scan-subread/src/app-state.ts

src/app-state.ts (1059 bytes)
1 // What the Android Back button does, and when the screen stays on. Pure: no DOM.
2 
3 import type { FollowMode } from './follower';
4 
5 /**
6  * The step of the Back button: close the page jump, close the drawer, or
7  * put the reader in the background.
8  */
9 export type BackStep = 'close-jump' | 'close-drawer' | 'minimize';
10 
11 /**
12  * The step of the Back button. The reader never finishes its activity:
13  * Android then destroys the WebView, and the reader loses its state.
14  */
15 export function backStep(open: { jump: boolean; drawer: boolean }): BackStep {
16   if (open.jump) return 'close-jump';
17   if (open.drawer) return 'close-drawer';
18   return 'minimize';
19 }
20 
21 /**
22  * True when the screen stays on: while the app shows, a book is open, the
23  * player plays and the follow is not off. During read-along the user does
24  * not touch the screen, so without this the screen turns off.
25  */
26 export function keepScreenOn(s: {
27   active: boolean;
28   book: boolean;
29   playing: boolean;
30   mode: FollowMode;
31 }): boolean {
32   return s.active && s.book && s.playing && s.mode !== 'off';
33 }