Add uniqueKey function

useful when the react component is displaying the search to ensure
it redraws when required

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@canterbury-air-patrol/sar-search-patterns",
-  "version": "0.1.1",
+  "version": "0.1.2",
   "description": "Draw SAR Search Patterns",
   "main": "dist/index.js",
   "module": "dist/index.mjs",

sar-search-patterns.ts

@@ -56,6 +56,10 @@ class SearchPattern {
   nextLeg() {
     this.currentLeg++
   }
+
+  uniqueKey(): string {
+    return `${this.searchType}-${this.sweepWidth}-${this.searchLegs}-${this.currentLeg}`
+  }
 }
 
 function move(from: xy, direction: number, distance: number) {
@@ -114,6 +118,10 @@ class SectorSearch extends SearchPattern {
       lastPoint = to
     }
   }
+
+  uniqueKey(): string {
+    return `${this.searchType}-${this.sweepWidth}-${this.searchLegs}-${this.currentLeg}-${this.startingDirection}-${this.multiplier}-${this.iterations}`
+  }
 }
 
 class ExpandingBoxSearch extends SearchPattern {
@@ -140,6 +148,10 @@ class ExpandingBoxSearch extends SearchPattern {
       from = to
     }
   }
+
+  uniqueKey(): string {
+    return `${this.searchType}-${this.sweepWidth}-${this.searchLegs}-${this.currentLeg}-${this.startingDirection}-${this.iterations}`
+  }
 }
 
 class CreepingLineAheadSearch extends SearchPattern {
@@ -188,6 +200,10 @@ class CreepingLineAheadSearch extends SearchPattern {
       this.searchLegs.push(new SearchLeg(from, to, distance, direction))
     }
   }
+
+  uniqueKey(): string {
+    return `${this.searchType}-${this.sweepWidth}-${this.searchLegs}-${this.currentLeg}-${this.legLength}-${this.legs}-${this.progressDirection}`
+  }
 }
 
 export { SearchPattern, SearchLeg, SectorSearch, ExpandingBoxSearch, CreepingLineAheadSearch }