selector initial implementation

js/UEBlueprintSelect.js

@@ -0,0 +1,45 @@
+export default class UEBlueprintSelect {
+    constructor(blueprintNode, options) {
+        this.blueprintNode = blueprintNode;
+        this.mousePosition = [0, 0];
+        this.clickButton = options?.clickButton ?? 0
+        this.exitSelectAnyButton = options?.exitSelectAnyButton ?? true
+        let self = this;
+        this.mouseDownHandler = function (e) {
+            switch (e.button) {
+                case self.clickButton:
+                    self.clicked(e.clientX, e.clientY)
+                    break
+                default:
+                    if (!self.exitSelectAnyButton) {
+                        self.mouseUpHandler(e)
+                    }
+                    break
+            }
+        };
+        this.mouseMoveHandler = function (e) {
+            self.blueprintNode.doSelecting(e.clientX, e.clientY)
+        }
+        this.mouseUpHandler = function (e) {
+            if (!self.exitSelectAnyButton || e.button == self.clickButton) {
+                // Remove the handlers of `mousemove` and `mouseup`
+                document.removeEventListener('mousemove', self.mouseMoveHandler)
+                document.removeEventListener('mouseup', self.mouseUpHandler)
+            }
+        }
+        this.blueprintNode.addEventListener('mousedown', this.mouseDownHandler)
+        this.blueprintNode.addEventListener('contextmenu', e => e.preventDefault())
+    }
+
+    unlistenDOMElement() {
+        this.blueprintNode.removeEventListener('mousedown', this.mouseDownHandler)
+    }
+
+    clicked(x, y) {
+        // Attach the listeners to `document`
+        document.addEventListener('mousemove', this.mouseMoveHandler)
+        document.addEventListener('mouseup', this.mouseUpHandler)
+        // Start selecting
+        this.blueprintNode.startSelecting(x, y)
+    }
+}