FranklinWH-wiki/client/docs/.vitepress/theme/components/ExcalidrawView.vue

<template>
  <div ref="canvasContainer" class="excalidraw-wrapper" @click="showCanvasTop" />
  <div ref="canvasFloating" v-if="showFullView" class="floating-canvas" @mousedown="onMouseDown" @wheel.prevent="onWheel" @click="onCloseFloating" />
</template>

<script setup lang="ts">
import { onMounted, ref, nextTick, onUnmounted } from 'vue'
import { withBase } from 'vitepress';
import { exportToCanvas } from '@excalidraw/excalidraw'
import { ExportedDataState } from '@excalidraw/excalidraw/data/types'

interface Props {
  filePath: string;
}

const props = defineProps<Props>()

const canvasContainer = ref<HTMLCanvasElement | null>(null)
const canvasFloating = ref<HTMLCanvasElement | null>(null)

const showFullView = ref(false);

let excalidrawJson: ExportedDataState | undefined = undefined
let topCanvas: HTMLCanvasElement | undefined = undefined

let scale = 1;
let origin = { x: 0, y: 0 };
let lastMouse = { x: 0, y: 0 };
let dragging = false;
let hasMoved = false; // 标记是否拖动过

const dblclickCanvasHandler = () => {
  origin = { x: 0, y: 0 };
  scale = 1;
  updateTransform();
};

function showCanvasTop() {
  showFullView.value = true;

  // 等待 DOM 渲染后复制内容
  nextTick(async () => {
    if (canvasFloating.value && excalidrawJson) {
      const canvas = await drawCanvas(
        excalidrawJson, 
        canvasFloating.value.clientWidth, 
        canvasFloating.value.clientHeight
      )

      if (canvas) {
        topCanvas = canvas
        canvas.style.transform = `translate(0px, 0px) scale(1)`;
        origin = { x: 0, y: 0 };
        scale = 1;
        canvasFloating.value.appendChild(canvas)

        // 双击重置
        canvas.addEventListener('dblclick', dblclickCanvasHandler);
      }
    }
  });
}

function closeFullView() {
  showFullView.value = false;

  if (topCanvas) {
    topCanvas.removeEventListener('dblclick', dblclickCanvasHandler);
  }

  if (canvasFloating.value) {
    canvasFloating.value.innerHTML = ''; // 清空 canvas
  }
}

function onCloseFloating() {
  if (hasMoved) {
    hasMoved = false;
    return; // 用户拖动过，不关闭
  }
  closeFullView()
}

function onMouseDown(e: MouseEvent) {
  // 如果按的是 canvas，就拖动
  if (topCanvas && topCanvas.contains(e.target as Node)) {
    dragging = true;
    hasMoved = false; // 重置状态
    lastMouse = { x: e.clientX, y: e.clientY };

    const onMouseMove = (e: MouseEvent) => {
      if (!dragging) return;
      const dx = e.clientX - lastMouse.x;
      const dy = e.clientY - lastMouse.y;

      // 如果移动距离大于阈值，认为已经拖动过
      if (Math.abs(dx) > 2 || Math.abs(dy) > 2) {
        hasMoved = true;
      }

      origin.x += dx;
      origin.y += dy;
      lastMouse = { x: e.clientX, y: e.clientY };
      updateTransform();
    };

    const onMouseUp = () => {
      dragging = false;
      window.removeEventListener('mousemove', onMouseMove);
      window.removeEventListener('mouseup', onMouseUp);
    };

    // 添加鼠标事件监控
    window.addEventListener('mousemove', onMouseMove);
    window.addEventListener('mouseup', onMouseUp);
  }
}

function updateTransform() {
  if (topCanvas) {
    topCanvas.style.transform = `translate(${origin.x}px, ${origin.y}px) scale(${scale})`;
  }
}

function onWheel(e: WheelEvent) {
  const delta = -e.deltaY;
  const factor = delta > 0 ? 1.1 : 0.9;
  scale *= factor;
  scale = Math.min(Math.max(0.2, scale), 10); // 限制缩放范围
  updateTransform();
}

const getExcalidraw = async (path: string): Promise<ExportedDataState | undefined> => {
  const res = await fetch(withBase(path)).catch((err) => {
    console.log("excalidraw file err: ", err)
  })
  if (!res) return undefined

  const json = await res.json()
  return json
}

const drawCanvas = async (data: ExportedDataState, width: number, height: number): Promise<HTMLCanvasElement> => {
  // const maxWidthOrHeight = width > height ? height : width
  // 改为只限制宽度，因为渲染前父窗口高度可能为0，导致maxWidthOrHeight不生效
  const maxWidthOrHeight = width
  const canvas = await exportToCanvas({
    ...data,
    maxWidthOrHeight,// 绘制的最大高度或宽度，设置maxWidthOrHeight后getDimensions则不生效
    // getDimensions: (width: number, height: number) => {
    //   return {
    //     width,
    //     height,
    //     scale: 1
    //   }
    // }, // 参数为原始绘制尺寸，返回尺寸和比例 {width: number; height: number; scale: number}
    exportPadding: 10 // 添加边距，默认10
  })
  return canvas
}

function onKeyDown(e: KeyboardEvent) {
  if (e.key === 'Escape') {
    closeFullView()
  }
}

onMounted(async () => {
  console.log("excalidrawJson: ", props.filePath)
  excalidrawJson = await getExcalidraw(props.filePath)
  if (excalidrawJson && canvasContainer.value) {
    let excalidrawCanvas = await drawCanvas(excalidrawJson, canvasContainer.value.clientWidth, canvasContainer.value.clientHeight)

    if (excalidrawCanvas) {
      canvasContainer.value.appendChild(excalidrawCanvas)
    }

    // 使用 ResizeObserver 监听父容器宽度变化
    const resizeObserver = new ResizeObserver(async (entries: ResizeObserverEntry[]) => {
      for (const entry of entries) {
        const el = entry.target
        if (el === canvasContainer.value && excalidrawJson) {
          excalidrawCanvas = await drawCanvas(excalidrawJson, el.clientWidth, el.clientHeight)
        }
      }
    });
    resizeObserver.observe(canvasContainer.value!);
  }

  window.addEventListener('keydown', onKeyDown);
})

onUnmounted(() => {
  window.removeEventListener('keydown', onKeyDown);
})
</script>

<style scoped>
.excalidraw-wrapper {
  width: 100%;
  border: 1px solid #ddd;
}
.floating-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: rgba(0, 0, 0, 0.8);
  z-index: 9999;
  display: flex;
  justify-content: center;
  align-items: center;
  overflow: hidden;
  cursor: grab;
}
.floating-canvas:active {
  cursor: grabbing;
}
.floating-canvas canvas {
  /* max-width: 90vw; */
  max-width: none;
  /* max-height: 90vh; */
  max-height: none;
  box-shadow: 0 0 12px #fff;
  transition: transform 0.05s;
}
</style>