HOW - Canvas 入门系列之基于vue-konva的多维表格

<template>
  <v-stage ref="stage" :config="stageSize" @wheel="handleWheel">
    <!-- 其他代码省略 -->
    <v-layer>
      <v-rect
        v-for="(cell, index) in visibleCells"
        :key="index"
        :config="cellConfig(cell)"
      />
    </v-layer>
  </v-stage>
</template>
 
<script>
export default {
  data() {
    return {
      // 其他数据定义省略
      visibleCells: [], // 可见的单元格数组
    };
  },
  methods: {
    // 其他方法定义省略
    cellConfig(cell) {
      const x = (cell.col - this.startCol) * this.cellSize;
      const y = (cell.row - this.startRow) * this.cellSize;
      return {
        x,
        y,
        width: this.cellSize,
        height: this.cellSize,
        fill: this.getCellColor(cell),
        stroke: 'black',
        strokeWidth: 1,
      };
    },
    getCellColor(cell) {
      // 根据cell的值返回不同的颜色
      if (cell.value === 0) {
        return 'white';
      }
      return this.colorMap[cell.value];
    },
    handleWheel(e) {
      e.evt.preventDefault();
      const scaleBy = 1.2;
      const oldScale = this.scale;
      const newScale = e.evt.deltaY < 0 ? oldScale * scaleBy : oldScale / scaleBy;
      if (newScale >= this.minScale && newScale <= this.maxScale) {
        this.scale = newScale;
        this.updateVisibleCells();
        const stage = this.$refs.stage.getStage();
        const pointer = stage.getContainer().getPointerPosition();
        const dx = pointer.x - this.$refs.stage.getStage().getWidth() / 2;
        const dy = pointer.y - this.$refs.stage.getStage().getHeight() / 2;
        stage.position({ x: dx, y: dy });
      }
    },
    updateVisibleCells() {
      const cols = this.puzzle.cols;
      const rows = this.puzzle.rows;
      const startCol = Math.max(0, Math.floor(this.startCol));
      const startRow = Math.max(0, Math.floor(this.startRow));
      const endCol = startCol + cols - 1;
      const endRow = startRow + rows - 1;
      this.visibleCells = this.puzzle.cells
        .filter(cell => cell.row >= startRow && cell.row <= endRow &&
                        cell.col >= startCol && cell.col <= endCol);
    }
  },
  watch: {
    scale: 'updateVisibleCells',
  },
  mounted() {
    this.updateVisibleCells();
  }
};
</script>

在这个代码实例中，我们使用了Vue.js和vue-konva库来创建一个可缩放的电子表