package edu.hws.eck.mdb; import java.awt.*; import java.awt.event.*; import javax.swing.*; /** * This class defines a custom dialog box that asks the user to enter * a new size for the Mandelbrot image. The dialog box has two input * boxes where the user can enter integers. * @author David J. Eck */ public class SetImageSizeDialog extends JDialog { /** * This static convenience method will show a dialog of type * SetImageSizeDialog. It will not return until the user dismisses * the dialog, by clicking "OK" or "Cancel" or by clicking the * dialog's close box. The user is forced to either enter legal * inputs or to cancel the dialog. Legal input values are integers * in the range 10 to 5000. NOTE: If you use this method, you * don't have to worry about anything else in the class. * @param frame The "parent" of the dialog box. This frame is "blocked" * until the user closes the dialog box. * @param oldSize If non-null, then the values of oldSize.width and * oldSize.height are put in the input boxes. If null, the initial * values in the input boxes are set to 800 and 600. * @return null, if the user cancels the dialog or clicks OK without changing * the values in the input boxes; if the user changes the values and clicks * OK, then the return value is a Dimension object whose width * and height give the user's inputs. */ static Dimension showDialog(JFrame frame, Dimension oldSize) { SetImageSizeDialog dialog = new SetImageSizeDialog(frame,oldSize); dialog.setVisible(true); // does not return until the dialog box is dismissed Dimension newSize = dialog.getInputSize(); if (newSize == null || newSize.equals(oldSize)) return null; return newSize; } private Dimension inputSize; // This will be set to the user's input, // when the user clicks OK and the input // is legal. private JButton cancelButton; private JButton okButton; private JTextField widthInput; private JTextField heightInput; /** * This constructor creates the dialog's user interface and sets up * listeners to detect clicks on the buttons or on the dialog box's * close box. When the user clicks OK, the input boxes are checked. * If the input is legal, the dialog box is closed; if not, an error * message is displayed and the dialog stays up. Note that this constructor * does not make the dialog box visible. Note also that the dialog box * is set to DISPOSE itself when it is closed and so cannot be reused. * (For a reusable dialog, it should be "hidden" rather than disposed.) * @param frame the parent of this dialog box, which is blocked until * the dialog box is closed. * @param oldSize initial values for the input box */ public SetImageSizeDialog(JFrame frame, Dimension oldSize) { super(frame,I18n.tr("imagesizedialog.title"),true); // The "true" makes this a modal dialog that blocks its parent frame. JPanel content = new JPanel(); content.setLayout(new BorderLayout(10,10)); setContentPane(content); content.setBorder(BorderFactory.createEmptyBorder(10,10,10,10)); if (oldSize == null) oldSize = new Dimension(800,600); widthInput = new JTextField(""+oldSize.width, 4); heightInput = new JTextField(""+oldSize.height, 4); JPanel input = new JPanel(); input.add(Box.createHorizontalStrut(10)); input.add(new JLabel(I18n.tr("imagesizedialog.widthequals"))); input.add(widthInput); input.add(Box.createHorizontalStrut(10)); input.add(new JLabel(I18n.tr("imagesizedialog.heightequals"))); input.add(heightInput); cancelButton = new JButton(I18n.tr("button.cancel")); okButton = new JButton(I18n.tr("button.ok")); getRootPane().setDefaultButton(okButton); // This means that the OK button can be invoked by pressing return. JPanel buttons = new JPanel(); buttons.add(cancelButton); buttons.add(okButton); content.add( new JLabel(I18n.tr("imagesizedialog.question")), BorderLayout.NORTH ); // Message to user. content.add( input, BorderLayout.CENTER ); content.add( buttons, BorderLayout.SOUTH ); setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE); // Close window when user clicks its close box. pack(); setLocation(frame.getX()+50, frame.getY()+75); // Position near top left of frame. Dimension screensize = Toolkit.getDefaultToolkit().getScreenSize(); int x = getX(); // The next six lines ensure that the dialog box is actually on the screen! int y = getY(); if (x + getWidth() > screensize.width) x = screensize.width - getWidth() - 30; // Move left to bring dialog onto screen. if (y + getHeight() > screensize.height) y = screensize.height - getHeight() - 30; // Move up to bring dialog onto screen. setLocation(x,y); cancelButton.addActionListener( new ActionListener() { // When the user clicks Cancel, dispose the window. public void actionPerformed(ActionEvent evt) { dispose(); } }); okButton.addActionListener( new ActionListener() { // When the user clicks OK, check the input; close the window only if the input is legal. public void actionPerformed(ActionEvent evt) { if (checkInput()) dispose(); } }); } /** * After the dialog box has closed, this can be called to get * the user's response. * @return null, if dialog was canceled, or the width/height * entered by the user if not. */ public Dimension getInputSize() { return inputSize; } /** * This method is called when the user clicks OK. It gets the * user's input and checks whether it is legal * @return true if the input is legal, false if not. */ private boolean checkInput() { inputSize = null; int width, height; try { width = Integer.parseInt(widthInput.getText()); } catch (NumberFormatException e) { JOptionPane.showMessageDialog(this, I18n.tr("imagesizedialog.error.widthnotanumber", widthInput.getText())); widthInput.selectAll(); widthInput.requestFocus(); return false; } try { height = Integer.parseInt(heightInput.getText()); } catch (NumberFormatException e) { JOptionPane.showMessageDialog(this, I18n.tr("imagesizedialog.error.heightnotanumber", heightInput.getText())); heightInput.selectAll(); heightInput.requestFocus(); return false; } if (width < 10 || width > 5000) { JOptionPane.showMessageDialog(this, I18n.tr("imagesizedialog.error.badwidth", ""+width)); widthInput.selectAll(); widthInput.requestFocus(); return false; } else if (height < 10 || height > 5000) { JOptionPane.showMessageDialog(this, I18n.tr("imagesizedialog.error.badheight", ""+width)); heightInput.selectAll(); heightInput.requestFocus(); return false; } inputSize = new Dimension(width,height); return true; } }