diff --git a/frontend/components/tasks/sequenceLabeling/EntityItem.vue b/frontend/components/tasks/sequenceLabeling/EntityItem.vue
deleted file mode 100644
index 228e09df..00000000
--- a/frontend/components/tasks/sequenceLabeling/EntityItem.vue
+++ /dev/null
@@ -1,358 +0,0 @@
-<template>
-  <v-menu
-      v-if="label && !activeMenu"
-      v-model="showMenu"
-      offset-y
-  >
-    <template #activator="{ on }">
-      <span :id="'spn-' + spanid" :style="{ borderColor: color }" class="highlight bottom" v-on="on">
-        <span class="highlight__content">{{ content }}<v-icon class="delete" @click.stop="remove">mdi-close-circle</v-icon><span
-            v-if="!showMenu && sourceChunk.none" class="choose-link-type" @click.stop="showActiveLinks"></span><span
-            v-if="!showMenu && sourceChunk.id === spanid" class="active-link-source" @click.stop="abortNewLink"></span><span
-            v-if="sourceLinkType.id > -1 && sourceChunk.id && sourceChunk.id !== spanid" class="choose-target"
-            @click.stop="selectTarget"></span></span><span
-          :data-label="label" :style="{ backgroundColor: color, color: textColor }" class="highlight__label"/>
-      </span>
-    </template>
-
-    <v-list
-        dense
-        min-width="150"
-        max-height="400"
-        class="overflow-y-auto"
-    >
-      <v-list-item
-          v-for="(item, i) in labels"
-          :key="i"
-          v-shortkey.once="[item.suffixKey]"
-          @shortkey="update(item)"
-          @click="update(item)"
-      >
-        <v-list-item-content>
-          <v-list-item-title v-text="item.text"/>
-        </v-list-item-content>
-        <v-list-item-action>
-          <v-list-item-action-text v-text="item.suffixKey"/>
-        </v-list-item-action>
-      </v-list-item>
-    </v-list>
-  </v-menu>
-
-  <v-menu
-      v-else-if="label && activeMenu==='active-links'"
-      v-model="showActiveLinksMenu"
-      offset-y
-  >
-    <template #activator="{ on }">
-      <span :id="'spn-' + spanid" :style="{ borderColor: color }" class="highlight bottom" v-on="on">
-        <span class="highlight__content">{{ content }}<v-icon class="delete" @click.stop="remove">mdi-close-circle</v-icon><span
-            class="active-link-source" @click.stop="abortNewLink"></span></span><span
-          :data-label="label" :style="{ backgroundColor: color, color: textColor }" class="highlight__label"/>
-      </span>
-    </template>
-
-    <v-list
-        dense
-        min-width="150"
-        max-height="400"
-        class="overflow-y-auto"
-    >
-      <v-list-item @click.stop="showNewLinkTypes">
-        <v-list-item-content>
-          <v-list-item-title>new relation...</v-list-item-title>
-        </v-list-item-content>
-      </v-list-item>
-
-      <v-list-item
-          v-for="(link, i) in sourceChunk.links"
-          :key="i"
-      >
-        <v-list-item-content>
-          <v-list-item-subtitle v-text="link.targetLabel"></v-list-item-subtitle>
-        </v-list-item-content>
-
-        <v-list-item-action>
-          <v-btn icon @click.stop="deleteLink(link, i)">
-            <v-icon color="grey lighten-1">mdi-delete</v-icon>
-          </v-btn>
-        </v-list-item-action>
-      </v-list-item>
-    </v-list>
-  </v-menu>
-
-  <v-menu
-      v-else-if="label && activeMenu==='new-link'"
-      v-model="showNewLinkMenu"
-      offset-y
-  >
-    <template #activator="{ on }">
-      <span :id="'spn-' + spanid" :style="{ borderColor: color }" class="highlight bottom" v-on="on">
-        <span class="highlight__content">{{ content }}<v-icon class="delete" @click.stop="remove">mdi-close-circle</v-icon><span
-            class="active-link-source" @click.stop="abortNewLink"></span></span><span
-          :data-label="label" :style="{ backgroundColor: color, color: textColor }" class="highlight__label"/>
-      </span>
-    </template>
-
-    <v-list
-        dense
-        min-width="150"
-        max-height="400"
-        class="overflow-y-auto"
-    >
-      <v-list-item>
-        <v-list-item-content>
-          <v-list-item-title>choose relation type:</v-list-item-title>
-        </v-list-item-content>
-      </v-list-item>
-
-      <v-list-item
-          v-for="(type, i) in linkTypes"
-          :key="i"
-          @click="selectNewLinkType(type)"
-      >
-        <v-list-item-action>
-          <v-list-item-action-text v-text="type.name"/>
-        </v-list-item-action>
-      </v-list-item>
-    </v-list>
-  </v-menu>
-
-  <span v-else :class="[newline ? 'newline' : '']">{{ content }}</span>
-</template>
-
-<script>
-import {idealColor} from '~/plugins/utils.js'
-
-export default {
-  props: {
-    spanid: {
-      type: Number,
-      default: 0,
-      required: true
-    },
-    content: {
-      type: String,
-      default: '',
-      required: true
-    },
-    label: {
-      type: String,
-      default: ''
-    },
-    color: {
-      type: String,
-      default: '#64FFDA'
-    },
-    labels: {
-      type: Array,
-      default: () => [],
-      required: true
-    },
-    linkTypes: {
-      type: Array,
-      default: () => [],
-      required: true
-    },
-    newline: {
-      type: Boolean
-    },
-    sourceChunk: {
-      type: Object,
-      default: () => {
-      }
-    },
-    sourceLinkType: {
-      type: Object,
-      default: () => {
-      },
-      required: true
-    }
-  },
-
-  data() {
-    return {
-      showMenu: false,
-      showActiveLinksMenu: false,
-      showNewLinkMenu: false,
-      showChangeLinkMenu: false,
-      activeMenu: false
-    }
-  },
-
-  computed: {
-    textColor() {
-      return idealColor(this.color)
-    }
-  },
-
-  methods: {
-    update(label) {
-      this.$emit('update', label)
-      this.closeAllMenus();
-    },
-
-    remove() {
-      this.$emit('remove')
-    },
-
-    closeAllMenus() {
-      this.showMenu = false;
-      this.showActiveLinksMenu = false;
-      this.showNewLinkMenu = false;
-      this.showChangeLinkMenu = false;
-      this.activeMenu = false;
-    },
-
-    showActiveLinks() {
-      this.closeAllMenus();
-      this.showActiveLinksMenu = true;
-      this.activeMenu = 'active-links';
-      this.$emit('selectSource');
-    },
-
-    showNewLinkTypes() {
-      this.closeAllMenus();
-      this.activeMenu = 'new-link';
-      this.showNewLinkMenu = true;
-    },
-
-    deleteLink(link, i) {
-      this.$emit('deleteLink', {id: link.id, ndx: i});
-    },
-
-    selectNewLinkType(type) {
-      this.closeAllMenus();
-      this.$emit('selectNewLinkType', type);
-    },
-
-    changeLinkType(type) {
-      this.closeAllMenus();
-      this.$emit('changeLinkType', type);
-    },
-
-    selectTarget() {
-      this.closeAllMenus();
-      this.$emit('selectTarget');
-    },
-
-    abortNewLink() {
-      this.closeAllMenus();
-      this.$emit('hideAllLinkMenus');
-    }
-  }
-}
-</script>
-
-<style scoped>
-.highlight.blue {
-  background: #edf4fa !important;
-}
-
-.highlight.bottom {
-  display: block;
-  white-space: normal;
-}
-
-.highlight:first-child {
-  margin-left: 0;
-}
-
-.highlight {
-  border: 2px solid;
-  margin: 4px 6px 4px 3px;
-  vertical-align: middle;
-  box-shadow: 2px 4px 20px rgba(0, 0, 0, .1);
-  position: relative;
-  cursor: default;
-  min-width: 26px;
-  line-height: 22px;
-  display: flex;
-}
-
-.highlight .delete {
-  top: -15px;
-  left: -13px;
-  position: absolute;
-  display: none;
-}
-
-.highlight:hover .delete {
-  display: block;
-}
-
-.highlight .choose-link-type:before {
-  content: 'R';
-}
-
-.highlight .active-link-source:before {
-  content: 'R';
-}
-
-.highlight .choose-target:before {
-  content: '+';
-}
-
-.highlight .choose-link-type,
-.highlight .active-link-source,
-.highlight .choose-target {
-  display: none;
-  position: absolute;
-  top: -12px;
-  right: -11px;
-  width: 20px;
-  background: rgba(0, 0, 0, 0.54);
-  color: #ffffff;
-  border-radius: 30px;
-  cursor: pointer;
-  text-align: center;
-}
-
-.highlight:hover .choose-link-type,
-.highlight:hover .choose-target {
-  display: block;
-}
-
-.highlight .active-link-source {
-  display: block;
-  background: #00a4cf;
-  color: #ffffff;
-}
-
-.highlight__content {
-  display: flex;
-  flex-wrap: wrap;
-  align-items: center;
-  padding: 2px 2px 0 6px;
-}
-
-.highlight.bottom .highlight__content:after {
-  content: " ";
-  padding-right: 3px;
-}
-
-.highlight__label {
-  line-height: 14px;
-  align-items: center;
-  justify-content: center;
-  display: flex;
-  padding: 0 8px;
-  text-align: center;
-  -webkit-user-select: none;
-  -moz-user-select: none;
-  -ms-user-select: none;
-  user-select: none;
-  color: white;
-}
-
-.highlight__label::after {
-  content: attr(data-label);
-  display: block;
-  font-size: 14px;
-  -webkit-font-smoothing: subpixel-antialiased;
-  letter-spacing: .1em;
-}
-
-.newline {
-  width: 100%;
-}
-</style>
diff --git a/frontend/components/tasks/sequenceLabeling/EntityItemBox.vue b/frontend/components/tasks/sequenceLabeling/EntityItemBox.vue
deleted file mode 100644
index 143fef99..00000000
--- a/frontend/components/tasks/sequenceLabeling/EntityItemBox.vue
+++ /dev/null
@@ -1,501 +0,0 @@
-<template>
-  <div id="connections-wrapper">
-    <div class="highlight-container highlight-container--bottom-labels" @click="open" @touchend="open">
-      <entity-item
-          v-for="(chunk, i) in chunks"
-          :key="i"
-          :spanid="chunk.id"
-          :content="chunk.text"
-          :newline="chunk.newline"
-          :label="chunk.label"
-          :color="chunk.color"
-          :labels="labels"
-          :link-types="linkTypes"
-          :source-chunk="sourceChunk"
-          :source-link-type="sourceLinkType"
-          @remove="deleteAnnotation(chunk.id)"
-          @update="updateEntity($event.id, chunk.id)"
-          @selectSource="selectSource(chunk)"
-          @selectTarget="selectTarget(chunk)"
-          @deleteLink="deleteLink($event.id, $event.ndx)"
-          @selectNewLinkType="selectNewLinkType($event)"
-          @hideAllLinkMenus="hideAllLinkMenus()"
-      />
-      <v-menu
-          v-model="showMenu"
-          :position-x="x"
-          :position-y="y"
-          absolute
-          offset-y
-      >
-        <v-list
-            dense
-            min-width="150"
-            max-height="400"
-            class="overflow-y-auto"
-        >
-          <v-list-item
-              v-for="(label, i) in labels"
-              :key="i"
-              v-shortkey="[label.suffixKey]"
-              @shortkey="assignLabel(label.id)"
-              @click="assignLabel(label.id)"
-          >
-            <v-list-item-content>
-              <v-list-item-title v-text="label.text"/>
-            </v-list-item-content>
-            <v-list-item-action>
-              <v-list-item-action-text v-text="label.suffixKey"/>
-            </v-list-item-action>
-          </v-list-item>
-        </v-list>
-      </v-menu>
-    </div>
-
-    <canvas id="connections">
-    </canvas>
-  </div>
-</template>
-
-<script>
-import EntityItem from './EntityItem'
-
-export default {
-  components: {
-    EntityItem
-  },
-
-  props: {
-    text: {
-      type: String,
-      default: '',
-      required: true
-    },
-    labels: {
-      type: Array,
-      default: () => ([]),
-      required: true
-    },
-    linkTypes: {
-      type: Array,
-      default: () => ([]),
-      required: true
-    },
-    entities: {
-      type: Array,
-      default: () => ([]),
-      required: true
-    },
-    deleteAnnotation: {
-      type: Function,
-      default: () => ([]),
-      required: true
-    },
-    updateEntity: {
-      type: Function,
-      default: () => ([]),
-      required: true
-    },
-    addEntity: {
-      type: Function,
-      default: () => ([]),
-      required: true
-    },
-    sourceChunk: {
-      type: Object,
-      default: () => {
-      },
-      required: true
-    },
-    sourceLinkType: {
-      type: Object,
-      default: () => {
-      },
-      required: true
-    },
-    selectSource: {
-      type: Function,
-      default: () => ([]),
-      required: true
-    },
-    selectTarget: {
-      type: Function,
-      default: () => ([]),
-      required: true
-    },
-    deleteLink: {
-      type: Function,
-      default: () => ([]),
-      required: true
-    },
-    selectNewLinkType: {
-      type: Function,
-      default: () => ([]),
-      required: true
-    },
-    hideAllLinkMenus: {
-      type: Function,
-      default: () => ([]),
-      required: true
-    }
-  },
-
-  data() {
-    return {
-      showMenu: false,
-      x: 0,
-      y: 0,
-      start: 0,
-      end: 0
-    }
-  },
-
-  computed: {
-    sortedEntities() {
-      return this.entities.slice().sort((a, b) => a.startOffset - b.startOffset)
-    },
-
-    chunks() {
-      let chunks = []
-      let startOffset = 0
-      // to count the number of characters correctly.
-      const characters = [...this.text]
-      for (const entity of this.sortedEntities) {
-        // add non-entities to chunks.
-        let piece = characters.slice(startOffset, entity.startOffset).join('')
-        chunks = chunks.concat(this.makeChunks(piece))
-        startOffset = entity.endOffset
-        // add entities to chunks.
-        const label = this.labelObject[entity.label]
-        piece = characters.slice(entity.startOffset, entity.endOffset).join('')
-        chunks.push({
-          id: entity.id,
-          label: label.text,
-          color: label.backgroundColor,
-          text: piece,
-          selectedAsLinkSource: false,
-          links: entity.links ? entity.links.map(link => {
-            return {
-              id: link.id,
-              type: link.type,
-              color: this.getColor(link.type),
-              targetId: link.annotation_id_2,
-              targetLabel: null // target label can be computed only after all chunks are made, see line 204
-            }
-          }) : null
-        })
-      }
-      // add the rest of text.
-      chunks = chunks.concat(this.makeChunks(characters.slice(startOffset, characters.length).join('')));
-
-      // populate the links. Must be done after chunk creation
-      chunks.forEach(chunk => {
-        if (chunk.links) {
-          chunk.links.forEach(link => {
-            link.targetLabel = chunks.find(target => target.id === link.targetId).text;
-          });
-        }
-      });
-
-      return chunks;
-    },
-
-    labelObject() {
-      const obj = {}
-      for (const label of this.labels) {
-        obj[label.id] = label
-      }
-      return obj
-    }
-  },
-
-  updated() {
-    this.$nextTick(() => {
-      const parentPos = document.getElementById('connections-wrapper').getBoundingClientRect();
-      const canvas = document.getElementById('connections');
-      canvas.width = parentPos.width;
-      canvas.height = parentPos.height;
-
-      const ctx = canvas.getContext('2d');
-      ctx.clearRect(0, 0, parentPos.width, parentPos.height);
-
-      const topPoints = this.drawnCountPoints(this.chunks.length);
-      const bottomPoints = this.drawnCountPoints(this.chunks.length);
-
-      const chunks = this.chunks;
-
-      chunks.forEach(function(sourceChunk, sourceNdx) {
-        if (sourceChunk.links) {
-          sourceChunk.links.forEach(function(link) {
-            let childPos = document.getElementById('spn-' + sourceChunk.id).getBoundingClientRect();
-            const y1 = childPos.y - parentPos.y;
-
-            childPos = document.getElementById('spn-' + link.targetId).getBoundingClientRect();
-            const y2 = childPos.y - parentPos.y;
-
-            const targetNdx = chunks.findIndex(ch => ch.id === link.targetId);
-
-            if (y1 < y2) {
-              bottomPoints[sourceNdx].count++;
-              topPoints[targetNdx].count++;
-
-            } else if (y1 > y2) {
-              topPoints[sourceNdx].count++;
-              bottomPoints[targetNdx].count++;
-
-            } else {
-              bottomPoints[sourceNdx].count++;
-              bottomPoints[targetNdx].count++;
-            }
-          });
-        }
-      });
-
-      chunks.forEach(function(sourceChunk, sourceNdx) {
-        if (sourceChunk.links) {
-          sourceChunk.links.forEach(function(link) {
-            const sourcePos = document.getElementById('spn-' + sourceChunk.id).getBoundingClientRect();
-            let x1 = sourcePos.x - parentPos.x;
-            let y1 = sourcePos.y - parentPos.y;
-
-            const targetPos = document.getElementById('spn-' + link.targetId).getBoundingClientRect();
-            let x2 = targetPos.x - parentPos.x;
-            let y2 = targetPos.y - parentPos.y;
-
-            const targetNdx = chunks.findIndex(ch => ch.id === link.targetId);
-
-            ctx.beginPath();
-            ctx.lineWidth = 3;
-            ctx.strokeStyle = link.color;
-
-            if (y1 < y2) {
-              bottomPoints[sourceNdx].drawn++;
-              topPoints[targetNdx].drawn++;
-
-              x1 += bottomPoints[sourceNdx].drawn * sourcePos.width / (bottomPoints[sourceNdx].count + 1);
-              y1 += sourcePos.height;
-
-              x2 += topPoints[targetNdx].drawn * targetPos.width / (topPoints[targetNdx].count + 1);
-
-              ctx.moveTo(x1, y1);
-              ctx.lineTo(x1, y1 + 12);
-              ctx.lineTo(x2, y2 - 12);
-              ctx.lineTo(x2, y2);
-              ctx.stroke();
-
-              ctx.fillStyle = link.color;
-              ctx.beginPath();
-              ctx.moveTo(x2, y2);
-              ctx.lineTo(x2 - 3, y2 - 5);
-              ctx.lineTo(x2 + 3, y2 - 5);
-              ctx.lineTo(x2, y2);
-              ctx.closePath();
-              ctx.stroke();
-
-            } else if (y1 > y2) {
-              topPoints[sourceNdx].drawn++;
-              bottomPoints[targetNdx].drawn++;
-
-              x1 += topPoints[sourceNdx].drawn * sourcePos.width / (topPoints[sourceNdx].count + 1);
-
-              x2 += bottomPoints[targetNdx].drawn * targetPos.width / (bottomPoints[targetNdx].count + 1);
-              y2 += targetPos.height;
-
-              ctx.moveTo(x1, y1);
-              ctx.lineTo(x1, y1 - 12);
-              ctx.lineTo(x2, y2 + 12);
-              ctx.lineTo(x2, y2);
-              ctx.stroke();
-
-              ctx.fillStyle = link.color;
-              ctx.beginPath();
-              ctx.moveTo(x2, y2);
-              ctx.lineTo(x2 - 3, y2 + 5);
-              ctx.lineTo(x2 + 3, y2 + 5);
-              ctx.lineTo(x2, y2);
-              ctx.closePath();
-              ctx.stroke();
-
-            } else {
-              bottomPoints[sourceNdx].drawn++;
-              bottomPoints[targetNdx].drawn++;
-
-              x1 += bottomPoints[sourceNdx].drawn * sourcePos.width / (bottomPoints[sourceNdx].count + 1);
-              y1 += sourcePos.height;
-
-              x2 += bottomPoints[targetNdx].drawn * targetPos.width / (bottomPoints[targetNdx].count + 1);
-              y2 += targetPos.height;
-
-              ctx.moveTo(x1, y1);
-              ctx.lineTo(x1, y1 + 12);
-              ctx.lineTo(x2, y2 + 12);
-              ctx.lineTo(x2, y2);
-              ctx.stroke();
-
-              ctx.fillStyle = link.color;
-              ctx.beginPath();
-              ctx.moveTo(x2, y2);
-              ctx.lineTo(x2 - 3, y2 + 5);
-              ctx.lineTo(x2 + 3, y2 + 5);
-              ctx.lineTo(x2, y2);
-              ctx.closePath();
-              ctx.stroke();
-            }
-          });
-        }
-      });
-    });
-  },
-
-  methods: {
-    makeChunks(text) {
-      const chunks = []
-      const snippets = text.split('\n')
-      for (const snippet of snippets.slice(0, -1)) {
-        chunks.push({
-          label: null,
-          color: null,
-          text: snippet + '\n',
-          newline: false
-        })
-        chunks.push({
-          label: null,
-          color: null,
-          text: '',
-          newline: true
-        })
-      }
-      chunks.push({
-        label: null,
-        color: null,
-        text: snippets.slice(-1)[0],
-        newline: false
-      })
-      return chunks
-    },
-
-    show(e) {
-      e.preventDefault()
-      this.showMenu = false
-      this.x = e.clientX || e.changedTouches[0].clientX
-      this.y = e.clientY || e.changedTouches[0].clientY
-      this.$nextTick(() => {
-        this.showMenu = true
-      })
-    },
-
-    setSpanInfo() {
-      let selection
-      // Modern browsers.
-      if (window.getSelection) {
-        selection = window.getSelection()
-      } else if (document.selection) {
-        selection = document.selection
-      }
-      // If nothing is selected.
-      if (selection.rangeCount <= 0) {
-        return
-      }
-      const range = selection.getRangeAt(0)
-      const preSelectionRange = range.cloneRange()
-      preSelectionRange.selectNodeContents(this.$el)
-      preSelectionRange.setEnd(range.startContainer, range.startOffset)
-      this.start = [...preSelectionRange.toString()].length
-      this.end = this.start + [...range.toString()].length
-    },
-
-    validateSpan() {
-      if ((typeof this.start === 'undefined') || (typeof this.end === 'undefined')) {
-        return false
-      }
-      if (this.start === this.end) {
-        return false
-      }
-      for (const entity of this.entities) {
-        if ((entity.startOffset <= this.start) && (this.start < entity.endOffset)) {
-          return false
-        }
-        if ((entity.startOffset < this.end) && (this.end <= entity.endOffset)) {
-          return false
-        }
-        if ((this.start < entity.startOffset) && (entity.endOffset < this.end)) {
-          return false
-        }
-      }
-      return true
-    },
-
-    open(e) {
-      this.$emit('hideAllLinkMenus');
-
-      this.setSpanInfo()
-      if (this.validateSpan()) {
-        this.show(e)
-      }
-    },
-
-    assignLabel(labelId) {
-      if (this.validateSpan()) {
-        this.addEntity(this.start, this.end, labelId)
-        this.showMenu = false
-        this.start = 0
-        this.end = 0
-      }
-    },
-
-    getColor(typeId) {
-      const type = this.linkTypes.find(type => type.id === typeId);
-      if (type) {
-        return type.color;
-      }
-      return "#787878";
-    },
-
-    drawnCountPoints(size) {
-      const points = Array(size);
-
-      for (let i = 0; i < points.length; i++) {
-        points[i] = {
-          drawn: 0,
-          count: 0
-        }
-      }
-
-      return points;
-    }
-  }
-}
-</script>
-
-<style scoped>
-.highlight-container.highlight-container--bottom-labels {
-  align-items: flex-start;
-}
-
-.highlight-container {
-  line-height: 70px !important;
-  display: flex;
-  flex-wrap: wrap;
-  white-space: pre-wrap;
-  cursor: default;
-  position: relative;
-  z-index: 1;
-}
-
-.highlight-container.highlight-container--bottom-labels .highlight.bottom {
-  margin-top: 6px;
-}
-
-#connections-wrapper {
-  position: relative;
-}
-
-#connections-wrapper canvas {
-  position: absolute;
-  top: 0;
-  left: 0;
-  width: 100%;
-  height: 100%;
-  z-index: 0;
-}
-</style>