src/vs/editor/browser/controller/textAreaHandler.ts/TextAreaHandler/prepareRender
class TextAreaHandler:	public prepareRender(ctx: RenderingContext): void {
		this._primaryCursorPosition = new Position(this._selections[0].positionLineNumber, this._selections[0].positionColumn);
		this._primaryCursorVisibleRange = ctx.visibleRangeForPosition(this._primaryCursorPosition);
		this._visibleTextArea?.prepareRender(ctx);
	}