From b8d619390afe4fe2dd41bf666782493a5e7711e0 Mon Sep 17 00:00:00 2001
From: Bruno Alves de Faria <brunoalvesdefaria@gmail.com>
Date: Tue, 29 May 2018 21:15:24 -0300
Subject: [PATCH] feat(bidirectional-tool): Reset rotation behaviour when
 long/short axes invert

---
 .../bidirectionalTool/invertHandles.js        | 42 +++++++++++++++++++
 .../bidirectionalTool/mouseDownCallback.js    |  9 +++-
 2 files changed, 49 insertions(+), 2 deletions(-)
 create mode 100644 Packages/ohif-lesiontracker/client/compatibility/bidirectionalTool/invertHandles.js

diff --git a/Packages/ohif-lesiontracker/client/compatibility/bidirectionalTool/invertHandles.js b/Packages/ohif-lesiontracker/client/compatibility/bidirectionalTool/invertHandles.js
new file mode 100644
index 000000000..8405a9c09
--- /dev/null
+++ b/Packages/ohif-lesiontracker/client/compatibility/bidirectionalTool/invertHandles.js
@@ -0,0 +1,42 @@
+const swapAttribute = (a, b, attribute) => {
+    const originalA = a[attribute];
+    const originalB = b[attribute];
+    a[attribute] = originalB;
+    b[attribute] = originalA;
+};
+
+const swapHandles = (a, b) => {
+    swapAttribute(a, b, 'x');
+    swapAttribute(a, b, 'y');
+    swapAttribute(a, b, 'moving');
+    swapAttribute(a, b, 'hover');
+    swapAttribute(a, b, 'active');
+    swapAttribute(a, b, 'selected');
+};
+
+function invertHandles(eventData, measurementData, handle) {
+    const { rowPixelSpacing, columnPixelSpacing } = eventData.image;
+    const { handles } = measurementData;
+    const { start, end, perpendicularStart, perpendicularEnd } = handles;
+
+    // Calculate the long axis length
+    const dx = (start.x - end.x) * (columnPixelSpacing || 1);
+    const dy = (start.y - end.y) * (rowPixelSpacing || 1);
+    const length = Math.sqrt(dx * dx + dy * dy);
+
+    // Calculate the short axis length
+    const wx = (perpendicularStart.x - perpendicularEnd.x) * (columnPixelSpacing || 1);
+    const wy = (perpendicularStart.y - perpendicularEnd.y) * (rowPixelSpacing || 1);
+    const width = Math.sqrt(wx * wx + wy * wy) || 0;
+
+    if (width > length) {
+        swapHandles(start, end);
+        swapHandles(start, perpendicularStart);
+        swapHandles(end, perpendicularEnd);
+        return Object.values(handles).find(h => h.moving === true);
+    }
+
+    return handle;
+}
+
+export default invertHandles;
diff --git a/Packages/ohif-lesiontracker/client/compatibility/bidirectionalTool/mouseDownCallback.js b/Packages/ohif-lesiontracker/client/compatibility/bidirectionalTool/mouseDownCallback.js
index 6bff924d0..f762cb54c 100644
--- a/Packages/ohif-lesiontracker/client/compatibility/bidirectionalTool/mouseDownCallback.js
+++ b/Packages/ohif-lesiontracker/client/compatibility/bidirectionalTool/mouseDownCallback.js
@@ -5,6 +5,7 @@ import { toolType, distanceThreshold } from './definitions';
 import mouseMoveCallback from './mouseMoveCallback';
 import pointNearTool from './pointNearTool';
 import moveHandle from './moveHandle';
+import invertHandles from './invertHandles';
 
 // Clear the selected state for the given handles object
 const unselectAllHandles = handles => {
@@ -88,9 +89,14 @@ export default function(event) {
     for (let i = 0; i < toolData.data.length; i++) {
         data = toolData.data[i];
         const handleParams = [element, data.handles, coords, distanceThreshold];
-        const handle = cornerstoneTools.getHandleNearImagePoint(...handleParams);
+        let handle = cornerstoneTools.getHandleNearImagePoint(...handleParams);
 
         if (handle) {
+            handle.moving = true;
+
+            // Invert handles if needed
+            handle = invertHandles(eventData, data, handle);
+
             // Hide the cursor to improve precision while resizing the line or set to move
             // if dragging text box
             $element.css('cursor', handle.hasBoundingBox ? 'move' : 'none');
@@ -99,7 +105,6 @@ export default function(event) {
             data.active = true;
 
             unselectAllHandles(data.handles);
-            handle.moving = true;
             moveHandle(eventData, toolType, data, handle, () => handleDoneMove(handle));
             event.stopImmediatePropagation();
             event.stopPropagation();