chore(modeling/BpmnLayouter): refactor boundary event layout

lib/features/modeling/BpmnLayouter.js

@@ -271,82 +271,85 @@ function getBoundaryEventPreferredLayouts(source, target) {
       targetMid = getMid(target),
       attachOrientation = getAttachOrientation(source),
       sourceLayout,
-      targetlayout;
+      targetLayout;
 
   var isLoop = isSame(source.host, target);
 
   var attachedToSide = isAnyOrientation(attachOrientation, [ 'top', 'right', 'bottom', 'left' ]);
 
-  var isHorizontalAttachOrientation = isHorizontalOrientation(attachOrientation);
-
   var targetOrientation = getOrientation(targetMid, sourceMid, {
     x: source.width / 2 + target.width / 2,
     y: source.height / 2 + target.height / 2
   });
 
   // source layout
-
+  sourceLayout = getBoundaryEventSourceLayout(attachOrientation, targetOrientation, attachedToSide, isLoop);
-  // attached to either top, right, bottom or left side
-  if (attachedToSide) {
-
-    sourceLayout = orientationDirectionMapping[
-      isHorizontalAttachOrientation ?
-        getHorizontalOrientation(attachOrientation) :
-        getVerticalOrientation(attachOrientation)
-    ];
-
-  } else
-
-  // attached to either top-right, top-left, bottom-right or bottom-left corner
-  {
-
-    // loop, same vertical or opposite horizontal orientation
-    if (isLoop ||
-      isSame(getVerticalOrientation(attachOrientation), getVerticalOrientation(targetOrientation)) ||
-      isOppositeOrientation(getHorizontalOrientation(attachOrientation), getHorizontalOrientation(targetOrientation))
-    ) {
-      sourceLayout = orientationDirectionMapping[getVerticalOrientation(attachOrientation)];
-    } else {
-      sourceLayout = orientationDirectionMapping[getHorizontalOrientation(attachOrientation)];
-    }
-
-  }
 
   // target layout
+  targetLayout = getBoundaryEventTargetLayout(attachOrientation, targetOrientation, attachedToSide, isLoop);
+
+  return [ sourceLayout + ':' + targetLayout ];
+}
+
+function getBoundaryEventSourceLayout(attachOrientation, targetOrientation, attachedToSide, isLoop) {
 
   // attached to either top, right, bottom or left side
   if (attachedToSide) {
-
+    return orientationDirectionMapping[attachOrientation];
-    // loop or opposite horizontal/vertical orientation
-    if (
-      isLoop ||
-      (isHorizontalAttachOrientation ?
-        isOppositeHorizontalOrientation(attachOrientation, targetOrientation) :
-        isOppositeVerticalOrientation(attachOrientation, targetOrientation))
-    ) {
-      targetlayout = isHorizontalAttachOrientation ? 'h' : 'v';
-    } else {
-      targetlayout = isHorizontalAttachOrientation ? 'v' : 'h';
-    }
-
-  } else
-
-  // attached to either top-right, top-left, bottom-right or bottom-left corner
-  {
-
-    // orientation is 'right', 'left'
-    // or same vertical orientation but also 'right' or 'left'
-    if (
-      isHorizontalOrientation(targetOrientation) ||
-      (isSame(getVerticalOrientation(attachOrientation), getVerticalOrientation(targetOrientation)) &&
-        getHorizontalOrientation(targetOrientation))
-    ) {
-      targetlayout = 'h';
-    } else {
-      targetlayout = 'v';
-    }
-
   }
 
-  return [ sourceLayout + ':' + targetlayout ];
+  // attached to either top-right, top-left, bottom-right or bottom-left corner
-}
+
+  // loop, same vertical or opposite horizontal orientation
+  if (isLoop ||
+    isSame(
+      getVerticalOrientation(attachOrientation), getVerticalOrientation(targetOrientation)
+    ) ||
+    isOppositeOrientation(
+      getHorizontalOrientation(attachOrientation), getHorizontalOrientation(targetOrientation)
+    )) {
+    return orientationDirectionMapping[getVerticalOrientation(attachOrientation)];
+  }
+
+  // fallback
+  return orientationDirectionMapping[getHorizontalOrientation(attachOrientation)];
+}
+
+function getBoundaryEventTargetLayout(attachOrientation, targetOrientation, attachedToSide, isLoop) {
+
+  // attached to either top, right, bottom or left side
+  if (attachedToSide) {
+    if (isHorizontalOrientation(attachOrientation)) {
+      // orientation is 'right' or 'left'
+
+      // loop or opposite horizontal orientation
+      if (isLoop || isOppositeHorizontalOrientation(attachOrientation, targetOrientation)) {
+        return 'h';
+      }
+
+      // fallback
+      return 'v';
+    } else {
+      // orientation is 'top' or 'bottom'
+
+      // loop or opposite vertical orientation
+      if (isLoop || isOppositeVerticalOrientation(attachOrientation, targetOrientation)) {
+        return 'v';
+      }
+
+      // fallback
+      return 'h';
+    }
+  }
+  // attached to either top-right, top-left, bottom-right or bottom-left corner
+
+  // orientation is 'right', 'left'
+  // or same vertical orientation but also 'right' or 'left'
+  if (isHorizontalOrientation(targetOrientation) ||
+    (isSame(getVerticalOrientation(attachOrientation), getVerticalOrientation(targetOrientation)) &&
+      getHorizontalOrientation(targetOrientation))) {
+    return 'h';
+  } else {
+    return 'v';
+  }
+}