fix: support function components in withTheme

Author: satya164

docs/pages/3.theming.md

@@ -105,20 +105,20 @@ Components wrapped with `withTheme` support the theme from the `Provider` as wel
 
 ## Customizing all instances of a component
 
-Sometimes you want to style a component in a different way everywhere and don't want to change the properties in the theme so that other components are not affected. For example, say you want to change the font of all your buttons, but don't want to change `theme.fonts.medium` because it affects other components.
+Sometimes you want to style a component in a different way everywhere and don't want to change the properties in the theme so that other components are not affected. For example, say you want to change the font for all your buttons, but don't want to change `theme.fonts.medium` because it affects other components.
 
 We don't have an API to do this, because you can already do it with components:
 
 ```js
 import * as React from 'react';
 import { Button } from 'react-native-paper';
 
-export default function RoundButton(props) {
+export default function FancyButton(props) {
   return <Button theme={{ fonts: { medium: 'Open Sans' } }} {...props} />;
 }
 ```
 
-Now you can use `RoundButton` everywhere instead of using `Button`.
+Now you can use your `FancyButton` component everywhere instead of using `Button` from Paper.
 
 ## Gotchas
 

src/components/Dialog/Dialog.js

@@ -3,7 +3,7 @@
 import * as React from 'react';
 import { StyleSheet, Platform, Animated } from 'react-native';
 import Modal from '../Modal';
-import { black, white } from '../../styles/colors';
+import { white } from '../../styles/colors';
 import Paper from '../Paper';
 import DialogActions from './DialogActions';
 import DialogTitle from './DialogTitle';
@@ -138,12 +138,6 @@ class Dialog extends React.Component<Props, void> {
   }
 }
 
-Dialog.defaultProps = {
-  dismissable: true,
-  titleColor: black,
-  visible: false,
-};
-
 export default withTheme(Dialog);
 
 const styles = StyleSheet.create({

src/core/withTheme.js

@@ -34,12 +34,13 @@ const REACT_METHODS = [
 const isClassComponent = (Component: any) =>
   Boolean(Component.prototype && Component.prototype.isReactComponent);
 
-export default function withTheme<P: {}, C: React.ComponentType<P>>(
+export default function withTheme<C: React.ComponentType<*>>(
   Comp: C
 ): C &
-  React.ComponentType<$Diff<P, { theme: Theme }> & { theme?: $Shape<Theme> }> {
+  React.ComponentType<
+    $Diff<React.ElementConfig<C>, { theme: Theme }> & { theme?: $Shape<Theme> }
+  > {
   class ThemedComponent extends React.Component<*> {
-    /* $FlowFixMe */
     static displayName = `withTheme(${Comp.displayName || Comp.name})`;
 
     _previous: ?{ a: Theme, b: ?$Shape<Theme>, result: Theme };