Plugin for iTerm2 (#3790)

* Plugin for iTerm2 on OSX

iTerm2 is a popular terminal emulator for OSX (https://www.iterm2.com).

The plugin currently implements one function, iterm2_profile, which
allows easily changing the currently selected user settings profile,
without creating a new tab or window, just by calling the function.

For example, this is handy for switching from a dark to a light colored
profile without having to re-open anything.

In addition, it also works within tmux running inside iTerm2.

* iTerm2 Plugin: Run any iTerm2 command

Refactored the plugin so that it can run arbitrary iTerm2 commands.
Should work with any of the supported commands, see
https://iterm2.com/documentation-escape-codes.html

* iTerm2 Plugin: Add functions to change tab color

plugins/iterm2/iterm2.plugin.zsh

@@ -0,0 +1,68 @@
+#####################################################
+# iTerm2 plugin for oh-my-zsh                       #
+# Author: Aviv Rosenberg (github.com/avivrosenberg) #
+#####################################################
+
+###
+# This plugin is only relevant if the terminal is iTerm2 on OSX.
+if [[ "$OSTYPE" == darwin* ]] && [[ -n "$ITERM_SESSION_ID" ]] ; then
+
+  ###
+  # Executes an arbitrary iTerm2 command via an escape code sequce.
+  # See https://iterm2.com/documentation-escape-codes.html for all supported commands.
+  # Example: $ _iterm2_command "1337;StealFocus"
+  function _iterm2_command() {
+    local cmd="$1"
+
+    # Escape codes for wrapping commands for iTerm2.
+    local iterm2_prefix="\x1B]"
+    local iterm2_suffix="\x07"
+
+    # If we're in tmux, a special escape code must be prepended/appended so that
+    # the iTerm2 escape code is passed on into iTerm2.
+    if [[ -n $TMUX ]]; then
+      local tmux_prefix="\x1BPtmux;\x1B"
+      local tmux_suffix="\x1B\\"
+    fi
+
+    echo -n "${tmux_prefix}${iterm2_prefix}${cmd}${iterm2_suffix}${tmux_suffix}"
+  }
+
+  ###
+  # iterm2_profile(): Function for changing the current terminal window's
+  # profile (colors, fonts, settings, etc).
+  # To change the current iTerm2 profile, call this function and pass in a name
+  # of another existing iTerm2 profile (name can contain spaces).
+  function iterm2_profile() {
+    # Desired name of profile
+    local profile="$1"
+
+    # iTerm2 command for changing profile
+    local cmd="1337;SetProfile=$profile"
+
+    # send the sequence
+    _iterm2_command "${cmd}"
+
+    # update shell variable
+    ITERM_PROFILE="$profile"
+  }
+
+  ###
+  # iterm2_tab_color(): Changes the color of iTerm2's currently active tab.
+  # Usage: iterm2_tab_color <red> <green> <blue>
+  #        where red/green/blue are on the range 0-255.
+  function iterm2_tab_color() {
+    _iterm2_command "6;1;bg;red;brightness;$1"
+    _iterm2_command "6;1;bg;green;brightness;$2"
+    _iterm2_command "6;1;bg;blue;brightness;$3"
+  }
+
+
+  ###
+  # iterm2_tab_color_reset(): Resets the color of iTerm2's current tab back to
+  # default.
+  function iterm2_tab_color_reset() {
+    _iterm2_command "6;1;bg;*;default"
+  }
+
+fi