refactor(grimshot): modularize and clean up with functional helpers

- Introduced functional helper methods: `when`, `if_else`, and `any` for cleaner, more maintainable logic. - Refactored conditional handling in `notifyOk`, `notifyError`, and `check` functions to leverage the new helper methods. - Moved usage message printing to a dedicated `printUsageMsg` function. - Extracted subject-specific logic (e.g., area, window, screen) into standalone functions: `selectArea`, `selectWindow`, etc. - Improved error handling by introducing functions like `handleScreenshotSuccess`, `handleScreenshotFailure`, and `handleSaveCopy`. - Reformatted code and improved readability by using consistent formatting for case statements and conditions. This refactor enhances code maintainability by isolating logic into reusable components, improving clarity and simplifying future changes.
OctopusET · Oct 7, 2024 · b5cd760 · b5cd760
1 parent 2d6e5a9
commit b5cd760
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diff --git a/functional-helpers b/functional-helpers
@@ -0,0 +1,33 @@
+#! /bin/sh
+when() {
+  condition=$1
+  action=$2
+
+  if eval "$condition"; then
+    eval "$action"
+  fi
+}
+
+whenOtherwise() {
+  condition=$1
+  true_action=$2
+  false_action=$3
+
+  if eval "$condition"; then
+    eval "$true_action"
+  else
+    eval "$false_action"
+  fi
+}
+
+any() {
+  for tuple in "$@"; do
+    condition=$(echo "$tuple" | cut -d: -f1)
+    action=$(echo "$tuple" | cut -d: -f2-)
+    if eval "$condition"; then
+      eval "$action"
+      return 0
+    fi
+  done
+  return 1  # No conditions matched
+}
diff --git a/grimshot b/grimshot
@@ -11,9 +11,10 @@
 ## Those are needed to be installed, if unsure, run `grimshot check`
 ##
 ## See `man 1 grimshot` or `grimshot usage` for further details.
+. ./functional-helpers
 
 getTargetDirectory() {
-  test -f "${XDG_CONFIG_HOME:-$HOME/.config}/user-dirs.dirs" && \
+  test -f "${XDG_CONFIG_HOME:-$HOME/.config}/user-dirs.dirs" &&
     . "${XDG_CONFIG_HOME:-$HOME/.config}/user-dirs.dirs"
 
   echo "${XDG_SCREENSHOTS_DIR:-${XDG_PICTURES_DIR:-$HOME}}"
@@ -27,34 +28,34 @@ while [ $# -gt 0 ]; do
   key="$1"
 
   case $key in
-    -n|--notify)
-      NOTIFY=yes
-      shift # past argument
-      ;;
-    -c|--cursor)
-      CURSOR=yes
-      shift # past argument
-      ;;
-    -w|--wait)
-      shift
-      WAIT="$1"
-      if echo "$WAIT" | grep "[^0-9]" -q; then
-        echo "invalid value for wait '$WAIT'" >&2
-        exit 3
-      fi
-      shift
-      ;;
-    *)    # unknown option
-      break # done with parsing --flags
-      ;;
+  -n | --notify)
+    NOTIFY=yes
+    shift # past argument
+    ;;
+  -c | --cursor)
+    CURSOR=yes
+    shift # past argument
+    ;;
+  -w | --wait)
+    shift
+    WAIT="$1"
+    if echo "$WAIT" | grep "[^0-9]" -q; then
+      echo "invalid value for wait '$WAIT'" >&2
+      exit 3
+    fi
+    shift
+    ;;
+  *)      # unknown option
+    break # done with parsing --flags
+    ;;
   esac
 done
 
 ACTION=${1:-usage}
 SUBJECT=${2:-screen}
 FILE=${3:-$(getTargetDirectory)/$(date -Ins).png}
 
-if [ "$ACTION" != "save" ] && [ "$ACTION" != "copy" ] && [ "$ACTION" != "savecopy" ] && [ "$ACTION" != "check" ]; then
+printUsageMsg() {
   echo "Usage:"
   echo "  grimshot [--notify] [--cursor] [--wait N] (copy|save) [active|screen|output|area|window|anything] [FILE|-]"
   echo "  grimshot check"
@@ -75,31 +76,34 @@ if [ "$ACTION" != "save" ] && [ "$ACTION" != "copy" ] && [ "$ACTION" != "savecop
   echo "  window: Manually select a window."
   echo "  anything: Manually select an area, window, or output."
   exit
-fi
+}
 
 notify() {
   notify-send -t 3000 -a grimshot "$@"
 }
+
 notifyOk() {
-  [ "$NOTIFY" = "no" ] && return
+  notify_disabled='[ "$NOTIFY" = "no" ]'
+  action_involves_saving='[ "$ACTION" = "save" ] || [ "$ACTION" = "savecopy" ]'
+
+  when "$notify_disabled" "return"
 
   TITLE=${2:-"Screenshot"}
   MESSAGE=${1:-"OK"}
 
-  if [ "$ACTION" = "save" ] || [ "$ACTION" = "savecopy" ]; then
-    notify "$TITLE" "$MESSAGE" -i "$FILE"
-  else
-    notify "$TITLE" "$MESSAGE"
-  fi
+  whenOtherwise "$action_involves_saving" \
+    'notify "$TITLE" "$MESSAGE" -i "$FILE"' \
+    'notify "$TITLE" "$MESSAGE"'
 }
+
 notifyError() {
-  if [ $NOTIFY = "yes" ]; then
-    TITLE=${2:-"Screenshot"}
-    MESSAGE=${1:-"Error taking screenshot with grim"}
-    notify -u critical "$TITLE" "$MESSAGE"
-  else
-    echo "$1"
-  fi
+  notify_enabled='[ "$NOTIFY" = "yes" ]'
+  TITLE=${2:-"Screenshot"}
+  MESSAGE=${1:-"Error taking screenshot with grim"}
+
+  whenOtherwise "$notify_enabled" \
+    'notify -u critical "$TITLE" "$MESSAGE"' \
+    'echo "$1"'
 }
 
 die() {
@@ -110,28 +114,33 @@ die() {
 
 check() {
   COMMAND=$1
-  if command -v "$COMMAND" > /dev/null 2>&1; then
-    RESULT="OK"
-  else
-    RESULT="NOT FOUND"
-  fi
+  command_exists='command -v "$COMMAND" > /dev/null 2>&1'
+
+  whenOtherwise "$command_exists" \
+    'RESULT="OK"' \
+    'RESULT="NOT FOUND"'
+
   echo "   $COMMAND: $RESULT"
 }
 
 takeScreenshot() {
   FILE=$1
   GEOM=$2
   OUTPUT=$3
-  if [ -n "$OUTPUT" ]; then
-    grim ${CURSOR:+-c} -o "$OUTPUT" "$FILE" || die "Unable to invoke grim"
-  elif [ -z "$GEOM" ]; then
-    grim ${CURSOR:+-c} "$FILE" || die "Unable to invoke grim"
-  else
-    grim ${CURSOR:+-c} -g "$GEOM" "$FILE" || die "Unable to invoke grim"
-  fi
-}
 
-if [ "$ACTION" = "check" ] ; then
+  output_provided='[ -n "$OUTPUT" ]'
+  geom_not_provided='[ -z "$GEOM" ]'
+
+  output_action='grim ${CURSOR:+-c} -o "$OUTPUT" "$FILE" || die "Unable to invoke grim"'
+  full_screenshot_action='grim ${CURSOR:+-c} "$FILE" || die "Unable to invoke grim"'
+  geometry_screenshot_action='grim ${CURSOR:+-c} -g "$GEOM" "$FILE" || die "Unable to invoke grim"'
+
+  any \
+    "$output_provided:$output_action" \
+    "$geom_not_provided:$full_screenshot_action" \
+    "true:$geometry_screenshot_action"
+}
+checkRequiredTools() {
   echo "Checking if required tools are installed. If something is missing, install it to your system and make it available in PATH..."
   check grim
   check slurp
@@ -140,61 +149,103 @@ if [ "$ACTION" = "check" ] ; then
   check jq
   check notify-send
   exit
-elif [ "$SUBJECT" = "area" ] ; then
+}
+
+selectArea() {
   GEOM=$(slurp -d)
-  # Check if user exited slurp without selecting the area
-  if [ -z "$GEOM" ]; then
-    exit 1
-  fi
+  geomIsEmpty='[ -z "$GEOM" ]'
+  when "$geomIsEmpty" "exit 1"
   WHAT="Area"
-elif [ "$SUBJECT" = "active" ] ; then
+}
+
+selectActiveWindow() {
   FOCUSED=$(swaymsg -t get_tree | jq -r 'recurse(.nodes[]?, .floating_nodes[]?) | select(.focused)')
   GEOM=$(echo "$FOCUSED" | jq -r '.rect | "\(.x),\(.y) \(.width)x\(.height)"')
   APP_ID=$(echo "$FOCUSED" | jq -r '.app_id')
   WHAT="$APP_ID window"
-elif [ "$SUBJECT" = "screen" ] ; then
+}
+
+selectScreen() {
   GEOM=""
   WHAT="Screen"
-elif [ "$SUBJECT" = "output" ] ; then
+}
+
+selectOutput() {
   GEOM=""
   OUTPUT=$(swaymsg -t get_outputs | jq -r '.[] | select(.focused)' | jq -r '.name')
   WHAT="$OUTPUT"
-elif [ "$SUBJECT" = "window" ] ; then
+}
+
+selectWindow() {
   GEOM=$(swaymsg -t get_tree | jq -r '.. | select(.pid? and .visible?) | .rect | "\(.x),\(.y) \(.width)x\(.height)"' | slurp -r)
-  # Check if user exited slurp without selecting the area
-  if [ -z "$GEOM" ]; then
-   exit 1
-  fi
+  geomIsEmpty='[ -z "$GEOM" ]'
+  when "$geomIsEmpty" "exit 1"
   WHAT="Window"
-elif [ "$SUBJECT" = "anything" ] ; then
+}
+
+selectAnything() {
   GEOM=$(swaymsg -t get_tree | jq -r '.. | select(.pid? and .visible?) | .rect | "\(.x),\(.y) \(.width)x\(.height)"' | slurp -o)
-  # Check if user exited slurp without selecting the area
-  if [ -z "$GEOM" ]; then
-    exit
-  fi
+  geomIsEmpty='[ -z "$GEOM" ]'
+  when "$geomIsEmpty" "exit 1"
   WHAT="Selection"
-else
-  die "Unknown subject to take a screen shot from" "$SUBJECT"
-fi
+}
+handleSaveCopy() {
+  wl-copy --type image/png <"$FILE" || die "Clipboard error"
+  MESSAGE="$MESSAGE and clipboard"
+}
 
-if [ "$WAIT" != "no" ]; then
-  sleep "$WAIT"
-fi
+handleScreenshotSuccess() {
+  TITLE="Screenshot of $SUBJECT"
+  MESSAGE=$(basename "$FILE")
+  isSaveCopy='[ "$ACTION" = "savecopy" ]'
+  when "$isSaveCopy" "handleSaveCopy"
+  notifyOk "$MESSAGE" "$TITLE"
+  echo "$FILE"
+}
+
+handleScreenshotFailure() {
+  notifyError "Error taking screenshot with grim"
+}
 
-if [ "$ACTION" = "copy" ] ; then
+handleCopy() {
   takeScreenshot - "$GEOM" "$OUTPUT" | wl-copy --type image/png || die "Clipboard error"
   notifyOk "$WHAT copied to clipboard"
-else
-  if takeScreenshot "$FILE" "$GEOM" "$OUTPUT"; then
-    TITLE="Screenshot of $SUBJECT"
-    MESSAGE=$(basename "$FILE")
-    if [ "$ACTION" = "savecopy" ]; then
-      wl-copy --type image/png < "$FILE" || die "Clipboard error"
-      MESSAGE="$MESSAGE and clipboard"
-    fi
-    notifyOk "$MESSAGE" "$TITLE"
-    echo "$FILE"
-  else
-    notifyError "Error taking screenshot with grim"
-  fi
-fi
+}
+
+handleSave() {
+  screenshotTaken="takeScreenshot \"$FILE\" \"$GEOM\" \"$OUTPUT\""
+  whenOtherwise "$screenshotTaken" \
+    "handleScreenshotSuccess" \
+    "handleScreenshotFailure"
+}
+
+handleScreenshot() {
+  actionIsInvalid='[ "$ACTION" != "save" ] && [ "$ACTION" != "copy" ] && [ "$ACTION" != "savecopy" ] && [ "$ACTION" != "check" ]'
+  actionIsCheck='[ "$ACTION" = "check" ]'
+  subjectIsArea='[ "$SUBJECT" = "area" ]'
+  subjectIsActiveWindow='[ "$SUBJECT" = "active" ]'
+  subjectIsScreen='[ "$SUBJECT" = "screen" ]'
+  subjectIsOutput='[ "$SUBJECT" = "output" ]'
+  subjectIsWindow='[ "$SUBJECT" = "window" ]'
+  subjectIsAnything='[ "$SUBJECT" = "anything" ]'
+
+  any \
+    "$actionIsInvalid:printUsageMsg" \
+    "$actionIsCheck:checkRequiredTools" \
+    "$subjectIsArea:selectArea" \
+    "$subjectIsActiveWindow:selectActiveWindow" \
+    "$subjectIsScreen:selectScreen" \
+    "$subjectIsOutput:selectOutput" \
+    "$subjectIsWindow:selectWindow" \
+    "$subjectIsAnything:selectAnything" || die "Unknown subject to take a screenshot from" "$SUBJECT"
+
+  wait='[ "$WAIT" != "no" ]'
+  when "$wait" "sleep $WAIT"
+
+  actionIsCopy='[ "$ACTION" = "copy" ]'
+
+  whenOtherwise "$actionIsCopy" \
+    "handleCopy" \
+    "handleSave"
+}
+handleScreenshot