Intro to Java. Write a Java application that can display a moving banner across

Question

Intro to Java.

Write a Java application that can display a moving banner across a window. There will be a text field the user can enter the content of the marques and OK button will send the entered content to display. There will be also a color chooser the user can change the color of the marques, and a combo box or list the user can select the size of fonts for the marques (at least 5 different fonts ranged from 14 to 22). It’s up to you to decide which GUI components you choose to accomplish the color chooser. You may consider using a combo box or list with at least 5 colors to be chosen if you feel difficulty to use JColorChooser. Finally, there will be another button to exit the execution of the program

Explanation / Answer

please check with the following code :

rgb chooser

import java.awt.*;
import java.awt.event.*;
  
public class colorchooser extends Panel implements AdjustmentListener {

private Scrollbar redScroll, greenScroll, blueScroll; // Scroll bars.

private Label redLabel, greenLabel, blueLabel; // For displaying RGB values.


private Canvas colorCanvas; // Color patch for displaying the color.

public colorchooser() { // Constructor.

/* Create Scrollbars with possible values from 0 to 255. */

redScroll = new Scrollbar(Scrollbar.HORIZONTAL, 0, 10, 0, 265);
greenScroll = new Scrollbar(Scrollbar.HORIZONTAL, 0, 10, 0, 265);
blueScroll = new Scrollbar(Scrollbar.HORIZONTAL, 0, 10, 0, 265);

/* Create Labels showing current RGB and HSB values. */

redLabel = new Label(" R = 0");
greenLabel = new Label(" G = 0");
blueLabel = new Label(" B = 0");

/* Set background colors for Scrollbars and Labels, so they don't
inherit the gray background of the applet. */

redScroll.setBackground(Color.lightGray);
greenScroll.setBackground(Color.lightGray);
blueScroll.setBackground(Color.lightGray);

redLabel.setBackground(Color.white);
greenLabel.setBackground(Color.white);
blueLabel.setBackground(Color.white);

/* Set the panel to listen for changes to the Scrollbars' values */

redScroll.addAdjustmentListener(this);
greenScroll.addAdjustmentListener(this);
blueScroll.addAdjustmentListener(this);

/* Create a canvas whose background color will always be set to the
currently selected color. */

colorCanvas = new Canvas();
colorCanvas.setBackground(Color.black);

/* Create the applet layout, which consists of a row of
three equal-sized regions holding the Scrollbars,
the Labels, and the color patch. The background color
of the applet is gray, which will show around the edges
and between components. */

setLayout(new GridLayout(1,3,3,3));
setBackground(Color.gray);
Panel scrolls = new Panel();
Panel labels = new Panel();

add(scrolls);
add(labels);
add(colorCanvas);

/* Add the Scrollbars and the Labels to their respective panels. */

scrolls.setLayout(new GridLayout(3,1,2,2));
scrolls.add(redScroll);
scrolls.add(greenScroll);
scrolls.add(blueScroll);

labels.setLayout(new GridLayout(3,1,2,2));
labels.add(redLabel);
labels.add(greenLabel);
labels.add(blueLabel);

} // end init();


public Color getColor() {
// Get the color currently displayed by the component.
int r = redScroll.getValue();
int g = greenScroll.getValue();
int b = blueScroll.getValue();
return new Color(r, g, b);
}


public void setColor(Color c) {
// Set the component to display the given color.
// (Ignore this if c is null.)
if (c != null) {
int r = c.getRed(); // Get the color levels from the color.
int g = c.getGreen();
int b = c.getBlue();
redLabel.setText(" R = " + r); // Set the labels.
greenLabel.setText(" G = " + g);
blueLabel.setText(" B = " + b);
redScroll.setValue(r); // Set the scrollbars.
greenScroll.setValue(g);
blueScroll.setValue(b);
colorCanvas.setBackground(new Color(r,g,b)); // Set the canvas.
colorCanvas.repaint();
}
}


public Dimension getMinimumSize() {
// Specify the minimum reasonable size of this component.
return new Dimension(150,40);
}


public Dimension getPreferredSize() {
// Specify the preferred size of this component.
return new Dimension(280,80);
}

  
public void adjustmentValueChanged(AdjustmentEvent evt) {
// This is called when the user has changed the values on
// one of the scrollbars. All the scrollbars are checked,
// the labels are set to display the correct values,
// and the color patch is reset to correspond to the new color.
int r = redScroll.getValue();
int g = greenScroll.getValue();
int b = blueScroll.getValue();
redLabel.setText(" R = " + r);
greenLabel.setText(" G = " + g);
blueLabel.setText(" B = " + b);
colorCanvas.setBackground(new Color(r,g,b));
colorCanvas.repaint(); // Redraw the canvas in its new color.
} // end adjustmentValueChanged
  

public Insets getInsets() {
// The system calls this method to find out how much space to
// leave between the edges of the applet and the components that
// it contains. I want a 2-pixel border at each edge.
return new Insets(2,2,2,2);
}

} // end class RGBColorChooser
  

A small applet to test the component class:

/*
This is a trivial applet that tests the colorchooser class.
In particular, it tests the setColor() method in that class by
setting the color to a random color when the user clicks on a button.
*/
  
  
import java.awt.*;
import java.awt.event.*;
import java.applet.*;
  
  
public class TestRGB extends Applet implements ActionListener {
  
colorchooser rgb;
  
public void init() {
setLayout(new BorderLayout(5,5));
rgb = new colorchooser();
add(rgb, BorderLayout.CENTER);
Button button = new Button("Set Random Color");
button.addActionListener(this);
add(button, BorderLayout.SOUTH);
}

public void actionPerformed(ActionEvent evt) {
int r = (int)(Math.random()*256) + 1;
int g = (int)(Math.random()*256) + 1;
int b = (int)(Math.random()*256) + 1;
rgb.setColor( new Color(r,g,b) );
}
  
}

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