duplicate point on cmd+d (#1831)

src/actions/actionDuplicateSelection.tsx

@@ -8,10 +8,47 @@ import { ToolButton } from "../components/ToolButton";
 import { clone } from "../components/icons";
 import { t } from "../i18n";
 import { getShortcutKey } from "../utils";
+import { LinearElementEditor } from "../element/linearElementEditor";
+import { mutateElement } from "../element/mutateElement";
 
 export const actionDuplicateSelection = register({
   name: "duplicateSelection",
   perform: (elements, appState) => {
+    // duplicate point if selected while editing multi-point element
+    if (appState.editingLinearElement) {
+      const { activePointIndex, elementId } = appState.editingLinearElement;
+      const element = LinearElementEditor.getElement(elementId);
+      if (!element || activePointIndex === null) {
+        return false;
+      }
+      const { points } = element;
+      const selectedPoint = points[activePointIndex];
+      const nextPoint = points[activePointIndex + 1];
+      mutateElement(element, {
+        points: [
+          ...points.slice(0, activePointIndex + 1),
+          nextPoint
+            ? [
+                (selectedPoint[0] + nextPoint[0]) / 2,
+                (selectedPoint[1] + nextPoint[1]) / 2,
+              ]
+            : [selectedPoint[0] + 30, selectedPoint[1] + 30],
+          ...points.slice(activePointIndex + 1),
+        ],
+      });
+      return {
+        appState: {
+          ...appState,
+          editingLinearElement: {
+            ...appState.editingLinearElement,
+            activePointIndex: activePointIndex + 1,
+          },
+        },
+        elements,
+        commitToHistory: true,
+      };
+    }
+
     const groupIdMap = new Map();
     return {
       appState,

src/actions/types.ts

@@ -2,12 +2,15 @@ import React from "react";
 import { ExcalidrawElement } from "../element/types";
 import { AppState } from "../types";
 
-export type ActionResult = {
+/** if false, the action should be prevented */
+export type ActionResult =
+  | {
       elements?: readonly ExcalidrawElement[] | null;
       appState?: AppState | null;
       commitToHistory: boolean;
       syncHistory?: boolean;
-};
+    }
+  | false;
 
 type ActionFn = (
   elements: readonly ExcalidrawElement[],

src/components/App.tsx

@@ -269,14 +269,15 @@ class App extends React.Component<any, AppState> {
     );
   }
 
-  private syncActionResult = withBatchedUpdates((res: ActionResult) => {
+  private syncActionResult = withBatchedUpdates(
-    if (this.unmounted) {
+    (actionResult: ActionResult) => {
+      if (this.unmounted || actionResult === false) {
         return;
       }
 
       let editingElement: AppState["editingElement"] | null = null;
-    if (res.elements) {
+      if (actionResult.elements) {
-      res.elements.forEach((element) => {
+        actionResult.elements.forEach((element) => {
           if (
             this.state.editingElement?.id === element.id &&
             this.state.editingElement !== element &&
@@ -285,26 +286,26 @@ class App extends React.Component<any, AppState> {
             editingElement = element;
           }
         });
-      globalSceneState.replaceAllElements(res.elements);
+        globalSceneState.replaceAllElements(actionResult.elements);
-      if (res.commitToHistory) {
+        if (actionResult.commitToHistory) {
           history.resumeRecording();
         }
       }
 
-    if (res.appState || editingElement) {
+      if (actionResult.appState || editingElement) {
-      if (res.commitToHistory) {
+        if (actionResult.commitToHistory) {
           history.resumeRecording();
         }
         this.setState(
           (state) => ({
-          ...res.appState,
+            ...actionResult.appState,
             editingElement:
-            editingElement || res.appState?.editingElement || null,
+              editingElement || actionResult.appState?.editingElement || null,
             isCollaborating: state.isCollaborating,
             collaborators: state.collaborators,
           }),
           () => {
-          if (res.syncHistory) {
+            if (actionResult.syncHistory) {
               history.setCurrentState(
                 this.state,
                 globalSceneState.getElementsIncludingDeleted(),
@@ -313,7 +314,8 @@ class App extends React.Component<any, AppState> {
           },
         );
       }
-  });
+    },
+  );
 
   // Lifecycle
 

src/locales/en.json

@@ -128,7 +128,7 @@
     "resize": "You can constrain proportions by holding SHIFT while resizing,\nhold ALT to resize from the center",
     "rotate": "You can constrain angles by holding SHIFT while rotating",
     "lineEditor_info": "Double-click or press Enter to edit points",
-    "lineEditor_pointSelected": "Press Delete to remove point or drag to move",
+    "lineEditor_pointSelected": "Press Delete to remove point, CtrlOrCmd+D to duplicate, or drag to move",
     "lineEditor_nothingSelected": "Select a point to move or remove, or hold Alt and click to add new points"
   },
   "errorSplash": {