TypeScript d3.select函數代碼示例

function drawLegendValues(elem, colorScale, rangeFrom, rangeTo, maxValue, minValue, legendWidth) {
  let legendElem = $(elem).find('svg');
  let legend = d3.select(legendElem.get(0));

  if (legendWidth <= 0 || legendElem.get(0).childNodes.length === 0) {
    return;
  }

  let legendValueScale = d3.scaleLinear()
    .domain([0, rangeTo])
    .range([0, legendWidth]);

  let ticks = buildLegendTicks(0, rangeTo, maxValue, minValue);
  let xAxis = d3.axisBottom(legendValueScale)
    .tickValues(ticks)
    .tickSize(2);

  let colorRect = legendElem.find(":first-child");
  let posY = colorRect.height() + 2;
  let posX = getSvgElemX(colorRect);

  d3.select(legendElem.get(0)).append("g")
    .attr("class", "axis")
    .attr("transform", "translate(" + posX + "," + posY + ")")
    .call(xAxis);

  legend.select(".axis").select(".domain").remove();
}

 function highlightCard(event) {
   let color = d3.select(event.target).style("fill");
   let highlightColor = d3.color(color).darker(2);
   let strokeColor = d3.color(color).brighter(4);
   let current_card = d3.select(event.target);
   tooltip.originalFillColor = color;
   current_card.style("fill", highlightColor)
   .style("stroke", strokeColor)
   .style("stroke-width", 1);
 }

function drawColorLegend(elem, colorScheme, rangeFrom, rangeTo, maxValue, minValue) {
  let legendElem = $(elem).find('svg');
  let legend = d3.select(legendElem.get(0));
  clearLegend(elem);

  let legendWidth = Math.floor(legendElem.outerWidth()) - 30;
  let legendHeight = legendElem.attr("height");

  let rangeStep = 1;
  if (rangeTo - rangeFrom > legendWidth) {
    rangeStep = Math.floor((rangeTo - rangeFrom) / legendWidth);
  }
  let widthFactor = legendWidth / (rangeTo - rangeFrom);
  let valuesRange = d3.range(rangeFrom, rangeTo, rangeStep);

  let colorScale = getColorScale(colorScheme, maxValue, minValue);
  legend.selectAll(".heatmap-color-legend-rect")
    .data(valuesRange)
    .enter().append("rect")
    .attr("x", d => d * widthFactor)
    .attr("y", 0)
    .attr("width", rangeStep * widthFactor + 1) // Overlap rectangles to prevent gaps
    .attr("height", legendHeight)
    .attr("stroke-width", 0)
    .attr("fill", d => colorScale(d));

  drawLegendValues(elem, colorScale, rangeFrom, rangeTo, maxValue, minValue, legendWidth);
}

function drawSimpleOpacityLegend(elem, options) {
  let legendElem = $(elem).find('svg');
  clearLegend(elem);

  let legend = d3.select(legendElem.get(0));
  let legendWidth = Math.floor(legendElem.outerWidth());
  let legendHeight = legendElem.attr("height");

  if (legendWidth) {
    let legendOpacityScale;
    if (options.colorScale === 'linear') {
      legendOpacityScale = d3.scaleLinear()
      .domain([0, legendWidth])
      .range([0, 1]);
    } else if (options.colorScale === 'sqrt') {
      legendOpacityScale = d3.scalePow().exponent(options.exponent)
      .domain([0, legendWidth])
      .range([0, 1]);
    }

    let rangeStep = 10;
    let valuesRange = d3.range(0, legendWidth, rangeStep);
    var legendRects = legend.selectAll(".heatmap-opacity-legend-rect").data(valuesRange);

    legendRects.enter().append("rect")
      .attr("x", d => d)
      .attr("y", 0)
      .attr("width", rangeStep)
      .attr("height", legendHeight)
      .attr("stroke-width", 0)
      .attr("fill", options.cardColor)
      .style("opacity", d => legendOpacityScale(d));
  }
}

function drawOpacityLegend(elem, options, rangeFrom, rangeTo, maxValue, minValue) {
  let legendElem = $(elem).find('svg');
  let legend = d3.select(legendElem.get(0));
  clearLegend(elem);

  let legendWidth = Math.floor(legendElem.outerWidth()) - 30;
  let legendHeight = legendElem.attr("height");

  let rangeStep = 10;
  let widthFactor = legendWidth / (rangeTo - rangeFrom);
  let valuesRange = d3.range(rangeFrom, rangeTo, rangeStep);

  let opacityScale = getOpacityScale(options, maxValue, minValue);
  legend.selectAll(".heatmap-opacity-legend-rect")
    .data(valuesRange)
    .enter().append("rect")
    .attr("x", d => d * widthFactor)
    .attr("y", 0)
    .attr("width", rangeStep * widthFactor)
    .attr("height", legendHeight)
    .attr("stroke-width", 0)
    .attr("fill", options.cardColor)
    .style("opacity", d => opacityScale(d));

  drawLegendValues(elem, opacityScale, rangeFrom, rangeTo, maxValue, minValue, legendWidth);
}

  function addHeatmapCanvas() {
    let heatmap_elem = $heatmap[0];

    width = Math.floor($heatmap.width()) - padding.right;
    height = Math.floor($heatmap.height()) - padding.bottom;

    cardPadding = panel.cards.cardPadding !== null ? panel.cards.cardPadding : CARD_PADDING;
    cardRound = panel.cards.cardRound !== null ? panel.cards.cardRound : CARD_ROUND;

    if (heatmap) {
      heatmap.remove();
    }

    heatmap = d3.select(heatmap_elem)
      .append("svg")
      .attr("width", width)
      .attr("height", height);
  }

function drawSimpleColorLegend(elem, colorScale) {
  let legendElem = $(elem).find('svg');
  clearLegend(elem);

  let legendWidth = Math.floor(legendElem.outerWidth());
  let legendHeight = legendElem.attr("height");

  if (legendWidth) {
    let valuesNumber = Math.floor(legendWidth / 2);
    let rangeStep  = Math.floor(legendWidth / valuesNumber);
    let valuesRange = d3.range(0, legendWidth, rangeStep);

    let legend = d3.select(legendElem.get(0));
    var legendRects = legend.selectAll(".heatmap-color-legend-rect").data(valuesRange);

    legendRects.enter().append("rect")
      .attr("x", d => d)
      .attr("y", 0)
      .attr("width", rangeStep + 1) // Overlap rectangles to prevent gaps
      .attr("height", legendHeight)
      .attr("stroke-width", 0)
      .attr("fill", d => colorScale(d));
  }
}

 function resetCardHighLight(event) {
   d3.select(event.target).style("fill", tooltip.originalFillColor)
   .style("stroke", tooltip.originalFillColor)
   .style("stroke-width", 0);
 }

 add() {
   this.tooltip = d3.select("body")
     .append("div")
     .attr("class", "heatmap-tooltip graph-tooltip grafana-tooltip");
 }