From 1bfd9c0e913f3eefc4593f6c344db1ae1f6e4df4 Mon Sep 17 00:00:00 2001
From: Alex Grozav <alex@grozav.com>
Date: Fri, 13 Dec 2024 11:20:53 +0200
Subject: [PATCH] feat(editor): Support adding nodes via drag and drop from
 node creator on new canvas (#12197)

---
 .../Node/NodeCreator/ItemTypes/NodeItem.vue   | 35 +++++--------------
 .../src/components/canvas/Canvas.vue          | 35 ++++++++++++-------
 .../background/CanvasBackground.test.ts       | 33 +++++++++++++++++
 .../elements/background/CanvasBackground.vue  | 24 +++++++++++++
 .../CanvasBackgroundStripedPattern.vue        |  0
 .../CanvasBackground.test.ts.snap             | 11 ++++++
 packages/editor-ui/src/views/NodeView.v2.vue  | 24 +++++++++++++
 packages/editor-ui/src/views/NodeView.vue     |  5 +--
 8 files changed, 123 insertions(+), 44 deletions(-)
 create mode 100644 packages/editor-ui/src/components/canvas/elements/background/CanvasBackground.test.ts
 create mode 100644 packages/editor-ui/src/components/canvas/elements/background/CanvasBackground.vue
 rename packages/editor-ui/src/components/canvas/elements/{ => background}/CanvasBackgroundStripedPattern.vue (100%)
 create mode 100644 packages/editor-ui/src/components/canvas/elements/background/__snapshots__/CanvasBackground.test.ts.snap

diff --git a/packages/editor-ui/src/components/Node/NodeCreator/ItemTypes/NodeItem.vue b/packages/editor-ui/src/components/Node/NodeCreator/ItemTypes/NodeItem.vue
index 9b4a8614d2..b982e4ecee 100644
--- a/packages/editor-ui/src/components/Node/NodeCreator/ItemTypes/NodeItem.vue
+++ b/packages/editor-ui/src/components/Node/NodeCreator/ItemTypes/NodeItem.vue
@@ -9,7 +9,6 @@ import {
 } from '@/constants';
 
 import { isCommunityPackageName } from '@/utils/nodeTypesUtils';
-import { getNewNodePosition, NODE_SIZE } from '@/utils/nodeViewUtils';
 import { useNodeCreatorStore } from '@/stores/nodeCreator.store';
 import NodeIcon from '@/components/NodeIcon.vue';
 
@@ -93,15 +92,6 @@ const isTrigger = computed<boolean>(() => {
 });
 
 function onDragStart(event: DragEvent): void {
-	/**
-	 * Workaround for firefox, that doesn't attach the pageX and pageY coordinates to "ondrag" event.
-	 * All browsers attach the correct page coordinates to the "dragover" event.
-	 * @bug https://bugzilla.mozilla.org/show_bug.cgi?id=505521
-	 */
-	document.body.addEventListener('dragover', onDragOver);
-
-	const { pageX: x, pageY: y } = event;
-
 	if (event.dataTransfer) {
 		event.dataTransfer.effectAllowed = 'copy';
 		event.dataTransfer.dropEffect = 'copy';
@@ -113,22 +103,9 @@ function onDragStart(event: DragEvent): void {
 	}
 
 	dragging.value = true;
-	draggablePosition.value = { x, y };
-}
-
-function onDragOver(event: DragEvent): void {
-	if (!dragging.value || (event.pageX === 0 && event.pageY === 0)) {
-		return;
-	}
-
-	const [x, y] = getNewNodePosition([], [event.pageX - NODE_SIZE / 2, event.pageY - NODE_SIZE / 2]);
-
-	draggablePosition.value = { x, y };
 }
 
 function onDragEnd(): void {
-	document.body.removeEventListener('dragover', onDragOver);
-
 	dragging.value = false;
 	setTimeout(() => {
 		draggablePosition.value = { x: -100, y: -100 };
@@ -144,7 +121,7 @@ function onCommunityNodeTooltipClick(event: MouseEvent) {
 
 <template>
 	<!-- Node Item is draggable only if it doesn't contain actions -->
-	<n8n-node-creator-node
+	<N8nNodeCreatorNode
 		:draggable="!showActionArrow"
 		:class="$style.nodeItem"
 		:description="description"
@@ -176,12 +153,16 @@ function onCommunityNodeTooltipClick(event: MouseEvent) {
 			/>
 		</template>
 		<template #dragContent>
-			<div ref="draggableDataTransfer" :class="$style.draggableDataTransfer" />
-			<div v-show="dragging" :class="$style.draggable" :style="draggableStyle">
+			<div
+				ref="draggableDataTransfer"
+				v-show="dragging"
+				:class="$style.draggable"
+				:style="draggableStyle"
+			>
 				<NodeIcon :node-type="nodeType" :size="40" :shrink="false" @click.capture.stop />
 			</div>
 		</template>
-	</n8n-node-creator-node>
+	</N8nNodeCreatorNode>
 </template>
 
 <style lang="scss" module>
diff --git a/packages/editor-ui/src/components/canvas/Canvas.vue b/packages/editor-ui/src/components/canvas/Canvas.vue
index 84f2bc729f..82566cdd68 100644
--- a/packages/editor-ui/src/components/canvas/Canvas.vue
+++ b/packages/editor-ui/src/components/canvas/Canvas.vue
@@ -8,7 +8,6 @@ import type {
 } from '@/types';
 import type { Connection, XYPosition, NodeDragEvent, GraphNode } from '@vue-flow/core';
 import { useVueFlow, VueFlow, PanelPosition, MarkerType } from '@vue-flow/core';
-import { Background } from '@vue-flow/background';
 import { MiniMap } from '@vue-flow/minimap';
 import Node from './elements/nodes/CanvasNode.vue';
 import Edge from './elements/edges/CanvasEdge.vue';
@@ -25,7 +24,7 @@ import { GRID_SIZE } from '@/utils/nodeViewUtils';
 import { CanvasKey } from '@/constants';
 import { onKeyDown, onKeyUp, useThrottleFn } from '@vueuse/core';
 import CanvasArrowHeadMarker from './elements/edges/CanvasArrowHeadMarker.vue';
-import CanvasBackgroundStripedPattern from './elements/CanvasBackgroundStripedPattern.vue';
+import CanvasBackground from './elements/background/CanvasBackground.vue';
 import { useCanvasTraversal } from '@/composables/useCanvasTraversal';
 import { NodeConnectionType } from 'n8n-workflow';
 
@@ -65,6 +64,7 @@ const emit = defineEmits<{
 	'run:workflow': [];
 	'save:workflow': [];
 	'create:workflow': [];
+	'drag-and-drop': [position: XYPosition, event: DragEvent];
 }>();
 
 const props = withDefaults(
@@ -535,6 +535,20 @@ function onContextMenuAction(action: ContextMenuAction, nodeIds: string[]) {
 	}
 }
 
+/**
+ * Drag and drop
+ */
+
+function onDragOver(event: DragEvent) {
+	event.preventDefault();
+}
+
+function onDrop(event: DragEvent) {
+	const position = getProjectedPosition(event);
+
+	emit('drag-and-drop', position, event);
+}
+
 /**
  * Minimap
  */
@@ -626,6 +640,7 @@ provide(CanvasKey, {
 		:id="id"
 		:nodes="nodes"
 		:edges="connections"
+		:class="classes"
 		:apply-changes="false"
 		:connection-line-options="{ markerEnd: MarkerType.ArrowClosed }"
 		:connection-radius="60"
@@ -635,7 +650,6 @@ provide(CanvasKey, {
 		:snap-grid="[GRID_SIZE, GRID_SIZE]"
 		:min-zoom="0"
 		:max-zoom="4"
-		:class="classes"
 		:selection-key-code="selectionKeyCode"
 		:pan-activation-key-code="panningKeyCode"
 		:disable-keyboard-a11y="true"
@@ -649,6 +663,8 @@ provide(CanvasKey, {
 		@move-end="onPaneMoveEnd"
 		@node-drag-stop="onNodeDragStop"
 		@selection-drag-stop="onSelectionDragStop"
+		@dragover="onDragOver"
+		@drop="onDrop"
 	>
 		<template #node-canvas-node="nodeProps">
 			<Node
@@ -687,16 +703,7 @@ provide(CanvasKey, {
 
 		<CanvasArrowHeadMarker :id="arrowHeadMarkerId" />
 
-		<Background data-test-id="canvas-background" pattern-color="#aaa" :gap="GRID_SIZE">
-			<template v-if="readOnly" #pattern-container="patternProps">
-				<CanvasBackgroundStripedPattern
-					:id="patternProps.id"
-					:x="viewport.x"
-					:y="viewport.y"
-					:zoom="viewport.zoom"
-				/>
-			</template>
-		</Background>
+		<CanvasBackground :viewport="viewport" :striped="readOnly" />
 
 		<Transition name="minimap">
 			<MiniMap
@@ -736,6 +743,8 @@ provide(CanvasKey, {
 
 <style lang="scss" module>
 .canvas {
+	width: 100%;
+	height: 100%;
 	opacity: 0;
 
 	&.ready {
diff --git a/packages/editor-ui/src/components/canvas/elements/background/CanvasBackground.test.ts b/packages/editor-ui/src/components/canvas/elements/background/CanvasBackground.test.ts
new file mode 100644
index 0000000000..cef24134a8
--- /dev/null
+++ b/packages/editor-ui/src/components/canvas/elements/background/CanvasBackground.test.ts
@@ -0,0 +1,33 @@
+import { createComponentRenderer } from '@/__tests__/render';
+import CanvasBackground from '@/components/canvas/elements/background/CanvasBackground.vue';
+
+const renderComponent = createComponentRenderer(CanvasBackground);
+
+describe('CanvasBackground', () => {
+	it('should render the background with the correct gap', () => {
+		const { getByTestId, html } = renderComponent({
+			props: { striped: false, viewport: { x: 0, y: 0, zoom: 1 } },
+		});
+		const background = getByTestId('canvas-background');
+
+		expect(background).toBeInTheDocument();
+		expect(html()).toMatchSnapshot();
+	});
+
+	it('should render the striped pattern when striped is true', () => {
+		const { getByTestId } = renderComponent({
+			props: { striped: true, viewport: { x: 0, y: 0, zoom: 1 } },
+		});
+		const pattern = getByTestId('canvas-background-striped-pattern');
+
+		expect(pattern).toBeInTheDocument();
+	});
+
+	it('should not render the striped pattern when striped is false', () => {
+		const { getByTestId } = renderComponent({
+			props: { striped: false, viewport: { x: 0, y: 0, zoom: 1 } },
+		});
+
+		expect(() => getByTestId('canvas-background-striped-pattern')).toThrow();
+	});
+});
diff --git a/packages/editor-ui/src/components/canvas/elements/background/CanvasBackground.vue b/packages/editor-ui/src/components/canvas/elements/background/CanvasBackground.vue
new file mode 100644
index 0000000000..a15ff96a9b
--- /dev/null
+++ b/packages/editor-ui/src/components/canvas/elements/background/CanvasBackground.vue
@@ -0,0 +1,24 @@
+<script setup lang="ts">
+import { GRID_SIZE } from '@/utils/nodeViewUtils';
+import CanvasBackgroundStripedPattern from './CanvasBackgroundStripedPattern.vue';
+import { Background } from '@vue-flow/background';
+import type { ViewportTransform } from '@vue-flow/core';
+
+defineProps<{
+	striped: boolean;
+	viewport: ViewportTransform;
+}>();
+</script>
+<template>
+	<Background data-test-id="canvas-background" pattern-color="#aaa" :gap="GRID_SIZE">
+		<template v-if="striped" #pattern-container="patternProps">
+			<CanvasBackgroundStripedPattern
+				:id="patternProps.id"
+				data-test-id="canvas-background-striped-pattern"
+				:x="viewport.x"
+				:y="viewport.y"
+				:zoom="viewport.zoom"
+			/>
+		</template>
+	</Background>
+</template>
diff --git a/packages/editor-ui/src/components/canvas/elements/CanvasBackgroundStripedPattern.vue b/packages/editor-ui/src/components/canvas/elements/background/CanvasBackgroundStripedPattern.vue
similarity index 100%
rename from packages/editor-ui/src/components/canvas/elements/CanvasBackgroundStripedPattern.vue
rename to packages/editor-ui/src/components/canvas/elements/background/CanvasBackgroundStripedPattern.vue
diff --git a/packages/editor-ui/src/components/canvas/elements/background/__snapshots__/CanvasBackground.test.ts.snap b/packages/editor-ui/src/components/canvas/elements/background/__snapshots__/CanvasBackground.test.ts.snap
new file mode 100644
index 0000000000..fa764fae2f
--- /dev/null
+++ b/packages/editor-ui/src/components/canvas/elements/background/__snapshots__/CanvasBackground.test.ts.snap
@@ -0,0 +1,11 @@
+// Vitest Snapshot v1, https://vitest.dev/guide/snapshot.html
+
+exports[`CanvasBackground > should render the background with the correct gap 1`] = `
+"<svg class="vue-flow__background vue-flow__container" style="height: 100%; width: 100%;" data-test-id="canvas-background">
+  <pattern id="pattern-vue-flow-0" x="0" y="0" width="20" height="20" patternTransform="translate(-11,-11)" patternUnits="userSpaceOnUse">
+    <circle cx="0.5" cy="0.5" r="0.5" fill="#aaa"></circle>
+    <!---->
+  </pattern>
+  <rect x="0" y="0" width="100%" height="100%" fill="url(#pattern-vue-flow-0)"></rect>
+</svg>"
+`;
diff --git a/packages/editor-ui/src/views/NodeView.v2.vue b/packages/editor-ui/src/views/NodeView.v2.vue
index 65a141295e..d2962af705 100644
--- a/packages/editor-ui/src/views/NodeView.v2.vue
+++ b/packages/editor-ui/src/views/NodeView.v2.vue
@@ -49,6 +49,7 @@ import type {
 import { CanvasNodeRenderType, CanvasConnectionMode } from '@/types';
 import {
 	CHAT_TRIGGER_NODE_TYPE,
+	DRAG_EVENT_DATA_KEY,
 	EnterpriseEditionFeature,
 	MAIN_HEADER_TABS,
 	MANUAL_CHAT_TRIGGER_NODE_TYPE,
@@ -1442,6 +1443,28 @@ function onClickPane(position: CanvasNode['position']) {
 	setNodeSelected();
 }
 
+/**
+ * Drag and Drop events
+ */
+
+async function onDragAndDrop(position: VueFlowXYPosition, event: DragEvent) {
+	if (!event.dataTransfer) {
+		return;
+	}
+
+	const dropData = jsonParse<AddedNodesAndConnections>(
+		event.dataTransfer.getData(DRAG_EVENT_DATA_KEY),
+	);
+
+	if (dropData) {
+		const insertNodePosition: XYPosition = [position.x, position.y];
+
+		await onAddNodesAndConnections(dropData, true, insertNodePosition);
+
+		onToggleNodeCreator({ createNodeActive: false, hasAddedNodes: true });
+	}
+}
+
 /**
  * Custom Actions
  */
@@ -1615,6 +1638,7 @@ onBeforeUnmount(() => {
 		@save:workflow="onSaveWorkflow"
 		@create:workflow="onCreateWorkflow"
 		@viewport-change="onViewportChange"
+		@drag-and-drop="onDragAndDrop"
 	>
 		<div v-if="!isCanvasReadOnly" :class="$style.executionButtons">
 			<CanvasRunWorkflowButton
diff --git a/packages/editor-ui/src/views/NodeView.vue b/packages/editor-ui/src/views/NodeView.vue
index b200903eac..25daff29f4 100644
--- a/packages/editor-ui/src/views/NodeView.vue
+++ b/packages/editor-ui/src/views/NodeView.vue
@@ -2056,10 +2056,7 @@ export default defineComponent({
 			);
 			if (dropData) {
 				const mousePosition = this.getMousePositionWithinNodeView(event);
-				const insertNodePosition = [
-					mousePosition[0] - NodeViewUtils.NODE_SIZE / 2 + NodeViewUtils.GRID_SIZE,
-					mousePosition[1] - NodeViewUtils.NODE_SIZE / 2,
-				] as XYPosition;
+				const insertNodePosition: XYPosition = [mousePosition[0], mousePosition[1]];
 
 				await this.onAddNodes(dropData, true, insertNodePosition);
 				this.createNodeActive = false;