Refactor common options into opt hooks

lib/opt_hooks.sh

@@ -0,0 +1,75 @@
+#!/usr/bin/env bash
+# -----------------------------------------------------------------------------
+# bat-extras | Copyright (C) 2019 eth-p | MIT License
+#
+# Repository: https://github.com/eth-p/bat-extras
+# Issues:     https://github.com/eth-p/bat-extras/issues
+# -----------------------------------------------------------------------------
+
+
+# -----------------------------------------------------------------------------
+# Hooks:
+# -----------------------------------------------------------------------------
+
+# Option parser hook: color support.
+# This will accept --no-color, or --color.
+# It will also try to accept --color=never|always|auto.
+#
+# The variable OPT_COLOR will be set depending on whether or not a TTY is
+# detected and whether or not --color/--no-color is specified.
+hook_color() {
+	SHIFTOPT_HOOKS+=("__shiftopt_hook__color")
+	__shiftopt_hook__color() {
+		case "$OPT" in
+			--no-color) OPT_COLOR=false; printc_init "$OPT_COLOR";;
+			--color)    {
+				case "$OPT_VAL" in
+					auto)        :;;
+					always|true) OPT_COLOR=true;  printc_init "$OPT_COLOR";;
+					never|false) OPT_COLOR=false; printc_init "$OPT_COLOR";;
+				esac
+			};;
+
+			*) return 1;;
+		esac
+	}
+
+	# Default color support.
+	if [[ -z "$OPT_COLOR" ]]; then
+		if [[ -t 1 ]]; then
+			OPT_COLOR=true
+		else
+			OPT_COLOR=false
+		fi
+		printc_init "$OPT_COLOR"
+	fi
+}
+
+# Option parser hook: pager support.
+# This will accept --pager='pager', --no-pager
+hook_pager() {
+	SHIFTOPT_HOOKS+=("__shiftopt_hook__pager")
+	__shiftopt_hook__pager() {
+		case "$OPT" in
+	    	# Specify paging.
+			--no-pager)   shiftval; SCRIPT_PAGER_CMD='';;
+			--paging)     shiftval; {
+				case "$OPT_VAL" in
+					auto)   :;;
+					never)  SCRIPT_PAGER_CMD='';;
+					always) :;;
+				esac
+			};;
+
+			# Specify the pager.
+			--pager) {
+				shiftval;
+				SCRIPT_PAGER_CMD=($OPT_VAL);
+				PAGER_ARGS=()
+			};;
+
+			*) return 1;;
+		esac
+	}
+}
+