java applet's

Kraken

Design and implement a Java application that draws shapes on the screen.

Your application should provide a facility for drawing, resizing and dragging the shape around the screen. The user should be able to select the required shape and the system should provide a facility to calculate the area of the shape.

i have no idea of java applets to this level any pointers or assistance would be great.

yossarin

a quick look at the sun site gives us the following

'Methods for Drawing and Event Handling':
http://java.sun.com/docs/books/tutorial/applet/overview/componentMethods.html
for event/ MouseListener user-applet interaction

and

'Moving an Image across a screen':
http://java.sun.com/docs/books/tutorial/uiswing/painting/movingImage.html
for simple threaded animation

look at those for a start

yoss

Puck

Doesn't your homework ask you to do an application and not an Applet?

Kraken

its not homework me just wants to try it.
Have tried and failed miserably. Couldnt get it to do anything i wanted it to. going to give up. If anyone wants to throw up some thing like what i am looking for ill take a look it might inspire me to try again and improve on my own. which i think i deleted...

Kraken

[code]
import java.awt.*;

class Dot
{
int left, top;
Color color;
String labl;
Font fnt;

Dot(String lbl, int l, int t, Color c, Font f)
{
labl = lbl;
left = l;
top = t;
color = c;
fnt = f;
}
public int widthOf() { return 0; }
public int heightOf() { return 0; }
public void setWidth(int w) {}
public void setHeight(int h) {}
public void setLabel(String s) { labl = s; }
public void setLeft(int l) { left = l; }
public void setTop(int t) { top = t; }
public void setColor(Color c) { color = c; }
public int leftOf() { return left; }
public int topOf() { return top; }
public Color colorOf() { return color; }
public String labelOf() { return labl; }
public void draw (Graphics q) {}
public boolean find (int x, int y) { return false; }
public void setFont(Font f) { fnt = f; }
public Font getFont() { return fnt; }
}

class RectDot extends Dot
{
int width, height;

RectDot (String s, int l, int t, int w, int h, Color c, Font f)
{
super(s,l,t,c,f);
width = w;
height = h;
}
public int widthOf() { return width; }
public int heightOf() { return height; }
public void setWidth(int w) { width = w; }
public void setHeight(int h) { height = h; }
public boolean find(int x, int y)
{
if (super.leftOf() < x && x < super.leftOf()+width &&
super.topOf() < y && y < super.topOf()+height)
return true;
return false;
}
public void draw(Graphics g)
{
g.setFont(super.getFont());
int w = 20;
int h = 10;
g.setColor(colorOf());
g.fillRect(leftOf(), topOf(), width, height);
g.setColor(Color.black);
g.drawString(labl, leftOf()-w/2+width/2, topOf()+h/4+height/2);
}
}

class OvalDot extends Dot
{
int width, height;

OvalDot (String s, int l, int t, int w, int h, Color c, Font f)
{
super(s,l,t,c,f);
width = w;
height = h;
}

public int widthOf() { return width; }
public int heightOf() { return height; }
public void setWidth(int w) { width = w; }
public void setHeight(int h) { height = h; }

public boolean find(int x, int y)
{
if (super.leftOf() < x && x < super.leftOf()+width &&
super.topOf() < y && y < super.topOf()+height)
return true;
return false;
}

public void draw(Graphics g)
{
g.setFont(super.getFont());
int w = 20;
int h = 10;
g.setColor(colorOf());
g.fillOval(leftOf(), topOf(), width, height);
g.setColor(Color.black);
g.drawString(labl, leftOf()-w/2+width/2, topOf()+h/4+height/2);
}
}

class CircDot extends Dot
{
int diam;

CircDot (String s, int l, int t, int d, Color c, Font f)
{
super(s,l,t,c,f);
diam = d;
}

public int widthOf() { return diam; }
public int heightOf() { return diam; }
public int diameterOf() { return diam; }
public void setWidth(int w) { diam = w; }
public void setHeight(int h) { diam = h; }
public void setDiam(int d) { diam = d; }

public boolean find (int x, int y)
{
if (super.leftOf() < x && x < super.leftOf()+diam &&
super.topOf() < y && y < super.topOf()+diam)
return true;
return false;
}

Kraken

public void draw(Graphics g)
{
g.setFont(super.getFont());
int w = 20;
int h = 10;
g.setColor(colorOf());
g.fillOval(leftOf(), topOf(), diam, diam);
g.setColor(new Color(0,0,0));
g.drawString(labl, leftOf()-w/2+diam/2, topOf()+h/4+diam/2);
}
}

public class ObjectsApplet extends java.applet.Applet
{
String fontstylechoice[] = { "Helvetica", "Times Roman", "Courier",
"Dialog", "DialogInput", "Zapf Dingbats" };
String fontstyleselect[] = { "Helvetica", "TimesRoman", "Courier",
"Dialog", "DialogInput", "ZapfDingbats" };
int nfontstyles = 6;
String fontsizechoice[] = { "6", "8", "10", "12", "14", "16", "18" };
int nfontsizes = 7;
Button redbutton, bluebutton, greenbutton, rectbutton, textbutton,
circbutton, ovalbutton, objectbutton, bigbutton, smallbutton,
fontbutton;
TextField namefield;
Panel mainpanel;
Dot dot[] = new Dot[100];
int ndots = 0, current = -1;
Color dotcolor = Color.red;
Dot pick = null;
int fontstyle = 0;
int fontsz = 0;
Font myfont = new Font(fontstyleselect[fontstyle], Font.PLAIN,
Integer.parseInt(fontsizechoice[fontsz]));
int diffx, diffy;
Choice fonttype, fontsize;

public void init()
{
setLayout(new BorderLayout());
Panel p = new Panel();
p.setLayout(new GridLayout(18,1));
p.add(new Label(""));
p.add(redbutton = new Button("Red"));
p.add(bluebutton = new Button("Blue"));
p.add(greenbutton = new Button("Green"));
p.add(new Label(""));
p.add(rectbutton = new Button("Rectangle"));
p.add(circbutton = new Button("Circle"));
p.add(ovalbutton = new Button("Oval"));
p.add(new Label(""));
p.add(bigbutton = new Button("Bigger"));
p.add(smallbutton = new Button("Smaller"));
p.add(new Label(""));
p.add(textbutton = new Button("Set Text"));
p.add(new Label(""));
p.add(fonttype = new Choice());
for (int i=0 ; i < nfontstyles ; i++)
fonttype.addItem(fontstylechoice);
p.add(fontsize = new Choice());
for (int i=0 ; i < nfontsizes ; i++)
fontsize.addItem(fontsizechoice);
p.add(fontbutton = new Button("Set Font"));
p.add(new Label(""));
add("East", p);
Panel q = new Panel();
q.setLayout(new GridLayout(1,2));
q.add(objectbutton = new Button("New Object"));
q.add(namefield = new TextField(24));
add("South", q);
mainpanel = new Panel();
add("Center", mainpanel);
}

Image offscreen;
Dimension offscreensize;
Graphics offgraphics;

public void update(Graphics g)
{
Dimension d = size();
if ((offscreen == null) || (d.width != offscreensize.width) ||
(d.height != offscreensize.height))
{
offscreen = createImage(d.width, d.height);
offscreensize = d;
offgraphics = offscreen.getGraphics();
offgraphics.setFont(getFont());
}

offgraphics.setColor(getBackground());
offgraphics.fillRect(0, 0, d.width, d.height);
for (int i=0 ; i < ndots ; i++) dot.draw(offgraphics);
g.drawImage(offscreen, 0, 0, null);
}

public boolean mouseDown(Event evt, int x, int y)
{
for (int i=0 ; i < ndots ; i++)
{
if (dot.find(x,y))
{
pick = dot;
current = i;
diffx = dot.leftOf()-x;
diffy = dot.topOf()-y;
break;
}
}
return true;
}

public boolean mouseDrag (Event evt, int x, int y)
{
if (pick != null)
{
pick.setLeft(x+diffx);
pick.setTop(y+diffy);
update(mainpanel.getGraphics());
}
return true;
}

public boolean mouseUp (Event evt, int x, int y)
{
pick = null;
return true;
}

public boolean action (Event evt, Object obj)
{
if (evt.target == fonttype) {
fontstyle = fonttype.getSelectedIndex();
myfont = new Font(fontstyleselect[fontstyle], Font.PLAIN,
Integer.parseInt(fontsizechoice[fontsz]));
} else
if (evt.target == fontsize) {
fontsz = fontsize.getSelectedIndex();
myfont = new Font(fontstyleselect[fontstyle], Font.PLAIN,
Integer.parseInt(fontsizechoice[fontsz]));
} else
if (evt.target == redbutton) {
if (current != -1) dot[current].setColor(dotcolor = Color.red);
} else
if (evt.target == greenbutton) {
if (current != -1) dot[current].setColor(dotcolor = Color.green);
} else
if (evt.target == bluebutton) {
if (current != -1) dot[current].setColor(dotcolor = Color.blue);
} else
if (evt.target == rectbutton) {
if (current != -1)
dot[current] = new RectDot(dot[current].labelOf(),
dot[current].leftOf(),
dot[current].topOf(),
dot[current].widthOf(),
dot[current].heightOf(),
dot[current].colorOf(),
dot[current].getFont());
} else
if (evt.target == circbutton) {
if (current != -1)
dot[current] = new CircDot(dot[current].labelOf(),
dot[current].leftOf(),
dot[current].topOf(),
dot[current].widthOf(),
dot[current].colorOf(),
dot[current].getFont());
} else
if (evt.target == ovalbutton) {
if (current != -1)
dot[current] = new OvalDot(dot[current].labelOf(),
dot[current].leftOf(),
dot[current].topOf(),
2*dot[current].widthOf(),
dot[current].heightOf(),
dot[current].colorOf(),
dot[current].getFont());
} else
if (evt.target == objectbutton) {
current = ndots;
dot[ndots++] = new CircDot(namefield.getText(), 100, 100, 30,
dotcolor, myfont);
} else
if (evt.target == smallbutton) {
if (current != -1)
{
dot[current].setWidth(dot[current].widthOf()-1);
dot[current].setHeight(dot[current].heightOf()-1);
}
} else
if (evt.target == bigbutton) {
if (current != -1)
{
dot[current].setWidth(dot[current].widthOf()+1);
dot[current].setHeight(dot[current].heightOf()+1);
}
} else
if (evt.target == textbutton) {
if (current != -1) dot[current].setLabel(namefield.getText());
} else
if (evt.target == fontbutton) {
if (current != -1) dot[current].setFont(myfont);
}
update(mainpanel.getGraphics());

return super.action(evt, obj);
}
}
[/code]
here is the nearest thing i could find to what i want.... it gave me loads of ideas and helped me greatly just put it here in case any of ye wanna look..............