fix(subtitles): Styles.

 - Move the styles from css to tss-react ones
 - Dynamic fontSize based on the visible area of the page
 - Remove the gaps in the background when a line is wrapped.
 - Change the text color to white.
 - Remove transparency.

css/_transcription-subtitles.scss

@@ -1,26 +0,0 @@
-.transcription-subtitles {
-    bottom: $newToolbarSize + 40px;
-    font-size: 16px;
-    font-weight: 1000;
-    left: 50%;
-    max-width: 50vw;
-    opacity: 0.80;
-    overflow-wrap: break-word;
-    pointer-events: none;
-    position: absolute;
-    text-shadow: 0px 0px 1px rgba(0,0,0,0.3),
-    0px 1px 1px rgba(0,0,0,0.3),
-    1px 0px 1px rgba(0,0,0,0.3),
-    0px 0px 1px rgba(0,0,0,0.3);
-    transform: translateX(-50%);
-    z-index: 7;
-
-    &.lifted {
-        // Lift subtitle above toolbar+dominant speaker box.
-        bottom: $newToolbarSize + 36px + 40px;
-    }
-
-    span {
-        background: black;
-    }
-}

css/main.scss

@@ -61,7 +61,6 @@ $flagsImagePath: "../images/";
 @import 'filmstrip/vertical_filmstrip_overrides';
 @import 'unsupported-browser/main';
 @import 'deep-linking/main';
-@import 'transcription-subtitles';
 @import '_meetings_list.scss';
 @import 'navigate_section_list';
 @import 'third-party-branding/google';

react/features/base/ui/functions.web.ts

@@ -1,5 +1,5 @@
 /* eslint-disable @typescript-eslint/naming-convention */
-import { adaptV4Theme, createTheme } from '@mui/material/styles';
+import { Theme, adaptV4Theme, createTheme } from '@mui/material/styles';
 
 import { ITypography, IPalette as Palette1 } from '../ui/types';
 
@@ -107,3 +107,14 @@ export function operatesWithEnterKey(element: Element): boolean {
 
     return false;
 }
+
+/**
+ * Returns a common spacing from the bottom of the page for floating elements over the video space.
+ *
+ * @param {Theme} theme - The current theme.
+ * @param {boolean} isToolbarVisible - Whether the toolbar is visible or not.
+ * @returns {number}
+ */
+export function getVideospaceFloatingElementsBottomSpacing(theme: Theme, isToolbarVisible: boolean) {
+    return parseInt(isToolbarVisible ? theme.spacing(12) : theme.spacing(6), 10);
+}

react/features/display-name/components/web/DisplayNameBadge.tsx

@@ -1,6 +1,8 @@
 import React from 'react';
 import { makeStyles } from 'tss-react/mui';
 
+import { DISPLAY_NAME_VERTICAL_PADDING } from './styles';
+
 const useStyles = makeStyles()(theme => {
     const { text01 } = theme.palette;
 
@@ -11,7 +13,7 @@ const useStyles = makeStyles()(theme => {
             color: text01,
             maxWidth: '50%',
             overflow: 'hidden',
-            padding: '2px 16px',
+            padding: `${DISPLAY_NAME_VERTICAL_PADDING / 2}px 16px`,
             textOverflow: 'ellipsis',
             whiteSpace: 'nowrap'
         }

react/features/display-name/components/web/StageParticipantNameLabel.tsx

@@ -10,20 +10,22 @@ import {
     isWhiteboardParticipant
 } from '../../../base/participants/functions';
 import { withPixelLineHeight } from '../../../base/styles/functions.web';
+import { getVideospaceFloatingElementsBottomSpacing } from '../../../base/ui/functions.web';
 import { getLargeVideoParticipant } from '../../../large-video/functions';
 import { isToolboxVisible } from '../../../toolbox/functions.web';
 import { isLayoutTileView } from '../../../video-layout/functions.web';
 
 import DisplayNameBadge from './DisplayNameBadge';
+import { getStageParticipantTypography } from './styles';
 
 const useStyles = makeStyles()(theme => {
     return {
         badgeContainer: {
-            ...withPixelLineHeight(theme.typography.bodyShortRegularLarge),
+            ...withPixelLineHeight(getStageParticipantTypography(theme)),
             alignItems: 'center',
             display: 'inline-flex',
             justifyContent: 'center',
-            marginBottom: theme.spacing(7),
+            marginBottom: getVideospaceFloatingElementsBottomSpacing(theme, false),
             transition: 'margin-bottom 0.3s',
             pointerEvents: 'none',
             position: 'absolute',
@@ -33,7 +35,7 @@ const useStyles = makeStyles()(theme => {
             zIndex: 1
         },
         containerElevated: {
-            marginBottom: theme.spacing(12)
+            marginBottom: getVideospaceFloatingElementsBottomSpacing(theme, true)
         }
     };
 });

react/features/display-name/components/web/styles.ts

@@ -0,0 +1,26 @@
+import { Theme } from '@mui/material';
+
+/**
+ * The vertical padding for the display name.
+ */
+export const DISPLAY_NAME_VERTICAL_PADDING = 4;
+
+/**
+ * Returns the typography for stage participant display name badge.
+ *
+ * @param {Theme} theme - The current theme.
+ * @returns {ITypographyType}
+ */
+export function getStageParticipantTypography(theme: Theme) {
+    return theme.typography.bodyShortRegularLarge;
+}
+
+/**
+ * Returns the height + padding for stage participant display name badge.
+ *
+ * @param {Theme} theme - The current theme.
+ * @returns {number}
+ */
+export function getStageParticipantNameLabelHeight(theme: Theme) {
+    return getStageParticipantTypography(theme).lineHeight ?? 0 + DISPLAY_NAME_VERTICAL_PADDING;
+}

react/features/subtitles/components/web/Captions.tsx

@@ -1,25 +1,85 @@
+import { Theme } from '@mui/material';
 import React, { ReactElement } from 'react';
 import { connect } from 'react-redux';
+import { withStyles } from 'tss-react/mui';
 
 import { IReduxState } from '../../../app/types';
 import { getLocalParticipant } from '../../../base/participants/functions';
+import { getVideospaceFloatingElementsBottomSpacing } from '../../../base/ui/functions.web';
+import { getStageParticipantNameLabelHeight } from '../../../display-name/components/web/styles';
 import { getLargeVideoParticipant } from '../../../large-video/functions';
 import { isLayoutTileView } from '../../../video-layout/functions.web';
+import { calculateSubtitlesFontSize } from '../../functions.web';
 import {
     AbstractCaptions,
     type IAbstractCaptionsProps,
     _abstractMapStateToProps
 } from '../AbstractCaptions';
 
-
 interface IProps extends IAbstractCaptionsProps {
 
+    /**
+     * The height of the visible area.
+     */
+    _clientHeight?: number;
+
     /**
      * Whether the subtitles container is lifted above the invite box.
      */
     _isLifted: boolean | undefined;
+
+    /**
+     * An object containing the CSS classes.
+     */
+    classes?: Partial<Record<keyof ReturnType<typeof styles>, string>>;
 }
 
+
+const styles = (theme: Theme, props: IProps) => {
+    const { _isLifted = false, _clientHeight } = props;
+    const fontSize = calculateSubtitlesFontSize(_clientHeight);
+    const padding = Math.ceil(0.2 * fontSize);
+
+    // Currently the subtitles position are not affected by the toolbar visibility.
+    let bottom = getVideospaceFloatingElementsBottomSpacing(theme, true);
+
+    // This is the case where we display the onstage participant display name
+    // below the subtitles.
+    if (_isLifted) {
+        // 10px is the space between the onstage participant display name label and subtitles. We also need
+        // to add the padding of the subtitles because it will decrease the gap between the label and subtitles.
+        bottom += getStageParticipantNameLabelHeight(theme) + 10 + padding;
+    }
+
+    return {
+        transcriptionSubtitles: {
+            bottom,
+            fontSize: `${fontSize}px`,
+            left: '50%',
+            maxWidth: '50vw',
+            overflowWrap: 'break-word' as const,
+            pointerEvents: 'none' as const,
+            position: 'absolute' as const,
+            textShadow: `
+                0px 0px 1px rgba(0,0,0,0.3),
+                0px 1px 1px rgba(0,0,0,0.3),
+                1px 0px 1px rgba(0,0,0,0.3),
+                0px 0px 1px rgba(0,0,0,0.3)`,
+            transform: 'translateX(-50%)',
+            zIndex: 7, // The popups are with z-index 8. This z-index has to be lower.
+            lineHeight: 1.2,
+
+            span: {
+                color: '#fff',
+                background: 'black',
+
+                // without this when the text is wrapped on 2+ lines there will be a gap in the background:
+                padding: `${padding}px 0px`
+            }
+        }
+    };
+};
+
 /**
  * React {@code Component} which can display speech-to-text results from
  * Jigasi as subtitles.
@@ -53,12 +113,10 @@ class Captions extends AbstractCaptions<IProps> {
      * @returns {ReactElement} - The subtitles container.
      */
     _renderSubtitlesContainer(paragraphs: Array<ReactElement>): ReactElement {
-        const className = this.props._isLifted
-            ? 'transcription-subtitles lifted'
-            : 'transcription-subtitles';
+        const classes = withStyles.getClasses(this.props);
 
         return (
-            <div className = { className } >
+            <div className = { classes.transcriptionSubtitles } >
                 { paragraphs }
             </div>
         );
@@ -77,11 +135,13 @@ function mapStateToProps(state: IReduxState) {
     const isTileView = isLayoutTileView(state);
     const largeVideoParticipant = getLargeVideoParticipant(state);
     const localParticipant = getLocalParticipant(state);
+    const { clientHeight } = state['features/base/responsive-ui'];
 
     return {
         ..._abstractMapStateToProps(state),
-        _isLifted: Boolean(largeVideoParticipant && largeVideoParticipant?.id !== localParticipant?.id && !isTileView)
+        _isLifted: Boolean(largeVideoParticipant && largeVideoParticipant?.id !== localParticipant?.id && !isTileView),
+        _clientHeight: clientHeight
     };
 }
 
-export default connect(mapStateToProps)(Captions);
+export default connect(mapStateToProps)(withStyles(Captions, styles));

react/features/subtitles/constants.ts

@@ -0,0 +1,4 @@
+/**
+ * The minimum font size for subtitles.
+ */
+export const MIN_SUBTITLES_FONT_SIZE = 16;

react/features/subtitles/functions.web.ts

@@ -1,5 +1,7 @@
 /* eslint-disable max-params, max-len */
 
+import { MIN_SUBTITLES_FONT_SIZE } from './constants';
+
 /**
  * Logs when about the received transcription chunk.
  *
@@ -17,3 +19,17 @@ export const notifyTranscriptionChunkReceived = (transcriptMessageID: string, la
         participant,
         ...text
     });
+
+/**
+ * Calculates the font size for the subtitles.
+ *
+ * @param {number} clientHeight - The height of the visible area of the window.
+ * @returns {number}
+ */
+export function calculateSubtitlesFontSize(clientHeight?: number) {
+    if (typeof clientHeight === 'undefined') {
+        return MIN_SUBTITLES_FONT_SIZE;
+    }
+
+    return Math.max(Math.floor(clientHeight * 0.04), MIN_SUBTITLES_FONT_SIZE);
+}

react/features/toolbox/constants.ts

@@ -84,7 +84,6 @@ export const ZINDEX_DIALOG_PORTAL = 302;
  */
 export const SPINNER_COLOR = '#929292';
 
-
 /**
  * The list of all possible UI buttons.
  *