Connection State: Support browser online state, add animation

src/components/left/ConnectionState.tsx

@@ -1,9 +1,7 @@
-import React, { FC } from '../../lib/teact/teact';
-import { withGlobal } from '../../lib/teact/teactn';
+import React, { memo, FC } from '../../lib/teact/teact';
 
 import { GlobalState } from '../../global/types';
 
-import { pick } from '../../util/iteratees';
 import useLang from '../../hooks/useLang';
 
 import Spinner from '../ui/Spinner';
@@ -12,12 +10,10 @@ import './ConnectionState.scss';
 
 type StateProps = Pick<GlobalState, 'connectionState'>;
 
-const ConnectionState: FC<StateProps> = ({ connectionState }) => {
+const ConnectionState: FC<StateProps> = () => {
   const lang = useLang();
 
-  const isConnecting = connectionState === 'connectionStateConnecting';
-
-  return isConnecting && (
+  return (
     <div id="ConnectionState" dir={lang.isRtl ? 'rtl' : undefined}>
       <Spinner color="black" />
       <div className="state-text">{lang('WaitingForNetwork')}</div>
@@ -25,6 +21,4 @@ const ConnectionState: FC<StateProps> = ({ connectionState }) => {
   );
 };
 
-export default withGlobal(
-  (global): StateProps => pick(global, ['connectionState']),
-)(ConnectionState);
+export default memo(ConnectionState);

src/components/left/main/LeftMain.scss

@@ -6,9 +6,20 @@
   overflow: hidden;
   z-index: 1;
 
+  .connection-state-wrapper {
+    position: absolute;
+    top: 3.75rem;
+    width: 100%;
+  }
+
   > .Transition {
     flex: 1;
     overflow: hidden;
+    transition: transform 300ms ease;
+
+    &.pull-down {
+      transform: translateY(3.75rem);
+    }
   }
 
   .ChatFolders {

src/components/left/main/LeftMain.tsx

@@ -1,10 +1,14 @@
 import React, {
-  FC, memo, useState, useRef, useCallback, useEffect,
+  FC, useState, useRef, useCallback, useEffect,
 } from '../../../lib/teact/teact';
+import { withGlobal } from '../../../lib/teact/teactn';
 
+import { GlobalState } from '../../../global/types';
 import { LeftColumnContent } from '../../../types';
 
 import { IS_TOUCH_ENV } from '../../../util/environment';
+import { pick } from '../../../util/iteratees';
+import useBrowserOnline from '../../../hooks/useBrowserOnline';
 
 import Transition from '../../ui/Transition';
 import LeftMainHeader from './LeftMainHeader';
@@ -13,6 +17,7 @@ import ChatFolders from './ChatFolders';
 import LeftSearch from '../search/LeftSearch.async';
 import ContactList from './ContactList.async';
 import NewChatButton from '../NewChatButton';
+import ShowTransition from '../../ui/ShowTransition';
 
 import './LeftMain.scss';
 
@@ -26,7 +31,7 @@ type OwnProps = {
   onReset: () => void;
 };
 
-type StateProps = {};
+type StateProps = Pick<GlobalState, 'connectionState'>;
 
 const TRANSITION_RENDER_COUNT = Object.keys(LeftColumnContent).length / 2;
 const BUTTON_CLOSE_DELAY_MS = 250;
@@ -40,9 +45,13 @@ const LeftMain: FC<OwnProps & StateProps> = ({
   onSearchQuery,
   onContentChange,
   onReset,
+  connectionState,
 }) => {
   const [isNewChatButtonShown, setIsNewChatButtonShown] = useState(IS_TOUCH_ENV);
 
+  const isBrowserOnline = useBrowserOnline();
+  const isConnecting = !isBrowserOnline || connectionState === 'connectionStateConnecting';
+
   const isMouseInside = useRef(false);
 
   const handleSelectSettings = useCallback(() => {
@@ -121,13 +130,16 @@ const LeftMain: FC<OwnProps & StateProps> = ({
         onSelectArchived={handleSelectArchived}
         onReset={onReset}
       />
-      <ConnectionState />
+      <ShowTransition isOpen={isConnecting} isCustom className="connection-state-wrapper opacity-transition slow">
+        {() => <ConnectionState />}
+      </ShowTransition>
       <Transition
         name="zoom-fade"
         renderCount={TRANSITION_RENDER_COUNT}
         activeKey={content}
         shouldCleanup
         cleanupExceptionKey={LeftColumnContent.ChatList}
+        className={isConnecting ? 'pull-down' : undefined}
       >
         {(isActive) => {
           switch (content) {
@@ -159,4 +171,6 @@ const LeftMain: FC<OwnProps & StateProps> = ({
   );
 };
 
-export default memo(LeftMain);
+export default withGlobal<OwnProps>(
+  (global): StateProps => pick(global, ['connectionState']),
+)(LeftMain);

src/hooks/useBackgroundMode.ts

@@ -1,9 +1,9 @@
 import { useEffect } from '../lib/teact/teact';
 
-export default (
+export default function useBackgroundMode(
   onBlur: AnyToVoidFunction,
   onFocus: AnyToVoidFunction,
-) => {
+) {
   useEffect(() => {
     if (!document.hasFocus()) {
       onBlur();
@@ -17,4 +17,4 @@ export default (
       window.removeEventListener('blur', onBlur);
     };
   }, [onBlur, onFocus]);
-};
+}

src/hooks/useBrowserOnline.ts

@@ -0,0 +1,21 @@
+import { useEffect, useState } from '../lib/teact/teact';
+
+export default function useBrowserOnline() {
+  const [isOnline, setIsOnline] = useState(window.navigator.onLine);
+
+  useEffect(() => {
+    function handleChange() {
+      setIsOnline(window.navigator.onLine);
+    }
+
+    window.addEventListener('online', handleChange);
+    window.addEventListener('offline', handleChange);
+
+    return () => {
+      window.removeEventListener('offline', handleChange);
+      window.removeEventListener('online', handleChange);
+    };
+  }, []);
+
+  return isOnline;
+}