How To Clear Textarea In Java

#1

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Clearing Text from a Text Field

Posted 29 August 2009 - 02:02 PM

The following code runs a simple window. The only thing I don't know how to do is to clear the text from the field after the user hit the Calculate button. When the user hits the Calculate button whatever the user put in the field stays there. Is there any methods that would do this for me?

import javax.swing.*; import java.awt.event.*; import java.text.DecimalFormat;  public class PropertyTaxWindow extends JFrame { 	private JPanel panel; 	private JLabel messageLabel; 	private JTextField valueTextField; 	private JButton calcButton; 	private JButton exitButton; 	private final int WINDOW_WIDTH = 400; 	private final int WINDOW_HEIGHT = 100; 	 	// Constructor 	public PropertyTaxWindow() 	{ 		// Set the window title 		setTitle("Assessment Value and Property Tax Calculator"); 		 		// Set the size of the window 		setSize(WINDOW_WIDTH, WINDOW_HEIGHT); 		 		// Specify what happens when the close button is clicked 		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 		 		// Build the panel and add it to the frame 		buildPanel(); 		 		// Add the panel to the frame's content pane 		add(panel); 		 		// Display the window 		setVisible(true); 	} 	 	// buildPanel() method 	private void buildPanel() 	{ 		// Create a label to display instructions 		messageLabel = new JLabel("Enter the actual value of the property"); 		 		// Create a text field 		valueTextField = new JTextField(10); 		 		// Create a calculate button 		calcButton = new JButton("Calculate"); 		 		// Add an action listener to the calcButton 		calcButton.addActionListener(new CalcButtonListener()); 		 		// Create an exit button 		exitButton = new JButton("Exit"); 		 		// Add an action listener to the exitButton 		exitButton.addActionListener(new ExitButtonListener()); 		 		// Create JPanel object 		panel = new JPanel(); 		 		// Add componets to the panel 		panel.add(messageLabel); 		panel.add(valueTextField); 		panel.add(calcButton); 		panel.add(exitButton); 	} 	 	// Private inner class that handles the event when the user clicks the Calculate Button 	private class CalcButtonListener implements ActionListener 	{ 		public void actionPerformed(ActionEvent e) 		{ 			String input; 			float actualValue; 			float assessmentValue; 			float propertyTax; 			final float ASSESSMENT_VALUE_PERCENT = 0.6f; 			final float TAX = 0.64f; 			final float DIVIDER = 100.0F; 			 			// Get the text entered 			input = valueTextField.getText(); 			 			// Convert to a float 			actualValue = Float.parseFloat(input); 			 			// Calculate the assessment value 			assessmentValue = actualValue * ASSESSMENT_VALUE_PERCENT; 			 			// Calculate property tax 			propertyTax = assessmentValue / DIVIDER * TAX; 			 			// Format the output to two decimal places 			DecimalFormat decimal = new DecimalFormat("0.00"); 			 			// Display the result 			JOptionPane.showMessageDialog(null, "Actual Value: $"+ decimal.format(actualValue) + 												"\nAssessment Value: $"+ decimal.format(assessmentValue) + 												"\nProperty Tax: $"+ decimal.format(propertyTax)); 		} 	} 	 	// Private inner class for the Exit Button 	private class ExitButtonListener implements ActionListener 	{ 		public void actionPerformed(ActionEvent e) 		{ 			System.exit(0); 		} 	} 	 	// Main method that runs the program 	public static void main(String[] args) 	{ 		new PropertyTaxWindow(); 	} }

*Edited: intermediate tag removed

This post has been edited by pbl: 29 August 2009 - 10:14 PM

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#2 Locke

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Re: Clearing Text from a Text Field

Posted 29 August 2009 - 02:03 PM

You can just use valueTextField.setText(""); to reset the text to empty.

#3 Tyler E

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Re: Clearing Text from a Text Field

Posted 29 August 2009 - 02:11 PM

That worked great thank you. Now is there any way to put the focus back on that field.

#4 syfran

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Re: Clearing Text from a Text Field

Posted 29 August 2009 - 02:34 PM

call requestFocus() or grabFocus() on the textField

This post has been edited by syfran: 29 August 2009 - 02:35 PM

#5 Locke

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Re: Clearing Text from a Text Field

Posted 29 August 2009 - 03:29 PM

View Post syfran, on 29 Aug, 2009 - 03:34 PM, said:

call requestFocus() or grabFocus() on the textField

It's better practice to use requestFocusInWindow(), as the requestFocus() method's procedure is platform dependent.

This post has been edited by Locke: 29 August 2009 - 03:30 PM

#6 Tyler E

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Re: Clearing Text from a Text Field

Posted 29 August 2009 - 05:23 PM

Thank you both, my program works the way I want it to now

#7 pbl

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Re: Clearing Text from a Text Field

Posted 29 August 2009 - 10:14 PM

Really basic question.
"Intermediate" tag removed