editor: add grid + snap toggles

packages/editor/src/editor/Canvas.tsx

@@ -14,6 +14,7 @@ export interface CanvasProps {
   scale: number;
   panX: number;
   panY: number;
+  gridEnabled: boolean;
   guides: { xs: number[]; ys: number[] };
   onSelectSingle(id?: string): void;
   onToggleSelect(id: string): void;
@@ -276,6 +277,19 @@ export function Canvas(props: CanvasProps) {
             position: 'relative',
           }}
         >
+          {props.gridEnabled ? (
+            <div
+              style={{
+                position: 'absolute',
+                inset: 0,
+                backgroundImage:
+                  'linear-gradient(to right, rgba(255,255,255,0.06) 1px, transparent 1px), linear-gradient(to bottom, rgba(255,255,255,0.06) 1px, transparent 1px)',
+                backgroundSize: '20px 20px',
+                pointerEvents: 'none',
+              }}
+            />
+          ) : null}
+
           {/* guides (snap lines) */}
           {props.guides.xs.map((x) => (
             <div

packages/editor/src/editor/EditorApp.tsx

@@ -213,6 +213,31 @@ export function EditorApp() {
         </Space>
 
         <Space size={8}>
+          <Button
+            size="small"
+            type={state.canvas.gridEnabled ? 'default' : 'text'}
+            onClick={() => dispatch({ type: 'toggleGrid' })}
+            style={
+              state.canvas.gridEnabled
+                ? { background: 'rgba(59,130,246,0.16)', color: '#e2e8f0', border: '1px solid rgba(59,130,246,0.35)' }
+                : { color: '#94a3b8' }
+            }
+          >
+            Grid
+          </Button>
+          <Button
+            size="small"
+            type={state.canvas.snapEnabled ? 'default' : 'text'}
+            onClick={() => dispatch({ type: 'toggleSnap' })}
+            style={
+              state.canvas.snapEnabled
+                ? { background: 'rgba(34,197,94,0.12)', color: '#e2e8f0', border: '1px solid rgba(34,197,94,0.30)' }
+                : { color: '#94a3b8' }
+            }
+          >
+            Snap
+          </Button>
+          <Divider type="vertical" style={{ borderColor: 'rgba(255,255,255,0.10)' }} />
           <Button size="small" style={{ background: 'rgba(255,255,255,0.06)', color: '#e2e8f0', border: 'none' }}>
             Preview
           </Button>
@@ -446,6 +471,7 @@ export function EditorApp() {
             scale={state.canvas.scale}
             panX={state.canvas.panX}
             panY={state.canvas.panY}
+            gridEnabled={state.canvas.gridEnabled}
             guides={state.canvas.guides}
             onSelectSingle={(id) => dispatch({ type: 'selectSingle', id })}
             onToggleSelect={(id) => dispatch({ type: 'toggleSelect', id })}

packages/editor/src/editor/store.ts

@@ -34,6 +34,8 @@ export type EditorAction =
   | { type: 'setScale'; scale: number }
   | { type: 'panBy'; dx: number; dy: number }
   | { type: 'zoomAt'; scale: number; anchor: { x: number; y: number } }
+  | { type: 'toggleGrid' }
+  | { type: 'toggleSnap' }
   | { type: 'beginPan'; start: { screenX: number; screenY: number } }
   | { type: 'updatePan'; current: { screenX: number; screenY: number } }
   | { type: 'endPan' }
@@ -271,6 +273,8 @@ export function createInitialState(): EditorRuntimeState {
       scale: 1,
       panX: 0,
       panY: 0,
+      gridEnabled: false,
+      snapEnabled: true,
       guides: { xs: [], ys: [] },
       isDragging: false,
       isPanning: false,
@@ -366,6 +370,28 @@ export function editorReducer(state: EditorRuntimeState, action: EditorAction):
       };
     }
 
+    case 'toggleGrid': {
+      return {
+        ...state,
+        canvas: {
+          ...state.canvas,
+          gridEnabled: !state.canvas.gridEnabled,
+        },
+      };
+    }
+
+    case 'toggleSnap': {
+      // Clearing guides prevents stale guide lines when turning snap off mid-drag.
+      return {
+        ...state,
+        canvas: {
+          ...state.canvas,
+          snapEnabled: !state.canvas.snapEnabled,
+          guides: { xs: [], ys: [] },
+        },
+      };
+    }
+
     case 'updateWidgetRect': {
       const target = state.doc.screen.nodes.find((n) => n.id === action.id);
       if (!target) return state;
@@ -874,8 +900,8 @@ export function editorReducer(state: EditorRuntimeState, action: EditorAction):
 
       const bounds = action.bounds;
 
-      // goView-like: only snap when a single node is selected.
-      const canSnap = state.selection.ids.length === 1;
+      // goView-like: only snap when enabled and a single node is selected.
+      const canSnap = state.canvas.snapEnabled && state.selection.ids.length === 1;
       const movingId = state.selection.ids[0];
 
       const others = canSnap
@@ -1058,8 +1084,8 @@ export function editorReducer(state: EditorRuntimeState, action: EditorAction):
         h: Math.max(0, newH),
       };
 
-      // goView-like: only snap when resizing a single selected node.
-      const canSnap = state.selection.ids.length === 1;
+      // goView-like: only snap when enabled and resizing a single selected node.
+      const canSnap = state.canvas.snapEnabled && state.selection.ids.length === 1;
       const movingId = drag.targetId;
 
       const others = canSnap

packages/editor/src/editor/types.ts

@@ -16,6 +16,8 @@ export interface EditorCanvasState {
   scale: number;
   panX: number;
   panY: number;
+  gridEnabled: boolean;
+  snapEnabled: boolean;
   guides: {
     xs: number[];
     ys: number[];