Very urgently. Please help.


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Thread: Very urgently. Please help.

  1. #1
    tomsng Guest

    Very urgently. Please help.


    Dear all,
    I need to pass my homework tomorrow, but i spent 2 more hrs still cannt complete
    it. please help.
    I need to do a class that just two checkbox in the applet, one is circle,
    one is rectangle. when user click the circle, it draw circle, when the user
    click rectangle, it draws rectangle. If user unclick, the circle or rectangle
    should disappear.
    Here is my coding, please help.
    ***********************************************
    import java.awt.*;
    import javax.swing.*;
    import java.applet.*;
    import java.awt.event.* ;

    public class DrawObject extends JApplet implements ItemListener
    {
    public boolean lCir = false, lRect = false;
    public JPanel chkPanel = new JPanel();
    JCheckBox chkCir = new JCheckBox("Draw CIRCLE");
    JCheckBox chkRect = new JCheckBox("Draw RECTANGEL");

    public void init()
    {
    chkPanel.setLayout(new FlowLayout());
    chkCir.addItemListener(this);
    chkPanel.add(chkCir);
    chkRect.addItemListener(this);
    chkPanel.add(chkRect);
    getContentPane().setLayout(new FlowLayout());
    getContentPane().add(chkPanel);
    setSize(400,400);
    }

    public void itemStateChanged(ItemEvent e)
    {
    lCir = chkCir.isSelected();
    lRect = chkRect.isSelected();
    repaint();
    }

    public void paint(Graphics s)
    {
    super.paint(s);
    if (lCir = true)
    s.fillOval(100,100,50,50);
    if (lRect = true)
    s.fillRect(200,200,40,40);
    }
    }
    ****************************************************************
    <HTML>
    <APPLET CODE = "DrawObject.class" width = 400 height = 400>
    </APPLET>
    </HTML>
    ****************************************************************
    I dont know why the first time it draw circle and rectangle even i set
    the two boolean to false.
    I dont know why i click the checkbox , it doesnt do anything.

    Thank a lot

    Toms


  2. #2
    meadandale Guest

    Re: Very urgently. Please help.


    "tomsng" <tomsng@sinaman.com> wrote:
    >
    >Dear all,
    >I need to pass my homework tomorrow, but i spent 2 more hrs still cannt

    complete
    >it. please help.


    Toms,

    Most of us have taken Java courses and have done the work ourselves. That
    is how you learn and how you earn the right to be called a programmer. Everyone
    of us has spent sleepless nights debugging to find an insidious bug. If you
    are having problems, I suggest that you see your instructor or a tutor for
    your course. We aren't going to do your homework for you.

    Regards,

    C--

  3. #3
    Mike M Guest

    Re: Very urgently. Please help.


    To answer your question about why you see the circle and rectangle upon initialization...check
    out your paint method. You are assigning the value true to each of your
    boolean variables thereby forcing the boolean evaluation to true...you want
    to evaluate whether the value is equivalent to true or false. In order to
    do that you must use == operator.

    Cheers,
    Mike

    "tomsng" <tomsng@sinaman.com> wrote:
    >
    >Dear all,
    >I need to pass my homework tomorrow, but i spent 2 more hrs still cannt

    complete
    >it. please help.
    >I need to do a class that just two checkbox in the applet, one is circle,
    >one is rectangle. when user click the circle, it draw circle, when the user
    >click rectangle, it draws rectangle. If user unclick, the circle or rectangle
    >should disappear.
    >Here is my coding, please help.
    >***********************************************
    >import java.awt.*;
    >import javax.swing.*;
    >import java.applet.*;
    >import java.awt.event.* ;
    >
    >public class DrawObject extends JApplet implements ItemListener
    >{
    > public boolean lCir = false, lRect = false;
    > public JPanel chkPanel = new JPanel();
    > JCheckBox chkCir = new JCheckBox("Draw CIRCLE");
    > JCheckBox chkRect = new JCheckBox("Draw RECTANGEL");
    >
    > public void init()
    > {
    > chkPanel.setLayout(new FlowLayout());
    > chkCir.addItemListener(this);
    > chkPanel.add(chkCir);
    > chkRect.addItemListener(this);
    > chkPanel.add(chkRect);
    > getContentPane().setLayout(new FlowLayout());
    > getContentPane().add(chkPanel);
    > setSize(400,400);
    > }
    >
    > public void itemStateChanged(ItemEvent e)
    > {
    > lCir = chkCir.isSelected();
    > lRect = chkRect.isSelected();
    > repaint();
    > }
    >
    > public void paint(Graphics s)
    > {
    > super.paint(s);
    > if (lCir = true)
    > s.fillOval(100,100,50,50);
    > if (lRect = true)
    > s.fillRect(200,200,40,40);
    > }
    >}
    >****************************************************************
    ><HTML>
    ><APPLET CODE = "DrawObject.class" width = 400 height = 400>
    ></APPLET>
    ></HTML>
    >****************************************************************
    >I dont know why the first time it draw circle and rectangle even i set
    >the two boolean to false.
    >I dont know why i click the checkbox , it doesnt do anything.
    >
    >Thank a lot
    >
    >Toms
    >



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