您只需定義一個可擴展結構類的typescript類即可。
export interface IMindObjectOptions {
item: IMindItem;
}
export interface IMindExpanderOptions extends IMindObjectOptions {
x: number;
y: number;
radius: number;
isExpanded: boolean;
}
export class MindExpander extends fabric.Circle implements IMindObjectOptions {
public constructor(options: IMindExpanderOptions) {
const circleOptions: ICircleOptions = {
originX: "center",
originY: "center",
left: options.x,
top: options.y,
radius: options.radius,
stroke: "#000000",
fill: options.isExpanded ? "#00FFFF": "#00FF00",
selectable: false
};
super(circleOptions);
this.item = options.item;
}
public readonly item: IMindItem;
}
!上面的代碼在瀏覽器中工作正常,但不在nodejs環境中。
要enviornment的NodeJS工作,比如運行單元測試沒有瀏覽器,你需要:
import {assert} from "chai";
import * as f from 'fabric';
import {ITextOptions} from "fabric";
declare function require(s: string): any;
declare const __dirname: string;
const fabric = require("fabric").fabric;
interface ITextConstructor {
new(text: string, options: ITextOptions): f.Text;
}
function getTextConstructor(): ITextConstructor {
return fabric.Text;
}
describe("nodejs setup", function() {
it("fabric is imported correctly", function() {
const x = fabric.Text as f.Text;
assert.equal(typeof x, "function");
});
it("fabric class is extensible", function() {
class SubText extends getTextConstructor() {
public constructor(text: string, options: fabric.ITextOptions) {
super(text, options);
}
}
const c = new SubText("Hello", {left: 100, top: 100});
assert.equal(c.text, "Hello");
assert.isNotNull(c);
});
});
我明白上面的答案,但有沒有因爲過任何變化?此外,我不確定我的.ts文件中的導入聲明的格式,以便使用結構。 –