/**
* Sets the layout of the applet window to BorderLayout, creates all the components and associates
* them with event listeners if neccessary.
*/
private void initComponents() {
setLayout(new BorderLayout());
setBackground(java.awt.Color.white);
// get the initial expression from the parameters
String expr = getParameter("initialExpression");
// write the expression into the text field
if (expr != null) exprField = new java.awt.TextField(expr);
else exprField = new java.awt.TextField("");
// adjust various settings for the expression field
exprField.setBackground(java.awt.Color.white);
exprField.setName("exprField");
exprField.setFont(new java.awt.Font("Dialog", 0, 11));
exprField.setForeground(java.awt.Color.black);
exprField.addTextListener(
new java.awt.event.TextListener() {
public void textValueChanged(java.awt.event.TextEvent evt) {
exprFieldTextValueChanged(evt);
}
});
add("North", exprField);
// create the graph canvas and add it
graphCanvas = new GraphCanvas(expr, exprField);
add("Center", graphCanvas);
}
/** Repaints the graphCanvas whenever the text in the expression field changes. */
private void exprFieldTextValueChanged(java.awt.event.TextEvent evt) {
String newExpressionString = exprField.getText();
graphCanvas.setExpressionString(newExpressionString);
graphCanvas.repaint();
}