UI Components and Layouts

/**
 * Base class for all UI elements providing core functionality
 */
class ViewBase {
  // Core properties
  id: string;
  className: string;
  style: Style;
  parent: ViewBase;
  isLoaded: boolean;
  
  // Event handling
  on(eventName: string, callback: Function): void;
  off(eventName: string, callback?: Function): void;
  notify(data: EventData): void;
  
  // Lifecycle methods
  addEventListener(arg: string | EventData, callback?: Function): void;
  removeEventListener(arg: string | EventData, callback?: Function): void;
}

/**
 * Enhanced base class with layout and visual properties
 */
class View extends ViewBase {
  // Layout properties
  width: number | string;
  height: number | string;
  minWidth: number;
  minHeight: number;
  margin: string | number;
  padding: string | number;
  
  // Visual properties
  visibility: "visible" | "hidden" | "collapse";
  opacity: number;
  backgroundColor: string;
  color: string;
  
  // Transform properties
  translateX: number;
  translateY: number;
  scaleX: number;
  scaleY: number;
  rotate: number;
  
  // Layout methods
  measure(widthMeasureSpec: number, heightMeasureSpec: number): void;
  layout(left: number, top: number, right: number, bottom: number): void;
  getMeasuredWidth(): number;
  getMeasuredHeight(): number;
}

/**
 * Base class for all layout containers
 */
class LayoutBase extends View {
  addChild(view: View): void;
  insertChild(child: View, atIndex: number): void;
  removeChild(child: View): void;
  removeChildren(): void;
  getChildAt(index: number): View;
  getChildIndex(child: View): number;
  getChildrenCount(): number;
  
  // Layout properties
  padding: string | number;
  paddingTop: number;
  paddingRight: number;
  paddingBottom: number;
  paddingLeft: number;
}

/**
 * Stack layout - arranges children in a single row or column
 */
class StackLayout extends LayoutBase {
  orientation: "vertical" | "horizontal";
}

/**
 * Grid layout - arranges children in rows and columns
 */
class GridLayout extends LayoutBase {
  columns: string; // e.g., "*, 100, auto"
  rows: string;    // e.g., "*, 50, auto"
  
  static setColumn(view: View, value: number): void;
  static getColumn(view: View): number;
  static setRow(view: View, value: number): void;
  static getRow(view: View): number;
  static setColumnSpan(view: View, value: number): void;
  static setRowSpan(view: View, value: number): void;
}

/**
 * Absolute layout - positions children using absolute coordinates
 */
class AbsoluteLayout extends LayoutBase {
  static setLeft(view: View, value: number): void;
  static setTop(view: View, value: number): void;
  static getLeft(view: View): number;
  static getTop(view: View): number;
}

/**
 * Dock layout - docks children to sides and fills remaining space
 */
class DockLayout extends LayoutBase {
  stretchLastChild: boolean;
  
  static setDock(view: View, value: "left" | "top" | "right" | "bottom"): void;
  static getDock(view: View): string;
}

/**
 * Wrap layout - arranges children in rows, wrapping to new row when needed
 */
class WrapLayout extends LayoutBase {
  orientation: "horizontal" | "vertical";
  itemWidth: number;
  itemHeight: number;
}

/**
 * Flexbox layout - CSS flexbox-style layout
 */
class FlexboxLayout extends LayoutBase {
  flexDirection: "row" | "row-reverse" | "column" | "column-reverse";
  flexWrap: "nowrap" | "wrap" | "wrap-reverse";
  justifyContent: "flex-start" | "flex-end" | "center" | "space-between" | "space-around";
  alignItems: "flex-start" | "flex-end" | "center" | "baseline" | "stretch";
  alignContent: "flex-start" | "flex-end" | "center" | "space-between" | "space-around" | "stretch";
}

import { StackLayout, GridLayout, Button, Label } from "tns-core-modules";

// Stack layout example
const stack = new StackLayout();
stack.orientation = "vertical";

const header = new Label();
header.text = "Welcome";
stack.addChild(header);

const button = new Button();
button.text = "Click Me";
stack.addChild(button);

// Grid layout example
const grid = new GridLayout();
grid.columns = "*, 100"; // flexible, fixed 100
grid.rows = "auto, *";   // auto-size, flexible

const title = new Label();
title.text = "Title";
GridLayout.setColumn(title, 0);
GridLayout.setRow(title, 0);
GridLayout.setColumnSpan(title, 2);
grid.addChild(title);

/**
 * Clickable button control
 */
class Button extends View {
  text: string;
  textWrap: boolean;
  
  // Events
  static tapEvent: "tap";
}

/**
 * Text display control
 */
class Label extends View {
  text: string;
  textWrap: boolean;
  textAlignment: "left" | "center" | "right";
  
  // Rich text support
  formattedText: FormattedString;
}

/**
 * Single-line text input control
 */
class TextField extends EditableTextBase {
  text: string;
  hint: string;
  secure: boolean;
  keyboardType: "datetime" | "phone" | "number" | "url" | "email";
  returnKeyType: "done" | "next" | "go" | "search" | "send";
  autocapitalizationType: "none" | "words" | "sentences" | "allCharacters";
  autocorrect: boolean;
  
  // Events
  static textChangeEvent: "textChange";
  static returnPressEvent: "returnPress";
  
  dismissSoftInput(): void;
}

/**
 * Multi-line text input control
 */
class TextView extends EditableTextBase {
  text: string;
  hint: string;
  editable: boolean;
  maxLines: number;
}

/**
 * Base class for editable text controls
 */
class EditableTextBase extends View {
  keyboardType: string;
  returnKeyType: string;
  autocapitalizationType: string;
  autocorrect: boolean;
  updateTextTrigger: "focusLost" | "textChanged";
  
  dismissSoftInput(): void;
}

/**
 * Image display control
 */
class Image extends View {
  src: string | ImageSource;
  imageSource: ImageSource;
  isLoading: boolean;
  stretch: "none" | "aspectFill" | "aspectFit" | "fill";
  loadMode: "sync" | "async";
  
  // Events
  static isLoadingChangeEvent: "isLoadingChange";
}

/**
 * Toggle switch control
 */
class Switch extends View {
  checked: boolean;
  
  // Events
  static checkedChangeEvent: "checkedChange";
}

/**
 * Numeric slider control
 */
class Slider extends View {
  value: number;
  minValue: number;
  maxValue: number;
  
  // Events
  static valueChangeEvent: "valueChange";
}

/**
 * Progress indicator control
 */
class Progress extends View {
  value: number;
  maxValue: number;
}

/**
 * Loading indicator control
 */
class ActivityIndicator extends View {
  busy: boolean;
}

/**
 * List view for displaying collections of data
 */
class ListView extends View {
  items: any[] | ObservableArray<any>;
  itemTemplate: string | Template;
  itemTemplateSelector: Function;
  separatorColor: string;
  rowHeight: number;
  
  // Events
  static itemLoadingEvent: "itemLoading";
  static itemTapEvent: "itemTap";
  static loadMoreItemsEvent: "loadMoreItems";
  
  refresh(): void;
  scrollToIndex(index: number): void;
  isItemAtIndexVisible(index: number): boolean;
}

/**
 * Segmented control for selecting from options
 */
class SegmentedBar extends View {
  items: SegmentedBarItem[];
  selectedIndex: number;
  selectedBackgroundColor: string;
  
  // Events
  static selectedIndexChangeEvent: "selectedIndexChange";
}

class SegmentedBarItem {
  title: string;
}

/**
 * Date picker control
 */
class DatePicker extends View {
  year: number;
  month: number;
  day: number;
  date: Date;
  minDate: Date;
  maxDate: Date;
  
  // Events
  static dateChangeEvent: "dateChange";
}

/**
 * Time picker control
 */
class TimePicker extends View {
  hour: number;
  minute: number;
  time: Date;
  minHour: number;
  maxHour: number;
  minuteInterval: number;
  
  // Events
  static timeChangeEvent: "timeChange";
}

/**
 * List picker for selecting from options
 */
class ListPicker extends View {
  items: any[];
  selectedIndex: number;
  selectedValue: any;
  
  // Events
  static selectedIndexChangeEvent: "selectedIndexChange";
}

/**
 * Web view for displaying web content
 */
class WebView extends View {
  url: string;
  src: string;
  canGoBack: boolean;
  canGoForward: boolean;
  
  loadUrl(url: string): void;
  goBack(): void;
  goForward(): void;
  reload(): void;
  
  // Events
  static loadStartedEvent: "loadStarted";
  static loadFinishedEvent: "loadFinished";
}

/**
 * Application page container
 */
class Page extends View {
  content: View;
  actionBar: ActionBar;
  navigationContext: any;
  frame: Frame;
  
  // Events
  static loadedEvent: "loaded";
  static navigatedToEvent: "navigatedTo";
  static navigatedFromEvent: "navigatedFrom";
  
  // Modal methods
  showModal(moduleName: string, context?: any, closeCallback?: Function, fullscreen?: boolean): void;
  closeModal(...args: any[]): void;
}

/**
 * Navigation frame container
 */
class Frame extends View {
  currentPage: Page;
  currentEntry: NavigationEntry;
  backStack: BackstackEntry[];
  animated: boolean;
  
  navigate(entry: string | NavigationEntry): void;
  goBack(to?: BackstackEntry): void;
  canGoBack(): boolean;
  
  // Events
  static navigatingToEvent: "navigatingTo";
  static navigatedToEvent: "navigatedTo";
}

interface NavigationEntry {
  moduleName?: string;
  context?: any;
  animated?: boolean;
  transition?: NavigationTransition;
  backstackVisible?: boolean;
  clearHistory?: boolean;
}

/**
 * Action bar for page headers
 */
class ActionBar extends View {
  title: string;
  navigationButton: NavigationButton;
  actionItems: ActionItems;
  flat: boolean;
}

class ActionItem extends ViewBase {
  text: string;
  icon: string;
  position: "left" | "right" | "popup";
  
  // Events
  static tapEvent: "tap";
}

/**
 * Scrollable content container
 */
class ScrollView extends ContentView {
  orientation: "horizontal" | "vertical";
  scrollBarIndicatorVisible: boolean;
  isScrollEnabled: boolean;
  
  scrollToVerticalOffset(value: number, animated: boolean): void;
  scrollToHorizontalOffset(value: number, animated: boolean): void;
  
  // Events
  static scrollEvent: "scroll";
}

/**
 * Content container view
 */
class ContentView extends View {
  content: View;
  layoutView: View;
}

import { ListView, Page, ObservableArray } from "tns-core-modules";

// ListView with data binding
const listView = new ListView();
const items = new ObservableArray([
  { name: "Item 1", description: "First item" },
  { name: "Item 2", description: "Second item" }
]);

listView.items = items;
listView.on(ListView.itemTapEvent, (args) => {
  console.log("Tapped item:", args.index);
});

// Page with navigation
const page = new Page();
page.on(Page.navigatedToEvent, (args) => {
  console.log("Navigated to page");
});

// Modal dialog
page.showModal("modal-page", { data: "context" }, (result) => {
  console.log("Modal closed with result:", result);
});