NativeScript/tns-core-modules/ui/page/page-common.ts

import { Page as PageDefinition, NavigatedData, ShownModallyData } from ".";
import {
    ContentView, View, eachDescendant, Property, CssProperty, Color, isIOS,
    booleanConverter, resetCSSProperties, Style, EventData
} from "../content-view";
import { Frame, topmost as topmostFrame } from "../frame";
import { ActionBar } from "../action-bar";
import { KeyframeAnimationInfo } from "../animation/keyframe-animation";
import { File, path, knownFolders } from "../../file-system";
import { profile } from "../../profiling";

export * from "../content-view";

export class PageBase extends ContentView implements PageDefinition {

    public static navigatingToEvent = "navigatingTo";
    public static navigatedToEvent = "navigatedTo";
    public static navigatingFromEvent = "navigatingFrom";
    public static navigatedFromEvent = "navigatedFrom";
  
    private _navigationContext: any;
    private _actionBar: ActionBar;

    public _frame: Frame;
    
    public actionBarHidden: boolean;
    public enableSwipeBackNavigation: boolean;
    public backgroundSpanUnderStatusBar: boolean;
    public hasActionBar: boolean;
    
    get navigationContext(): any {
        return this._navigationContext;
    }

    get actionBar(): ActionBar {
        if (!this._actionBar) {
            this.hasActionBar = true;
            this._actionBar = new ActionBar();
            this._addView(this._actionBar);
        }
        return this._actionBar;
    }
    set actionBar(value: ActionBar) {
        if (!value) {
            throw new Error("ActionBar cannot be null or undefined.");
        }

        if (this._actionBar !== value) {
            if (this._actionBar) {
                this._removeView(this._actionBar);
            }
            this.hasActionBar = true;
            this._actionBar = value;
            this._addView(this._actionBar);
        }
    }

    get statusBarStyle(): "light" | "dark" {
        return this.style.statusBarStyle;
    }
    set statusBarStyle(value: "light" | "dark") {
        this.style.statusBarStyle = value;
    }

    public get androidStatusBarBackground(): Color {
        return this.style.androidStatusBarBackground;
    }
    public set androidStatusBarBackground(value: Color) {
        this.style.androidStatusBarBackground = value;
    }

    get page(): PageDefinition {
        return this;
    }

    public _addChildFromBuilder(name: string, value: any) {
        if (value instanceof ActionBar) {
            this.actionBar = value;
        } else {
            super._addChildFromBuilder(name, value);
        }
    }

    public getKeyframeAnimationWithName(animationName: string): KeyframeAnimationInfo {
        return this._styleScope.getKeyframeAnimationWithName(animationName);
    }

    get frame(): Frame {
        const frame = this.parent;
        return frame instanceof Frame ? frame : undefined;
    }
    
    private createNavigatedData(eventName: string, isBackNavigation: boolean): NavigatedData {
        return {
            eventName: eventName,
            object: this,
            context: this.navigationContext,
            isBackNavigation: isBackNavigation
        };
    }

    @profile
    public onNavigatingTo(context: any, isBackNavigation: boolean, bindingContext?: any) {
        this._navigationContext = context;

        //https://github.com/NativeScript/NativeScript/issues/731
        if (!isBackNavigation && bindingContext !== undefined && bindingContext !== null) {
            this.bindingContext = bindingContext;
        }
        this.notify(this.createNavigatedData(PageBase.navigatingToEvent, isBackNavigation));
    }

    @profile
    public onNavigatedTo(isBackNavigation: boolean) {
        this.notify(this.createNavigatedData(PageBase.navigatedToEvent, isBackNavigation));
    }

    @profile
    public onNavigatingFrom(isBackNavigation: boolean) {
        this.notify(this.createNavigatedData(PageBase.navigatingFromEvent, isBackNavigation));
    }

    @profile
    public onNavigatedFrom(isBackNavigation: boolean) {
        this.notify(this.createNavigatedData(PageBase.navigatedFromEvent, isBackNavigation));

        this._navigationContext = undefined;
    }

    public eachChildView(callback: (child: View) => boolean) {
        super.eachChildView(callback);
        if (this.actionBar) {
            callback(this.actionBar);
        }
    }

    get _childrenCount(): number {
        return (this.content ? 1 : 0) + (this._actionBar ? 1 : 0);
    }
}

PageBase.prototype.recycleNativeView = "never";

export interface PageBase {
    on(eventNames: string, callback: (data: EventData) => void, thisArg?: any): void;
    on(event: "navigatingTo", callback: (args: NavigatedData) => void, thisArg?: any): void;
    on(event: "navigatedTo", callback: (args: NavigatedData) => void, thisArg?: any): void;
    on(event: "navigatingFrom", callback: (args: NavigatedData) => void, thisArg?: any): void;
    on(event: "navigatedFrom", callback: (args: NavigatedData) => void, thisArg?: any): void;
    on(event: "showingModally", callback: (args: ShownModallyData) => void, thisArg?: any): void;
    on(event: "shownModally", callback: (args: ShownModallyData) => void, thisArg?: any);
}

/**
 * Dependency property used to hide the Navigation Bar in iOS and the Action Bar in Android.
 */
export const actionBarHiddenProperty = new Property<PageBase, boolean>({ name: "actionBarHidden", affectsLayout: isIOS, valueConverter: booleanConverter });
actionBarHiddenProperty.register(PageBase);

/**
 * Dependency property that specify if page background should span under status bar.
 */
export const backgroundSpanUnderStatusBarProperty = new Property<PageBase, boolean>({ name: "backgroundSpanUnderStatusBar", defaultValue: false, affectsLayout: isIOS, valueConverter: booleanConverter });
backgroundSpanUnderStatusBarProperty.register(PageBase);

/**
 * Dependency property used to control if swipe back navigation in iOS is enabled.
 * This property is iOS specific. Default value: true
 */
export const enableSwipeBackNavigationProperty = new Property<PageBase, boolean>({ name: "enableSwipeBackNavigation", defaultValue: true, valueConverter: booleanConverter });
enableSwipeBackNavigationProperty.register(PageBase);

/**
 * Property backing statusBarStyle.
 */
export const statusBarStyleProperty = new CssProperty<Style, "light" | "dark">({ name: "statusBarStyle", cssName: "status-bar-style" });
statusBarStyleProperty.register(Style);

/**
 * Property backing androidStatusBarBackground.
 */
export const androidStatusBarBackgroundProperty = new CssProperty<Style, Color>({
    name: "androidStatusBarBackground", cssName: "android-status-bar-background",
    equalityComparer: Color.equals, valueConverter: (v) => new Color(v)
});
androidStatusBarBackgroundProperty.register(Style);