Software design - wizard
Hi,
I am working on a project which has a large number of wizard type
forms. A great deal fall into the functional pattern of
a) Display a list of (business) objects
b) User selects from list and presses Next
c) Display a form to edit selected (business object)
d) Click apply or finish etc.
So I wrote some code to do that, for reference it is shown below.
I have a class 'FormWizard' which is reponsible for the basic UI frame,
selecting from a list, next etc.
I have a model 'FormWizardModel' which contains all the actions and
data FormWizard needs to work.
I have one implementation - a UserWizard which populates the wizard
model with the actions, and most importantly a standalone jpanel to
edit users.
Sound good? Maybe, I had a troubleshoot bugs a number of times which
usually indicates a weak design. The main problem was passing in null
values to the FormWizard due to the timing of when the Next button
ActionListener was pressed.
I resolved that but I am not overly happy as you have this shared
FormWizardModel which is populated at alternating times by either the
UserWizard or the FormWizard and that seems dangerous as it is
difficult using just code inspection to determine the state of the
FormWizardModel at any point in time. The reason it is written that
way though is primarily to serve seperating the code that will change
with each Wizard implementation.
This *MUST* be a common design pattern - can anyone help me improve
mine.
Here are my main classes skipping the ordinary getters and setters:
public class FormWizardModel {
private String screen1Title;
private String screen2Title;
private ActionListener finishAction;
private ActionListener nextAction;
private ResultList resultList;
private JPanel screen2Panel;
private String finishButtonText = "Finish";
private Object userObject;
private Dimension screen1Size = UIProperties.DIALOG_SIZE_450_330;
private Dimension screen2Size = UIProperties.DIALOG_SIZE_450_330;
}
public class UserWizard {
private FormWizardModel m = new FormWizardModel();
private FormWizard wizard;
public UserWizard(JFrame frame) {
wizard = new FormWizard(frame, m);
}
public void start() throws Exception {
m.setNextAction(getNextAction());
m.setFinishButtonText("Close");
m.setResultList(getList());
//TODO get this title from reference
m.setScreen1Title("Select user");
m.setScreen2Size(UIProperties.WINDOW_SIZE_600_400);
wizard.start();
}
private ResultList getList() throws Exception {
UserList users = SecurityServices.getUsers();
ApplicationControlList acl1 =
SecurityServices.getAppControlsByUser(ApplicationGroup.USERSEARCHRESULTS);
users.setColumnOrder(acl1);
return users;
}
private ActionListener getNextAction() throws Exception {
return new ActionListener() {
public void actionPerformed(ActionEvent e) {
UserModel rm = (UserModel) m.getUserObject();
m.setScreen2Title(rm.getDisplayName());
UserFormController userFormController = new UserFormController();
UserFormUI ui = userFormController.start(rm);
m.setScreen2Panel(ui.getMainPanel());
}
};
}
}
public class UserWizard {
private FormWizardModel m = new FormWizardModel();
private FormWizard wizard;
public UserWizard(JFrame frame) {
wizard = new FormWizard(frame, m);
}
public void start() throws Exception {
m.setNextAction(getNextAction());
m.setFinishButtonText("Close");
m.setResultList(getList());
//TODO get this title from reference
m.setScreen1Title("Select user");
m.setScreen2Size(UIProperties.WINDOW_SIZE_600_400);
wizard.start();
}
private ResultList getList() throws Exception {
UserList users = SecurityServices.getUsers();
ApplicationControlList acl1 =
SecurityServices.getAppControlsByUser(ApplicationGroup.USERSEARCHRESULTS);
users.setColumnOrder(acl1);
return users;
}
private ActionListener getNextAction() throws Exception {
return new ActionListener() {
public void actionPerformed(ActionEvent e) {
UserModel rm = (UserModel) m.getUserObject();
m.setScreen2Title(rm.getDisplayName());
UserFormController userFormController = new
UserFormController();
UserFormUI ui = userFormController.start(rm);
m.setScreen2Panel(ui.getMainPanel());
}
};
}
}
public class FormWizard {
private JFrame parentFrame;
protected UICenterSouthDialog screen1SelectReport;
protected UICenterSouthDialog screen2Dialog;
protected MultiColumnList screen1List;
protected PanelButtonWizard screen1Dialog;
protected PanelButtonWizard screen2Buttons;
private FormWizardModel m;
public FormWizard(JFrame frame, FormWizardModel m) {
super();
this.m = m;
this.parentFrame = frame;
}
public void start() throws Exception {
screen1SelectReport = new UICenterSouthDialog();
screen1SelectReport.setSize(m.getScreen1Size());
screen2Dialog = new UICenterSouthDialog();
buildScreen1(m.getScreen1Title(), m.getResultList());
buildScreen2(m.getScreen2Title(), m.getFinishButtonText());
addScreen1Listeners();
screen2Dialog.setSize(m.getScreen2Size());
addScreen2Listeners(m.getFinishAction());
screen1SelectReport.setVisible(true);
}
public void addScreen1Listeners() {
screen1List.addListSelectionListener(new ListSelectionListener()
{
public void valueChanged(ListSelectionEvent e) {
if (screen1List.isRowSelected()) {
screen1SelectReport.setUserObject(screen1List.getSelectedRow());
m.setUserObject(screen1List.getSelectedRow());
}
screen1Dialog.getCmdNext().setEnabled(screen1List.isRowSelected());
}
});
screen1Dialog.getCmdCancel().addActionListener(new
ActionListener() {
public void actionPerformed(ActionEvent e) {
screen1SelectReport.dispose();
}
});
screen1Dialog.getCmdNext().addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e) {
try {
screen2Dialog.getCenterPanel().removeAll();
if (m.getNextAction() != null) {
m.getNextAction().actionPerformed(e);
}
screen2Dialog.getCenterPanel().add(m.getScreen2Panel(),
BorderLayout.CENTER);
screen2Dialog.setVisible(true);
screen1SelectReport.setVisible(false);
} catch (Exception ex) {
Debug.LogException(this, ex);
}
}
});
}
public void addScreen2Listeners(final ActionListener finishAction) {
screen2Buttons.getCmdCancel().addActionListener(new
ActionListener() {
public void actionPerformed(ActionEvent e) {
screen2Dialog.dispose();
}
});
screen2Buttons.getCmdBack().addActionListener(new
ActionListener() {
public void actionPerformed(ActionEvent e) {
screen1SelectReport.setVisible(true);
screen2Dialog.setVisible(false);
}
});
screen2Buttons.getCmdFinish().addActionListener(new
ActionListener() {
public void actionPerformed(ActionEvent e) {
try {
screen2Dialog.setVisible(false);
if (finishAction != null) {
finishAction.actionPerformed(e);
}
} catch (Exception ex) {
Debug.LogException(this, ex);
}
}
});
}
private void buildScreen1(String title, ResultList list) throws
Exception {
screen1SelectReport.setTitle(title);
// Report list
screen1List = new MultiColumnList();
screen1List.setTableModel(list, 80);
screen1SelectReport.getCenterPanel().add(screen1List,
BorderLayout.CENTER);
// Buttons
screen1Dialog = new PanelButtonWizard();
screen1Dialog.setButtonState(true, false,false, false);
screen1SelectReport.getSouthPanel().add(screen1Dialog,
BorderLayout.CENTER);
if (list.getRowCount() > 0) {
screen1List.selectRow(0);
screen1SelectReport.setUserObject(screen1List.getSelectedRow());
m.setUserObject(screen1List.getSelectedRow());
screen1Dialog.setButtonState(true, false,true, false);
}
}
private void buildScreen2(String screen2Title, String
finishButtonText) throws Exception {
// Controls
screen2Dialog.setTitle(screen2Title);
// Buttons
screen2Buttons = new PanelButtonWizard();
screen2Buttons.getCmdFinish().setText(finishButtonText);
screen2Buttons.setButtonState(true, true, false, true);
screen2Dialog.getSouthPanel().add(screen2Buttons,
BorderLayout.CENTER);
}
}