* The sliders are the info panel of an integer respectively a double variable. * This sample project is a data class which uses the integer and double * objects as a inspectable numbers. That is, in this project the current * value of the numbers are obtain via their getValue and setValue method. * Simulatenously and independently, a GUI interface to these number may be * constructed, which is here done in the info panel of this project. *
* Note the handling of panels is encapsulated in the corresponding
* class PjSlider_IP. I.e. this project class contains the values of the sliders,
* but not the interface handling. Basically, the separation of interface and data
* class allows that this class is fully functional even in batch operation.
*
* @see jv.number.PuDouble
* @see jv.number.PuInteger
* @author Ulrich Reitebuch, Konrad Polthier
* @version 16.09.01, 1.50 revised (kp) Panel stuff moved to PjSlider_IP.
* 16.09.01, 1.10 revised (kp) Name changed from slider_Applet.java.
* 14.04.00, 1.00 created (ur)
*/
public class PjSlider extends PjProject {
protected PuInteger m_intSlider;
protected PuDouble m_doubleSlider;
protected double m_product;
/**
* Constructor: Creates instances of slider classes.
*/
public PjSlider (){
super("Slider Demonstration");
// Create an instance of "PuInteger" and an instance of "PuDouble".
// The first argument for creating PuInteger or PuDouble is a string,
// in this case "Integer" resp. "Double", which is the name of the object.
// This name will appear inside the slider panel on the left side.
// The second argument for creating PuInteger or PuDouble instances, in this case "this", has to fullfill
// the interface "PsUpdateIf" (in this case this is warranteed by extending jv.project.PjProject),
// particularly it must implement the method "public boolean update (Object)", which is called,
// whenever the value of the slider panel is modified, or when an update
// of the slider is performed.
m_intSlider = new PuInteger("Integer", this);
m_doubleSlider = new PuDouble("Double", this);
init();
}
/**
* Initialization and configuration of sliders.
* At first, some default values of the two sliders are set.
* These default values are used for initialization of the slider
* and whenever the slider is reset.
*/
public void init() {
// The method setDefBounds defines the minimum value, the maximum value,
// the line increment and the page increment for the slider.
// The bounds and increments can also be changed later by the method PuInteger.setBounds
// resp. PuDouble.setBounds.
m_intSlider.setDefBounds(-10, 10, 1, 5);
// The method setDefValue defines the initial value. The value can also be changed later
// by the method setValue(Integer) resp. setValue(Double).
m_intSlider.setDefValue(4);
// The method PuInteger.init() resp. PuDouble.init() must be called to set the slider to it's
// initial values.
m_intSlider.init();
// Now the same procedure with the double slider.
m_doubleSlider.setDefBounds(-10., 10., 0.1, 1.);
m_doubleSlider.setDefValue(2.3);
m_doubleSlider.init();
// Initialize the product variable.
computeProduct();
}
/**
* This method allows to react whenever a slider is touched.
* Since this project is the parent of both sliders, this method
* is called whenever an update of a slider is invoked.
*/
public boolean update(Object event) {
if (event==m_intSlider || event==m_doubleSlider) {
// Update the product variable if the value of a slider has changed.
computeProduct();
// Update parents, dependent objects and the info panel of this class
update(this);
return true;
}
return super.update(event);
}
/**
* Get the current value of the product.
*/
public double getProduct() { return m_product; }
/** Compute product of values of the two sliders. */
public void computeProduct () {
//The methods PuInteger.getValue() and PuDouble.getValue() return the int/double
//value defined by the slider.
m_product = m_doubleSlider.getValue() * m_intSlider.getValue();
}
}