Don't show segment if POWERLEVEL9K_VI_INSERT_MODE_STRING == ''

README.md

@@ -621,6 +621,8 @@ you are using the [ZSH Line Editor](http://zsh.sourceforge.net/Doc/Release/Zsh-L
 |`POWERLEVEL9K_VI_INSERT_MODE_STRING`|`"INSERT"`|String to display while in 'Insert' mode.|
 |`POWERLEVEL9K_VI_COMMAND_MODE_STRING`|`"NORMAL"`|String to display while in 'Command' mode.|
 
+To hide the segment entirely when in `INSERT` mode, set `POWERLEVEL9K_VI_INSERT_MODE_STRING=''`
+
 #### Unit Test Ratios
 
 The `symfony2_tests` and `rspec_stats` segments both show a ratio of "real"

powerlevel9k.zsh-theme

@@ -1366,6 +1366,7 @@ prompt_vi_mode() {
       "$1_prompt_segment" "$0_NORMAL" "$2" "$DEFAULT_COLOR" "default" "$POWERLEVEL9K_VI_COMMAND_MODE_STRING"
     ;;
     main|viins|*)
+      if [[ -z $POWERLEVEL9K_VI_INSERT_MODE_STRING ]]; then return; fi
       "$1_prompt_segment" "$0_INSERT" "$2" "$DEFAULT_COLOR" "blue" "$POWERLEVEL9K_VI_INSERT_MODE_STRING"
     ;;
   esac