Merge branch 'restrict-polygon-element' into 'master'

Restrict a polygon to the element's bounding box

Closes #750

See merge request !1041

vue/Image/InteractiveImage.vue

@@ -393,6 +393,7 @@ export default {
     },
     editPolygon (position, action) {
       const polygon = this.selectedElement && [...this.selectedElement.zone.polygon]
+      const point = this.elementLimits(position)
       if (action === 'up') {
         // Create a temporary edited element with drawn polygon first and last point
         if (!polygon) {
@@ -400,7 +401,7 @@ export default {
             id: 'created-polygon',
             zone: {
               image: { ...this.element.zone.image },
-              polygon: [position, position]
+              polygon: [point, point]
             }
           })
           return
@@ -411,12 +412,12 @@ export default {
         } else if (magnetized && polygon.some(pt => pointsEqual(position, pt))) {
           // Do not allow to reuse an existing point
         } else {
-          polygon.push(position)
+          polygon.push(point)
         }
       } else if (this.selectedElement && action === 'move') {
         this.magnetize(position, polygon)
         // Add a segment between the last polygon point and the current cursor position
-        polygon.splice(-1, 1, this.elementLimits(position))
+        polygon.splice(-1, 1, point)
       } else if (this.selectedElement && action === 'dbClick') {
         polygon.push(polygon[0])
         if (this.selectedElement) return this.create()