Changes

Here we will add other necessary commands to our application. We add the command Handler classes the same way we added the PrintHandler class, and then will add the commands to the menuContribution Extension point. However, in order to be able to implement the command execute method, we need to wait until we add the view and the Jface tableViewer to our application. So wee ad we add the commands then leave the implementation part and come back to it after the View and editor view creation is done. So for implementation, we assume that you have gone through those parts of the tutorial.

==== "Delete Add Student" Command ====For implementing the "AddStudent" command, we are highly depended on the use of Editor view, so after adding the command Handler class and add the command to the menuContribution extension point, we will leave this part of tutorial and will come back to it for the implementation of the execute method in the handler class. However this will not be the only code, related to the "AddStudent" command. The reason is, we are going to modify and use the editor view to create a new student. So basically, when user clicks on the "Add Student" on the top bar, the editor view will open up and enables user to enter the information for a new student and there will be a "Save" button to save the student, Then the table viewer will show the updated data, and the editor view will close.<br/> Here is what user can see by clicking on the "Add Student" button:<br/>[[Image: RCPCommandAddRun.jpg | 700px]]<br/><br/>Add the "AddStudent" command to the commands extension point the same way you added the Print command, and create its Handler class.<br/>[[Image: RCPCommand13.jpg | 700px]]<br/><br/>[[Image: RCPCommand14.jpg | 400px]]<br/>

Add the command you just created to the menuContribution you have in the extension point (the same one you added Print command to). <br/> [[Image: RCPCommand17RCPCommand16.jpg | 400px700px]]<br/>

'''Implementing the AddStudent command'''<br/>Please do this part, after the view, Jface viewer and Editor view is added and working properly.<br/>1. Implementing the execute method of the command handler class:<br/>This code will get access to the page and creates an empty editor input (sending it the id of string "0" indicating that it belongs to no student), then tries to open the editor with that input id.<code>AddStudent.java </code><source lang=java>package cs.ecl.rcp.simplercp.commands; import org.eclipse.core.commands.AbstractHandler;import org.eclipse.core.commands.ExecutionEvent;import org.eclipse.core.commands.ExecutionException;import org.eclipse.core.commands.IHandler;import org.eclipse.ui.IWorkbenchPage;import org.eclipse.ui.IWorkbenchWindow;import org.eclipse.ui.PartInitException;import org.eclipse.ui.handlers.HandlerUtil; import cs.ecl.rcp.simplercp.editor.MyStudentEditor;import cs.ecl.rcp.simplercp.editor.MyStudentEditorInput;  public class AddStudent extends AbstractHandler implements IHandler {  @Override public Object execute(ExecutionEvent event) throws ExecutionException { IWorkbenchWindow window =HandlerUtil.getActiveWorkbenchWindow(event); IWorkbenchPage page =window.getActivePage(); MyStudentEditorInput input = new MyStudentEditorInput("0"); try { page.openEditor(input, MyStudentEditor.ID);  } catch (PartInitException e) { throw new RuntimeException(e); }  return null; } } </source><br/><br/>2. Modifying the MyStudentEditorInput class:<br/>we will override the "equals"method to recognize if the input object to the method equals this object (EditorInput).This ensures that if you click on Add Student" command several times, only one editor window will open and consequent calls to the command will only set focus on the open editor view.<code>MyStudentEditorInput.java </code><source lang=java>/ Added For NewStudent Command @Override public boolean equals(Object obj) { if (this == obj) return true; if (obj == null) return false; if (getClass() != obj.getClass()) return false; MyStudentEditorInput other =(MyStudentEditorInput) obj; if (id !=other.id) return false; return true; }</source> <br/><br/>3. Modifying the editor view (MyStudentEditor class).<br/>Here we do the following changes: a) make the Text objects, a member of the class, so that they can be used in other methods. <code>MyStudentEditor.java </code><source lang=java>public class MyStudentEditor extends EditorPart { public static final String ID ="cs.ecl.rcp.simplercp.editor.studenteditor"; private Student student; private MyStudentEditorInput input; // Added For NewStudent Command private Text text; private Text text1; private Text text2; private Text text3;</source>

[[Image b) Modify the "init" method so it distinguishes between a new and existing student input object, and creates an empty student object for the input with id "0": RCPCommand13 <code>MyStudentEditor.java </code><source lang=java>public void init(IEditorSite site, IEditorInput input) throws PartInitException { if (!(input instanceof MyStudentEditorInput)) { throw new RuntimeException("Wrong input"); }  MyStudentEditorInput new_name = (MyStudentEditorInput) input; this.input = (MyStudentEditorInput) input; setSite(site); setInput(input); // Added For NewStudent Command if(this.input.getId()=="0"){ student = new Student (); setPartName("New Student"); } else { student = ModelProvider.INSTANCE.getPersonById(this.input.getId()); setPartName("Student " + student.jpg | 400px]]getLastName()); } } <br/source> 

[[Image: RCPCommand14 c)Modify the "createPartControl" method to 1)check if the student object properties are null to prevent referencing null when the student object is a new one. 2)To add a save button to the window with the listener. when clicked, the save button will set the text field inputs as the student property and adds the student to the ModelProvider class, then refreshes the tableViewer and closes the editor window. The save button only appears for the new student editor.<br/> <code>MyStudentEditor.java </code><source lang=java> // Modified For NewStudent Command @Override public void createPartControl(Composite parent) { GridLayout layout = new GridLayout(); layout.numColumns = 2; parent.setLayout(layout); Label label = new Label(parent, SWT.BORDER); label.setText("ID"); text = new Text(parent, SWT.BORDER); if (student.getId()!=null) text.setText(student.getId()); text.setLayoutData(new GridData(SWT.FILL, SWT.BEGINNING, true, false)); Label label1 = new Label(parent, SWT.BORDER); label1.setText("First Name"); text1 = new Text(parent, SWT.BORDER); if (student.getFirstName()!=null) text1.setText(student.getFirstName()); text1.setLayoutData(new GridData(SWT.FILL, SWT.BEGINNING, true, false)); Label label2 = new Label(parent, SWT.BORDER); label2.setText("Last Name"); text2 = new Text(parent, SWT.BORDER); if (student.getLastName()!=null) text2.setText(student.getLastName()); text2.setLayoutData(new GridData(SWT.FILL, SWT.BEGINNING, true, false)); Label label3 = new Label(parent, SWT.BORDER); label3.setText("Program"); text3 = new Text(parent, SWT.BORDER); if (student.getProgram()!=null) text3.setText(student.getProgram()); text3.setLayoutData(new GridData(SWT.FILL, SWT.BEGINNING, true, false)); // Added For NewStudent Command Button btnSave = new Button(parent, SWT.PUSH); btnSave.setText("Save"); btnSave.setVisible(false); if (this.input.getId()=="0") btnSave.setVisible(true); btnSave.addSelectionListener(new SelectionAdapter() { public void widgetSelected(SelectionEvent e) { if (text.getText().length() != 0 && text1.getText().length() != 0 && text2.getText().length() != 0 && text3.getText().length() != 0) { student.setId(text.getText()); student.setFirstName(text1.getText()); student.setLastName(text2.getText()); student.setProgram(text3.getText()); ModelProvider students =ModelProvider.INSTANCE; students.getStudents().add(student); IWorkbenchWindow window = getSite().getWorkbenchWindow(); IWorkbenchPage page = window.getActivePage(); StudentsView view = (StudentsView) page.findView(StudentsView.ID); view.getViewer().refresh(); getSite().getPage().closeEditor(getSite().getPage().findEditor(getEditorInput()) , false); } } }); }</source><br/>When modifying the code, add necessary imports when the eclipse code editor creates error of not finding some classes.<br/> ==== "Delete Student" Command ====Add the "DeleteStudent" command to commands extension point and create the Handler Class.jpg | 400px]]<br/>

[[Image: RCPCommand15RCPCommand17.jpg | 400px700px]]<br/>

Add the command you just created to the menuContribution extension point.<br/>[[Image: RCPCommand16RCPCommand18.jpg | 400px700px]]<br/>