Code Completion provides users with a list of suggested completions for partially typed texts in the editor and various dialog input fields.
The Code Completion module was created to replace the original legacy editor code completion which lacked several key requirements:
The Code Completion module is located under
/cvs/editor/completion directory. It provides the
with a simple API for showing and hiding of the completion
and with SPI defining the completion providers that is located
and the implementation located in
The API is small and it only allows to explicitly show or hide the completion window.
It's being used by code templates that need to explicitly show the code completion window when tabbing to a particular parameter.
There may be certain actions that want to ensure that the code completion is hidden at the time when they are invoked. For example the actions pasting the content of the completion item into the document.
Completion infrastructure needs to obtain the results that are then displayed
in the completion window.
There are three types of displayed results related to the current caret offset:
For the purpose of obtaining these completion results
There may be an arbitrary number of independent completion providers for a single completion popup window.
The completion providers are registered through the xml layer into Editors/<mime-type>/CompletionProviders. Once the document with the particular mime-type gets loaded the corresponding completion providers will get instantiated and used.
The code completion's infrastructure invokes the requests for the completion results in the AWT thread.
Therefore all the methods of the completion providers are invoked in AWT thread but they may reschedule their processing into other threads.
The completion provider creates a task that computes the resulting
data that will then be displayed by the code completion infrastructure.
The task creation and computation are called synchronously from the AWT event dispatch thread.
However there can be potentially long-running tasks (e.g. working with MDR) that are not desirable to be run in AWT thread.
Therefore the completion infrastructure provides a listener to which the completion task notifies the results.
The support class AsyncCompletionTask allows to post the task computation into
The completion task computes a collection of completion items
which are then collected by the completion infrastructure and displayed.
Displaying. Each completion item must be able to display itself in a
Sorting. The completion items may come from different completion providers and they must be sorted before displaying. The sort order should not only be alphabetical but it should also allow a prioritization of the items according to their importance in the given context.
Actions. The interaction of the user with the completion item is done by interacting with item's input map and action map.
Documentation. The item may want to display additional detailed information in a documentation popup window.
The prototype implementation of the module is available in cvs on the completion branch. Also, the prototype implementation of the Java completion provider exists in /cvs/java/editor on the completion branch. An additional time will be needed for cleaning-up the editor module from the existing code completion infrastructure (5 man-days), convering the existing completion supports (e.g. JSP Completion, XML Completion) into the completion providers (5 man-days), polishing the Code Completion module itself to e.g. work with the existing code completion options, etc. (3 working man-days), and the overall module stabilization (5 man-days).
There are no expected milestones yet.Question (arch-quality): How will the quality of your code be tested and how are future regressions going to be prevented? Answer:
The unit tests will be created to cover the functionality testing.
The proper instantiation of the registered completion providers will be tested.
Asynchronous task execution.
Various semantics e.g. prohibition of repetitive result notification from the completion provider.
The sources for the module are in the Apache Git repositories or in the GitHub repositories.
The module has dependency on the EditorModuleAPI module. It uses this dependency to read the old code completion options stored as a part of the editor module.
The default answer to this question is:
These modules are required in project.xml:
The module does not depend on any outside project.Question (dep-platform): On which platforms does your module run? Does it run in the same way on each? Answer:
The module runs on any platform that provides the required JRE.Question (dep-jre): Which version of JRE do you need (1.2, 1.3, 1.4, etc.)? Answer:
JRE 1.4 and higher.Question (dep-jrejdk): Do you require the JDK or is the JRE enough? Answer:
JRE is sufficient.
No additional files.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:
The module can be installed anywhere.Question (deploy-packages): Are packages of your module made inaccessible by not declaring them public? Answer:
Yes, only the Code Completion SPI is 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: Nothing.
Yes.Question (compat-standards): Does the module implement or define any standards? Is the implementation exact or does it deviate somehow? Answer:
The module does not define nor implement any standard.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:
The Code Completion module should be able to read the existing code completion related options
stored as part of the editor settings.
In a future, we plan to introduce some additional options related to e.g. sorting the code completion results, etc.
XXX no answer for compat-deprecation
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:
The module reads CompletionProviders registered for the given mime-type
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:
XXX no answer for resources-preferences
org.openide.util.Lookupor any similar technology to find any components to communicate with? Which ones? Answer:
No.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:
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: org.netbeans.ui.editor.completion - Since version 1.8 the completion cooperates with UI Gestures Collector by sending following messages to the
-J-Dorg.netbeans.modules.editor.completion.slowness.reportproperty to more than 2000 ms (the default value). Question (exec-component): Is execution of your code influenced by any (string) property of any of your components? Answer:
No.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:
No.Question (exec-threading): What threading models, if any, does your module adhere to? How the project behaves with respect to threading? Answer:
XXX no answer for exec-threadingQuestion (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 files are read or written to the disk.Question (format-dnd): Which protocols (if any) does your code understand during Drag & Drop? Answer:
The module does not use Drag & Drop.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
The module does not work with the clipboard.
org.netbeans.modules.editor.completion.Completion is created on the module startup.
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:
Number of CompletionProviders registered for a document mime-type.Question (perf-limit): Are there any hard-coded or practical limits in the number or size of elements your code can handle? Answer:
There are no hard-coded limits. However, due to performance reasons, the number of CompletionProviders registered with a mime-type should be held as low as possible.Question (perf-mem): How much memory does your component consume? Estimate with a relation to the number of windows, etc. Answer:
No answer.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.Question (perf-progress): Does your module execute any long-running tasks? Answer:
Computing of the code completion results is potentially a long-running task. The Code Completion SPI is constructed in such a way that it provides CompletinProviders with a possibility to run their tasks asynchronously.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:
Currently, there is no way to enforce the performance of the plugged in code.