[UI] Replace vue-bar-graph with chart.js

- The usage of the `vue-bar-graph` is complicated, because of the `GSAP`
dependency they pull in, the dependency uses a non-free license.
- The code is rewritten to use the `chart.js` library, which is already
used to draw other charts in the activity tab. Due to the limitation of
`chart.js`, we have to create a plugin in order to have images as labels
and do click handling for those images.
- The chart isn't the same as the previous one, once again simply due to
how `chart.js` works, the amount of commits isn't drawn anymore in the
bar, you instead have to hover over it or look at the y-axis.
- Resolves #4569

web_src/js/components/RepoActivityTopAuthors.vue

@@ -1,14 +1,36 @@
 <script>
-import VueBarGraph from 'vue-bar-graph';
+import {Bar} from 'vue-chartjs';
+import {
+  Chart,
+  Tooltip,
+  BarElement,
+  CategoryScale,
+  LinearScale,
+} from 'chart.js';
+import {chartJsColors} from '../utils/color.js';
 import {createApp} from 'vue';
 
+Chart.defaults.color = chartJsColors.text;
+Chart.defaults.borderColor = chartJsColors.border;
+
+Chart.register(
+  CategoryScale,
+  LinearScale,
+  BarElement,
+  Tooltip,
+);
+
 const sfc = {
-  components: {VueBarGraph},
+  components: {Bar},
+  props: {
+    locale: {
+      type: Object,
+      required: true,
+    },
+  },
   data: () => ({
     colors: {
       barColor: 'green',
-      textColor: 'black',
-      textAltColor: 'white',
     },
 
     // possible keys:
@@ -18,42 +40,108 @@ const sfc = {
     // * login: (...)
     // * name: (...)
     activityTopAuthors: window.config.pageData.repoActivityTopAuthors || [],
+    i18nCommitActivity: this,
   }),
-  computed: {
+  methods: {
     graphPoints() {
-      return this.activityTopAuthors.map((item) => {
-        return {
-          value: item.commits,
-          label: item.name,
-        };
-      });
+      return {
+        datasets: [{
+          label: this.locale.commitActivity,
+          data: this.activityTopAuthors.map((item) => item.commits),
+          backgroundColor: this.colors.barColor,
+          barThickness: 40,
+          borderWidth: 0,
+          tension: 0.3,
+        }],
+        labels: this.activityTopAuthors.map((item) => item.name),
+      };
     },
-    graphAuthors() {
-      return this.activityTopAuthors.map((item, idx) => {
-        return {
-          position: idx + 1,
-          ...item,
-        };
-      });
-    },
-    graphWidth() {
-      return this.activityTopAuthors.length * 40;
+    getOptions() {
+      return {
+        responsive: true,
+        maintainAspectRatio: false,
+        animation: true,
+        scales: {
+          x: {
+            type: 'category',
+            grid: {
+              display: false,
+            },
+            ticks: {
+              color: 'transparent', // Disable drawing of labels on the x-axis.
+            },
+          },
+          y: {
+            ticks: {
+              stepSize: 1,
+            },
+          },
+        },
+      };
     },
   },
   mounted() {
     const refStyle = window.getComputedStyle(this.$refs.style);
-    const refAltStyle = window.getComputedStyle(this.$refs.altStyle);
-
     this.colors.barColor = refStyle.backgroundColor;
-    this.colors.textColor = refStyle.color;
-    this.colors.textAltColor = refAltStyle.color;
+
+    for (const item of this.activityTopAuthors) {
+      const img = new Image();
+      img.src = item.avatar_link;
+      item.avatar_img = img;
+    }
+
+    Chart.register({
+      id: 'image_label',
+      afterDraw: (chart) => {
+        const xAxis = chart.boxes[0];
+        const yAxis = chart.boxes[1];
+        for (const [index] of xAxis.ticks.entries()) {
+          const x = xAxis.getPixelForTick(index);
+          const img = this.activityTopAuthors[index].avatar_img;
+
+          chart.ctx.save();
+          chart.ctx.drawImage(img, 0, 0, img.naturalWidth, img.naturalHeight, x - 10, yAxis.bottom + 10, 20, 20);
+          chart.ctx.restore();
+        }
+      },
+      beforeEvent: (chart, args) => {
+        const event = args.event;
+        if (event.type !== 'mousemove' && event.type !== 'click') return;
+
+        const yAxis = chart.boxes[1];
+        if (event.y < yAxis.bottom + 10 || event.y > yAxis.bottom + 30) {
+          chart.canvas.style.cursor = '';
+          return;
+        }
+
+        const xAxis = chart.boxes[0];
+        const pointIdx = xAxis.ticks.findIndex((_, index) => {
+          const x = xAxis.getPixelForTick(index);
+          return event.x >= x - 10 && event.x <= x + 10;
+        });
+
+        if (pointIdx === -1) {
+          chart.canvas.style.cursor = '';
+          return;
+        }
+
+        chart.canvas.style.cursor = 'pointer';
+        if (event.type === 'click' && this.activityTopAuthors[pointIdx].home_link) {
+          window.location.href = this.activityTopAuthors[pointIdx].home_link;
+        }
+      },
+    });
   },
 };
 
 export function initRepoActivityTopAuthorsChart() {
   const el = document.getElementById('repo-activity-top-authors-chart');
   if (el) {
-    createApp(sfc).mount(el);
+    createApp(sfc, {
+      locale: {
+        commitActivity: el.getAttribute('data-locale-commit-activity'),
+      },
+    }).mount(el);
   }
 }
 
@@ -62,50 +150,6 @@ export default sfc; // activate the IDE's Vue plugin
 <template>
   <div>
     <div class="activity-bar-graph" ref="style" style="width: 0; height: 0;"/>
-    <div class="activity-bar-graph-alt" ref="altStyle" style="width: 0; height: 0;"/>
-    <vue-bar-graph
-      :points="graphPoints"
-      :show-x-axis="true"
-      :show-y-axis="false"
-      :show-values="true"
-      :width="graphWidth"
-      :bar-color="colors.barColor"
-      :text-color="colors.textColor"
-      :text-alt-color="colors.textAltColor"
-      :height="100"
-      :label-height="20"
-    >
-      <template #label="opt">
-        <g v-for="(author, idx) in graphAuthors" :key="author.position">
-          <a
-            v-if="opt.bar.index === idx && author.home_link"
-            :href="author.home_link"
-          >
-            <image
-              :x="`${opt.bar.midPoint - 10}px`"
-              :y="`${opt.bar.yLabel}px`"
-              height="20"
-              width="20"
-              :href="author.avatar_link"
-            />
-          </a>
-          <image
-            v-else-if="opt.bar.index === idx"
-            :x="`${opt.bar.midPoint - 10}px`"
-            :y="`${opt.bar.yLabel}px`"
-            height="20"
-            width="20"
-            :href="author.avatar_link"
-          />
-        </g>
-      </template>
-      <template #title="opt">
-        <tspan v-for="(author, idx) in graphAuthors" :key="author.position">
-          <tspan v-if="opt.bar.index === idx">
-            {{ author.name }}
-          </tspan>
-        </tspan>
-      </template>
-    </vue-bar-graph>
+    <Bar height="150px" :data="graphPoints()" :options="getOptions()"/>
   </div>
 </template>