[add] Image support for blurRadius, tintColor, and shadows

Use CSS filters to implement React Native image styles.

Ref #362
Ref #548

packages/react-native-web/src/exports/Image/ImageStylePropTypes.js

@@ -22,11 +22,11 @@ const ImageStylePropTypes = {
   backgroundColor: ColorPropType,
   opacity: number,
   resizeMode: oneOf(Object.keys(ImageResizeMode)),
+  tintColor: ColorPropType,
   /**
    * @platform unsupported
    */
   overlayColor: string,
-  tintColor: ColorPropType,
   /**
    * @platform web
    */

packages/react-native-web/src/exports/Image/__tests__/__snapshots__/index-test.js.snap

@@ -1,5 +1,7 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
+exports[`components/Image prop "blurRadius" 1`] = `"blur(5px)"`;
+
 exports[`components/Image prop "defaultSource" sets background image when value is a string 1`] = `"url(\\"https://google.com/favicon.ico\\")"`;
 
 exports[`components/Image prop "defaultSource" sets background image when value is an object 1`] = `"url(\\"https://google.com/favicon.ico\\")"`;
@@ -14,4 +16,6 @@ exports[`components/Image prop "resizeMode" value "stretch" 1`] = `"100% 100%"`;
 
 exports[`components/Image prop "resizeMode" value "undefined" 1`] = `"cover"`;
 
-exports[`components/Image prop "style" correctly supports "resizeMode" property 1`] = `"contain"`;
+exports[`components/Image prop "style" supports "resizeMode" property 1`] = `"contain"`;
+
+exports[`components/Image prop "style" supports "shadow" properties (convert to filter) 1`] = `"drop-shadow(1px 1px 0px rgba(255,0,0,1.00))"`;

packages/react-native-web/src/exports/Image/__tests__/index-test.js

@@ -36,6 +36,12 @@ describe('components/Image', () => {
     expect(component.prop('accessible')).toBe(false);
   });
 
+  test('prop "blurRadius"', () => {
+    const defaultSource = { uri: 'https://google.com/favicon.ico' };
+    const component = shallow(<Image blurRadius={5} defaultSource={defaultSource} />);
+    expect(findImageSurfaceStyle(component).filter).toMatchSnapshot();
+  });
+
   describe('prop "defaultSource"', () => {
     test('sets background image when value is an object', () => {
       const defaultSource = { uri: 'https://google.com/favicon.ico' };
@@ -207,11 +213,29 @@ describe('components/Image', () => {
   });
 
   describe('prop "style"', () => {
-    test('correctly supports "resizeMode" property', () => {
+    test('supports "resizeMode" property', () => {
       const component = shallow(<Image style={{ resizeMode: Image.resizeMode.contain }} />);
       expect(findImageSurfaceStyle(component).backgroundSize).toMatchSnapshot();
     });
 
+    test('supports "shadow" properties (convert to filter)', () => {
+      const component = shallow(
+        <Image style={{ shadowColor: 'red', shadowOffset: { width: 1, height: 1 } }} />
+      );
+      expect(findImageSurfaceStyle(component).filter).toMatchSnapshot();
+    });
+
+    test('supports "tintcolor" property (convert to filter)', () => {
+      const defaultSource = { uri: 'https://google.com/favicon.ico' };
+      const component = shallow(
+        <Image defaultSource={defaultSource} style={{ tintColor: 'red' }} />
+      );
+      // filter
+      expect(findImageSurfaceStyle(component).filter).toContain('url(#tint-');
+      // svg
+      expect(component.childAt(2).type()).toBe('svg');
+    });
+
     test('removes other unsupported View styles', () => {
       const component = shallow(<Image style={{ overlayColor: 'red', tintColor: 'blue' }} />);
       expect(component.props().style.overlayColor).toBeUndefined();

packages/react-native-web/src/exports/Image/index.js

@@ -11,6 +11,7 @@
 import applyNativeMethods from '../../modules/applyNativeMethods';
 import createElement from '../createElement';
 import { getAssetByID } from '../../modules/AssetRegistry';
+import resolveShadowValue from '../StyleSheet/resolveShadowValue';
 import ImageLoader from '../../modules/ImageLoader';
 import ImageResizeMode from './ImageResizeMode';
 import ImageSourcePropType from './ImageSourcePropType';
@@ -73,6 +74,20 @@ const resolveAssetUri = source => {
   return uri;
 };
 
+let filterId = 0;
+
+const createTintColorSVG = (tintColor, id) =>
+  tintColor && id != null ? (
+    <svg style={{ position: 'absolute', height: 0, visibility: 'hidden', width: 0 }}>
+      <defs>
+        <filter id={`tint-${id}`}>
+          <feFlood floodColor={`${tintColor}`} />
+          <feComposite in2="SourceAlpha" operator="atop" />
+        </filter>
+      </defs>
+    </svg>
+  ) : null;
+
 type State = {
   shouldDisplaySource: boolean
 };
@@ -86,6 +101,7 @@ class Image extends Component<*, State> {
 
   static propTypes = {
     ...ViewPropTypes,
+    blurRadius: number,
     defaultSource: ImageSourcePropType,
     draggable: bool,
     onError: func,
@@ -98,7 +114,6 @@ class Image extends Component<*, State> {
     style: StyleSheetPropType(ImageStylePropTypes),
     // compatibility with React Native
     /* eslint-disable react/sort-prop-types */
-    blurRadius: number,
     capInsets: shape({ top: number, left: number, bottom: number, right: number }),
     resizeMethod: oneOf(['auto', 'resize', 'scale'])
     /* eslint-enable react/sort-prop-types */
@@ -118,6 +133,7 @@ class Image extends Component<*, State> {
 
   static resizeMode = ImageResizeMode;
 
+  _filterId = 0;
   _imageRef = null;
   _imageRequestId = null;
   _imageState = null;
@@ -130,6 +146,8 @@ class Image extends Component<*, State> {
     const shouldDisplaySource = ImageUriCache.has(uri);
     this.state = { shouldDisplaySource };
     this._imageState = getImageState(uri, shouldDisplaySource);
+    this._filterId = filterId;
+    filterId++;
   }
 
   componentDidMount() {
@@ -170,13 +188,13 @@ class Image extends Component<*, State> {
     const {
       accessibilityLabel,
       accessible,
+      blurRadius,
       defaultSource,
       draggable,
       onLayout,
       source,
       testID,
       /* eslint-disable */
-      blurRadius,
       capInsets,
       onError,
       onLoad,
@@ -206,10 +224,35 @@ class Image extends Component<*, State> {
     const backgroundImage = displayImageUri ? `url("${displayImageUri}")` : null;
     const flatStyle = { ...StyleSheet.flatten(this.props.style) };
     const finalResizeMode = resizeMode || flatStyle.resizeMode || ImageResizeMode.cover;
-    // View doesn't support these styles
+
+    // CSS filters
+    const filters = [];
+    const tintColor = flatStyle.tintColor;
+    if (flatStyle.filter) {
+      filters.push(flatStyle.filter);
+    }
+    if (blurRadius) {
+      filters.push(`blur(${blurRadius}px)`);
+    }
+    if (flatStyle.shadowOffset) {
+      const shadowString = resolveShadowValue(flatStyle);
+      if (shadowString) {
+        filters.push(`drop-shadow(${shadowString})`);
+      }
+    }
+    if (flatStyle.tintColor) {
+      filters.push(`url(#tint-${this._filterId})`);
+    }
+
+    // these styles were converted to filters
+    delete flatStyle.shadowColor;
+    delete flatStyle.shadowOpacity;
+    delete flatStyle.shadowOffset;
+    delete flatStyle.shadowRadius;
+    delete flatStyle.tintColor;
+    // these styles are not supported on View
     delete flatStyle.overlayColor;
     delete flatStyle.resizeMode;
-    delete flatStyle.tintColor;
 
     // Accessibility image allows users to trigger the browser's image context menu
     const hiddenImage = displayImageUri
@@ -240,10 +283,12 @@ class Image extends Component<*, State> {
           style={[
             styles.image,
             resizeModeStyles[finalResizeMode],
-            backgroundImage && { backgroundImage }
+            backgroundImage && { backgroundImage },
+            filters.length > 0 && { filter: filters.join(' ') }
           ]}
         />
         {hiddenImage}
+        {createTintColorSVG(tintColor, this._filterId)}
       </View>
     );
   }

packages/react-native-web/src/exports/StyleSheet/createReactDOMStyle.js

@@ -9,6 +9,7 @@
 
 import normalizeColor from '../../modules/normalizeColor';
 import normalizeValue from './normalizeValue';
+import resolveShadowValue from './resolveShadowValue';
 
 /**
  * The browser implements the CSS cascade, where the order of properties is a
@@ -82,16 +83,9 @@ const defaultOffset = { height: 0, width: 0 };
  * Shadow
  */
 
-// TODO: add inset and spread support
 const resolveShadow = (resolvedStyle, style) => {
-  const { boxShadow, shadowColor, shadowOffset, shadowOpacity, shadowRadius } = style;
-  const { height, width } = shadowOffset || defaultOffset;
-  const offsetX = normalizeValue(null, width);
-  const offsetY = normalizeValue(null, height);
-  const blurRadius = normalizeValue(null, shadowRadius || 0);
-  const color = normalizeColor(shadowColor || 'black', shadowOpacity);
-
-  const shadow = `${offsetX} ${offsetY} ${blurRadius} ${color}`;
+  const { boxShadow } = style;
+  const shadow = resolveShadowValue(style);
   resolvedStyle.boxShadow = boxShadow ? `${boxShadow}, ${shadow}` : shadow;
 };
 

packages/react-native-web/src/exports/StyleSheet/resolveShadowValue.js

@@ -0,0 +1,27 @@
+/**
+ * Copyright (c) 2018-present, Nicolas Gallagher.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow
+ */
+
+import normalizeColor from '../../modules/normalizeColor';
+import normalizeValue from './normalizeValue';
+
+const defaultOffset = { height: 0, width: 0 };
+
+const resolveShadowValue = (style: Object) => {
+  const { shadowColor, shadowOffset, shadowOpacity, shadowRadius } = style;
+  const { height, width } = shadowOffset || defaultOffset;
+  const offsetX = normalizeValue(null, width);
+  const offsetY = normalizeValue(null, height);
+  const blurRadius = normalizeValue(null, shadowRadius || 0);
+  const color = normalizeColor(shadowColor || 'black', shadowOpacity);
+  if (color) {
+    return `${offsetX} ${offsetY} ${blurRadius} ${color}`;
+  }
+};
+
+export default resolveShadowValue;

packages/website/storybook/1-components/Image/ImageScreen.js

@@ -21,6 +21,7 @@ import UIExplorer, {
   Description,
   DocItem,
   Section,
+  StyleList,
   storiesOf
 } from '../../ui-explorer';
 
@@ -34,6 +35,12 @@ const ImageScreen = () => (
     <Section title="Props">
       <DocItem name="...View props" />
 
+      <DocItem
+        name="blurRadius"
+        typeInfo="?number"
+        description="The blur radius of the blur filter added to the image"
+      />
+
       <DocItem
         name="defaultSource"
         typeInfo="?object"
@@ -122,7 +129,11 @@ const ImageScreen = () => (
         }}
       />
 
-      <DocItem name="style" typeInfo="?style" />
+      <DocItem
+        name="style"
+        typeInfo="?style"
+        description={<StyleList stylePropTypes={stylePropTypes} />}
+      />
     </Section>
 
     <Section title="Properties">
@@ -168,4 +179,17 @@ const ImageScreen = () => (
   </UIExplorer>
 );
 
+const stylePropTypes = [
+  {
+    name: '...View#style'
+  },
+  {
+    name: 'resizeMode'
+  },
+  {
+    name: 'tintColor',
+    typeInfo: 'color'
+  }
+];
+
 storiesOf('Components', module).add('Image', ImageScreen);