Arch Answers for Terminal Emulator module

General Informations

Question (arch-what): What is this project good for?
Answer: The Terminal Emulator is a library used to display process output. It is designed to operate in a variety of modes, up to and including full emulation of an ANSI character terminal, similar to xterm and so on. NetBeans normally uses it to implement the Output Window, where it mostly acts as a "dumb terminal" for use in capturing output from compilers and programs run by the user; it features hyperlinks which may be used for e.g. compiler error messages. In more advanced modes it can even be used to run e.g. VI or Emacs, display margin glyphs, and so on. There is a complete functional specification available.

Project and platform dependencies

Question (dep-nb): What other NetBeans projects does this one depend on?
Answer: None, it is a standalone library that could be used in other applications.
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: Should be platform-independent, as it is just a Swing component. Expects that CRNL translations have been taken care of; pluggable line discipline handlers support this. If used as a full screen-oriented terminal emulator, it would need to be attached to code that would handle PTYs, signals, etc. This would probably need to be JNI, but no such code is included as part of the library itself.
Question (dep-jre): Which version of JRE do you need (1.2, 1.3, 1.4, etc.)?
Answer: 1.3.
Question (dep-jrejdk): Do you require the JDK or is the JRE enough?
Answer: JRE.

Deployment

Question (deploy-jar): Do you deploy just module JAR file(s) or other files as well?
Answer: Just a JAR.
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: Either.
Question (deploy-packages): Are packages of your module made inaccessible by not declaring them public?
Answer: No, there is only one package and it contains public API classes.

Compatiblity with environment

Question (compat-i18n): Is your module correctly internationalized?
Answer: The terminal emulator does not display any particular strings or icons except what is sent to it. Double-width display of oriental characters (e.g. Japanese) is supported.
Question (compat-standards): Does the module implement or define any standards? Is the implementation exact or does it deviate somehow?
Answer:

The emulator should comply with the general ANSI term specification given by ISO/IEC 6429:1992(E) / ANSI X3.64-1979. Its particular compliance levels are closest to the Solaris dtterm. Subprocesses expecting xterm or vt220 emulation should be fine as well.

The library package provides some API documentation for use by embedding applications. A subset of this API is used by the NetBeans core-output.jar module to implement the Output Window.

Question (compat-version): Can your module coexist with earlier and future versions? 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: N/A; no persisted settings.

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.

Lookup of components

Question (lookup-lookup): Does your module use org.openide.util.Lookup 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: No.

Execution Environment

Question (exec-property): Is execution of your code influenced by any environment or Java system (System.getProperty) property?
Answer: No.
Question (exec-component): Is execution of your code influenced by any (string) property of any of your components?
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.

Format of files and protocols

Question (format-types): Which file formats (if any) does your code read or write on disk?
Answer: N/A
Question (format-dnd): Which protocols (if any) does your code understand during Drag & Drop?
Answer: N/A
Question (format-clipboard): Which data flavors (if any) does your code read from or insert to the clipboard?
Answer: Plain Unicode text.

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? Please include some estimates.
Answer: Only the size of the history buffer is relevant (to memory consumption).
Question (perf-limit): Are there any hardcoded or practical limits in the number or size of elements your code can handle?
Answer: No. There is a history buffer with a fixed number of lines, so output exceeding this buffer size will continue to be displayed while earlier lines are discarded, keeping a fixed update speed for new output, subject to garbage collection etc. There will be a modest hiccup in display if more than 2³² lines of text are displayed, estimated to occur after several days running at full throttle.
Question (perf-mem): How much memory does your component consume? Estimate with a relation to the number of windows, etc.
Answer: The visible screen and the scrollback buffer are kept in memory; each line is stored as a character array, so given an average of twenty characters per line, with a default history size of 10000, and including some overhead for character attribute storage etc., we can estimate a standing memory consumption after heavy usage of around one megabyte.
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: 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 enablement logic?
Answer: No.