GButton doesn't fire events in eclipse (G4P)

Hi, i'm new to this forum as well as to processing.

When i try to run the G4P example "G4P_Sketchpad" in eclipse the "btnClear"-Button won't fire an event when clicked. The same code in the processing-IDE is working but when run from eclipse the button is not firing events to handleButtonEvents(GButton button, GEvent event).

any help is appreciated. here comes the code copied from eclipse:

regards

package myPackageName;

import processing.core.*;
import g4p_controls.*;

public class View extends PApplet {

    GPanel pnl;
    GSketchPad spad;
    GButton btnClear;
    PGraphics pg;

    public static void main(String[] args) {
        PApplet.main(View.class.getName());
    }

    public void settings() {
        size(1024, 768);
    }

    public void setup() {
        // Now create and clear graphic to be used (JAVA parameter
        // parameter is only needed for Processing 1.5.1)
        pg = createGraphics(640, 480);
        clearGraphic();
        // Create the G4P control to position and display the graphic
        spad = new GSketchPad(this, 0, 0, 350, 200);
        // Set the graphic for this control.
        // The graphic will be scaled to fit the control.
        spad.setGraphic(pg);
        // Create the button to clear the graphic
        btnClear = new GButton(this, 0, 0, 80, 20, "Clear");
        // Create the panel and add the controls
        pnl = new GPanel(this, 0, 0, 400, 300, "Sketch Test");
        pnl.addControl(btnClear, 10, 24);
        pnl.addControl(spad, 10, 50);
        // Expand the panel
        pnl.setCollapsed(false);
    }

    public void draw() {
        background(240);
        // Every 20th frame update the sketchpad graphic
        if (frameCount % 20 == 0)
            updateGraphic();
    }

    void handleButtonEvents(GButton button, GEvent event) {
        if(button == btnClear && event == GEvent.CLICKED) {
            clearGraphic();
        }
        // debug
        println(button);
        println(event);
    }

    // Clear the sketchpad graphic
    void clearGraphic() {
        pg.beginDraw();
        pg.background(255, 255, 200);
        pg.noFill();
        pg.ellipseMode(CORNERS);
        pg.endDraw();
    }

    // Add a line or ellipse to the sketchpad graphic
    void updateGraphic() {
        float x0 = random(10, pg.width - 10);
        float x1 = random(10, pg.width - 10);
        float y0 = random(10, pg.height - 10);
        float y1 = random(10, pg.height - 10);
        int col = color(random(64, 255), random(64, 255), random(64, 255));
        pg.beginDraw();
        pg.stroke(col);
        pg.strokeWeight(random(2, 5));
        if (random(0, 1) < 0.5f)
            pg.line(x0, y0, x1, y1);
        else
            pg.ellipse(x0, y0, x1, y1);
        pg.endDraw();
    }
}