The Eclipse Platform allows you to view the files comprising a system, to modify these files, and to run a program. This demo will give you a quick tour of the functionalities you need to know to carry out this study.


The Eclipse graphical user interface (or Workbench), can be organized into various perspectives. A Perspective is simply a pre-determined set of views. For this study, you will only use the Java Perspective. A perspective tool bar is on the left of the Eclipse Workbench. To open the Java perspective, click on the top button and select Java Perspective, or, alternately, click on the Java perspective shortcut button. You can also use the general menu: select Window | Open Perspective, and select the Java Perspective. By default, the Java perspective includes four views: The package explorer (on the left), the editor (in the middle), the outline view (on the right), and the tasks view (on the bottom). If at any point your views get mixed up, you can come back to the default Java perspective by selecting the menu Window | Reset Perspective. However, it is not recommended to do this as some short cuts which are preset for this study will be removed. The package explorer, editor, and task views will be explained in detail as part of this demo. The outline view will not be used in this study. You should close the view by clicking on the X in the top right corner, and refrain from using it during the study. To open or close individual views, use the menu and select Window | Show View. To close all the editors, use the menu and select File | Close All.


  1. Close the Java perspective (right-click on the button with the 'J' in its icon, in the left tool bar, and select close.
  2. Open the Java perspective (in the same tool bar, click on the button with the 'plus' in its icon. Choose Java from the menu.
  3. Close the Outline view.
  4. Close all the editors.
  5. Close the package explorer.
  6. Open the package explorer (In the workbench menu, select Window | Show View | Packages. You might have to close the hierarchy view to reveal the package view).

Package Explorer

The Package Explorer contains the structure and files of the system you are to modify. In this demo, we use the example system JHotDraw 5.3. The top-level node in the package explorer is the the project: JHotDraw5.3. Clicking on the plus sign expands the project to reveal its various components: in this case a single source directory. Double-clicking on the source directory (or clicking on the corresponding plus sign) will reveal all the packages and source directories which constitute the system. The package directories contain java files, and the other directories contains other source files such as icons. If you expand the CH.ifa.draw.figures package, a collection of Java source objects will appear. There are various actions you can perform on Java files. Double-click on the object. The code for this file should appear in the editor. You can also expand an object. Expand the object. This will reveal the internal structure of the object, in this case, an import declarations node and the ArrowTip class. Expand the ArrowTip class. You will see the class members. A red square indicates a private member, a yellow diamond a protected member, a blue triangle a default member, and a green circle a public member. Clicking on a member will show the declaration of this member in the editor. To create a new element in the package explorer, right-click on a package a select New.


  1. Show the file in the Editor.
  2. Display the fDrawing field in the window.
  3. Create a new class Test in the package CH.ifa.draw.contrib.


The editor lets you change a file. Modifications in a Java file are automaticaly compiled in the project when a file is saved. To save a file in the editor, type Ctrl-S, or use the File menu. If file contains compilation errors, they will automatically be indicated in the editor. Errors for which a suggestion is available are indicated on the left side bar with a yellow light bulb. Clicking on the light bulb will reveal a set of possible corrections. Otherwise, the error will be indicated with a red X. All errors also appear in the task view, in at the bottom of the screen. Clicking on a task in the task view will show the corresponding part in the code which needs to be addressed. The side bar on the right of the editor contains bookmarks for the various errors. The editor also supports an auto-completion feature. When an identifier is partially typed, typing Ctrl-Spacebar will attempt to complete the identifier. Ctrl-Spacebar after a type name will attempt to enter an import declaration for this name.


  1. Open
  2. Change getAngle() to getAngleX().
  3. Observe the different errors and bookmarks. Click on the errors in the Tasks view to go to the corresponding location in the editor. Use the bookmarks in the right side bar to navigate to the locations of the errors.
  4. Make a new TextFigure object in the ArrowTip constructor to show the autocomplete.


It is possible to search for the references and declarations to a class or class member, either from the package explorer, or through a search menu. To start a general search, select Search from the menu, then click on the Java Search tab. The results of the search will be displayed in a view below the editor. Clicking on a search result will display the corresponding code in the editor. Right-clicking on a search result will allow you to perform new searches, for the references or declarations of the search result element. It is also possible to launch a search from the package explorer. Right-click on an element and select references or declarations, and then Workspace. This will produce a list of all the elements in the workspace referring to the selected element.


  1. Search for all Text* class declarations.
  2. Sort by parent name (Right-click in the search results view, and select Sort by | Parent Name.
  3. Search for references to class TextHolder: Right-click on TextHolder in the search results view, and select References | Workspace.
  4. Display a few of them in the editor.
  5. Obtain all the methods accessing the field CH.ifa.draw.figures.TextTool.fTypingTarget (in the search results or in the package explorer, right-click on the field, and select References | Workspace.
  6. Display the field accesses by double-clicking on the search results.
  7. Remove all searches by clicking on the 5th icon from the left in the search results tool bar.

Running a program

You run a compiled program by launching it through the run button on the menu, or through the Run | Run... menu. The configuration for the program you will need to execute will be pre-set for you.


  1. Run the JHotDraw5.3 configuration.