fix(editor): suface component can be null (#12270)

Closes: BS-3149

<!-- This is an auto-generated comment: release notes by coderabbit.ai -->

## Summary by CodeRabbit

- **Refactor**
  - Improved internal handling of surface components across various tools, resulting in safer and more consistent access patterns.
  - Enhanced code maintainability and reliability without altering any visible features or user workflows.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

blocksuite/affine/gfx/brush/src/eraser-tool.ts

@@ -34,6 +34,10 @@ export class EraserTool extends BaseTool {
 
   private readonly _eraseTargets = new Set<GfxModel>();
 
+  private get _surfaceComponent() {
+    return this.gfx.surfaceComponent as SurfaceBlockComponent | null;
+  }
+
   private readonly _loop = () => {
     const now = Date.now();
     const elapsed = now - this._timestamp;
@@ -59,7 +63,7 @@ export class EraserTool extends BaseTool {
         })
       );
       this._overlay.d = d;
-      (this.gfx.surfaceComponent as SurfaceBlockComponent)?.refresh();
+      this._surfaceComponent?.refresh();
     }
     this._timer = requestAnimationFrame(this._loop);
   };
@@ -81,9 +85,7 @@ export class EraserTool extends BaseTool {
       return;
     }
 
-    (
-      this.gfx.surfaceComponent as SurfaceBlockComponent
-    )?.renderer.removeOverlay(this._overlay);
+    this._surfaceComponent?.renderer.removeOverlay(this._overlay);
     this._erasable.clear();
     this._eraseTargets.clear();
   }
@@ -150,8 +152,7 @@ export class EraserTool extends BaseTool {
       ...this.gfx.layer.blocks,
     ]);
     this._loop();
-    (this.gfx.surfaceComponent as SurfaceBlockComponent)?.renderer.addOverlay(
-      this._overlay
-    );
+
+    this._surfaceComponent?.renderer.addOverlay(this._overlay);
   }
 }

blocksuite/affine/gfx/mindmap/src/interactivity/mind-map-drag.ts

@@ -312,7 +312,8 @@ export class MindMapDragExtension extends InteractivityExtension {
     mindmapNode: MindmapNode,
     pos: { x: number; y: number }
   ) {
-    const surfaceBlock = this.gfx.surfaceComponent as SurfaceBlockComponent;
+    const surfaceBlock = this.gfx
+      .surfaceComponent as SurfaceBlockComponent | null;
     const renderer = surfaceBlock?.renderer;
     const indicatorOverlay = this._indicatorOverlay;
 

blocksuite/affine/gfx/note/src/note-tool.ts

@@ -47,20 +47,22 @@ export class NoteTool extends BaseTool<NoteToolOption> {
 
   private _noteOverlay: NoteOverlay | null = null;
 
+  private get _surfaceComponent() {
+    return this.gfx.surfaceComponent as SurfaceBlockComponent | null;
+  }
+
   // Ensure clear overlay before adding a new note
   private _clearOverlay() {
     this._noteOverlay = this._disposeOverlay(this._noteOverlay);
     this._draggingNoteOverlay = this._disposeOverlay(this._draggingNoteOverlay);
-    (this.gfx.surfaceComponent as SurfaceBlockComponent).refresh();
+    this._surfaceComponent?.refresh();
   }
 
   private _disposeOverlay(overlay: NoteOverlay | null) {
     if (!overlay) return null;
 
     overlay.dispose();
-    (
-      this.gfx.surfaceComponent as SurfaceBlockComponent
-    )?.renderer.removeOverlay(overlay);
+    this._surfaceComponent?.renderer.removeOverlay(overlay);
     return null;
   }
 
@@ -69,7 +71,7 @@ export class NoteTool extends BaseTool<NoteToolOption> {
     if (!this._noteOverlay) return;
 
     this._noteOverlay.globalAlpha = 0;
-    (this.gfx.surfaceComponent as SurfaceBlockComponent)?.refresh();
+    this._surfaceComponent?.refresh();
   }
 
   private _resize(shift = false) {
@@ -102,7 +104,7 @@ export class NoteTool extends BaseTool<NoteToolOption> {
     if (!this._noteOverlay) return;
     this._noteOverlay.x = x;
     this._noteOverlay.y = y;
-    (this.gfx.surfaceComponent as SurfaceBlockComponent).refresh();
+    this._surfaceComponent?.refresh();
   }
 
   override activate() {
@@ -111,9 +113,7 @@ export class NoteTool extends BaseTool<NoteToolOption> {
     const background = attributes.background;
     this._noteOverlay = new NoteOverlay(this.gfx, background);
     this._noteOverlay.text = this.activatedOption.tip;
-    (this.gfx.surfaceComponent as SurfaceBlockComponent).renderer.addOverlay(
-      this._noteOverlay
-    );
+    this._surfaceComponent?.renderer.addOverlay(this._noteOverlay);
   }
 
   override click(e: PointerEventState): void {
@@ -176,9 +176,7 @@ export class NoteTool extends BaseTool<NoteToolOption> {
       this.std.get(EditPropsStore).lastProps$.value['affine:note'];
     const background = attributes.background;
     this._draggingNoteOverlay = new DraggingNoteOverlay(this.gfx, background);
-    (this.gfx.surfaceComponent as SurfaceBlockComponent).renderer.addOverlay(
-      this._draggingNoteOverlay
-    );
+    this._surfaceComponent?.renderer.addOverlay(this._draggingNoteOverlay);
   }
 
   override mounted() {

blocksuite/affine/gfx/note/src/overlay/overlay.ts

@@ -1,5 +1,5 @@
 import {
-  type SurfaceBlockComponent,
+  getSurfaceComponent,
   ToolOverlay,
 } from '@blocksuite/affine-block-surface';
 import { type Color, DefaultTheme } from '@blocksuite/affine-model';
@@ -36,7 +36,8 @@ export class NoteOverlay extends ToolOverlay {
         if (this.gfx.tool.currentToolName$.value !== 'affine:note') return;
         const tool = this.gfx.tool.currentTool$.peek() as NoteTool;
         this.text = this._getOverlayText(tool.activatedOption.tip);
-        (this.gfx.surfaceComponent as SurfaceBlockComponent).refresh();
+        const surface = getSurfaceComponent(this.gfx.std);
+        surface?.refresh();
       })
     );
   }
@@ -139,7 +140,8 @@ export class DraggingNoteOverlay extends NoteOverlay {
     this.disposables.add(
       this.slots.draggingNoteUpdated.subscribe(({ xywh }) => {
         [this.x, this.y, this.width, this.height] = xywh;
-        (this.gfx.surfaceComponent as SurfaceBlockComponent).refresh();
+        const surface = getSurfaceComponent(this.gfx.std);
+        surface?.refresh();
       })
     );
   }

blocksuite/affine/gfx/shape/src/overlay/shape-overlay.ts

@@ -1,7 +1,7 @@
 import {
+  getSurfaceComponent,
   type Options,
   type RoughCanvas,
-  type SurfaceBlockComponent,
   ToolOverlay,
 } from '@blocksuite/affine-block-surface';
 import {
@@ -87,7 +87,8 @@ export class ShapeOverlay extends ToolOverlay {
           shapeStyle
         );
 
-        (this.gfx.surfaceComponent as SurfaceBlockComponent).refresh();
+        const surface = getSurfaceComponent(this.gfx.std);
+        surface?.refresh();
       })
     );
   }

blocksuite/affine/gfx/shape/src/shape-tool.ts

@@ -41,6 +41,10 @@ export class ShapeTool extends BaseTool<ShapeToolOption> {
   // shape overlay
   private _shapeOverlay: ShapeOverlay | null = null;
 
+  private get _surfaceComponent() {
+    return this.gfx.surfaceComponent as SurfaceBlockComponent | null;
+  }
+
   private _spacePressedCtx: {
     draggingArea: IBound & {
       endX: number;
@@ -91,7 +95,7 @@ export class ShapeTool extends BaseTool<ShapeToolOption> {
   private _hideOverlay() {
     if (!this._shapeOverlay) return;
     this._shapeOverlay.globalAlpha = 0;
-    (this.gfx.surfaceComponent as SurfaceBlockComponent)?.refresh();
+    this._surfaceComponent?.refresh();
   }
 
   private _resize(shiftPressed = false, spacePressed = false) {
@@ -152,7 +156,7 @@ export class ShapeTool extends BaseTool<ShapeToolOption> {
     if (!this._shapeOverlay) return;
     this._shapeOverlay.x = x;
     this._shapeOverlay.y = y;
-    (this.gfx.surfaceComponent as SurfaceBlockComponent)?.refresh();
+    this._surfaceComponent?.refresh();
   }
 
   override activate() {
@@ -163,11 +167,11 @@ export class ShapeTool extends BaseTool<ShapeToolOption> {
     if (!this._shapeOverlay) return;
 
     this._shapeOverlay.dispose();
-    (
-      this.gfx.surfaceComponent as SurfaceBlockComponent
-    )?.renderer.removeOverlay(this._shapeOverlay);
+
+    this._surfaceComponent?.renderer.removeOverlay(this._shapeOverlay);
     this._shapeOverlay = null;
-    (this.gfx.surfaceComponent as SurfaceBlockComponent)?.renderer.refresh();
+
+    this._surfaceComponent?.renderer.refresh();
   }
 
   override click(e: PointerEventState): void {
@@ -223,9 +227,7 @@ export class ShapeTool extends BaseTool<ShapeToolOption> {
       fillColor: attributes.fillColor,
       strokeColor: attributes.strokeColor,
     });
-    (this.gfx.surfaceComponent as SurfaceBlockComponent)?.renderer.addOverlay(
-      this._shapeOverlay
-    );
+    this._surfaceComponent?.renderer.addOverlay(this._shapeOverlay);
   }
 
   override deactivate() {