paint-ui/tools/eyedropper-tool.ts

import { BaseTool } from './base-tool';
import type { PointerState, ToolSettings } from '@/types';
import { getColorAtPoint } from '@/lib/color-utils';
import { useColorStore } from '@/store/color-store';

/**
 * Eyedropper tool - Pick color from canvas
 */
export class EyedropperTool extends BaseTool {
  constructor() {
    super('Eyedropper');
  }

  onPointerDown(
    pointer: PointerState,
    ctx: CanvasRenderingContext2D,
    settings: ToolSettings
  ): void {
    this.pickColor(pointer.x, pointer.y, ctx);
  }

  onPointerMove(
    pointer: PointerState,
    ctx: CanvasRenderingContext2D,
    settings: ToolSettings
  ): void {
    if (!this.isDrawing) return;
    this.pickColor(pointer.x, pointer.y, ctx);
  }

  onPointerUp(): void {
    this.isDrawing = false;
  }

  private pickColor(x: number, y: number, ctx: CanvasRenderingContext2D): void {
    const color = getColorAtPoint(ctx, Math.floor(x), Math.floor(y));
    useColorStore.getState().setPrimaryColor(color);
  }

  getCursor(): string {
    return 'crosshair';
  }
}