refactor(app): folder structure, components cleanup

src/components/UserSelection/index.js

@@ -0,0 +1,109 @@
+import React, { useEffect, useRef, useState, memo } from 'react';
+import { useStoreActions } from 'easy-peasy';
+
+const initialRect = {
+  startX: 0,
+  startY: 0,
+  x: 0,
+  y: 0,
+  width: 0,
+  height: 0,
+  draw: false
+};
+
+function getMousePosition(evt) {
+  const containerBounds = document.querySelector('.react-graph').getBoundingClientRect();
+
+  return {
+    x: evt.clientX - containerBounds.left,
+    y: evt.clientY - containerBounds.top,
+  };
+}
+
+export default memo(() => {
+  const selectionPane = useRef(null);
+  const [rect, setRect] = useState(initialRect);
+  const setSelection = useStoreActions(a => a.setSelection);
+  const updateSelection = useStoreActions(a => a.updateSelection);
+  const setNodesSelection = useStoreActions(a => a.setNodesSelection);
+
+  useEffect(() => {
+    function onMouseDown(evt) {
+      const mousePos = getMousePosition(evt);
+
+      setRect((currentRect) => ({
+        ...currentRect,
+        startX: mousePos.x,
+        startY: mousePos.y,
+        x: mousePos.x,
+        y: mousePos.y,
+        draw: true
+      }));
+
+      setSelection(true);
+    }
+
+    function onMouseMove(evt) {
+      setRect((currentRect) => {
+        if (!currentRect.draw) {
+          return currentRect;
+        }
+
+        const mousePos = getMousePosition(evt);
+        const negativeX = mousePos.x < currentRect.startX;
+        const negativeY = mousePos.y < currentRect.startY;
+        const nextRect = {
+          ...currentRect,
+          x: negativeX ? mousePos.x : currentRect.x,
+          y: negativeY ? mousePos.y : currentRect.y,
+          width: negativeX ? currentRect.startX - mousePos.x : mousePos.x - currentRect.startX,
+          height: negativeY ? currentRect.startY - mousePos.y : mousePos.y - currentRect.startY,
+        };
+
+        updateSelection(nextRect);
+
+        return nextRect;
+      });
+    }
+
+    function onMouseUp() {
+      setRect((currentRect) => {
+        setNodesSelection({ isActive: true, selection: currentRect });
+        setSelection(false);
+
+        return {
+          ...currentRect,
+          draw: false
+        };
+      });
+    }
+
+    selectionPane.current.addEventListener('mousedown', onMouseDown);
+    selectionPane.current.addEventListener('mousemove', onMouseMove);
+    selectionPane.current.addEventListener('mouseup', onMouseUp);
+
+    return () => {
+      selectionPane.current.removeEventListener('mousedown', onMouseDown);
+      selectionPane.current.removeEventListener('mousemove', onMouseMove);
+      selectionPane.current.removeEventListener('mouseup', onMouseUp);
+    };
+  }, []);
+
+  return (
+    <div
+      className="react-graph__selectionpane"
+      ref={selectionPane}
+    >
+      {(rect.draw || rect.fixed) && (
+        <div
+          className="react-graph__selection"
+          style={{
+            width: rect.width,
+            height: rect.height,
+            transform: `translate(${rect.x}px, ${rect.y}px)`
+          }}
+        />
+      )}
+    </div>
+  );
+});