CODEWITHSUNDEEP
mapboxmapbox-gl-js
Toli
Toli

Reputation: 5777

In mapbox how do I move a Feature to top (z-index wise)?

I have a layer full of state border "Features". When a user clicks on a State, I want to move that state's Feature to the top of the stack (z-index wise).

export function drawStateBorders() {
  $.getJSON('https://www.mapbox.com/mapbox-gl-js/assets/us_states.geojson').then((data) => {
    this.stateGeoJSON = data;

    this.map
      .addSource('states', {
        type: 'geojson',
        data,
      })
      .addLayer({
        id: 'state-borders',
        type: 'line',
        source: 'states',
        paint: {
          'line-color': [
            'case', ['boolean', ['feature-state', 'selected'], false],
            '#8d8b76',
            '#bfe2ab',
          ],
          'line-width': [
            'case', ['boolean', ['feature-state', 'selected'], false],
            6,
            3,
          ],
        },
      });
  });
}

When I select the state

export function stateSelected(state) {
  const stateFeatures = this.map.queryRenderedFeatures({
    layers: ['state-borders'],
    filter: [
      '==', 'STATE_NAME', state,
    ],
  });

  const features = this.stateGeoJSON.features;
  const currentFeature = stateFeatures[0];

  if (!currentFeature) {
    return;
  }

  // same state
  if (currentFeature.id === this.selectedStateId) return;

  // move to front HERE ?????

  // old selected state
  if (this.selectedStateId) {
    this.map.setFeatureState({
      source: 'states',
      id: this.selectedStateId,
    }, {
      selected: false,
    });
  }

  this.selectedStateId = currentFeature.id;

  this.map.setFeatureState({
    source: 'states',
    id: this.selectedStateId,
  }, {
    selected: true,
  });
}

So far I've tried

  features.splice(features.indexOf(currentFeature), 1);
  features.push(currentFeature);
  this.map.getSource('states').setData(this.stateGeoJSON);

This seems to do some really crazy stuff to the array (duplicating some states, removing others). No idea what's happening

Upvotes: 3

Views: 7391

Answers (1)

Toli
Toli

Reputation: 5777

Adding the state to another layer worked (thanks @AndrewHarvey for the advice).

In case anyone is interested here is my code 

export function stateSelected(state) {
  const features = this.stateGeoJSON.features;
  const currentFeature = features.find(s => s.properties.NAME === state);

  if (!currentFeature) {
    return;
  }

  // removes active layer
  this.removeLayersContaining('state-borders-active');
  this.drawActiveStateLayer(currentFeature);
}


export function drawActiveStateLayer(feature) {
  this.map
    .addLayer({
      id: 'state-borders-active',
      type: 'line',
      source: {
        type: 'geojson',
        data: feature
      },
      paint: {
        'line-color': '#8d8b76',
        'line-width': 6,
      },
    });
}

export function drawStateBorders() {
  $.getJSON('states.json').then((data) => {

    this.stateGeoJSON = data;

    this.map
      .addSource('states', {
        type: 'geojson',
        data,
      })
      .addLayer({
        id: 'state-borders',
        type: 'line',
        source: 'states',
        paint: {
          'line-color': '#bfe2ab',
          'line-width':  3,
        },
      });
  });

Also this is the shapefile I'm using: http://eric.clst.org/assets/wiki/uploads/Stuff/gz_2010_us_040_00_500k.json

Upvotes: 2

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