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diff --git a/man/9/0intro b/man/9/0intro new file mode 100644 index 00000000..4b7cd4fd --- /dev/null +++ b/man/9/0intro @@ -0,0 +1,134 @@ +.TH INTRO 9 +.SH NAME +intro \- introduction to Inferno Tk +.SH DESCRIPTION +This section of the manual provides a reference for the Inferno +Tk implementation, +which is accessed by Limbo programs via +.IR tk (2), +and from +.IR sh (1) +via +.IR sh-tk (1). +.PP +The following pages were derived by Vita Nuova from documentation that is +.IP +Copyright © 1990 The Regents of the University of California +.br +Copyright © 1994-1996 Sun Microsystems, Inc. +.br +See +.IR copyright (9) +for the full copyright notice. +.PP +The format of the pages has changed to follow the format of the rest of +this manual, but more important, the content has been changed +(typically in small ways) to reflect the variant of Tk implemented by +Inferno. +.SS Programming Interface +The interface to Inferno Tk is exclusively through the +.IR tk (2) +module; all the Tk commands described in this section of +the manual are excecuted by passing them as strings to the +.B cmd +function in that module. +The Inferno Tk implementation is based on the Tk 4.0 documentation, +but there are many differences, probably the greatest of which is that +there is no associated Tcl implementation, so almost every +Inferno application using Tk will need to have some Limbo code +associated with it (the +.IR sh-tk (1) +shell module can also fulful this rôle). See ``An Overview of Limbo/Tk'' +in Volume 2 for a tutorial-style introduction to the use of Inferno Tk +which summarises the differences from Tk 4.0. +.SS Tk Commands +The command string passed to +.B tk->cmd +may contain one or more Tk commands, separated by semicolons. +A semicolon is not a command separator when it is nested in braces +.RB ( {} ) +or brackets +.RB ( [] ) +or it is escaped by a backslash +.RB ( \e ). +Each command is divided into +.IR words : +sequences of characters separated by one or more +blanks and tabs. +.PP +There is also a `super quote' convention: at any point in the command +string a single quote mark +.RB ( ' ) +means that the entire rest of the string should be treated as one word. +.PP +A word beginning with an opening brace +.RB ( { ) +continues until the balancing closing brace +.RB ( } ) +is reached. The outer brace characters are stripped. A backslash +can be used to escape a brace in this context. Backslash +characters not used to escape braces are left unchanged. +.PP +A word beginning with an opening bracket +.RB ( [ ) +continues until the balancing closing bracket +.RB ( ] ) +is reached. The enclosed string is then evaluated as if it +were a command string, and the resulting value +is used as the contents of the word. +.PP +Single commands are executed in order until they are all done +or an error is encountered. By convention, an error is signaled by a +return value starting with an exclamation mark +.RB ( ! ). +The return value from +.B tk->cmd +is the return value of the first error-producing +command or else the return value of the final single command. +.PP +To execute a single command, the first word is examined. It +must either begin with dot +.RB ( . ) +in which case it must name an existing widget, which will +interpret the rest of the command according to its type, +or one of the following words, each of which is +documented in a manual page of that name in this section: +.EX + +bind focus lower scrollbar +button frame menu see +canvas grab menubutton send +checkbutton grid pack text +cursor image radiobutton update +destroy label raise variable +entry listbox scale +.EE +.SS Widget Options +Each manual page in this section documents the options +that a particular command will accept. A number of options +are common to several of the widgets and are named as +``standard options'' near the beginning of the manual page +for each widget. These options are documented in +.IR options (9). +The types of value required as arguments to options within +Inferno Tk are documented under +.IR types (9). +.SH SEE ALSO +.IR options (9), +.IR types (9), +.IR tk (2), +.IR sh-tk (1), +.IR tkcmd (1), +.IR wmlib (2), +.IR draw-intro (2), +``An Overview of Limbo/Tk'' in Volume 2. +.SH BUGS +The bracket +.RB ( [] ) +command interpretation is not applied consistently throughout +the Inferno Tk commands (notably, the argument to +the +.IR send (9) +command will not interpret this correctly). +Moreover, if the string to be substituted is significantly bigger +than the command it was substituting, then it will be truncated. |