import java.awt.GridLayout;
import java.awt.event.MouseEvent;
import javax.swing.GroupLayout;
import javax.swing.JFrame;
import javax.swing.JButton;
import javax.swing.JLabel;
import java.awt.event.MouseAdapter;
import javax.swing.JTextField;

/**
 * Displays the grafical interface for converting Fahrenheit to Celsius and back again. 
 * @author Rainier
 */
public class ConversionFrame extends JFrame
{  
    GroupLayout layout;
    JLabel jLblFarenheid = new JLabel("Farenheid");
    JLabel jLblCelsius = new JLabel("Celcius");
    JLabel jLblMessage = new JLabel();
    JTextField jTxtFarenheid = new JTextField();
    JTextField jTxtCelsius = new JTextField();
    JButton jBtnConvert = new JButton();
    
    /** Creates a new instance of ConversionFrame */
    public ConversionFrame() 
    {
        //Set the label of the frame.
        super("Conversion application");
        this.setSize(600,180);
        
        //When pressing the "X" unload the application.
        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
        
        //We will place the labels textboxes and button on the right position of the frame.
        setFrameLayout();
        
        //Hook up a Mouse click event handler to the ConvertButton           
        jBtnConvert.addMouseListener (new java.awt.event.MouseAdapter() {   
                 public void mouseClicked(MouseEvent evt) {
                    jBtnConvertClicked(evt);
                 }
            }     
        );
        
    }
    /**
     * Event handler for when the Convert button gets clicked.
     */
    private void jBtnConvertClicked(MouseEvent evt)
    {
        String celsius = jTxtCelsius.getText();
        String farenheid = jTxtFarenheid.getText();
        FarenhetiCelsiusAdapter adapter = new FarenhetiCelsiusAdapter();
        
        //Make sure we do not have any spaces in the textbox.
        celsius = celsius.trim();
        farenheid = farenheid.trim();
        
        //In case none of the textboxes are filled. Display the text You are required to fill one of the textboxes for the conversion.
        if(celsius.length() ==0 && farenheid.length() ==0)
        {
            jLblMessage.setText("You are required to fill one of the textboxes for the conversion.");
            jLblMessage.setVisible(true);
        }
        
        if(celsius.length() !=0 && farenheid.length()!=0)
        {
             jLblMessage.setText("Both text boxes are filled, please fill in just one the application will calculate the value of the other.");
             jLblMessage.setVisible(true);
        }
        
         try
        {
            //If the celsius textbox is filled and the farenheid textbox is not filled.
            //fill the adapter with the celsius value and retrieve the farenheid value.
            if(celsius.trim().length()!=0 && farenheid.trim().length()==0)
            {
                adapter.setCelsius(Double.parseDouble( celsius ));
                jTxtFarenheid.setText( String.valueOf( adapter.getFarenheid() ));
            }

            //If the Farenheid value is filled and the celsius not.
            //fill the adapter with the farenheid value and retrieve the celsius value.
             if(celsius.trim().length()==0 && farenheid.trim().length()!=0)
            {
                adapter.setFarenheid(Double.parseDouble( farenheid ));
                jTxtCelsius.setText( String.valueOf( adapter.getCelsius() ) );
            }
        }
        catch(NumberFormatException ex)
        {
            jLblMessage.setText("Please enter only numeric values into the text boxes.");
        }
        
    }
    
    /**
     * Places the controls on the right position of the form.
     */
    private void setFrameLayout()
    {
         //We want to make GroupLayout on the default contentpane ofthe frame.
       GroupLayout layout = new GroupLayout(getContentPane());
       setLayout(layout);
       
       jBtnConvert.setText("Convert");
       
       // Turn on automatically adding gaps between components
       layout.setAutoCreateGaps(true);

       // Turn on automatically creating gaps between components that touch
       // the edge of the container and the container.
       layout.setAutoCreateContainerGaps(true);

       // Create a sequential group for the horizontal axis.
       // I look at this as defining what will be placed in which column of a table 
       // (I can view it as a table because I used the auto create gaps
       // if you want to define the position yourself remove the autogaps and add gaps just as you would add components.)
       // In this case I will add the label for Celsius and the label for Farenheid to the first column.
       // I will add 
       GroupLayout.SequentialGroup hGroup = layout.createSequentialGroup();
       
       hGroup.addGroup(
               layout.createParallelGroup().addComponent(jLblCelsius).addComponent(jLblFarenheid));
      
       hGroup.addGroup(
               layout.createParallelGroup().addComponent(jTxtCelsius).addComponent(jTxtFarenheid).addComponent(jBtnConvert).addComponent(jLblMessage));
      
       // Create a sequential group for the vertical axis.
       // Same Idea as the horizontal axis but here we are saying what will be in which "row" of the "table""
      GroupLayout.SequentialGroup vGroup = layout.createSequentialGroup();
      
      vGroup.addGroup(
              layout.createParallelGroup(GroupLayout.Alignment.BASELINE).addComponent(jLblCelsius).addComponent(jTxtCelsius));
       vGroup.addGroup(
               layout.createParallelGroup(GroupLayout.Alignment.BASELINE).addComponent(jLblFarenheid).addComponent(jTxtFarenheid));
       vGroup.addGroup(
               layout.createParallelGroup(GroupLayout.Alignment.BASELINE).addComponent(jBtnConvert));
       vGroup.addGroup(
               layout.createParallelGroup(GroupLayout.Alignment.BASELINE).addComponent(jLblMessage));
       
       // Now we set the horizontal and the vertical groups which we defined above.
       // In effect we have defined for each component where the component will be placed on the horizontal axis and where it will be placed on the vertical axis.
       layout.setHorizontalGroup(hGroup);
       layout.setVerticalGroup(vGroup);
    }   
}