Allow customization of terminal title

Add GEOMETRY_TITLE and GEOMETRY_CMDTITLE display locations.
Geometry was already controlling the terminal title. This change uses the geometry function plumbing to display information there.
The original explicit title-controlling code displayed the name and arguments of the currently-executing command. This change introduces a new geometry_cmd function to display this information from within the GEOMETRY_CMDTITLE configuration.

The riskiest change in this code is the hand-rolled deansi function. The colored output of geometry functions displays poorly in the terminal title, so non-text information needed to be removed.

changelog.md

@@ -4,6 +4,8 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## Unreleased
+- Add GEOMETRY_TITLE and GEOMETRY_CMDTITLE as display locations
+- Add geometry_cmd function to display currently-running command in GEOMETRY_CMDTITLE
 
 ### Fixed
 - Fix git functions erroring out in non-git directories (thanks @duncanbeevers!)

geometry.zsh

@@ -9,12 +9,16 @@ typeset -gA GEOMETRY; GEOMETRY[ROOT]=${0:A:h}
 (($+GEOMETRY_PROMPT)) || GEOMETRY_PROMPT=(geometry_echo geometry_status geometry_path)
 (($+GEOMETRY_RPROMPT)) || GEOMETRY_RPROMPT=(geometry_exec_time geometry_git geometry_hg geometry_echo)
 (($+GEOMETRY_INFO)) || GEOMETRY_INFO=()
+(($+GEOMETRY_TITLE)) || GEOMETRY_TITLE=(geometry_path)
+(($+GEOMETRY_CMDTITLE)) || GEOMETRY_CMDTITLE=(geometry_cmd geometry_hostname)
 
 autoload -U add-zsh-hook
 
 function { local fun; for fun ("${GEOMETRY[ROOT]}"/functions/*) . $fun }
 
 (( $+functions[ansi] )) || ansi() { (($# - 2)) || echo -n "%F{$1}$2%f"; }
+(( $+functions[deansi] )) || deansi() { (($# - 1)) || echo -n "$(echo "$1" | sed s/$(echo "\033")\\\[\[0-9\]\\\{1,2\\\}m//g)"; }
+(( $+functions[geometry_cmd])) || geometry_cmd() { echo $GEOMETRY_LAST_CMD }
 
 # Takes number of seconds and formats it for humans
 # from https://github.com/sindresorhus/pretty-time-zsh
@@ -59,13 +63,25 @@ geometry::hostcolor() {
   echo ${colors[${index}]}
 }
 
-# set title to COMMAND @ CURRENT_DIRECTORY
-geometry::set_title() { print -n "\e]0;${2} @ ${PWD##*/}\a"; }
-add-zsh-hook preexec geometry::set_title
+# set cmd title (while command is running)
+geometry::set_cmdtitle() {
+  # Make command title available for optional consumption by geometry_cmd
+  GEOMETRY_LAST_CMD=$2
+  local ansiCmdTitle=$(print -P $(geometry::wrap $PWD $GEOMETRY_CMDTITLE))
+  local cmdTitle=$(deansi "$ansiCmdTitle")
 
-# clear title after command ends
-geometry::clear_title() { print -n '\e]0;%~\a'; }
-add-zsh-hook precmd geometry::clear_title
+  echo -ne "\e]1;$cmdTitle\a"
+}
+add-zsh-hook preexec geometry::set_cmdtitle
+
+# set ordinary title (after command has completed)
+geometry::set_title() {
+  local ansiTitle=$(print -P $(geometry::wrap $PWD $GEOMETRY_TITLE))
+  local title=$(deansi "$ansiTitle")
+
+  echo -ne "\e]1;$title\a"
+}
+add-zsh-hook precmd geometry::set_title
 
 # join outputs of functions - pwd first
 geometry::wrap() {

readme.md

@@ -43,17 +43,27 @@ tool          | add to `.zshrc`
 
 ![showing prompt customization with new function](./images/screenshots/functions.png)
 
-Geometry has very little architecture. Three environment variables define what is shown on the left, right, and on enter - `GEOMETRY_PROMPT`, `GEOMETRY_RPROMPT`, and `GEOMETRY_INFO`.
+Geometry displays output in several places. The output displayed in each location is determined by the plugins configured for that location.
+These are the supported locations, along with the environment variable used to configure each one.
 
-Most of these functions only show up if it makes sense to (for example, `geometry_git` only shows up if in a git repository).
+Variable Name        | Text display location                                             
+---------------------|-------------------------------------------------------
+GEOMETRY_PROMPT      | Text shown to the left of the cursor
+GEOMETRY_RPROMPT     | Text shown at the right edge of the terminal
+GEOMETRY_INFO        | Text shown after pressing enter with no input
+GEOMETRY_TITLE       | Text shown in the terminal title
+GEOMETRY_CMDTITLE    | Text shown in the terminal title when a command is run
 
-To customize the prompt, just add any function to any of the `GEOMETRY_PROMPT`, `GEOMETRY_RPROMPT`, or `GEOMETRY_INFO` variables:
+To customize the prompt, add any function to the list of functions for the desired display location:
 
 ```sh
 GEOMETRY_PROMPT=(geometry_status geometry_path) # redefine left prompt
 GEOMETRY_RPROMPT+=(geometry_exec_time pwd)      # append exec_time and pwd right prompt
+GEOMETRY_TITLE=(geometry_node)
 ```
 
+Most of these functions only show up if it makes sense to (for example, `geometry_git` only shows up if in a git repository).
+
 Please check out and share third-party functions on our [functions wiki page][]
 
 For more details on how to create a function, check out [our contribution guide][]