NetBeans Architecture Answers for Visual Library API module

General Information

Question (arch-what): What is this project good for?
Answer:

The Visual Library 2.0 is the next generation of the original Graph Library 1.0. It is designed for a general visualization with a support for graph-oriented modeling. Its focus is to become a part of the NetBeans platform and unify the visualization (UI and API) used in NetBeans-Platform-based applications. See https://netbeans.apache.org/front/main/projects/graph/ web-site for details. See documentation for complete set of use-cases and code-snippets.

Question (arch-overall): Describe the overall architecture.
Answer: VisualLibraryAPI -

The API provides a set of reusable pieces - widgets. By composing them you are creating a visualization. Each widget has various properties including layout, border, assigned actions, ... The library contains a set of pre-defined widgets that can be extended. All pluggable pieces are declared as interfaces or abstract classes - WidgetAction, Anchor, AnchorShape, PointShape, Animator, Border, GraphLayout, LookFeel, Layout, SceneLayout, Router, CollisionsCollector. Also they all have their built-in implementation.

Question (arch-usecases): Describe the main use cases of the new API. Who will use it under what circumstances? What kind of code would typically need to be written to use the module?
Answer:

See documentation for complete set of use-cases.

Question (arch-time): What are the time estimates of the work?
Answer:

Already done.

Question (arch-quality): How will the quality of your code be tested and how are future regressions going to be prevented?
Answer:

The quality is covered by a set of tests in the graph/examples module. The tests are visual and requires to be run manually.

Question (arch-where): Where one can find sources for your module?
Answer:

The sources for the module are in the Apache Git repositories or in the GitHub repositories.

Project and platform dependencies

Question (dep-nb): What other NetBeans projects and modules does this one depend on?
Answer:

These modules are required in project.xml:

• CommonAnnotationsAPI - The module is needed for compilation. The module is used during runtime. Specification version 1.11 is required.
• UtilitiesAPI - The module is needed for compilation. The module is used during runtime. Specification version 9.3 is required.
• WeakListener.setAccessible - The module is needed for compilation. The module is used during runtime. Specification version 9.3 is required.
• LookupAPI - The module is needed for compilation. The module is used during runtime. Specification version 8.0 is required.
• org.openide.awt - The module is needed for compilation. The module is used during runtime. Specification version 7.82 is required.
Question (dep-non-nb): What other projects outside NetBeans does this one depend on?
Answer:

None.

Question (dep-platform): On which platforms does your module run? Does it run in the same way on each?
Answer:

It runs on any platform with JavaSE 5.0+ and AWT/Swing.

Question (dep-jre): Which version of JRE do you need (1.2, 1.3, 1.4, etc.)?
Answer:

Requires JRE 5.0+.

Question (dep-jrejdk): Do you require the JDK or is the JRE enough?
Answer:

JRE is enough.

Deployment

Question (deploy-jar): Do you deploy just module JAR file(s) or other files as well?
Answer:

Just the jar file of the library.

Question (deploy-nbm): Can you deploy an NBM via the Update Center?
Answer:

Yes.

Question (deploy-shared): Do you need to be installed in the shared location only, or in the user directory only, or can your module be installed anywhere?
Answer:

No.

Question (deploy-packages): Are packages of your module made inaccessible by not declaring them public?
Answer:

Only org.netbeans.api.visual.* packages are public.

Question (deploy-dependencies): What do other modules need to do to declare a dependency on this one, in addition to or instead of the normal module dependency declaration (e.g. tokens to require)?
Answer:

No. Just set a normal project dependency on org.netbeans.api.visual (spec no.: 2.0) module.

Compatibility with environment

Question (compat-i18n): Is your module correctly internationalized?
Answer:

Yes. There is no i18n-able string.

Question (compat-standards): Does the module implement or define any standards? Is the implementation exact or does it deviate somehow?
Answer:

No.

Question (compat-version): Can your module coexist with earlier and future versions of itself? Can you correctly read all old settings? Will future versions be able to read your current settings? Can you read or politely ignore settings stored by a future version?
Answer:

Yes, it can. No settings are stored.

Question (compat-deprecation): How the introduction of your project influences functionality provided by previous version of the product?
Answer:

Previous Graph Library 1.0 API is deprecated now and is going to be unsupported. The Visual Library 2.0 API is a full replacement of the previous version.

Access to resources

Question (resources-file): Does your module use java.io.File directly?
Answer:

No.

Question (resources-layer): Does your module provide own layer? Does it create any files or folders in it? What it is trying to communicate by that and with which components?
Answer:

No.

Question (resources-read): Does your module read any resources from layers? For what purpose?
Answer:

No.

Question (resources-mask): Does your module mask/hide/override any resources provided by other modules in their layers?
Answer:

No.

Question (resources-preferences): Does your module uses preferences via Preferences API? Does your module use NbPreferences or or regular JDK Preferences ? Does it read, write or both ? Does it share preferences with other modules ? If so, then why ?
Answer:

No.

Lookup of components

Question (lookup-lookup): Does your module use org.openide.util.Lookup or any similar technology to find any components to communicate with? Which ones?
Answer:

No. Lookup is used for future extensibility of Widget class.

Question (lookup-register): Do you register anything into lookup for other code to find?
Answer:

No.

Question (lookup-remove): Do you remove entries of other modules from lookup?
Answer:

No.

Execution Environment

Question (exec-property): Is execution of your code influenced by any environment or Java system (System.getProperty) property? On a similar note, is there something interesting that you pass to java.util.logging.Logger? Or do you observe what others log?
Answer:

For scene rendering, rendering hints in "awt.font.desktophints" property are used.

Question (exec-component): Is execution of your code influenced by any (string) property of any of your components?
Answer:

PanAction requires a scene view JComponent to be placed into JScrollPane. For scene rendering, rendering hints in "awt.font.desktophints" property are used.

Question (exec-ant-tasks): Do you define or register any ant tasks that other can use?
Answer:

No.

Question (exec-classloader): Does your code create its own class loader(s)?
Answer:

No.

Question (exec-reflection): Does your code use Java Reflection to execute other code?
Answer:

No.

Question (exec-privateaccess): Are you aware of any other parts of the system calling some of your methods by reflection?
Answer:

No.

Question (exec-process): Do you execute an external process from your module? How do you ensure that the result is the same on different platforms? Do you parse output? Do you depend on result code?
Answer:

No.

Question (exec-introspection): Does your module use any kind of runtime type information (instanceof, work with java.lang.Class, etc.)?
Answer:

AddRemoveControlPointAction must be assigned to ConnectionWidget only. SceneAction.animateBackgroundColor could be used only for Widget with a Color background otherwise white color is used. CycleObjectSceneFocusProvider could be used for ObjectScene only. Object in ObjectScene cannot based on Widget class. LabelWidget has to have a Color-based background for proper work of its paintAsDisabled property. LayoutFactory.getActiveCard and LayoutFactory.setActiveCard expects a widget with a CardLayout assigned. MoveControlPointAction must be assigned to ConnectionWidget only. ObjectSceneRectangularSelectProvider works select ConnectionWidget by their linear path between control points and other widgets are selected by their boundary. PanAction requires a scene view JComponent to be placed into a JScrollPane. ReconnectAction must be assigned to ConnectionWidget only. WidgetCollisionCollector is treats ConnectionWidget specially by their linear path between control points and only for horizontal or vertical segments.

VerticalFlowLayout and HorizontalFlowLayout recognizes a Number-class constraint assigned to a child widget of a parent widget where the layout is assigned.

Question (exec-threading): What threading models, if any, does your module adhere to? How the project behaves with respect to threading?
Answer:

All methods in the API has to be called in AWT-thread only. Widget.Dependency and Scene.SceneListener is notified asynchronously at the moment when a scene is validation or painting. Other listeners are notified synchronously.

Question (security-policy): Does your functionality require modifications to the standard policy file?
Answer:

No.

Question (security-grant): Does your code grant additional rights to some other code?
Answer:

No.

Format of files and protocols

Question (format-types): Which protocols and file formats (if any) does your module read or write on disk, or transmit or receive over the network? Do you generate an ant build script? Can it be edited and modified?
Answer:

None.

Question (format-dnd): Which protocols (if any) does your code understand during Drag & Drop?
Answer:

None. Particular DnD logic has to be implemented by a user of the library.

Question (format-clipboard): Which data flavors (if any) does your code read from or insert to the clipboard (by access to clipboard on means calling methods on java.awt.datatransfer.Transferable?
Answer:

None.

Performance and Scalability

Question (perf-startup): Does your module run any code on startup?
Answer:

No.

Question (perf-exit): Does your module run any code on exit?
Answer:

No.

Question (perf-scale): Which external criteria influence the performance of your program (size of file in editor, number of files in menu, in source directory, etc.) and how well your code scales?
Answer:

The only critical problem is the OrthogonalSearchRouter implementation which significantly slow-down performance in a scene with +-50 objects and +-50 connections.

Question (perf-limit): Are there any hard-coded or practical limits in the number or size of elements your code can handle?
Answer:

OrthogonalSearchRouter works with a scene of size [-10000,-10000,20000,20000] pixels. Other limits are defined by Integer.MAX_VALUE.

Question (perf-mem): How much memory does your component consume? Estimate with a relation to the number of windows, etc.
Answer:

It depends on a scene, number of widgets and actions. Usually 100-200 bytes per a widget. A scene has a single primary and multiple secondary view. Each represented as a JComponent.

Question (perf-wakeup): Does any piece of your code wake up periodically and do something even when the system is otherwise idle (no user interaction)?
Answer:

No. Only when an animation is started. It should last in 500ms unless it is invoked again.

Question (perf-progress): Does your module execute any long-running tasks?
Answer:

No.

Question (perf-huge_dialogs): Does your module contain any dialogs or wizards with a large number of GUI controls such as combo boxes, lists, trees, or text areas?
Answer:

No.

Question (perf-menus): Does your module use dynamically updated context menus, or context-sensitive actions with complicated and slow enablement logic?
Answer:

No.

Question (perf-spi): How the performance of the plugged in code will be enforced?
Answer:

It is not enforced. The performance could be broken by plugging any custom implementation of an interface.