refactor: extract common builder

blocksuite/affine/gfx/connector/src/element-renderer/connector-dom/index.ts

@@ -5,7 +5,7 @@ import {
   DefaultTheme,
   type PointStyle,
 } from '@blocksuite/affine-model';
-import { PointLocation } from '@blocksuite/global/gfx';
+import { PointLocation, SVGPathBuilder } from '@blocksuite/global/gfx';
 
 import { isConnectorWithLabel } from '../../connector-manager.js';
 import { DEFAULT_ARROW_SIZE } from '../utils.js';
@@ -17,60 +17,6 @@ interface PathBounds {
   maxY: number;
 }
 
-interface PathCommand {
-  command: string;
-  coordinates: number[];
-}
-
-class SVGPathBuilder {
-  private commands: PathCommand[] = [];
-
-  moveTo(x: number, y: number): this {
-    this.commands.push({
-      command: 'M',
-      coordinates: [x, y],
-    });
-    return this;
-  }
-
-  lineTo(x: number, y: number): this {
-    this.commands.push({
-      command: 'L',
-      coordinates: [x, y],
-    });
-    return this;
-  }
-
-  curveTo(
-    cp1x: number,
-    cp1y: number,
-    cp2x: number,
-    cp2y: number,
-    x: number,
-    y: number
-  ): this {
-    this.commands.push({
-      command: 'C',
-      coordinates: [cp1x, cp1y, cp2x, cp2y, x, y],
-    });
-    return this;
-  }
-
-  build(): string {
-    const pathSegments = this.commands.map(cmd => {
-      const coords = cmd.coordinates.join(' ');
-      return `${cmd.command} ${coords}`;
-    });
-
-    return pathSegments.join(' ');
-  }
-
-  clear(): this {
-    this.commands = [];
-    return this;
-  }
-}
-
 function calculatePathBounds(path: PointLocation[]): PathBounds {
   if (path.length === 0) {
     return { minX: 0, minY: 0, maxX: 0, maxY: 0 };

blocksuite/affine/gfx/shape/src/element-renderer/shape-dom/index.ts

@@ -1,6 +1,7 @@
 import type { DomRenderer } from '@blocksuite/affine-block-surface';
 import type { ShapeElementModel } from '@blocksuite/affine-model';
 import { DefaultTheme } from '@blocksuite/affine-model';
+import { SVGShapeBuilder } from '@blocksuite/global/gfx';
 
 import { manageClassNames, setStyles } from './utils';
 
@@ -122,25 +123,22 @@ export const shapeDomRenderer = (
     element.style.backgroundColor = 'transparent'; // Host element is transparent
 
     const strokeW = model.strokeWidth;
-    const halfStroke = strokeW / 2; // Calculate half stroke width for point adjustment
 
     let svgPoints = '';
     if (model.shapeType === 'diamond') {
-      // Adjusted points for diamond
-      svgPoints = [
-        `${unscaledWidth / 2},${halfStroke}`,
-        `${unscaledWidth - halfStroke},${unscaledHeight / 2}`,
-        `${unscaledWidth / 2},${unscaledHeight - halfStroke}`,
-        `${halfStroke},${unscaledHeight / 2}`,
-      ].join(' ');
+      // Generate diamond points using shared utility
+      svgPoints = SVGShapeBuilder.diamond(
+        unscaledWidth,
+        unscaledHeight,
+        strokeW
+      );
     } else {
-      // triangle
-      // Adjusted points for triangle
-      svgPoints = [
-        `${unscaledWidth / 2},${halfStroke}`,
-        `${unscaledWidth - halfStroke},${unscaledHeight - halfStroke}`,
-        `${halfStroke},${unscaledHeight - halfStroke}`,
-      ].join(' ');
+      // triangle - generate triangle points using shared utility
+      svgPoints = SVGShapeBuilder.triangle(
+        unscaledWidth,
+        unscaledHeight,
+        strokeW
+      );
     }
 
     // Determine if stroke should be visible and its color

blocksuite/framework/global/src/__tests__/svg-path.unit.spec.ts

@@ -0,0 +1,73 @@
+import { describe, expect, test } from 'vitest';
+
+import { SVGPathBuilder, SVGShapeBuilder } from '../gfx/svg-path.js';
+
+describe('SVGPathBuilder', () => {
+  test('should build a simple path', () => {
+    const pathBuilder = new SVGPathBuilder();
+    const result = pathBuilder.moveTo(10, 20).lineTo(30, 40).build();
+
+    expect(result).toBe('M 10 20 L 30 40');
+  });
+
+  test('should build a path with curves', () => {
+    const pathBuilder = new SVGPathBuilder();
+    const result = pathBuilder
+      .moveTo(0, 0)
+      .curveTo(10, 0, 10, 10, 20, 10)
+      .build();
+
+    expect(result).toBe('M 0 0 C 10 0 10 10 20 10');
+  });
+
+  test('should build a closed path', () => {
+    const pathBuilder = new SVGPathBuilder();
+    const result = pathBuilder
+      .moveTo(0, 0)
+      .lineTo(10, 0)
+      .lineTo(5, 10)
+      .closePath()
+      .build();
+
+    expect(result).toBe('M 0 0 L 10 0 L 5 10 Z');
+  });
+
+  test('should clear commands', () => {
+    const pathBuilder = new SVGPathBuilder();
+    pathBuilder.moveTo(10, 20).lineTo(30, 40);
+    pathBuilder.clear();
+    const result = pathBuilder.moveTo(0, 0).build();
+
+    expect(result).toBe('M 0 0');
+  });
+});
+
+describe('SVGShapeBuilder', () => {
+  test('should generate diamond polygon points', () => {
+    const result = SVGShapeBuilder.diamond(100, 80, 2);
+    expect(result).toBe('50,1 99,40 50,79 1,40');
+  });
+
+  test('should generate triangle polygon points', () => {
+    const result = SVGShapeBuilder.triangle(100, 80, 2);
+    expect(result).toBe('50,1 99,79 1,79');
+  });
+
+  test('should generate diamond path', () => {
+    const result = SVGShapeBuilder.diamondPath(100, 80, 2);
+    expect(result).toBe('M 50 1 L 99 40 L 50 79 L 1 40 Z');
+  });
+
+  test('should generate triangle path', () => {
+    const result = SVGShapeBuilder.trianglePath(100, 80, 2);
+    expect(result).toBe('M 50 1 L 99 79 L 1 79 Z');
+  });
+
+  test('should handle zero stroke width', () => {
+    const diamondResult = SVGShapeBuilder.diamond(100, 80, 0);
+    expect(diamondResult).toBe('50,0 100,40 50,80 0,40');
+
+    const triangleResult = SVGShapeBuilder.triangle(100, 80, 0);
+    expect(triangleResult).toBe('50,0 100,80 0,80');
+  });
+});

blocksuite/framework/global/src/gfx/index.ts

@@ -4,4 +4,5 @@ export * from './math.js';
 export * from './model/index.js';
 export * from './perfect-freehand/index.js';
 export * from './polyline.js';
+export * from './svg-path.js';
 export * from './xywh.js';

blocksuite/framework/global/src/gfx/svg-path.ts

@@ -0,0 +1,160 @@
+interface PathCommand {
+  command: string;
+  coordinates: number[];
+}
+
+/**
+ * A utility class for building SVG path strings using command-based API.
+ * Supports moveTo, lineTo, curveTo operations and can build complete path strings.
+ */
+export class SVGPathBuilder {
+  private commands: PathCommand[] = [];
+
+  /**
+   * Move to a specific point without drawing
+   */
+  moveTo(x: number, y: number): this {
+    this.commands.push({
+      command: 'M',
+      coordinates: [x, y],
+    });
+    return this;
+  }
+
+  /**
+   * Draw a line to a specific point
+   */
+  lineTo(x: number, y: number): this {
+    this.commands.push({
+      command: 'L',
+      coordinates: [x, y],
+    });
+    return this;
+  }
+
+  /**
+   * Draw a cubic Bézier curve
+   */
+  curveTo(
+    cp1x: number,
+    cp1y: number,
+    cp2x: number,
+    cp2y: number,
+    x: number,
+    y: number
+  ): this {
+    this.commands.push({
+      command: 'C',
+      coordinates: [cp1x, cp1y, cp2x, cp2y, x, y],
+    });
+    return this;
+  }
+
+  /**
+   * Close the current path
+   */
+  closePath(): this {
+    this.commands.push({
+      command: 'Z',
+      coordinates: [],
+    });
+    return this;
+  }
+
+  /**
+   * Build the complete SVG path string
+   */
+  build(): string {
+    const pathSegments = this.commands.map(cmd => {
+      const coords = cmd.coordinates.join(' ');
+      return coords ? `${cmd.command} ${coords}` : cmd.command;
+    });
+
+    return pathSegments.join(' ');
+  }
+
+  /**
+   * Clear all commands and reset the builder
+   */
+  clear(): this {
+    this.commands = [];
+    return this;
+  }
+}
+
+/**
+ * Create SVG polygon points string for common shapes
+ */
+export class SVGShapeBuilder {
+  /**
+   * Generate diamond (rhombus) polygon points
+   */
+  static diamond(
+    width: number,
+    height: number,
+    strokeWidth: number = 0
+  ): string {
+    const halfStroke = strokeWidth / 2;
+    return [
+      `${width / 2},${halfStroke}`,
+      `${width - halfStroke},${height / 2}`,
+      `${width / 2},${height - halfStroke}`,
+      `${halfStroke},${height / 2}`,
+    ].join(' ');
+  }
+
+  /**
+   * Generate triangle polygon points
+   */
+  static triangle(
+    width: number,
+    height: number,
+    strokeWidth: number = 0
+  ): string {
+    const halfStroke = strokeWidth / 2;
+    return [
+      `${width / 2},${halfStroke}`,
+      `${width - halfStroke},${height - halfStroke}`,
+      `${halfStroke},${height - halfStroke}`,
+    ].join(' ');
+  }
+
+  /**
+   * Generate diamond path using SVGPathBuilder
+   */
+  static diamondPath(
+    width: number,
+    height: number,
+    strokeWidth: number = 0
+  ): string {
+    const halfStroke = strokeWidth / 2;
+    const pathBuilder = new SVGPathBuilder();
+
+    return pathBuilder
+      .moveTo(width / 2, halfStroke)
+      .lineTo(width - halfStroke, height / 2)
+      .lineTo(width / 2, height - halfStroke)
+      .lineTo(halfStroke, height / 2)
+      .closePath()
+      .build();
+  }
+
+  /**
+   * Generate triangle path using SVGPathBuilder
+   */
+  static trianglePath(
+    width: number,
+    height: number,
+    strokeWidth: number = 0
+  ): string {
+    const halfStroke = strokeWidth / 2;
+    const pathBuilder = new SVGPathBuilder();
+
+    return pathBuilder
+      .moveTo(width / 2, halfStroke)
+      .lineTo(width - halfStroke, height - halfStroke)
+      .lineTo(halfStroke, height - halfStroke)
+      .closePath()
+      .build();
+  }
+}