* Support showing modals with the default screen push/pop animation

* Set navigation bar color before modal is displayed

* Implement screenAnimationType property

controls animation type of all screens including modals.

Until now, buttons would use the same font family used by the title,
this commit introduces navBarButtonFontFamily property which allows to set
a different font family for title and buttons.

* Support subtitle FontFamily on size on Android

Font family can be either a .ttf/.otf asset or one of the default font families:

* sans-serif (regular)
* sans-serif-light
* sans-serif-condensed
* sans-serif-thin
* sans-serif-medium

* update docs

This commit adds support for fade and slide-horizontal animations for modals and a few other animation related changes:

* Support defining animationType when calling dismissModal
* Support fade and slide horizontal animations for modals
* Slightly reworked current screen animations timings
* Fixed slide-horizontal x offset and removed alpha

Ability to set a flat border under the TopBar. `topBarElevationShadowEnabled` should be set to true if using this feature.

* testing

* test

* try fix props on topTabs

* Test xml menu

* Add titleBarHeight

* Remove test

* Add to StyleParams

* Add topTabsHeight

* Fix styleParams type

* Add navBarFontBold

* Add typeface package

* Remove unused debugging

returns true if NavigationActivity is resumed (startApp was called)

* added method for getting the currently visible screen ID. Can be useful to decide if logic should be applied according to screen visibility, for example: set buttons/title dynamically, or even determine that you don’t need to show the same screen again if it’s the current one that’s showing

* Implement getCurrentlyVisibleScreenId on Android

Can be used statically:
Navigation.getCurrentlyVisibleScreenId() - returns the unique screen
instance id

With a navigator instance:
await this.props.navigator.screenIsCurrentlyVisible() - resolves a
promise that checks if the current screen is visible

* Add screen visibility listener which can be registered globally

API
new ScreenVisibilityListener({
    willAppear: ({screen, timestamp}) => console.log(`Displaying screen ${screen}`),
    didAppear: ({screen, timestamp}) => console.log(`Screen ${screen} displayed in ${Date.now() - timestamp} millis`)
  }).register();

todo
* Add timestamp to modal, resetTo
* implement unregister
* implement iOS

* Add global screen visibility listener to example app

* Think I better assign a value to emitter

* Send timestamp in resetTo

* Moved listener to library, it can be deleted from the app

* Add push and resetTo buttons to pushed screens

* Send appear/disappear events after animation ends

* Pass pop timestamp from js

* Send timestamp in popToRoot

* Add popToRoot button in push screen

* Add few navigation buttons to modal screen

* Pass timestamp to tabs

relevant only to first/initial tab

* Update timestamp when navigating between BottomTabs

* Send screen visible events after modal dismiss

* log willDisappear and didDisappear

* Report both start and end timestamps

* Implement unregister

* Send NavigationType parameter in visibilityEvent

This indicates the type of the navigation command that triggered the visibility change

* Rename pushInitialScreen to more explicit name

* Fix duplicate initialScreen visibility events

* Update screen visibility log statement

* Show popToRoot in modal screen only if screens were pushed

* implement global screen event for iOS

* fix lint issues

Usage:
    navBarCustomView: 'example.CustomTopBar', // registered component name
    navBarComponentAlignment: 'center' // 'center'/'fill'

* Add font family support on bottom tabs

* import missing classes

* import missing class

* update document

* Support customize icon for left nav button in android

* Add navBar navBarTextFontSize support for android

Currently startApp is called from global context which results in the
app being launched when headlessJs tasks run in the background.
In order to support this use case, while not breaking existing users,
this commit adds two mechanisms which should help users detrmine if
the native Activity is running and startApp can be called safely.

1. RNN.appLaunched event is emitted is SplashActivity starts and react
   context has already been created. This is the use case of openeing
   the app while headless js task was started or has just finished and
   react context is in a "pasued" state.

2. Navigation.isAppLaunched() convenience method has been added.
   It returns a promise which when resolved, indicates if the app
   is launched and we should show the ui or not.

Usage

import {Navigation, NativeEventsReceiver} from 'react-native-navigation';

Promise.resolve(Navigation.isAppLaunched())
  .then(appLaunched => {
    if (appLaunched) {
      startApp();
    } else {
      new NativeEventsReceiver().appLaunched(startApp);
    }
  });

function startApp() {
  Navigation.startTabBasedApp({ ... });
}

* Added tapBackgroundToDismiss to LightBox screens

* Updated LightBox readme

* Formatting updates

* Fixed ios selector

* Updated animationEnd hide method

Change bottom tab bar button image at runtime

Usage is identical to switchToTab, closes #842

This commit adds support for the following style properties:
titleBarTitleFontFamily - string, font name in assets
titleBarTitleTextCentered - boolean, default is false

* adding support for android centered title and custom font

* PR feedback

* Add view manager

* Don’t update screen style on ViewPagerScreenChangedEvent

* change version to legacy

* Fix headers after rebase

* version bump

* Add image to each list item

* Basics structure is done (I think)

toElement also animates into place, even though values are completely wrong.

* Stop relying on refs to resolve fromElements

* Hide only corresponding fromElement

* Animate sharedElements back into place on screen pop

* Update example project with Dota heroes

* Initial curved animation implementation

* Stop resolving sharedElement refs

* Move getLocationOnScreen to ViewUtils

* Parse control points passed from Js

* Scale animation works

Not sure about pivot coordinates yet.

* minor update to SharedElementsTransition screen

* Minor changes to example screens

* Draw shared elements on Screen

Ignore Z order and draw shared elements directly on screen

* stuff

* Start animation after views are drawn

* f

* Animate text color

* Less allocations when animating text color

* Switch from RGB to LAB 😎

* Save and restore SpannedString

* Use correct status bar height in Android M

* Pass show and hide duration from Js

* Fix flicker when show animation starts

* Make shared elements not clickable

motivation: might be related to some native crash

* Use linear interpolation as default interpolation

* Code cleanup

* Clear SharedElements refs when screen is destroyed

* Code cleanup

* Add decelerate interpolator

* No more occasional flicker on animation start (Hopefully 🙏)

* Add FastOutSlowIn interpolator

* Animate only visible shared elements

* Clip bounds animator somewhat works

* Hope fully no more flickery images

* Add interpolator to each animator

* some work on shared element screens

* rebase fix

* fix lint

* Add font family support on bottom tabs

* import missing classes

* import missing class

* update document

When snackbar cta is clicked - event is dispatched with the specified eventId

* Save titleBarHidden in screenParams when toggling TitleBar

* empty commit

Closes #681

collapsingToolBarExpendedColor - determines the TitleBar color in expended mode
showTitleWhenExpended - defaults to true when expended color is defined.

Implement backgroundColor and textColor style params

This reverts commit 326f4833f0.

This commit deprecates collapsingToolBarComponentHeight style property

This commit contains various fixes and enhancements, mostly because I
was too lazy to commit small changes.

* Add topBarCollapseOnScroll style property which compliments
  navBarHideOnScroll. This property is needed when showing a
  collapsing topTabs screen. In this case the developer might to keep
  the titleBar bar when the screen is collapsed.
* Reduce collapse sensitivity by taking scaled touch slop into account
* Cancel touches when collapsing. This fix prevents buttons from
  responding to touch events when collapse ends.

Add expendOnTopTabChange style property which defaults to true. Setting it to false

consider changing this later on

* Add showInAppNotification autoDismissTimerSec param

* Default autoDismissTimerSec of notification to 5, like on iOS

* Add param to disable notification auto-dismiss behaviour.

* Update showInAppNotification example with optional params

* Add .hideInAppNotification on android.

- Separate hide and show animations.
- Implement a little bit of throttling around successive calls to .showInAppNotification

* Update example to demo dismiss.