Extract element functions into modules (#207)

src/element/handlerRectangles.ts

@@ -0,0 +1,85 @@
+import { SceneState } from "../scene/types";
+import { ExcalidrawElement } from "./types";
+
+export function handlerRectangles(
+  element: ExcalidrawElement,
+  sceneState: SceneState
+) {
+  const elementX1 = element.x;
+  const elementX2 = element.x + element.width;
+  const elementY1 = element.y;
+  const elementY2 = element.y + element.height;
+
+  const margin = 4;
+  const minimumSize = 40;
+  const handlers: { [handler: string]: number[] } = {};
+
+  const marginX = element.width < 0 ? 8 : -8;
+  const marginY = element.height < 0 ? 8 : -8;
+
+  if (Math.abs(elementX2 - elementX1) > minimumSize) {
+    handlers["n"] = [
+      elementX1 + (elementX2 - elementX1) / 2 + sceneState.scrollX - 4,
+      elementY1 - margin + sceneState.scrollY + marginY,
+      8,
+      8
+    ];
+
+    handlers["s"] = [
+      elementX1 + (elementX2 - elementX1) / 2 + sceneState.scrollX - 4,
+      elementY2 - margin + sceneState.scrollY - marginY,
+      8,
+      8
+    ];
+  }
+
+  if (Math.abs(elementY2 - elementY1) > minimumSize) {
+    handlers["w"] = [
+      elementX1 - margin + sceneState.scrollX + marginX,
+      elementY1 + (elementY2 - elementY1) / 2 + sceneState.scrollY - 4,
+      8,
+      8
+    ];
+
+    handlers["e"] = [
+      elementX2 - margin + sceneState.scrollX - marginX,
+      elementY1 + (elementY2 - elementY1) / 2 + sceneState.scrollY - 4,
+      8,
+      8
+    ];
+  }
+
+  handlers["nw"] = [
+    elementX1 - margin + sceneState.scrollX + marginX,
+    elementY1 - margin + sceneState.scrollY + marginY,
+    8,
+    8
+  ]; // nw
+  handlers["ne"] = [
+    elementX2 - margin + sceneState.scrollX - marginX,
+    elementY1 - margin + sceneState.scrollY + marginY,
+    8,
+    8
+  ]; // ne
+  handlers["sw"] = [
+    elementX1 - margin + sceneState.scrollX + marginX,
+    elementY2 - margin + sceneState.scrollY - marginY,
+    8,
+    8
+  ]; // sw
+  handlers["se"] = [
+    elementX2 - margin + sceneState.scrollX - marginX,
+    elementY2 - margin + sceneState.scrollY - marginY,
+    8,
+    8
+  ]; // se
+
+  if (element.type === "arrow") {
+    return {
+      nw: handlers.nw,
+      se: handlers.se
+    };
+  }
+
+  return handlers;
+}