Initial commit

js/UEBlueprintDrag.js

@@ -0,0 +1,69 @@
+export default class UEBlueprintDrag {
+    constructor(draggedNode, options) {
+        this.blueprintNode = draggedNode;
+        this.mousePosition = [0, 0];
+        this.stepSize = 1
+        this.clickButton = options?.clickButton ?? 0
+        this.exitGrabSameButtonOnly = options?.exitGrabSameButtonOnly ?? false
+        let self = this;
+        this.mouseDownHandler = function (e) {
+            switch (e.button) {
+                case self.clickButton:
+                    self.clicked(e.clientX, e.clientY)
+                    break;
+                default:
+                    if (!self.exitGrabSameButtonOnly) {
+                        self.mouseUpHandler(e)
+                    }
+                    break;
+            }
+        };
+        this.mouseMoveHandler = function (e) {
+            let mousePosition = self.snapToGrid(e.clientX, e.clientY)
+            const d = [mousePosition[0] - self.mousePosition[0], mousePosition[1] - self.mousePosition[1]]
+
+            if (d[0] == 0 && d[1] == 0) {
+                return;
+            }
+
+            self.blueprintNode.addLocation(d)
+
+            // Reassign the position of mouse
+            self.mousePosition = mousePosition
+        };
+        this.mouseUpHandler = function (e) {
+            if (!self.exitGrabSameButtonOnly || e.button == self.clickButton) {
+                // Remove the handlers of `mousemove` and `mouseup`
+                document.removeEventListener('mousemove', self.mouseMoveHandler)
+                document.removeEventListener('mouseup', self.mouseUpHandler)
+            }
+        };
+        let element = this.blueprintNode.getDOMElement()
+        element.addEventListener('mousedown', this.mouseDownHandler)
+        element.addEventListener('contextmenu', e => e.preventDefault())
+    }
+
+    unlistenDOMElement() {
+        if (this.blueprintNode) {
+            this.blueprintNode.getDOMElement().removeEventListener('mousedown', this.mouseDownHandler)
+            return true
+        }
+        return false
+    }
+
+    snapToGrid(posX, posY) {
+        return [
+            this.stepSize * Math.round(posX / this.stepSize),
+            this.stepSize * Math.round(posY / this.stepSize)
+        ]
+    }
+
+    clicked(x, y) {
+        // Get the current mouse position
+        this.mousePosition = this.snapToGrid(x, y)
+        this.stepSize = parseInt(getComputedStyle(this.blueprintNode.getDOMElement()).getPropertyValue('--ueb-grid-snap'))
+        // Attach the listeners to `document`
+        document.addEventListener('mousemove', this.mouseMoveHandler)
+        document.addEventListener('mouseup', this.mouseUpHandler)
+    }
+}