Explicitly wait for Vega plots to be created before enabling various interactive things

[fedarko]

Currently, there is technically a small window of time where the plots are still being created by Vega* but none of my code is running (so the rrv UI is free to be used). It'd be a good idea to modify, e.g., makePlots() to make it explicitly asynchronous, and wait for the plots to be created.

In the meantime—before the plots would be created—the various UI elements in the app should be "disabled" (like in MetagenomeScope, sorta). I'd imagine that this would include the buttons for running text queries and taking screenshots, as well as the click events on the rank plot (... so just delay running addClickEventToRankPlotView()). Once the plots have finished loading, we could enable the UI elements.

[fedarko]

As eventual proof that this works: we should be able to programmatically create an RRVDisplay object and then call its destroy() method in the next line without any problems. (I actually tried to test the destroy() method and that failed for this reason -- which is why I stumbled upon this issue.)

See: (to be added eventually to test_rrvdisplay.js)

    describe("The RRVDisplay destructor (destroy())", function() {
        var rrv = new display.RRVDisplay(rankPlotJSON, samplePlotJSON);
        rrv.destroy();
        it("Properly clears DOM element bindings", function() {
            for (var i = 0; i < rrv.elementsWithOnClickBindings.length; i++) {
                chai.assert.isUndefined(
                    document.getElementById(rrv.elementsWithOnClickBindings[i]).onclick
                );
            }
        });
        it("Properly clears the #rankPlot and #samplePlot divs", function() {
            chai.assert.isEmpty(document.getElementById("rankPlot").innerHTML);
            chai.assert.isEmpty(document.getElementById("samplePlot").innerHTML);
        });
    });

[fedarko]

Yeah, I think this is a prerequisite before we can write JS tests that involve checks on the actual view objects.

Here's another test that should eventually be added to the RRVDisplay tests (under the "Multi-feature selections" describe block), but currently triggers a TypeError because it calls this.samplePlotView.change() when this.samplePlotView is still undefined:

                describe("Text searching", function() {
                    document.getElementById("topSearch").value = "text";
                    document.getElementById("botSearch").value = "text";
                    document.getElementById("topText").value = "Taxon";
                    document.getElementById("topText").value = "Yeet";
                    rrv.updateSamplePlotMulti();
                    it("Properly updates topFeatures and botFeatures", function() {
                        chai.assert.sameMembers(
                            [
                                "Taxon1",
                                "Taxon2",
                                "Taxon3|Yeet|100",
                                "Taxon4",
                                "Taxon5"
                            ],
                            rrv.topFeatures
                        );
                        chai.assert.equal(["Taxon3|Yeet|100"], rrv.botFeatures);
                    });
                });