UIPackage

Heatmap

Vue chart
Edit on GitHub

Grid heatmap wrapper around Apache ECharts with visualMap color ramp. Theme-aware via registry tokens.

Installation

$ npx shadcn-vue@latest add https://uipkge.dev/r/vue/heatmap.json

Or with the named registry: npx shadcn-vue@latest add @uipkge/heatmap

Examples

Props

Name Type / Values Default Required
data

[xIndex, yIndex, value]

[number, number, number][] required
xLabels string[] required
yLabels string[] required
height number | string 300 optional
min number optional
max number optional
option any optional
class string optional

Dependencies

Used by

Files (3)

  • app/components/ui/charts/heatmap/Heatmap.vue 3.1 kB
    <script setup lang="ts">
    import { computed } from 'vue'
    import { use } from 'echarts/core'
    import { CanvasRenderer } from 'echarts/renderers'
    import { HeatmapChart as EChartsHeatmap } from 'echarts/charts'
    import { GridComponent, TooltipComponent, VisualMapComponent } from 'echarts/components'
    import VChart from 'vue-echarts'
    import { cn } from '@/lib/utils'
    import { chartTooltipBg, chartTooltipBorder, chartTooltipText } from '../useChartTheme'
    
    use([CanvasRenderer, EChartsHeatmap, GridComponent, TooltipComponent, VisualMapComponent])
    
    interface Props {
      data: [number, number, number][] // [xIndex, yIndex, value]
      xLabels: string[]
      yLabels: string[]
      height?: number | string
      min?: number
      max?: number
      option?: any
      class?: string
    }
    
    const props = withDefaults(defineProps<Props>(), {
      height: 300,
    })
    
    const mergedOption = computed(() => {
      const values = props.data.map((d) => d[2])
      const computedMin = props.min ?? Math.min(...values)
      const computedMax = props.max ?? Math.max(...values)
    
      return {
        grid: { left: 16, right: 16, top: 16, bottom: 16, containLabel: true },
        tooltip: {
          position: 'top',
          backgroundColor: chartTooltipBg.value,
          borderColor: chartTooltipBorder.value,
          textStyle: { color: chartTooltipText.value, fontSize: 12 },
          formatter: (params: any) =>
            `${props.yLabels[params.value[1]]} / ${props.xLabels[params.value[0]]}: ${params.value[2]}`,
        },
        xAxis: {
          type: 'category',
          data: props.xLabels,
          splitArea: { show: true },
          axisLabel: { fontSize: 11 },
          axisTick: { show: false },
        },
        yAxis: {
          type: 'category',
          data: props.yLabels,
          splitArea: { show: true },
          axisLabel: { fontSize: 11 },
          axisTick: { show: false },
        },
        visualMap: {
          min: computedMin,
          max: computedMax,
          calculable: true,
          orient: 'horizontal',
          left: 'center',
          bottom: 0,
          itemWidth: 12,
          itemHeight: 80,
          inRange: {
            color: ['#e0f2fe', '#3b82f6', '#1e3a8a'],
          },
          textStyle: { fontSize: 10 },
        },
        series: (() => {
          const series = [
            {
              type: 'heatmap',
              data: props.data,
              label: { show: false },
              itemStyle: { borderRadius: 2, borderWidth: 0 },
              emphasis: {
                itemStyle: { shadowBlur: 10, shadowColor: 'rgba(0,0,0,0.2)' },
              },
            },
          ]
          const userSeries = (props.option as any)?.series
          return Array.isArray(userSeries) ? series.map((s, i) => ({ ...s, ...(userSeries[i] ?? {}) })) : series
        })(),
        // visualMap / tooltip / axes overrides still spread on top — strip
        // `series` so it doesn't clobber the merged result above.
        ...(() => {
          const { series: _, ...rest } = (props.option as any) ?? {}
          return rest
        })(),
      }
    })
    </script>
    
    <template>
      <div
        role="img"
        tabindex="0"
        :style="{ height: /^\d+$/.test(String(height)) ? `${height}px` : String(height) }"
        :class="cn('focus-visible:ring-ring w-full focus-visible:ring-2 focus-visible:outline-none', props.class)"
      >
        <VChart :option="mergedOption" :autoresize="true" class="size-full" />
      </div>
    </template>
  • app/components/ui/charts/heatmap/index.ts 0 kB
    export { default as Heatmap } from './Heatmap.vue'
  • app/components/ui/charts/useChartTheme.ts 6.4 kB
    import { computed, ref, type ComputedRef } from 'vue'
    
    // Chart palette is driven by Tailwind v4 CSS variables (`--chart-1`..`--chart-5`,
    // `--muted-foreground`, `--border`, `--popover`, etc.) so dark/light flips
    // happen automatically when the consumer toggles their theme class. The
    // values resolve at runtime via `getComputedStyle`, so they pick up whatever
    // the consumer set in their own `tailwind.css` -- no fork required.
    //
    // We bump `themeKey` whenever `<html>` class/style changes (the typical
    // shadcn dark-mode pivot) so every consuming `computed` re-resolves and
    // downstream ECharts options re-paint.
    
    const themeKey = ref(0)
    
    if (typeof window !== 'undefined') {
      // Bump once on the first paint so post-hydration getComputedStyle reads
      // the *resolved* CSS values (during SSR-built bundles the very first
      // computed pass returns the fallbacks below).
      requestAnimationFrame(() => themeKey.value++)
      new MutationObserver(() => themeKey.value++).observe(document.documentElement, {
        attributes: true,
        attributeFilter: ['class', 'style', 'data-theme'],
      })
    }
    
    // Lazy canvas context used to normalize any CSS color string (including
    // `oklch(...)`, `oklab(...)`, `color(display-p3 ...)`) into a hex / rgba
    // string ECharts' canvas renderer can consume. Without this, code that
    // does `color + '40'` (8-digit hex alpha trick) produces invalid color
    // strings like `oklch(...)40` and the canvas API throws.
    let _hexCanvas: CanvasRenderingContext2D | null = null
    function toHex(cssColor: string): string {
      if (typeof document === 'undefined') return cssColor
      if (!_hexCanvas) {
        _hexCanvas = document.createElement('canvas').getContext('2d')
      }
      if (!_hexCanvas) return cssColor
      // Reset, then assign; the browser normalizes whatever it accepted into
      // the canonical hex/rgba form when read back.
      _hexCanvas.fillStyle = '#000'
      _hexCanvas.fillStyle = cssColor
      return _hexCanvas.fillStyle as string
    }
    
    // Convert any CSS color (hex, rgb, oklch, color()) + alpha 0..1 to a
    // canvas-safe rgba(r,g,b,a). `colorString + '40'` (8-digit hex alpha)
    // only works when `colorString` is `#rrggbb`; once tokens resolve to
    // oklch() post-hydration the gradient stops break and the canvas paint
    // throws every frame. Stay defensive and always return rgba.
    export function toRgba(cssColor: string, alpha: number): string {
      if (typeof document === 'undefined') return cssColor
      if (!_hexCanvas) {
        _hexCanvas = document.createElement('canvas').getContext('2d')
      }
      if (!_hexCanvas) return cssColor
      _hexCanvas.fillStyle = '#000'
      _hexCanvas.fillStyle = cssColor
      const normalized = _hexCanvas.fillStyle as string
      if (normalized.startsWith('#') && normalized.length === 7) {
        const r = parseInt(normalized.slice(1, 3), 16)
        const g = parseInt(normalized.slice(3, 5), 16)
        const b = parseInt(normalized.slice(5, 7), 16)
        return `rgba(${r},${g},${b},${alpha})`
      }
      if (normalized.startsWith('rgba(')) {
        return normalized.replace(/,\s*[\d.]+\s*\)$/, `,${alpha})`)
      }
      if (normalized.startsWith('rgb(')) {
        return normalized.replace(/^rgb\(/, 'rgba(').replace(/\)$/, `,${alpha})`)
      }
      // Canvas refused to parse this color -- ship the original string and
      // let ECharts complain (better than crashing the paint loop).
      return cssColor
    }
    
    function resolveVar(name: string, fallback: string): string {
      if (typeof window === 'undefined') return fallback
      const v = getComputedStyle(document.documentElement).getPropertyValue(name).trim()
      if (!v) return fallback
      return toHex(v)
    }
    
    // SSR / pre-hydration fallback palette. Hex values picked to roughly
    // match the shadcn Neutral defaults in `tailwind.css` so the first paint
    // doesn't flicker.
    const CHART_FALLBACK = ['#f59e0b', '#14b8a6', '#3b82f6', '#f97316', '#eab308']
    
    export const chartColors: ComputedRef<string[]> = computed(() => {
      themeKey.value
      return Array.from({ length: 5 }, (_, i) => resolveVar(`--chart-${i + 1}`, CHART_FALLBACK[i]!))
    })
    
    export const chartTextColor: ComputedRef<string> = computed(() => {
      themeKey.value
      return resolveVar('--muted-foreground', '#888888')
    })
    
    export const chartAxisColor: ComputedRef<string> = computed(() => {
      themeKey.value
      return resolveVar('--border', '#e5e5e5')
    })
    
    export const chartSplitLineColor: ComputedRef<string> = computed(() => {
      themeKey.value
      return resolveVar('--border', '#f0f0f0')
    })
    
    export const chartTooltipBg: ComputedRef<string> = computed(() => {
      themeKey.value
      return resolveVar('--popover', 'rgba(255,255,255,0.96)')
    })
    
    export const chartTooltipBorder: ComputedRef<string> = computed(() => {
      themeKey.value
      return resolveVar('--border', '#e5e5e5')
    })
    
    export const chartTooltipText: ComputedRef<string> = computed(() => {
      themeKey.value
      return resolveVar('--popover-foreground', '#333333')
    })
    
    // Two-level deep merge for ECharts option blocks (xAxis, yAxis, grid,
    // tooltip, legend, singleAxis, parallel, etc.). The top-level keys merge
    // shallowly, but one nested level (axisLabel, axisLine, splitLine, etc.)
    // merges shallowly too so a consumer passing `xAxis: { axisLabel: { fontSize: 9 } }`
    // doesn't blow away the wrapper's `color` + base font defaults on the same
    // axisLabel block. Arrays + primitives replace outright.
    //
    // This is the merge strategy the chart wrappers use to fold `props.option`
    // onto their computed base option without forcing consumers to spell out
    // every default they want to preserve.
    export function mergeOptionBlock<T extends Record<string, any>>(base: T, user: Partial<T> | undefined): T {
      if (!user) return base
      const out: any = { ...base }
      for (const k of Object.keys(user)) {
        const bv = (base as any)[k]
        const uv = (user as any)[k]
        if (
          bv != null &&
          uv != null &&
          typeof bv === 'object' &&
          typeof uv === 'object' &&
          !Array.isArray(bv) &&
          !Array.isArray(uv)
        ) {
          out[k] = { ...bv, ...uv }
        } else {
          out[k] = uv
        }
      }
      return out
    }
    
    // Default gauge stoplight: teal (safe) -> amber (warning) -> red (danger).
    // Pulled off saturated green and onto teal so the gauge ties back to the
    // dashboard palette; red is kept as the universal "limit reached" cue.
    // GaugeChart consumes this via its `thresholds` prop default; consumers
    // pass their own array to override. Static because gauges have semantic
    // meaning (green safe / red danger) that we deliberately don't theme-flip.
    export const gaugeThresholds: [number, string][] = [
      [0.6, '#14b8a6'],
      [0.85, '#f59e0b'],
      [1, '#dc2626'],
    ]

Raw manifest: https://uipkge.dev/r/vue/heatmap.json