feat: add welcome screen when there si nothing to display in Home

closes #273

src/Home.js

@@ -13,7 +13,6 @@ import Typography from '@material-ui/core/Typography';
 import FavoriteIcon from '@material-ui/icons/Star';
 import HistoryIcon from '@material-ui/icons/History';
 import Divider from '@material-ui/core/Divider';
-import NoSpacesAvailable from './components/common/NoSpacesAvailable';
 import {
   HOME_MAIN_ID,
   FAVORITE_SPACES_WRAPPER_ID,
@@ -26,6 +25,7 @@ import SpaceGrid from './components/space/SpaceGrid';
 import Loader from './components/common/Loader';
 import Main from './components/common/Main';
 import { HOME_PATH } from './config/paths';
+import WelcomeContent from './components/common/WelcomeContent';
 
 const styles = theme => ({
   ...Styles(theme),
@@ -175,7 +175,7 @@ class Home extends Component {
   };
 
   render() {
-    const { classes, activity } = this.props;
+    const { classes, activity, spaces } = this.props;
     const { filteredFavoriteSpaces, filteredRecentSpaces } = this.state;
 
     const noSpacesAvailable =
@@ -198,7 +198,7 @@ class Home extends Component {
     return (
       <Main showSearch handleOnSearch={this.handleOnSearch} id={HOME_MAIN_ID}>
         {noSpacesAvailable ? (
-          <NoSpacesAvailable />
+          <WelcomeContent hasSavedSpaces={spaces.size > 0} />
         ) : (
           <div>
             {this.renderRecentSpaces()}

src/components/common/WelcomeContent.js

@@ -0,0 +1,138 @@
+import React, { Component } from 'react';
+import PropTypes from 'prop-types';
+import { withStyles } from '@material-ui/core/styles';
+import { withRouter } from 'react-router';
+import { withTranslation } from 'react-i18next';
+import Typography from '@material-ui/core/Typography/Typography';
+import { Online } from 'react-detect-offline';
+import Button from '@material-ui/core/Button';
+import ButtonGroup from '@material-ui/core/ButtonGroup';
+import Styles from '../../Styles';
+import logo from '../../data/icon.png';
+import {
+  SAVED_SPACES_PATH,
+  VISIT_PATH,
+  LOAD_SPACE_PATH,
+} from '../../config/paths';
+
+const styles = theme => ({
+  ...Styles(theme),
+  wrapper: {
+    display: 'flex',
+
+    alignItems: 'center',
+    justifyContent: 'center',
+    alignContent: 'center',
+    flexDirection: 'column',
+    height: '80%',
+
+    '& .MuiButtonGroup-groupedContainedPrimary:not(:last-child)': {
+      borderColor: 'white',
+    },
+  },
+  graaspLogo: {
+    width: '35%',
+    maxWidth: '400px',
+    minWidth: '200px',
+    marginTop: theme.spacing(3),
+  },
+
+  // similar layout to buttons in ButtonGroup for wrapped buttons
+  wrappedButton: {
+    background: theme.palette.primary.main,
+    borderRadius: 0,
+    borderRight: '1px solid white',
+    color: 'white',
+    padding: theme.spacing(0, 3),
+
+    '&:hover': {
+      background: theme.palette.primary.main,
+    },
+    // add border radius when is last button
+    '&.MuiButtonBase-root:last-child': {
+      borderTopRightRadius: '4px',
+      borderBottomRightRadius: '4px',
+    },
+  },
+});
+
+class WelcomeContent extends Component {
+  static propTypes = {
+    classes: PropTypes.shape({
+      graaspLogo: PropTypes.string.isRequired,
+      wrappedButton: PropTypes.string.isRequired,
+      wrapper: PropTypes.string.isRequired,
+    }).isRequired,
+    t: PropTypes.func.isRequired,
+    history: PropTypes.shape({
+      push: PropTypes.func.isRequired,
+    }).isRequired,
+    hasSavedSpaces: PropTypes.bool.isRequired,
+  };
+
+  handleGoToVisitSpace = () => {
+    const {
+      history: { push },
+    } = this.props;
+    push(VISIT_PATH);
+  };
+
+  handleGoToLoadSpace = () => {
+    const {
+      history: { push },
+    } = this.props;
+    push(LOAD_SPACE_PATH);
+  };
+
+  handleGoToSavedSpaces = () => {
+    const {
+      history: { push },
+    } = this.props;
+    push(SAVED_SPACES_PATH);
+  };
+
+  render() {
+    const { classes, t, hasSavedSpaces } = this.props;
+    return (
+      <div className={classes.wrapper}>
+        <img src={logo} alt={t('Graasp logo')} className={classes.graaspLogo} />
+        <Typography variant="h4" color="inherit" style={{ margin: '2rem' }}>
+          {t('Welcome to Graasp Desktop')}
+        </Typography>
+        <ButtonGroup
+          disableElevation
+          variant="contained"
+          color="primary"
+          aria-label="contained group primary button"
+        >
+          <Button onClick={this.handleGoToLoadSpace}>
+            {t('Load a Space')}
+          </Button>
+          ,
+          <Online>
+            {
+              // class wrappedButton is necessary to match the layout when encapsulated with Online tag
+            }
+            <Button
+              className={classes.wrappedButton}
+              onClick={this.handleGoToVisitSpace}
+            >
+              {t('Visit a Space')}
+            </Button>
+          </Online>
+          {hasSavedSpaces && (
+            <Button onClick={this.handleGoToSavedSpaces}>
+              {t('Go to Saved Spaces')}
+            </Button>
+          )}
+        </ButtonGroup>
+      </div>
+    );
+  }
+}
+
+const StyledComponent = withStyles(styles, { withTheme: true })(WelcomeContent);
+
+const TranslatedComponent = withTranslation()(StyledComponent);
+
+export default withRouter(TranslatedComponent);