是否可以在 d3js 中的同一折線圖上添加縮放和工具提示？

Question

目前我正在學習 d3js，我喜歡實現的功能之一是顯示工具提示和水平縮放。 我想出了如何在圖表中添加縮放功能（ working小提琴），但在將鼠標懸停在點上時添加工具提示感覺並不復雜。 在 d3js.js 中可能嗎？ 因為在縮放時我們在 svg 元素上添加了 rect 元素。 如果我們在圖表中添加 rect 元素意味着如何使此工具提示起作用。 需要 d3 忍者的幫助。

 var data = [{ date: "10:30:00", price: 36000 }, { date: "11:00:20", price: 40000 }, { date: "12:00:00", price: 38000 }, { date: "14:20:00", price: 50400 } ]; var svg = d3.select("svg"), margin = { top: 20, right: 20, bottom: 110, left: 40 }, margin2 = { top: 430, right: 20, bottom: 30, left: 40 }, width = +svg.attr("width") - margin.left - margin.right, height = +svg.attr("height") - margin.top - margin.bottom, height2 = +svg.attr("height") - margin2.top - margin2.bottom; var parseDate = d3.timeParse("%H:%M:%S"); //"%b %Y"); var x = d3.scaleTime().range([0, width]), x2 = d3.scaleTime().range([0, width]), y = d3.scaleLinear().range([height, 0]), y2 = d3.scaleLinear().range([height2, 0]); var xAxis = d3.axisBottom(x), xAxis2 = d3.axisBottom(x2), yAxis = d3.axisLeft(y); var brush = d3.brushX() .extent([ [0, 0], [width, height2] ]) .on("brush end", brushed); var zoom = d3.zoom() .scaleExtent([1, Infinity]) .translateExtent([ [0, 0], [width, height] ]) .extent([ [0, 0], [width, height] ]) .on("zoom", zoomed); var area = d3.line() //.curve(d3.curveMonotoneX) .x(function(d) { return x(d.date); }) .y(function(d) { return y(d.price); }); var area2 = d3.line() .curve(d3.curveMonotoneX) .x(function(d) { return x2(d.date); }) .y(function(d) { return y2(d.price); }); svg.append("defs").append("clipPath") .attr("id", "clip") .append("rect") .attr("width", width) .attr("height", height); var focus = svg.append("g") .attr("class", "focus") .attr("transform", "translate(" + margin.left + "," + margin.top + ")"); var context = svg.append("g") .attr("class", "context") .attr("transform", "translate(" + margin2.left + "," + margin2.top + ")"); function update() { for (var k in data) { type(data[k]); } x.domain(d3.extent(data, function(d) { return d.date; })); y.domain([0, d3.max(data, function(d) { return d.price; })]); x2.domain(x.domain()); y2.domain(y.domain()); focus.append("path") .datum(data) .attr("class", "area") .attr("d", area); focus.append("g") .attr("class", "axis axis--x") .attr("transform", "translate(0," + height + ")") .call(xAxis); focus.append("g") .attr("class", "axis axis--y") .call(yAxis); focus.selectAll("circle") .data(data) .enter().append("circle") .attr("class", "circle") .attr("r", 5) .style("fill", 'orange') .style("stroke", 'red') .style("stroke-width", "2") .attr("cx", function(d) { return x(d.date) }) .attr("cy", function(d) { return y(d.price); }); context.append("path") .datum(data) .attr("class", "area") .attr("d", area2); context.append("g") .attr("class", "axis axis--x") .attr("transform", "translate(0," + height2 + ")") .call(xAxis2); context.selectAll("circle") .data(data) .enter().append("circle") .attr("class", "circle") .attr("r", 1) .style("fill", 'blue') .style("stroke", 'red') .style("stroke-width", "2") .attr("cx", function(d) { return x(d.date) }) .attr("cy", function(d) { return y(d.price); }); context.append("g") .attr("class", "brush") .call(brush) .call(brush.move, x.range()); svg.append("rect") .attr("class", "zoom") .attr("width", width) .attr("height", height) .attr("transform", "translate(" + margin.left + "," + margin.top + ")") .call(zoom); } function brushed() { if (d3.event.sourceEvent && d3.event.sourceEvent.type === "zoom") return; // ignore brush-by-zoom var s = d3.event.selection || x2.range(); x.domain(s.map(x2.invert, x2)); focus.select(".area").attr("d", area); focus.selectAll('.circle') .attr("cx", function(d) { return x(d.date) }) .attr("cy", function(d) { return y(d.price); }); focus.select(".axis--x").call(xAxis); svg.select(".zoom").call(zoom.transform, d3.zoomIdentity .scale(width / (s[1] - s[0])) .translate(-s[0], 0)); } function zoomed() { if (d3.event.sourceEvent && d3.event.sourceEvent.type === "brush") return; // ignore zoom-by-brush var t = d3.event.transform; x.domain(t.rescaleX(x2).domain()); focus.select(".area").attr("d", area); focus.selectAll('.circle') .attr("cx", function(d) { return x(d.date) }) .attr("cy", function(d) { return y(d.price); }); focus.select(".axis--x").call(xAxis); context.select(".brush").call(brush.move, x.range().map(t.invertX, t)); context.selectAll('.circle') .attr("cx", function(d) { return x(d.date) }) .attr("cy", function(d) { return y(d.price); }); } function type(d) { d.date = parseDate(d.date); d.price = +d.price; return d; } update();

 .area { fill: none; stroke: #a2dced; stroke-width: 2; clip-path: url(#clip); } .zoom { cursor: move; fill: none; pointer-events: all; } rect.selection { fill: green; }

 <script src="https://d3js.org/d3.v4.min.js"></script> <svg width="960" height="500"></svg>

Answer 1

當然可以在 d3 中添加工具提示，有很多示例，甚至是舊版本的專用包。

您可以選擇在 SVG 內部（作為帶文本的矩形）或外部顯示工具提示，作為 div。 外部的好處是工具提示可以溢出SVG，缺點是定位可能更困難，尤其是滾動。

我在下面展示了一個非常簡單的實現，使用 DIV 工具提示。 我將.zoom rect 定位在.zoom后面，因此它們會改為捕獲鼠標事件，並添加到mouseenter和mouseleave事件偵聽器上。

 var data = [{ date: "10:30:00", price: 36000 }, { date: "11:00:20", price: 40000 }, { date: "12:00:00", price: 38000 }, { date: "14:20:00", price: 50400 } ]; var svg = d3.select("svg"), margin = { top: 20, right: 20, bottom: 110, left: 40 }, margin2 = { top: 430, right: 20, bottom: 30, left: 40 }, width = +svg.attr("width") - margin.left - margin.right, height = +svg.attr("height") - margin.top - margin.bottom, height2 = +svg.attr("height") - margin2.top - margin2.bottom; var parseDate = d3.timeParse("%H:%M:%S"); //"%b %Y"); var x = d3.scaleTime().range([0, width]), x2 = d3.scaleTime().range([0, width]), y = d3.scaleLinear().range([height, 0]), y2 = d3.scaleLinear().range([height2, 0]); var xAxis = d3.axisBottom(x), xAxis2 = d3.axisBottom(x2), yAxis = d3.axisLeft(y); var brush = d3.brushX() .extent([ [0, 0], [width, height2] ]) .on("brush end", brushed); var zoom = d3.zoom() .scaleExtent([1, Infinity]) .translateExtent([ [0, 0], [width, height] ]) .extent([ [0, 0], [width, height] ]) .on("zoom", zoomed); var area = d3.line() //.curve(d3.curveMonotoneX) .x(function(d) { return x(d.date); }) .y(function(d) { return y(d.price); }); var area2 = d3.line() .curve(d3.curveMonotoneX) .x(function(d) { return x2(d.date); }) .y(function(d) { return y2(d.price); }); svg.append("defs").append("clipPath") .attr("id", "clip") .append("rect") .attr("width", width) .attr("height", height); var focus = svg.append("g") .attr("class", "focus") .attr("transform", "translate(" + margin.left + "," + margin.top + ")"); var context = svg.append("g") .attr("class", "context") .attr("transform", "translate(" + margin2.left + "," + margin2.top + ")"); var tooltip = d3.select('body') .append('div') .attr('id', 'tooltip') .style("transform", "translate(" + margin.left + "px," + margin.top + "px)") .classed('hide', true); function update() { for (var k in data) { type(data[k]); } x.domain(d3.extent(data, function(d) { return d.date; })); y.domain([0, d3.max(data, function(d) { return d.price; })]); x2.domain(x.domain()); y2.domain(y.domain()); focus.append("path") .datum(data) .attr("class", "area") .attr("d", area); focus.append("g") .attr("class", "axis axis--x") .attr("transform", "translate(0," + height + ")") .call(xAxis); focus.append("g") .attr("class", "axis axis--y") .call(yAxis); focus.selectAll("circle") .data(data) .enter() .append("circle") .attr("class", "circle") .attr("r", 5) .style("fill", 'orange') .style("stroke", 'red') .style("stroke-width", "2") .attr("cx", function(d) { return x(d.date) }) .attr("cy", function(d) { return y(d.price); }) .on("mouseenter", function(d) { // Show the tooltip and position it correctly tooltip.classed('hide', false) .style('left', x(d.date).toString() + 'px') .style('top', y(d.price).toString() + 'px') .html("<p>Price: " + d.price + "</p>"); }) .on("mouseleave", function() { tooltip.classed('hide', true); }); context.append("path") .datum(data) .attr("class", "area") .attr("d", area2); context.append("g") .attr("class", "axis axis--x") .attr("transform", "translate(0," + height2 + ")") .call(xAxis2); context.selectAll("circle") .data(data) .enter().append("circle") .attr("class", "circle") .attr("r", 1) .style("fill", 'blue') .style("stroke", 'red') .style("stroke-width", "2") .attr("cx", function(d) { return x(d.date) }) .attr("cy", function(d) { return y(d.price); }); context.append("g") .attr("class", "brush") .call(brush) .call(brush.move, x.range()); // Insert the zoom rect *before* the circles, so the circles // are drawn in front of the recrt focus.insert("rect", "circle") .attr("class", "zoom") .attr("width", width) .attr("height", height) .call(zoom); } function brushed() { if (d3.event.sourceEvent && d3.event.sourceEvent.type === "zoom") return; // ignore brush-by-zoom var s = d3.event.selection || x2.range(); x.domain(s.map(x2.invert, x2)); focus.select(".area").attr("d", area); focus.selectAll('.circle') .attr("cx", function(d) { return x(d.date) }) .attr("cy", function(d) { return y(d.price); }); focus.select(".axis--x").call(xAxis); svg.select(".zoom").call(zoom.transform, d3.zoomIdentity .scale(width / (s[1] - s[0])) .translate(-s[0], 0)); } function zoomed() { if (d3.event.sourceEvent && d3.event.sourceEvent.type === "brush") return; // ignore zoom-by-brush var t = d3.event.transform; x.domain(t.rescaleX(x2).domain()); focus.select(".area").attr("d", area); focus.selectAll('.circle') .attr("cx", function(d) { return x(d.date) }) .attr("cy", function(d) { return y(d.price); }); focus.select(".axis--x").call(xAxis); context.select(".brush").call(brush.move, x.range().map(t.invertX, t)); context.selectAll('.circle') .attr("cx", function(d) { return x(d.date) }) .attr("cy", function(d) { return y(d.price); }); } function type(d) { d.date = parseDate(d.date); d.price = +d.price; return d; } update();

 .area { fill: none; stroke: #a2dced; stroke-width: 2; clip-path: url(#clip); } .zoom { cursor: move; fill: none; pointer-events: all; } rect.selection { fill: green; } #tooltip { position: absolute; border: solid 1px black; background: white; margin: 20px; } .hide { opacity: 0; }

 <script src="https://d3js.org/d3.v4.min.js"></script> <svg width="960" height="500"></svg>