Javier
Javier

Reputation: 2095

Export png from deckl map

I'm using react-map-gl with deck.gl to load layers into mapbox.

I'm trying to export a png image of the map with layers but when download the image doesn't show the layers.

The layers are: one GeojsonLayer and one HexagonalLayer.

How can show layers in my png??

<MapGL
  ref={this.mapRef}
  {...viewport}
  className="mapbox"
  mapStyle={mapStyle}
  mapboxApiAccessToken={MAPBOX_TOKEN}
  preserveDrawingBuffer={true}
  attributionControl={false}
  onLoad={this.handleLoad}
  onViewportChange={(viewport) => {
    viewport.width = "100%";
    viewport.height = "400px";
    this.setState({ viewport });
  }}
>
  <DeckGL layers={layers} onHover={this.onHoverDeckgl} viewState={viewport} />
</MapGL>;

// This is my method to download the image.

downloadImage = () => {
    const fileName = `${"Mapa"}_${moment().format(
        "DD_MM_YYYY_ HH_mm"
    )}.png`;

    const canvas = this.state.mapGL.getCanvas();
    canvas.toBlob(blob => {
        FileSaver.saveAs(blob, fileName);
    });
};

Upvotes: 1

Views: 2047

Answers (1)

Javier
Javier

Reputation: 2095

Finally, I did it!!!

I fould a solution to combine canvas from mapbox and canvas from deckgl.

  1. Aadd id to Deckgl Component and ref

    return (
         <DeckGL
            id="deck-gl-canvas"
            ref={this.deckRef}
            layers={layers}
            onHover={this.onHoverDeckgl}
            onLoad={this.handleLoad}
            viewState={viewport}
         >
            {this.renderTooltip()}
         </DeckGL>
    );
    
    // pass deck reference where will be action to download image
    handleLoad = () => {
        const deck = this.deckRef.current.deck;
        this.props.onGetDeckGL(deck);
    };
    
  2. add ref to Mapbox Component and pass will be the action to download image

  3. Call redraw to deck

  4. Combine canvas on a third canvas

    downloadImage = () => {
        const fileName = "Map.png";
    
        const { mapGL, deck } = this.state;
        const mapboxCanvas = mapGL.getCanvas(
            document.querySelector(".mapboxgl-canvas")
        );
        deck.redraw(true);
        const deckglCanvas = document.getElementById("deck-gl-canvas");
    
        let merge = document.createElement("canvas");
        merge.width = mapboxCanvas.width;
        merge.height = mapboxCanvas.height;
    
        var context = merge.getContext("2d");
    
        context.globalAlpha = 1.0;
        context.drawImage(mapboxCanvas, 0, 0);
        context.globalAlpha = 1.0;
        context.drawImage(deckglCanvas, 0, 0);
    
        merge.toBlob(blob => {
            FileSaver.saveAs(blob, fileName);
        });
    };
    

Upvotes: 4

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