From 3e55c967eee8fae0aa3196dafd55324f15390d4e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Torkel=20=C3=96degaard?= <torkel@grafana.org>
Date: Sat, 20 Feb 2021 09:02:06 +0100
Subject: [PATCH] Theming: Support for runtime theme switching and hooks for
 custom themes (#31301)

* WIP Custom themes

* Load custom themes from URL and via event

* Dynamic page background

* Header color change

* Fixing tests and emotion warnings

* Fixed test

* moving cx to getStyles

* Review fixes

* minor change
---
 packages/grafana-data/src/types/config.ts     |   1 +
 packages/grafana-runtime/src/config.ts        |   1 +
 packages/grafana-ui/src/types/icon.ts         |   2 +
 .../TracePageHeader/SpanGraph/Scrubber.tsx    |  56 ++++---
 .../src/TracePageHeader/TracePageHeader.tsx   |  20 +--
 pkg/api/dtos/index.go                         |   3 +
 pkg/api/index.go                              |   2 +-
 .../components/OrgActionBar/OrgActionBar.tsx  |   2 +-
 public/app/core/components/Page/Page.tsx      |  88 +++++------
 .../app/core/components/Page/PageContents.tsx |  14 +-
 .../components/PageHeader/PageHeader.test.tsx |  26 ++--
 .../core/components/PageHeader/PageHeader.tsx | 143 ++++++++----------
 public/app/core/utils/ConfigProvider.tsx      |  33 ++--
 public/app/plugins/panel/graph/graph.ts       |   4 +-
 public/app/types/events.ts                    |   6 +-
 public/sass/components/_page_header.scss      |   6 -
 16 files changed, 197 insertions(+), 210 deletions(-)

diff --git a/packages/grafana-data/src/types/config.ts b/packages/grafana-data/src/types/config.ts
index 43efe6b1786..655b6396742 100644
--- a/packages/grafana-data/src/types/config.ts
+++ b/packages/grafana-data/src/types/config.ts
@@ -125,4 +125,5 @@ export interface GrafanaConfig {
   http2Enabled: boolean;
   dateFormats?: SystemDateFormatSettings;
   sentry: SentryConfig;
+  customTheme?: any;
 }
diff --git a/packages/grafana-runtime/src/config.ts b/packages/grafana-runtime/src/config.ts
index 5685b0674ce..4eb8e96c0c2 100644
--- a/packages/grafana-runtime/src/config.ts
+++ b/packages/grafana-runtime/src/config.ts
@@ -69,6 +69,7 @@ export class GrafanaBootConfig implements GrafanaConfig {
   };
   marketplaceUrl?: string;
   expressionsEnabled = false;
+  customTheme?: any;
 
   constructor(options: GrafanaBootConfig) {
     this.theme = options.bootData.user.lightTheme ? getTheme(GrafanaThemeType.Light) : getTheme(GrafanaThemeType.Dark);
diff --git a/packages/grafana-ui/src/types/icon.ts b/packages/grafana-ui/src/types/icon.ts
index 72eead3f81c..03a6156aa9b 100644
--- a/packages/grafana-ui/src/types/icon.ts
+++ b/packages/grafana-ui/src/types/icon.ts
@@ -122,6 +122,7 @@ export type IconName =
   | 'cloud'
   | 'draggabledots'
   | 'folder-upload'
+  | 'palette'
   | 'gf-interpolation-linear'
   | 'gf-interpolation-smooth'
   | 'gf-interpolation-step-before'
@@ -246,6 +247,7 @@ export const getAvailableIcons = (): IconName[] => [
   'cloud',
   'draggabledots',
   'folder-upload',
+  'palette',
   'gf-interpolation-linear',
   'gf-interpolation-smooth',
   'gf-interpolation-step-before',
diff --git a/packages/jaeger-ui-components/src/TracePageHeader/SpanGraph/Scrubber.tsx b/packages/jaeger-ui-components/src/TracePageHeader/SpanGraph/Scrubber.tsx
index 61364e37dda..017ff5ea4d4 100644
--- a/packages/jaeger-ui-components/src/TracePageHeader/SpanGraph/Scrubber.tsx
+++ b/packages/jaeger-ui-components/src/TracePageHeader/SpanGraph/Scrubber.tsx
@@ -19,50 +19,56 @@ import { createStyle } from '../../Theme';
 import { css } from 'emotion';
 
 export const getStyles = createStyle(() => {
-  const ScrubberHandleExpansion = css`
-    label: ScrubberHandleExpansion;
-    cursor: col-resize;
-    fill-opacity: 0;
-    fill: #44f;
-  `;
-  const ScrubberHandle = css`
-    label: ScrubberHandle;
-    cursor: col-resize;
-    fill: #555;
-  `;
-  const ScrubberLine = css`
-    label: ScrubberLine;
-    pointer-events: none;
-    stroke: #555;
-  `;
   return {
+    ScrubberHandleExpansion: cx(
+      css`
+        label: ScrubberHandleExpansion;
+        cursor: col-resize;
+        fill-opacity: 0;
+        fill: #44f;
+      `,
+      'scrubber-handle-expansion'
+    ),
+    ScrubberHandle: cx(
+      css`
+        label: ScrubberHandle;
+        cursor: col-resize;
+        fill: #555;
+      `,
+      'scrubber-handle'
+    ),
+    ScrubberLine: cx(
+      css`
+        label: ScrubberLine;
+        pointer-events: none;
+        stroke: #555;
+      `,
+      'scrubber-line'
+    ),
     ScrubberDragging: css`
       label: ScrubberDragging;
-      & .${ScrubberHandleExpansion} {
+      & .scrubber-handle-expansion {
         fill-opacity: 1;
       }
-      & .${ScrubberHandle} {
+      & .scrubber-handle {
         fill: #44f;
       }
-      & > .${ScrubberLine} {
+      & > .scrubber-line {
         stroke: #44f;
       }
     `,
     ScrubberHandles: css`
       label: ScrubberHandles;
-      &:hover > .${ScrubberHandleExpansion} {
+      &:hover > .scrubber-handle-expansion {
         fill-opacity: 1;
       }
-      &:hover > .${ScrubberHandle} {
+      &:hover > .scrubber-handle {
         fill: #44f;
       }
-      &:hover + .${ScrubberLine} {
+      &:hover + .scrubber.line {
         stroke: #44f;
       }
     `,
-    ScrubberHandleExpansion,
-    ScrubberHandle,
-    ScrubberLine,
   };
 });
 
diff --git a/packages/jaeger-ui-components/src/TracePageHeader/TracePageHeader.tsx b/packages/jaeger-ui-components/src/TracePageHeader/TracePageHeader.tsx
index fcd3771c40f..ffcc1743e4b 100644
--- a/packages/jaeger-ui-components/src/TracePageHeader/TracePageHeader.tsx
+++ b/packages/jaeger-ui-components/src/TracePageHeader/TracePageHeader.tsx
@@ -36,10 +36,6 @@ import { createStyle } from '../Theme';
 import { uTxMuted } from '../uberUtilityStyles';
 
 const getStyles = createStyle((theme: Theme) => {
-  const TracePageHeaderOverviewItemValueDetail = css`
-    label: TracePageHeaderOverviewItemValueDetail;
-    color: #aaa;
-  `;
   return {
     TracePageHeader: css`
       label: TracePageHeader;
@@ -117,10 +113,16 @@ const getStyles = createStyle((theme: Theme) => {
       border-bottom: 1px solid #e4e4e4;
       padding: 0.25rem 0.5rem !important;
     `,
-    TracePageHeaderOverviewItemValueDetail,
+    TracePageHeaderOverviewItemValueDetail: cx(
+      css`
+        label: TracePageHeaderOverviewItemValueDetail;
+        color: #aaa;
+      `,
+      'trace-item-value-detail'
+    ),
     TracePageHeaderOverviewItemValue: css`
       label: TracePageHeaderOverviewItemValue;
-      &:hover > .${TracePageHeaderOverviewItemValueDetail} {
+      &:hover > .trace-item-value-detail {
         color: unset;
       }
     `,
@@ -163,13 +165,13 @@ export const HEADER_ITEMS = [
   {
     key: 'timestamp',
     label: 'Trace Start',
-    renderer(trace: Trace, styles?: ReturnType<typeof getStyles>) {
+    renderer(trace: Trace, styles: ReturnType<typeof getStyles>) {
       const dateStr = formatDatetime(trace.startTime);
       const match = dateStr.match(/^(.+)(:\d\d\.\d+)$/);
       return match ? (
-        <span className={styles?.TracePageHeaderOverviewItemValue}>
+        <span className={styles.TracePageHeaderOverviewItemValue}>
           {match[1]}
-          <span className={styles?.TracePageHeaderOverviewItemValueDetail}>{match[2]}</span>
+          <span className={styles.TracePageHeaderOverviewItemValueDetail}>{match[2]}</span>
         </span>
       ) : (
         dateStr
diff --git a/pkg/api/dtos/index.go b/pkg/api/dtos/index.go
index 00ddf796241..da40cea68ab 100644
--- a/pkg/api/dtos/index.go
+++ b/pkg/api/dtos/index.go
@@ -62,3 +62,6 @@ type NavLink struct {
 	HideFromTabs bool       `json:"hideFromTabs,omitempty"`
 	Children     []*NavLink `json:"children,omitempty"`
 }
+
+// NavIDCfg is the id for org configuration navigation node
+const NavIDCfg = "cfg"
diff --git a/pkg/api/index.go b/pkg/api/index.go
index ae2165cd6e1..adf939e06c9 100644
--- a/pkg/api/index.go
+++ b/pkg/api/index.go
@@ -282,7 +282,7 @@ func (hs *HTTPServer) getNavTree(c *models.ReqContext, hasEditPerm bool) ([]*dto
 
 	if len(configNodes) > 0 {
 		navTree = append(navTree, &dtos.NavLink{
-			Id:         "cfg",
+			Id:         dtos.NavIDCfg,
 			Text:       "Configuration",
 			SubTitle:   "Organization: " + c.OrgName,
 			Icon:       "cog",
diff --git a/public/app/core/components/OrgActionBar/OrgActionBar.tsx b/public/app/core/components/OrgActionBar/OrgActionBar.tsx
index 06d6b532ddc..f4afea627cc 100644
--- a/public/app/core/components/OrgActionBar/OrgActionBar.tsx
+++ b/public/app/core/components/OrgActionBar/OrgActionBar.tsx
@@ -4,7 +4,7 @@ import { LinkButton } from '@grafana/ui';
 
 export interface Props {
   searchQuery: string;
-  setSearchQuery: (value: string) => {};
+  setSearchQuery: (value: string) => void;
   linkButton: { href: string; title: string };
   target?: string;
 }
diff --git a/public/app/core/components/Page/Page.tsx b/public/app/core/components/Page/Page.tsx
index 15a5e665ca1..46ab58c25a9 100644
--- a/public/app/core/components/Page/Page.tsx
+++ b/public/app/core/components/Page/Page.tsx
@@ -1,62 +1,58 @@
 // Libraries
-import React, { Component, HTMLAttributes } from 'react';
+import React, { FC, HTMLAttributes, useEffect } from 'react';
 import { getTitleFromNavModel } from 'app/core/selectors/navModel';
 
 // Components
 import PageHeader from '../PageHeader/PageHeader';
 import { Footer } from '../Footer/Footer';
-import PageContents from './PageContents';
-import { CustomScrollbar } from '@grafana/ui';
-import { NavModel } from '@grafana/data';
-import { isEqual } from 'lodash';
+import { PageContents } from './PageContents';
+import { CustomScrollbar, useStyles } from '@grafana/ui';
+import { GrafanaTheme, NavModel } from '@grafana/data';
 import { Branding } from '../Branding/Branding';
+import { css } from 'emotion';
 
 interface Props extends HTMLAttributes<HTMLDivElement> {
   children: React.ReactNode;
   navModel: NavModel;
 }
 
-class Page extends Component<Props> {
-  static Header = PageHeader;
-  static Contents = PageContents;
-
-  componentDidMount() {
-    this.updateTitle();
-  }
-
-  componentDidUpdate(prevProps: Props) {
-    if (!isEqual(prevProps.navModel, this.props.navModel)) {
-      this.updateTitle();
-    }
-  }
-
-  updateTitle = () => {
-    const title = this.getPageTitle;
-    document.title = title ? title + ' - ' + Branding.AppTitle : Branding.AppTitle;
-  };
-
-  get getPageTitle() {
-    const { navModel } = this.props;
-    if (navModel) {
-      return getTitleFromNavModel(navModel) || undefined;
-    }
-    return undefined;
-  }
-
-  render() {
-    const { navModel, children, ...otherProps } = this.props;
-    return (
-      <div {...otherProps} className="page-scrollbar-wrapper">
-        <CustomScrollbar autoHeightMin={'100%'}>
-          <div className="page-scrollbar-content">
-            <PageHeader model={navModel} />
-            {children}
-            <Footer />
-          </div>
-        </CustomScrollbar>
-      </div>
-    );
-  }
+export interface PageType extends FC<Props> {
+  Header: typeof PageHeader;
+  Contents: typeof PageContents;
 }
 
+export const Page: PageType = ({ navModel, children, ...otherProps }) => {
+  const styles = useStyles(getStyles);
+
+  useEffect(() => {
+    const title = getTitleFromNavModel(navModel);
+    document.title = title ? `${title} - ${Branding.AppTitle}` : Branding.AppTitle;
+  }, [navModel]);
+
+  return (
+    <div {...otherProps} className={styles.wrapper}>
+      <CustomScrollbar autoHeightMin={'100%'}>
+        <div className="page-scrollbar-content">
+          <PageHeader model={navModel} />
+          {children}
+          <Footer />
+        </div>
+      </CustomScrollbar>
+    </div>
+  );
+};
+
+Page.Header = PageHeader;
+Page.Contents = PageContents;
+
 export default Page;
+
+const getStyles = (theme: GrafanaTheme) => ({
+  wrapper: css`
+    position: absolute;
+    top: 0;
+    bottom: 0;
+    width: 100%;
+    background: ${theme.colors.bg1};
+  `,
+});
diff --git a/public/app/core/components/Page/PageContents.tsx b/public/app/core/components/Page/PageContents.tsx
index a4dbdb2af6b..b9b4ef3156e 100644
--- a/public/app/core/components/Page/PageContents.tsx
+++ b/public/app/core/components/Page/PageContents.tsx
@@ -1,5 +1,5 @@
 // Libraries
-import React, { Component } from 'react';
+import React, { FC } from 'react';
 
 // Components
 import PageLoader from '../PageLoader/PageLoader';
@@ -9,12 +9,6 @@ interface Props {
   children: React.ReactNode;
 }
 
-class PageContents extends Component<Props> {
-  render() {
-    const { isLoading } = this.props;
-
-    return <div className="page-container page-body">{isLoading ? <PageLoader /> : this.props.children}</div>;
-  }
-}
-
-export default PageContents;
+export const PageContents: FC<Props> = ({ isLoading, children }) => {
+  return <div className="page-container page-body">{isLoading ? <PageLoader /> : children}</div>;
+};
diff --git a/public/app/core/components/PageHeader/PageHeader.test.tsx b/public/app/core/components/PageHeader/PageHeader.test.tsx
index f38839f145a..03ac4b58663 100644
--- a/public/app/core/components/PageHeader/PageHeader.test.tsx
+++ b/public/app/core/components/PageHeader/PageHeader.test.tsx
@@ -1,12 +1,10 @@
 import React from 'react';
 import PageHeader from './PageHeader';
-import { shallow, ShallowWrapper } from 'enzyme';
+import { render, screen } from '@testing-library/react';
 
 describe('PageHeader', () => {
-  let wrapper: ShallowWrapper<PageHeader>;
-
   describe('when the nav tree has a node with a title', () => {
-    beforeAll(() => {
+    it('should render the title', async () => {
       const nav = {
         main: {
           icon: 'folder-open',
@@ -17,17 +15,15 @@ describe('PageHeader', () => {
         },
         node: {},
       };
-      wrapper = shallow(<PageHeader model={nav as any} />);
-    });
 
-    it('should render the title', () => {
-      const title = wrapper.find('.page-header__title');
-      expect(title.text()).toBe('node');
+      render(<PageHeader model={nav as any} />);
+
+      expect(screen.getByRole('heading', { name: 'node' })).toBeInTheDocument();
     });
   });
 
   describe('when the nav tree has a node with breadcrumbs and a title', () => {
-    beforeAll(() => {
+    it('should render the title with breadcrumbs first and then title last', async () => {
       const nav = {
         main: {
           icon: 'folder-open',
@@ -39,15 +35,11 @@ describe('PageHeader', () => {
         },
         node: {},
       };
-      wrapper = shallow(<PageHeader model={nav as any} />);
-    });
 
-    it('should render the title with breadcrumbs first and then title last', () => {
-      const title = wrapper.find('.page-header__title');
-      expect(title.text()).toBe('Parent / child');
+      render(<PageHeader model={nav as any} />);
 
-      const parentLink = wrapper.find('.page-header__title > a.text-link');
-      expect(parentLink.prop('href')).toBe('parentUrl');
+      expect(screen.getByRole('heading', { name: 'Parent / child' })).toBeInTheDocument();
+      expect(screen.getByRole('link', { name: 'Parent' })).toBeInTheDocument();
     });
   });
 });
diff --git a/public/app/core/components/PageHeader/PageHeader.tsx b/public/app/core/components/PageHeader/PageHeader.tsx
index ee343356888..fa305235e3f 100644
--- a/public/app/core/components/PageHeader/PageHeader.tsx
+++ b/public/app/core/components/PageHeader/PageHeader.tsx
@@ -1,7 +1,7 @@
-import React from 'react';
+import React, { FC } from 'react';
 import { css } from 'emotion';
-import { Tab, TabsBar, Icon, IconName } from '@grafana/ui';
-import { NavModel, NavModelItem, NavModelBreadcrumb } from '@grafana/data';
+import { Tab, TabsBar, Icon, IconName, useStyles } from '@grafana/ui';
+import { NavModel, NavModelItem, NavModelBreadcrumb, GrafanaTheme } from '@grafana/data';
 import { PanelHeaderMenuItem } from 'app/features/dashboard/dashgrid/PanelHeader/PanelHeaderMenuItem';
 
 export interface Props {
@@ -71,86 +71,77 @@ const Navigation = ({ children }: { children: NavModelItem[] }) => {
   );
 };
 
-export default class PageHeader extends React.Component<Props, any> {
-  constructor(props: Props) {
-    super(props);
+export const PageHeader: FC<Props> = ({ model }) => {
+  const styles = useStyles(getStyles);
+
+  if (!model) {
+    return null;
   }
 
-  shouldComponentUpdate() {
-    //Hack to re-render on changed props from angular with the @observer decorator
-    return true;
-  }
+  const main = model.main;
+  const children = main.children;
 
-  renderTitle(title: string, breadcrumbs: NavModelBreadcrumb[]) {
-    if (!title && (!breadcrumbs || breadcrumbs.length === 0)) {
-      return null;
-    }
-
-    if (!breadcrumbs || breadcrumbs.length === 0) {
-      return <h1 className="page-header__title">{title}</h1>;
-    }
-
-    const breadcrumbsResult = [];
-    for (const bc of breadcrumbs) {
-      if (bc.url) {
-        breadcrumbsResult.push(
-          <a className="text-link" key={breadcrumbsResult.length} href={bc.url}>
-            {bc.title}
-          </a>
-        );
-      } else {
-        breadcrumbsResult.push(<span key={breadcrumbsResult.length}> / {bc.title}</span>);
-      }
-    }
-    breadcrumbsResult.push(<span key={breadcrumbs.length + 1}> / {title}</span>);
-
-    return <h1 className="page-header__title">{breadcrumbsResult}</h1>;
-  }
-
-  renderHeaderTitle(main: NavModelItem) {
-    const iconClassName =
-      main.icon === 'grafana'
-        ? css`
-            margin-top: 12px;
-          `
-        : css`
-            margin-top: 14px;
-          `;
-
-    return (
-      <div className="page-header__inner">
-        <span className="page-header__logo">
-          {main.icon && <Icon name={main.icon as IconName} size="xxxl" className={iconClassName} />}
-          {main.img && <img className="page-header__img" src={main.img} alt={`logo of ${main.text}`} />}
-        </span>
-
-        <div className="page-header__info-block">
-          {this.renderTitle(main.text, main.breadcrumbs ?? [])}
-          {main.subTitle && <div className="page-header__sub-title">{main.subTitle}</div>}
+  return (
+    <div className={styles.headerCanvas}>
+      <div className="page-container">
+        <div className="page-header">
+          {renderHeaderTitle(main)}
+          {children && children.length && <Navigation>{children}</Navigation>}
         </div>
       </div>
-    );
-  }
+    </div>
+  );
+};
 
-  render() {
-    const { model } = this.props;
+function renderHeaderTitle(main: NavModelItem) {
+  const marginTop = main.icon === 'grafana' ? 12 : 14;
 
-    if (!model) {
-      return null;
-    }
+  return (
+    <div className="page-header__inner">
+      <span className="page-header__logo">
+        {main.icon && <Icon name={main.icon as IconName} size="xxxl" style={{ marginTop }} />}
+        {main.img && <img className="page-header__img" src={main.img} alt={`logo of ${main.text}`} />}
+      </span>
 
-    const main = model.main;
-    const children = main.children;
-
-    return (
-      <div className="page-header-canvas">
-        <div className="page-container">
-          <div className="page-header">
-            {this.renderHeaderTitle(main)}
-            {children && children.length && <Navigation>{children}</Navigation>}
-          </div>
-        </div>
+      <div className="page-header__info-block">
+        {renderTitle(main.text, main.breadcrumbs ?? [])}
+        {main.subTitle && <div className="page-header__sub-title">{main.subTitle}</div>}
       </div>
-    );
-  }
+    </div>
+  );
 }
+
+function renderTitle(title: string, breadcrumbs: NavModelBreadcrumb[]) {
+  if (!title && (!breadcrumbs || breadcrumbs.length === 0)) {
+    return null;
+  }
+
+  if (!breadcrumbs || breadcrumbs.length === 0) {
+    return <h1 className="page-header__title">{title}</h1>;
+  }
+
+  const breadcrumbsResult = [];
+  for (const bc of breadcrumbs) {
+    if (bc.url) {
+      breadcrumbsResult.push(
+        <a className="text-link" key={breadcrumbsResult.length} href={bc.url}>
+          {bc.title}
+        </a>
+      );
+    } else {
+      breadcrumbsResult.push(<span key={breadcrumbsResult.length}> / {bc.title}</span>);
+    }
+  }
+  breadcrumbsResult.push(<span key={breadcrumbs.length + 1}> / {title}</span>);
+
+  return <h1 className="page-header__title">{breadcrumbsResult}</h1>;
+}
+
+const getStyles = (theme: GrafanaTheme) => ({
+  headerCanvas: css`
+    background: ${theme.colors.bg2};
+    border-bottom: 1px solid ${theme.colors.border1};
+  `,
+});
+
+export default PageHeader;
diff --git a/public/app/core/utils/ConfigProvider.tsx b/public/app/core/utils/ConfigProvider.tsx
index 97200b0cbca..23bafdc410b 100644
--- a/public/app/core/utils/ConfigProvider.tsx
+++ b/public/app/core/utils/ConfigProvider.tsx
@@ -1,7 +1,9 @@
-import React from 'react';
+import React, { useEffect, useState } from 'react';
 import { config, GrafanaBootConfig } from '@grafana/runtime';
-import { ThemeContext, getTheme } from '@grafana/ui';
-import { GrafanaThemeType } from '@grafana/data';
+import { ThemeContext } from '@grafana/ui';
+import { appEvents } from '../core';
+import { ThemeChangedEvent } from 'app/types/events';
+import { GrafanaTheme } from '@grafana/data';
 
 export const ConfigContext = React.createContext<GrafanaBootConfig>(config);
 export const ConfigConsumer = ConfigContext.Consumer;
@@ -10,23 +12,22 @@ export const provideConfig = (component: React.ComponentType<any>) => {
   const ConfigProvider = (props: any) => (
     <ConfigContext.Provider value={config}>{React.createElement(component, { ...props })}</ConfigContext.Provider>
   );
-
   return ConfigProvider;
 };
 
-export const getCurrentThemeName = () =>
-  config.bootData.user.lightTheme ? GrafanaThemeType.Light : GrafanaThemeType.Dark;
-
-export const getCurrentTheme = () => getTheme(getCurrentThemeName());
-
 export const ThemeProvider = ({ children }: { children: React.ReactNode }) => {
-  return (
-    <ConfigConsumer>
-      {(config) => {
-        return <ThemeContext.Provider value={getCurrentTheme()}>{children}</ThemeContext.Provider>;
-      }}
-    </ConfigConsumer>
-  );
+  const [theme, setTheme] = useState<GrafanaTheme>(config.theme);
+
+  useEffect(() => {
+    const sub = appEvents.subscribe(ThemeChangedEvent, (event) => {
+      config.theme = event.payload;
+      setTheme(event.payload);
+    });
+
+    return () => sub.unsubscribe();
+  }, []);
+
+  return <ThemeContext.Provider value={theme}>{children}</ThemeContext.Provider>;
 };
 
 export const provideTheme = (component: React.ComponentType<any>) => {
diff --git a/public/app/plugins/panel/graph/graph.ts b/public/app/plugins/panel/graph/graph.ts
index 91721fccb16..b415981378b 100644
--- a/public/app/plugins/panel/graph/graph.ts
+++ b/public/app/plugins/panel/graph/graph.ts
@@ -25,7 +25,7 @@ import { GraphLegendProps, Legend } from './Legend/Legend';
 
 import { GraphCtrl } from './module';
 import { graphTickFormatter, graphTimeFormat, IconName, MenuItem, MenuItemsGroup } from '@grafana/ui';
-import { getCurrentTheme, provideTheme } from 'app/core/utils/ConfigProvider';
+import { provideTheme } from 'app/core/utils/ConfigProvider';
 import {
   DataFrame,
   DataFrameView,
@@ -284,7 +284,7 @@ class GraphElement {
         };
         const fieldDisplay = getDisplayProcessor({
           field: { config: fieldConfig, type: FieldType.number },
-          theme: getCurrentTheme(),
+          theme: config.theme,
           timeZone: this.dashboard.getTimezone(),
         })(field.values.get(dataIndex));
         linksSupplier = links.length
diff --git a/public/app/types/events.ts b/public/app/types/events.ts
index ee323736397..0f922a8214b 100644
--- a/public/app/types/events.ts
+++ b/public/app/types/events.ts
@@ -1,4 +1,4 @@
-import { BusEventBase, eventFactory, TimeRange } from '@grafana/data';
+import { BusEventBase, BusEventWithPayload, eventFactory, GrafanaTheme, TimeRange } from '@grafana/data';
 import { DashboardModel } from 'app/features/dashboard/state';
 
 /**
@@ -156,3 +156,7 @@ export class RefreshEvent extends BusEventBase {
 export class RenderEvent extends BusEventBase {
   static type = 'render';
 }
+
+export class ThemeChangedEvent extends BusEventWithPayload<GrafanaTheme> {
+  static type = 'theme-changed';
+}
diff --git a/public/sass/components/_page_header.scss b/public/sass/components/_page_header.scss
index f345a7e43ae..e10f65ce223 100644
--- a/public/sass/components/_page_header.scss
+++ b/public/sass/components/_page_header.scss
@@ -1,9 +1,3 @@
-.page-header-canvas {
-  background: $page-header-bg;
-  box-shadow: $page-header-shadow;
-  border-bottom: 1px solid $page-header-border-color;
-}
-
 .page-header {
   padding: $space-xl 0 0 0;