MapComplete/src/index_theme.ts.template

import ThemeViewState from "./src/Models/ThemeViewState"
import SvelteUIElement from "./src/UI/Base/SvelteUIElement"
import ThemeViewGUI from "./src/UI/ThemeViewGUI.svelte"
import LayoutConfig from "./src/Models/ThemeConfig/LayoutConfig";
import MetaTagging from "./src/Logic/MetaTagging";
import { FixedUiElement } from "./src/UI/Base/FixedUiElement";

function webgl_support() {
    try {
        var canvas = document.createElement("canvas")
        return (
            !!window.WebGLRenderingContext &&
            (canvas.getContext("webgl") || canvas.getContext("experimental-webgl"))
        )
    } catch (e) {
        return false
    }
}

if (!webgl_support()) {
     new FixedUiElement("WebGL is not supported or not enabled. This is essential for MapComplete to function, please enable this.").SetClass("block alert").AttachTo("maindiv")
}else{
    MetaTagging.setThemeMetatagging(new ThemeMetaTagging())
    const state = new ThemeViewState(new LayoutConfig(<any> layout))
    const main = new SvelteUIElement(ThemeViewGUI, { state })
    main.AttachTo("maindiv")
}