[2581] Allow custom tools to control their creation position

Bug: #2581
Signed-off-by: Florian ROUËNÉ <florian.rouene@obeosoft.com>

CHANGELOG.adoc

@@ -121,6 +121,7 @@ It uses our algorithm instead of elk.js to perform the arrange-all.
 - https://github.com/eclipse-sirius/sirius-web/issues/2625[#2625] [diagram] Fix the line style computation on edge and border node.
 - https://github.com/eclipse-sirius/sirius-web/issues/2633[#2633] [diagram] Make sure the grid is visible when enabled, even when moving a non-droppable node
 - https://github.com/eclipse-sirius/sirius-web/issues/2635[#2635] [diagram] Fix an error when switching between react flow representations.
+- https://github.com/eclipse-sirius/sirius-web/issues/2581[#2581] [diagram] Fix an issue where nodes created by custom tool are always on the default position.
 
 === New Features
 

packages/diagrams/frontend/sirius-components-diagrams-reactflow/src/index.ts

@@ -45,3 +45,5 @@ export { DiagramPaletteToolContext } from './renderer/palette/DiagramPaletteTool
 export { DiagramPaletteToolContribution } from './renderer/palette/DiagramPaletteToolContribution';
 export type { DiagramPaletteToolContributionComponentProps } from './renderer/palette/DiagramPaletteToolContribution.types';
 export { DiagramRepresentation } from './representation/DiagramRepresentation';
+export { useLayout } from './renderer/layout/useLayout';
+export { usePaletteReferencePosition } from './renderer/palette/usePaletteReferencePosition';

packages/diagrams/frontend/sirius-components-diagrams-reactflow/src/renderer/palette/usePaletteReferencePosition.tsx

@@ -0,0 +1,40 @@
+/*******************************************************************************
+ * Copyright (c) 2023 Obeo.
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     Obeo - initial API and implementation
+ *******************************************************************************/
+import { useViewport } from 'reactflow';
+import { UsePaletteReferencePositionValue } from './usePaletteReferencePosition.types';
+import { useDiagramElementPalette } from './useDiagramElementPalette';
+import { useDiagramPalette } from './useDiagramPalette';
+
+export const usePaletteReferencePosition = (): UsePaletteReferencePositionValue => {
+  const { x: viewportX, y: viewportY, zoom: viewportZoom } = useViewport();
+  const { x: paletteElementX, y: paletteElementY, isOpened: isPaletteElementOpened } = useDiagramElementPalette();
+  const { x: paletteX, y: paletteY, isOpened: isPaletteOpened } = useDiagramPalette();
+
+  let x: number | null = null;
+  let y: number | null = null;
+
+  if (viewportZoom !== 0 && isPaletteOpened && paletteX && paletteY) {
+    x = (paletteX - viewportX) / viewportZoom;
+    y = (paletteY - viewportY) / viewportZoom;
+  }
+
+  if (viewportZoom !== 0 && isPaletteElementOpened && paletteElementX && paletteElementY) {
+    x = (paletteElementX - viewportX) / viewportZoom;
+    y = (paletteElementY - viewportY) / viewportZoom;
+  }
+
+  return {
+    x,
+    y,
+  };
+};

packages/diagrams/frontend/sirius-components-diagrams-reactflow/src/renderer/palette/usePaletteReferencePosition.types.ts

@@ -0,0 +1,16 @@
+/*******************************************************************************
+ * Copyright (c) 2023 Obeo.
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     Obeo - initial API and implementation
+ *******************************************************************************/
+export interface UsePaletteReferencePositionValue {
+  x: number | null;
+  y: number | null;
+}