From 63c25a452e97374ca95d533b20344735c6c9e7b0 Mon Sep 17 00:00:00 2001
From: Jose <jvargas@gitlab.com>
Date: Thu, 21 Jun 2018 15:41:20 -0500
Subject: Add bar chart component

---
 .../vue_shared/components/bar_chart.vue            | 391 +++++++++++++++++++++
 .../vue_shared/components/bar_chart_constants.js   |   4 +
 .../vue_shared/components/svg_gradient.vue         |  37 ++
 app/assets/stylesheets/pages/graph.scss            |  58 +++
 4 files changed, 490 insertions(+)
 create mode 100644 app/assets/javascripts/vue_shared/components/bar_chart.vue
 create mode 100644 app/assets/javascripts/vue_shared/components/bar_chart_constants.js
 create mode 100644 app/assets/javascripts/vue_shared/components/svg_gradient.vue

(limited to 'app')

diff --git a/app/assets/javascripts/vue_shared/components/bar_chart.vue b/app/assets/javascripts/vue_shared/components/bar_chart.vue
new file mode 100644
index 00000000000..3ced4eb691a
--- /dev/null
+++ b/app/assets/javascripts/vue_shared/components/bar_chart.vue
@@ -0,0 +1,391 @@
+<script>
+import * as d3 from 'd3';
+import tooltip from '../directives/tooltip';
+import Icon from './icon.vue';
+import SvgGradient from './svg_gradient.vue';
+import {
+  GRADIENT_COLORS,
+  GRADIENT_OPACITY,
+  INVERSE_GRADIENT_COLORS,
+  INVERSE_GRADIENT_OPACITY,
+} from './bar_chart_constants';
+
+/**
+ * Renders a bar chart that can be dragged(scrolled) when the number
+ * of elements to renders surpasses that of the available viewport space
+ * while keeping even padding and a width of 24px (customizable)
+ *
+ * It can render data with the following format:
+ * graphData: [{
+ *   name: 'element' // x domain data
+ *   value: 1 // y domain data
+ * }]
+ *
+ * Used in:
+ * - Contribution analytics - all of the rows describing pushes, merge requests and issues
+ */
+
+export default {
+  directives: {
+    tooltip,
+  },
+  components: {
+    Icon,
+    SvgGradient,
+  },
+  props: {
+    graphData: {
+      type: Array,
+      required: true,
+    },
+    barWidth: {
+      type: Number,
+      required: false,
+      default: 24,
+    },
+    yAxisLabel: {
+      type: String,
+      required: true,
+    },
+  },
+  data() {
+    return {
+      minX: -40,
+      minY: 0,
+      vbWidth: 0,
+      vbHeight: 0,
+      vpWidth: 0,
+      vpHeight: 350,
+      preserveAspectRatioType: 'xMidYMid meet',
+      containerMargin: {
+        leftRight: 30,
+      },
+      viewBoxMargin: {
+        topBottom: 150,
+      },
+      panX: 0,
+      xScale: {},
+      yScale: {},
+      zoom: {},
+      bars: {},
+      xGraphRange: 0,
+      isLoading: true,
+      paddingThreshold: 50,
+      showScrollIndicator: false,
+      showLeftScrollIndicator: false,
+      isGrabbed: false,
+      isPanAvailable: false,
+      gradientColors: GRADIENT_COLORS,
+      gradientOpacity: GRADIENT_OPACITY,
+      inverseGradientColors: INVERSE_GRADIENT_COLORS,
+      inverseGradientOpacity: INVERSE_GRADIENT_OPACITY,
+      maxTextWidth: 72,
+      rectYAxisLabelDims: {},
+      xAxisTextElements: {},
+      yAxisRectTransformPadding: 20,
+      yAxisTextTransformPadding: 10,
+      yAxisTextRotation: 90,
+    };
+  },
+  computed: {
+    svgViewBox() {
+      return `${this.minX} ${this.minY} ${this.vbWidth} ${this.vbHeight}`;
+    },
+    xAxisLocation() {
+      return `translate(${this.panX}, ${this.vbHeight})`;
+    },
+    barTranslationTransform() {
+      return `translate(${this.panX}, 0)`;
+    },
+    scrollIndicatorTransform() {
+      return `translate(${this.vbWidth - 80}, 0)`;
+    },
+    activateGrabCursor() {
+      return {
+        'svg-graph-container-with-grab': this.isPanAvailable,
+        'svg-graph-container-grabbed': this.isPanAvailable && this.isGrabbed,
+      };
+    },
+    yAxisLabelRectTransform() {
+      const rectWidth =
+        this.rectYAxisLabelDims.height != null ? this.rectYAxisLabelDims.height / 2 : 0;
+      const yCoord = this.vbHeight / 2 - rectWidth;
+
+      return `translate(${this.minX - this.yAxisRectTransformPadding}, ${yCoord})`;
+    },
+    yAxisLabelTextTransform() {
+      const rectWidth =
+        this.rectYAxisLabelDims.height != null ? this.rectYAxisLabelDims.height / 2 : 0;
+      const yCoord = this.vbHeight / 2 + rectWidth - 5;
+
+      return `translate(${this.minX + this.yAxisTextTransformPadding}, ${yCoord}) rotate(-${this.yAxisTextRotation})`;
+    },
+  },
+  mounted() {
+    if (!this.allValuesEmpty) {
+      this.draw();
+    }
+  },
+  methods: {
+    draw() {
+      // update viewport
+      this.vpWidth = this.$refs.svgContainer.clientWidth - this.containerMargin.leftRight;
+      // update viewbox
+      this.vbWidth = this.vpWidth;
+      this.vbHeight = this.vpHeight - this.viewBoxMargin.topBottom;
+      let padding = 0;
+      if (this.graphData.length * this.barWidth > this.vbWidth) {
+        this.xGraphRange = this.graphData.length * this.barWidth;
+        padding = this.calculatePadding(this.barWidth);
+        this.showScrollIndicator = true;
+        this.isPanAvailable = true;
+      } else {
+        this.xGraphRange = this.vbWidth - Math.abs(this.minX);
+      }
+
+      this.xScale = d3
+        .scaleBand()
+        .range([0, this.xGraphRange])
+        .round(true)
+        .paddingInner(padding);
+      this.yScale = d3.scaleLinear().rangeRound([this.vbHeight, 0]);
+
+      this.xScale.domain(this.graphData.map(d => d.name));
+      this.yScale.domain([0, d3.max(this.graphData.map(d => d.value))]);
+
+      // Zoom/Panning Function
+      this.zoom = d3
+        .zoom()
+        .translateExtent([[0, 0], [this.xGraphRange, this.vbHeight]])
+        .on('zoom', this.panGraph)
+        .on('end', this.removeGrabStyling);
+
+      const xAxis = d3.axisBottom().scale(this.xScale);
+
+      const yAxis = d3
+        .axisLeft()
+        .scale(this.yScale)
+        .ticks(4);
+
+      const renderedXAxis = d3
+        .select(this.$refs.baseSvg)
+        .select('.x-axis')
+        .call(xAxis);
+
+      this.xAxisTextElements = this.$refs.xAxis.querySelectorAll('text');
+
+      renderedXAxis.select('.domain').remove();
+
+      renderedXAxis
+        .selectAll('text')
+        .style('text-anchor', 'end')
+        .attr('dx', '-.3em')
+        .attr('dy', '-.95em')
+        .attr('class', 'tick-text')
+        .attr('transform', 'rotate(-90)');
+
+      renderedXAxis.selectAll('line').remove();
+
+      const { maxTextWidth } = this;
+      renderedXAxis.selectAll('text').each(function formatText() {
+        const axisText = d3.select(this);
+        let textLength = axisText.node().getComputedTextLength();
+        let textContent = axisText.text();
+        while (textLength > maxTextWidth && textContent.length > 0) {
+          textContent = textContent.slice(0, -1);
+          axisText.text(`${textContent}...`);
+          textLength = axisText.node().getComputedTextLength();
+        }
+      });
+
+      const width = this.vbWidth;
+
+      const renderedYAxis = d3
+        .select(this.$refs.baseSvg)
+        .select('.y-axis')
+        .call(yAxis);
+
+      renderedYAxis.selectAll('.tick').each(function createTickLines(d, i) {
+        if (i > 0) {
+          d3
+            .select(this)
+            .select('line')
+            .attr('x2', width)
+            .attr('class', 'axis-tick');
+        }
+      });
+
+      // Add the panning capabilities
+      if (this.isPanAvailable) {
+        d3
+          .select(this.$refs.baseSvg)
+          .call(this.zoom)
+          .on('wheel.zoom', null); // This disables the pan of the graph with the scroll of the mouse wheel
+      }
+
+      this.isLoading = false;
+      // Update the yAxisLabel coordinates
+      const labelDims = this.$refs.yAxisLabel.getBBox();
+      this.rectYAxisLabelDims = {
+        height: labelDims.width + 10,
+      };
+    },
+    panGraph() {
+      const allowedRightScroll = this.xGraphRange - this.vbWidth - this.paddingThreshold;
+      const graphMaxPan = Math.abs(d3.event.transform.x) < allowedRightScroll;
+      this.isGrabbed = true;
+      this.panX = d3.event.transform.x;
+
+      if (d3.event.transform.x === 0) {
+        this.showLeftScrollIndicator = false;
+      } else {
+        this.showLeftScrollIndicator = true;
+        this.showScrollIndicator = true;
+      }
+
+      if (!graphMaxPan) {
+        this.panX = -1 * (this.xGraphRange - this.vbWidth + this.paddingThreshold);
+        this.showScrollIndicator = false;
+      }
+    },
+    setTooltipTitle(data) {
+      return data !== null ? `${data.name}: ${data.value}` : '';
+    },
+    calculatePadding(desiredBarWidth) {
+      const widthWithMargin = this.vbWidth - Math.abs(this.minX);
+      const dividend = widthWithMargin - this.graphData.length * desiredBarWidth;
+      const divisor = widthWithMargin - desiredBarWidth;
+
+      return dividend / divisor;
+    },
+    removeGrabStyling() {
+      this.isGrabbed = false;
+    },
+    barHoveredIn(index) {
+      this.xAxisTextElements[index].classList.add('x-axis-text');
+    },
+    barHoveredOut(index) {
+      this.xAxisTextElements[index].classList.remove('x-axis-text');
+    },
+  },
+};
+</script>
+<template>
+  <div
+    ref="svgContainer"
+    :class="activateGrabCursor"
+    class="svg-graph-container"
+  >
+    <svg
+      ref="baseSvg"
+      :width="vpWidth"
+      :height="vpHeight"
+      :viewBox="svgViewBox"
+      :preserveAspectRatio="preserveAspectRatioType">
+      <g
+        ref="xAxis"
+        :transform="xAxisLocation"
+        class="x-axis"
+      />
+      <g v-if="!isLoading">
+        <template
+          v-for="(data, index) in graphData">
+          <rect
+            v-tooltip
+            :key="index"
+            :width="xScale.bandwidth()"
+            :x="xScale(data.name)"
+            :y="yScale(data.value)"
+            :height="vbHeight - yScale(data.value)"
+            :transform="barTranslationTransform"
+            :title="setTooltipTitle(data)"
+            class="bar-rect"
+            data-placement="top"
+            @mouseover="barHoveredIn(index)"
+            @mouseout="barHoveredOut(index)"
+          />
+        </template>
+      </g>
+      <rect
+        :height="vbHeight + 100"
+        transform="translate(-100, -5)"
+        width="100"
+        fill="#fff"
+      />
+      <g class="y-axis-label">
+        <line
+          :x1="0"
+          :x2="0"
+          :y1="0"
+          :y2="vbHeight"
+          transform="translate(-35, 0)"
+          stroke="black"
+        />
+        <!--Get text length and change the height of this rect accordingly-->
+        <rect
+          :height="rectYAxisLabelDims.height"
+          :transform="yAxisLabelRectTransform"
+          :width="30"
+          fill="#fff"
+        />
+        <text
+          ref="yAxisLabel"
+          :transform="yAxisLabelTextTransform"
+        >
+          {{ yAxisLabel }}
+        </text>
+      </g>
+      <g
+        class="y-axis"
+      />
+      <g v-if="showScrollIndicator">
+        <rect
+          :height="vbHeight + 100"
+          :transform="`translate(${vpWidth - 60}, -5)`"
+          width="40"
+          fill="#fff"
+        />
+        <icon
+          :x="vpWidth - 50"
+          :y="vbHeight / 2"
+          :width="14"
+          :height="14"
+          name="chevron-right"
+          class="animate-flicker"
+        />
+      </g>
+      <!--The line that shows up when the data elements surpass the available width -->
+      <g
+        v-if="showScrollIndicator"
+        :transform="scrollIndicatorTransform">
+        <rect
+          :height="vbHeight"
+          x="0"
+          y="0"
+          width="20"
+          fill="url(#shadow-gradient)"
+        />
+      </g>
+      <!--Left scroll indicator-->
+      <g
+        v-if="showLeftScrollIndicator"
+        transform="translate(0, 0)">
+        <rect
+          :height="vbHeight"
+          x="0"
+          y="0"
+          width="20"
+          fill="url(#left-shadow-gradient)"
+        />
+      </g>
+      <svg-gradient
+        :colors="gradientColors"
+        :opacity="gradientOpacity"
+        identifier-name="shadow-gradient"/>
+      <svg-gradient
+        :colors="inverseGradientColors"
+        :opacity="inverseGradientOpacity"
+        identifier-name="left-shadow-gradient"/>
+    </svg>
+  </div>
+</template>
diff --git a/app/assets/javascripts/vue_shared/components/bar_chart_constants.js b/app/assets/javascripts/vue_shared/components/bar_chart_constants.js
new file mode 100644
index 00000000000..6957b112da6
--- /dev/null
+++ b/app/assets/javascripts/vue_shared/components/bar_chart_constants.js
@@ -0,0 +1,4 @@
+export const GRADIENT_COLORS = ['#000', '#a7a7a7'];
+export const GRADIENT_OPACITY = ['0', '0.4'];
+export const INVERSE_GRADIENT_COLORS = ['#a7a7a7', '#000'];
+export const INVERSE_GRADIENT_OPACITY = ['0.4', '0'];
diff --git a/app/assets/javascripts/vue_shared/components/svg_gradient.vue b/app/assets/javascripts/vue_shared/components/svg_gradient.vue
new file mode 100644
index 00000000000..b61a1befcd6
--- /dev/null
+++ b/app/assets/javascripts/vue_shared/components/svg_gradient.vue
@@ -0,0 +1,37 @@
+<script>
+export default {
+  props: {
+    colors: {
+      type: Array,
+      required: true,
+    },
+    opacity: {
+      type: Array,
+      required: true,
+    },
+    identifierName: {
+      type: String,
+      required: true,
+    },
+  },
+};
+</script>
+<template>
+  <svg
+    height="0"
+    width="0">
+    <defs>
+      <linearGradient
+        :id="identifierName">
+        <stop
+          :stop-color="colors[0]"
+          :stop-opacity="opacity[0]"
+          offset="0%" />
+        <stop
+          :stop-color="colors[1]"
+          :stop-opacity="opacity[1]"
+          offset="100%" />
+      </linearGradient>
+    </defs>
+  </svg>
+</template>
diff --git a/app/assets/stylesheets/pages/graph.scss b/app/assets/stylesheets/pages/graph.scss
index 84da9180f93..49d8a5d959b 100644
--- a/app/assets/stylesheets/pages/graph.scss
+++ b/app/assets/stylesheets/pages/graph.scss
@@ -31,3 +31,61 @@
     color: $gl-text-red;
   }
 }
+
+.svg-graph-container {
+  width: 100%;
+
+  .axis-tick {
+    opacity: 0.4;
+  }
+
+  .tick-text {
+    fill: $gl-text-color-secondary;
+  }
+
+  .x-axis-text {
+    fill: $theme-gray-900;
+  }
+
+  .bar-rect {
+    fill: rgba($blue-500, 0.1);
+    stroke: $blue-500;
+  }
+
+  .bar-rect:hover {
+    fill: rgba($blue-700, 0.3);
+  }
+
+  .y-axis-label {
+    line {
+      stroke: $stat-graph-axis-fill;
+    }
+
+    text {
+      font-weight: bold;
+      font-size: 12px;
+      fill: $theme-gray-800;
+    }
+  }
+}
+
+.svg-graph-container-with-grab {
+  cursor: grab;
+  cursor: -webkit-grab;
+}
+
+.svg-graph-container-grabbed {
+  cursor: grabbing;
+  cursor: -webkit-grabbing;
+}
+
+@keyframes flickerAnimation {
+  0% { opacity: 1; }
+  50% { opacity: 0; }
+  100% { opacity: 1; }
+}
+
+.animate-flicker {
+  animation: flickerAnimation 1.5s infinite;
+  fill: $theme-gray-500;
+}
-- 
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