Relo是一个帮助开发人员研究大型代码库的好工具，目前已更名为architexa，是个eclipse的插件， 用来看代码感觉非常棒，和大家分享下!

官网：

http://www.architexa.com/

使用文档：

http://www.architexa.com/user-guide/Documenting

Creating a Layered Diagram

Architexa lets you create Layered Diagrams easily. Diagrams can be created from multiple places such as the package explorer, can be viewed in an Eclipse view or an editor, and can be updated easily by exploring around or just linking them to editor selections.

Starting from the package explorer

1. Right click on a project or package.
2. Select 'Open in Diagram' -> 'Layered Diagram'
3. The diagram will display the package or project and automatically open it to show its contents.

Creating a blank diagram in a new editor

1. In the toolbar, click the small drop down arrow on the right side 'Open a new diagram editor'  button.
2. Select 'New Layered Diagram'
3. Once you have a new editor drag in packages or classes from the package explorer to see how they interact.

Creating a blank diagram in a view

1. Go to "Window > Show View" and select the option "Other…"
2. Select "Layered Diagram" in the "Architexa" folder.
3. You will now have a Layered diagram in a view which you can move, resize, or drag to a separate screen.
4. Once you have a new view drag in packages or classes from the package explorer to see how they interact.

Using a linked view/editor to create a diagram

Follow the directions starting form step 2 here: Document while you work by creating a diagram in the background

More

For more help on opening diagrams see Opening Diagrams

How Layered Diagrams Work

Layered diagrams automatically organize your code into a hierarchy of layers based on the package structure.

• Items are organized in layers, with items towards the top of the diagram depend on those below. (When dependency cycles are found, Architexa uses sophisticated analyses to make a best guess).
• The size of packages indicates how many items they contain relative to other packages.
• The size of dependency arrows shows the strength of the dependency. If two packages have many more dependencies between them than other packages their connection will be much thicker.
• Items are nested based on directory/package nesting with each level of depth being represented by a different color.
• Mousing over a package or class highlights which items depend on or are depended on by others.
  • Items highlighted in white depend on the item being moused over
  • The moused over item depends on any items with a dark gray highlighting.
  • Items with the same light gray color as the moused over item indicate that there is a cycle here.

Exploring a Layered Diagram

Layered diagrams are great to quickly understand the high level concepts of a codebase. It quickly provide you keen insights in your code architecture, package dependencies and obvious design patterns. Following are simple things you can do to make your diagram work wether your motive is to understand the code or document it for others.

Opening a package

To open a package and view its contents simply double click on it. For packages containing 20+ classes this may take a few moments.

Moving and Layering

• You can drag packages and classes to new places within the diagram.
• Dragging an item onto a blank spot in a layer will add it to that location in the layer, even if it is between two items
• Dragging it on top of a package will open the package and add it inside
• Dragging it between two layers will add it to a new layer in that location
• Items dragged to a different depth within the tree structure will show the full path in their name
  • Clicking the parts of this name will add parent folders
• Moving items will not affect the organization of your actual code.

Adding a member

In the bottom right of any class or package that is not currently showing all its children, is a button labeled 'Members' Clicking this button will allow you to add any un-shown children to the diagram individually.

Adding a dependent / dependee

1. Click on a class or package
2. If there are any dependencies to other items an up / down arrow will show above/below the selected item
3. Clicking an arrow will allow you to show any items not already in the diagram that depend on (up) or are depended on (down)

Focusing on a specific package

If you have explored a diagram and now wish to focus your attention on a specific portion you can use the Focus command

1. Right click on the package you would like to focus on
2. Select 'Focus' from the context menu
3. This will remove everything else in the diagram and open the package if it is not already open

Breaking a package

If there are items in a package that you wish to see in relation to the parent package you will need to use the 'Break' command.

1. Right click on the package you would like to focus on
2. Select 'Break' from the context menu
3. This will remove the selected package but leave its children as children of the parent package.
4. The images below show the animation package before and after the break

Animation package before break

Animation package after break

Deleting an element

To delete any package, class, or layer simply click on it to select it and hit the delete key on your keyboard. You can also delete by right clicking on the selected item and clicking on the delete option in the context menu.

Changing how dependency arrows are shown

If you would like to see all the dependency arrows concurrently,

• Right click and select 'Downward Arrows' -> 'Show Always'

If you would like to prevent dependency arrows from showing on mouseover,

• Right click and select 'Downward Arrows' -> 'Show Never'

If you would like to see cycles,

• Right click and select 'Upward Arrows' -> 'Show Always'

Relayering

If you have moved elements in a layered diagram and would like the Architexa algorithm to re-adjust a specific package simply right click on the parent package and select 'Re-Layer'. This would re-order the package to the original layout.

Documenting with a Layered Diagram

Layered diagrams can be tricky to document with since they are so interactive. We have added a couple of nifty features to make this aspect easier.

• If you are creating a diagram to show the dependencies of a specific class or package, share the diagram while the class or package is selected and all shown dependency arrows will be shown in the created diagram.
• You can also select multiple items by holding ctrl and clicking on them. This will allow you to share a diagram and show dependencies of more than one item.
• Selecting an open package will show all the dependencies going into and out of that package. This is a good way to give a better understanding of what the contents of a package are used for.
• You can choose to show a single connection always:
  1. Click on a dependency between two items.
  2. Click the small 'Pin' button to save the connection.
  3. The connection will now show as a dotted/dashed line and be visible no matter which items you mouse over.

Layered Diagram Tasks

• Understand a new project, library, or section of code
• Find cycles in your architecture

Creating a Class Diagram

Architexa lets you create Class Diagrams easily. Diagrams can be created from multiple places such as the package explorer, from the Java editor or can be viewed in an Eclipse view. The diagrams can be updated easily and are good for documenting code.

Starting from the code

1. Right click inside the code. (Click on the method name in the class to display a method)
2. Select 'Open in Diagram' -> 'Class Diagram' to display in the diagram.

Starting from the package explorer

1. Right click on one or more classes/methods or a single package.
2. Select 'Open in Diagram' -> 'Class Diagram'
3. If you selected a package the diagram will show any classes within that package and automatically add any inheritance relationships between them.
4. If you selected a class(s)/method(s) the diagram will show it with its appropriate parents

Creating a blank diagram in a new editor

1. In the toolbar, click the small drop down arrow on the right side 'Open a new diagram editor'  button.
2. Select 'New Class Diagram'
3. Once you have a new editor drag in packages, classes, or methods/fields from the package explorer to see how they interact.

Creating a blank diagram in a view

1. Go to "Window > Show View" and select the option "Other…"
2. Select "Class Diagram" in the "Architexa" folder.
3. You will now have a class diagram in a view which you can move, resize, or drag to a separate screen.
4. Once you have a new view drag in packages, classes, or methods/fields from the package explorer to see how they interact.

Using a linked view/editor to create a diagram

Follow the directions starting form step 2 here: Document while you work by creating a diagram in the background

More

For more help on opening diagrams see Opening Diagrams

Exploring a Class Diagram

Class diagrams are best for showing how the classes of your project interact. You can easily see both inheritance relationships and method calls at the same time.

Moving items

You can move any element in a class diagram by clicking it and dragging it to where you want it. Each type of item (package, class, field/method) can be moved in a unique way.

• Moving a package moves all its children as well.
• Moving a class outside of its package will cause the package to expand in order to accommodate it. Similarly moving classes in a package closer together will cause the package to shrink around them.
• fields, methods, and nested classes can not be moved outside their parent class. However their order within the class can be changed by dragging them.

Deleting items

To delete a package, class, or method/field simply click on it and then click the 'X' button in the top right or hit the delete key on the keyboard. Caution: deleting an element will also delete it's children. (Deleting does not remove the actual code, but just removes the item from the current diagram)

Adding members

1. Selecting a class or method will cause a 'Members' button to appear in the bottom right corner of the selected element. You can click this button to see a list of items that can be added; classes for packages, and members, fields, and nested classes for classes.
2. Selecting an item in the list will add it to the diagram and also add appropriate relationships

Adding hierarchy relationships

Selecting a class that extends another class or implements an interface will result in an up arrow button showing at the top of the class. Similarly if an interface or class is selected within your diagram, you will see a downward arrow button.

1. Select a class or interface
2. Click an upward or downward button
3. Select an item from the list to add to the diagram or add all the items by clicking 'Show All'

Adding caller/callee

1. Select a method in your diagram. If one does not yet exist you can add it by dragging it from the package explorer or using the 'Members' button
2. If this method is called by other methods in your code you will see a left pointing arrow button on the left side.
3. If this method calls other methods in your code you will see a right pointing arrow button on the right side.
4. Clicking one of these buttons will allow you to add calling / called methods individually.
5. You can also click 'Show All' to show all methods calling/called

Advanced Commands

We provide some built in advanced commands to make some common tasks easier. To access advanced commands, right click on an item in the diagram and select the appropriate command from the context menu.

• Hide Package removes the selected package
• Show Supertype Hierarchy will add all classes/interfaces that this class extends/implements to the diagram, up to the Object Level.
• Show Subtype Hierarchy will add all classes that are extending this class and any classes extending them.
• Show Referencing Types + Methods will add any methods or fields that contain references to the selected class
• Show Containing Package will add the parent package back if it has been removed with the 'Hide Package' command

Documenting with a Class Diagram

A class diagram is a versatile tool for documenting your codebase. For best practices see:

• Documenting with a Class Diagram

Class Diagram Tasks

• Understand what you have been looking at (create diagram from tabs)

Creating a Sequence Diagram

Along with Class and Layered diagrams Architexa also lets you easily create Sequence Diagrams. Diagrams can be created from multiple places such as the package explorer, from the Java editor or can be viewed in an Eclipse view. The diagrams can be updated easily and are good for understanding the details of your code and document complex parts.

Starting from the code

1. Right click inside the code. (Click on the method name in the class to display a method)
2. Select 'Open in Diagram' -> 'Sequence Diagram' to display in the diagram.

Starting from the package explorer

1. Right click on a class or method.
2. Select 'Open in Diagram' -> 'Sequence Diagram' to display the class in the diagram.

Creating a blank diagram in a new editor

1. In the toolbar, click the small drop down arrow on the right side 'Open a new diagram editor'  button.
2. Select 'New Sequence Diagram'.
3. Once you have a new editor drag in classes or methods from the package explorer to see how they interact.

Creating a blank diagram in a view

1. Go to "Window > Show View" and select the option "Other…"
2. Select "Sequence Diagram" in the "Architexa" folder.
3. You will now have a Sequence diagram in a view which you can move, resize, or drag to a separate screen.
4. Once you have a new view drag in packages or classes from the package explorer to see how they interact.

Using a linked view/editor to create a diagram

Follow the directions starting from step 2 here: Document while you work by creating a diagram in the background

More

For more help on opening diagrams see Opening Diagrams

Exploring and Building a Sequence Diagram

Sequence diagrams are great to understand nitty gritty details of your code and especially beneficial when looking at complex parts of your code. They let you add specific details to your diagrams like method calls, overrides and also let you easily remove items which are not relevant.

Adding Methods

In order to add methods to a sequence diagram containing the parent class, follow these steps:

1. Select a class shown in the diagram.
2. A button will show up below the class name showing the number of members(Methods/Fields/Inner classes) present and not already added to the diagram.
3. Click on the button and select the method to add.

Adding Calls a Method Makes

To add calls to a diagram containing a method follow these steps:

1. Select a method.
2. If a call is made from the method which is already not present in the diagram a 'Calls made' arrow (top right corner pointing outward) will show up.
3. Click on the arrow and add the call you want to the diagram from the list shown.

Adding Callers to a Method

1. Select a method.
2. If a call is made to this method which is already not present in the diagram a 'Calls made to' arrow (top left corner pointing inward) will show up.
3. Click on the arrow and add the call you want to the diagram from the list shown.

Adding Override/Overridden Methods

If this method overrides a method in a different class, take the following steps to add the parent class and it's method.

1. Select a method.
2. If a overriding/implement method is present which is not present in the diagram an 'Overriden By' arrow (bottom left corner pointing upward) will show up.
3. If this method is an override to another method not present in the diagram an 'Overrides' arrow (top right corner pointing upward) will show up.
4. Click on the arrow and add the call you want to the diagram from the list shown.

Show Overrides

Show overriden

Documenting with Sequence diagrams

Sequence diagrams are a good way to document complicated control flows in your codebase. Read more here.

Sequence Diagrams Tasks

Grouping of Classes

Sometimes we might need to group intermediary calls in a diagram. This can be done by simply dragging a class(es) and dropping over another class. These classes will then be grouped together and result in the grouped class(color changed to brown). You can ungroup by right clicking and selecting ungroup from the menu or by simply double clicking on the grouped class.

Ease Code Reviews

Tasks/Have easier code reviews by understanding changes with diagrams

Simplify Debugging

Tasks/Debug easily by using diagrams to see control flow

Analyze Logic

Tasks/Analyze logic (and ensure all cases are handled effectively)