = (x - 10); // the 5 is to move the text a 5pixels to the left when it is rotated
offset = Math.abs(offset);
// rotateRadian = angle * Math.PI/180 ; //radians = degrees * pi/180
g.rotate(-rotateRadian);
double xtrans = 0, ytrans = 0;
double xrad = 0;
/*find the distance of the x after the rotation. : i.e. find the distance where the base of the isoceles triangle
* formed during the rotation forms a right-angle with the header of the rotated figure
*/
int isoAngle = (180 - headerAngle) / 2;
xrad = (isoAngle) * Math.PI / 180;
ytrans = Math.sin(xrad) * offset;
xtrans = Math.sqrt(Math.pow(offset, 2) - Math.pow(ytrans, 2));
labelX =
(x - 10)
- xtrans; // (x-5) because we want the label to start a few pixels before the vertical
// line
g.drawString(
tab.getColumnName(i),
(int) labelX,
(int)
((miny - 10)
+ ytrans)); // write the header on top of the line. Note the 10 is because we
// wanted the text to be 30 pixels above the vertical line.
// after writing the rotated text, continue with the normal rotation.
g.setTransform(orig);
/* Set the field dimensions. these dimensions represent the box around the vertical lines*/
verticalFields[i] =
new VerticalFields(
x - (verticalFieldWidth / 2), y - 20, line_height + 40, verticalFieldWidth);
/*Filling of selection*/
if (verticalFieldsDragged[i]
.getDragged()) { // if the column has been dragged, then fill the drag area
verticalFieldsDragged[i].setX(verticalFields[i].getX());
verticalFieldsDragged[i].setFill(true);
verticalFieldsDragged[i].draw(g);
} else if (i
== selectedColumn) { // if the whole column has been selected then fill the whole column
verticalFields[i].setFill(true);
verticalFields[i].draw(g);
}
x += separation;
}
// render top and bottom ovals at the endpoints of the vertical lines
x = init_x;
for (int i = 0; i < colCount; i++) {
bottomOvals[i] =
new SmallOvals(x - OVAL_WIDTH / 2, y + line_height + 20, OVAL_WIDTH, OVAL_HEIGHT);
topOvals[i] =
new SmallOvals(x - OVAL_WIDTH / 2, y - 20 - OVAL_HEIGHT, OVAL_WIDTH, OVAL_HEIGHT);
topOvals[i].setLabel(tab.getColumnName(i));
bottomOvals[i].setLabel(tab.getColumnName(i));
topOvals[i].draw(g);
bottomOvals[i].draw(g);
x += separation; // the horizontal separation of the vertical lines.
}
}
