Merge pull request #1175 from 0xProject/feature/instant/input-fees-rounding

[instant] Create a ScalingInput component and use it in the amount input and upgrade to styled-components v4

22 files changed, 473 insertions, 157 deletions

diff --git a/packages/instant/package.json b/packages/instant/package.json
index 421802530..be85b5062 100644
--- a/packages/instant/package.json
+++ b/packages/instant/package.json
@@ -58,7 +58,7 @@
         "react-redux": "^5.0.7",
         "redux": "^4.0.0",
         "redux-devtools-extension": "^2.13.5",
-        "styled-components": "^3.4.9",
+        "styled-components": "^4.0.2",
         "ts-optchain": "^0.1.1"
     },
     "devDependencies": {
@@ -73,6 +73,7 @@
         "@types/react-dom": "^16.0.8",
         "@types/react-redux": "^6.0.9",
         "@types/redux": "^3.6.0",
+        "@types/styled-components": "^4.0.1",
         "awesome-typescript-loader": "^5.2.1",
         "enzyme": "^3.6.0",
         "enzyme-adapter-react-16": "^1.5.0",
diff --git a/packages/instant/src/components/amount_input.tsx b/packages/instant/src/components/amount_input.tsx
deleted file mode 100644
index c89fb05ad..000000000
--- a/packages/instant/src/components/amount_input.tsx
+++ /dev/null
@@ -1,49 +0,0 @@
-import { BigNumber } from '@0x/utils';
-import * as _ from 'lodash';
-import * as React from 'react';
-
-import { ColorOption } from '../style/theme';
-import { util } from '../util/util';
-
-import { Container, Input } from './ui';
-
-export interface AmountInputProps {
-    fontColor?: ColorOption;
-    fontSize?: string;
-    value?: BigNumber;
-    onChange: (value?: BigNumber) => void;
-}
-
-export class AmountInput extends React.Component<AmountInputProps> {
-    public static defaultProps = {
-        onChange: util.boundNoop,
-    };
-    public render(): React.ReactNode {
-        const { fontColor, fontSize, value } = this.props;
-        return (
-            <Container borderBottom="1px solid rgba(255,255,255,0.3)" display="inline-block">
-                <Input
-                    fontColor={fontColor}
-                    fontSize={fontSize}
-                    onChange={this._handleChange}
-                    value={!_.isUndefined(value) ? value.toString() : ''}
-                    placeholder="0.00"
-                    width="2.2em"
-                />
-            </Container>
-        );
-    }
-    private readonly _handleChange = (event: React.ChangeEvent<HTMLInputElement>): void => {
-        const value = event.target.value;
-        let bigNumberValue;
-        if (!_.isEmpty(value)) {
-            try {
-                bigNumberValue = new BigNumber(event.target.value);
-            } catch {
-                // We don't want to allow values that can't be a BigNumber, so don't even call onChange.
-                return;
-            }
-        }
-        this.props.onChange(bigNumberValue);
-    };
-}
diff --git a/packages/instant/src/components/animations/slide_animations.tsx b/packages/instant/src/components/animations/slide_animations.tsx
index 1f10a2ed6..84280372b 100644
--- a/packages/instant/src/components/animations/slide_animations.tsx
+++ b/packages/instant/src/components/animations/slide_animations.tsx
@@ -1,6 +1,7 @@
 import * as React from 'react';
+import { Keyframes } from 'styled-components';
 
-import { keyframes, styled } from '../../style/theme';
+import { css, keyframes, styled } from '../../style/theme';
 
 const slideKeyframeGenerator = (fromY: string, toY: string) => keyframes`
     from {
@@ -15,7 +16,7 @@ const slideKeyframeGenerator = (fromY: string, toY: string) => keyframes`
 `;
 
 export interface SlideAnimationProps {
-    keyframes: string;
+    keyframes: Keyframes;
     animationType: string;
     animationDirection?: string;
 }
@@ -24,7 +25,10 @@ export const SlideAnimation =
     styled.div <
     SlideAnimationProps >
     `
-    animation-name: ${props => props.keyframes};
+    animation-name: ${props =>
+        css`
+            ${props.keyframes};
+        `};
     animation-duration: 0.3s;
     animation-timing-function: ${props => props.animationType};
     animation-delay: 0s;
diff --git a/packages/instant/src/components/asset_amount_input.tsx b/packages/instant/src/components/asset_amount_input.tsx
deleted file mode 100644
index c03ef1cf3..000000000
--- a/packages/instant/src/components/asset_amount_input.tsx
+++ /dev/null
@@ -1,39 +0,0 @@
-import { BigNumber } from '@0x/utils';
-import * as _ from 'lodash';
-import * as React from 'react';
-
-import { ColorOption } from '../style/theme';
-import { ERC20Asset } from '../types';
-import { assetUtils } from '../util/asset';
-import { util } from '../util/util';
-
-import { AmountInput, AmountInputProps } from './amount_input';
-import { Container, Text } from './ui';
-
-// Asset amounts only apply to ERC20 assets
-export interface AssetAmountInputProps extends AmountInputProps {
-    asset?: ERC20Asset;
-    onChange: (value?: BigNumber, asset?: ERC20Asset) => void;
-}
-
-export class AssetAmountInput extends React.Component<AssetAmountInputProps> {
-    public static defaultProps = {
-        onChange: util.boundNoop,
-    };
-    public render(): React.ReactNode {
-        const { asset, onChange, ...rest } = this.props;
-        return (
-            <Container>
-                <AmountInput {...rest} onChange={this._handleChange} />
-                <Container display="inline-block" marginLeft="10px">
-                    <Text fontSize={rest.fontSize} fontColor={ColorOption.white} textTransform="uppercase">
-                        {assetUtils.bestNameForAsset(asset)}
-                    </Text>
-                </Container>
-            </Container>
-        );
-    }
-    private readonly _handleChange = (value?: BigNumber): void => {
-        this.props.onChange(value, this.props.asset);
-    };
-}
diff --git a/packages/instant/src/components/erc20_asset_amount_input.tsx b/packages/instant/src/components/erc20_asset_amount_input.tsx
new file mode 100644
index 000000000..583fad28b
--- /dev/null
+++ b/packages/instant/src/components/erc20_asset_amount_input.tsx
@@ -0,0 +1,84 @@
+import * as _ from 'lodash';
+import * as React from 'react';
+
+import { ColorOption, transparentWhite } from '../style/theme';
+import { ERC20Asset } from '../types';
+import { assetUtils } from '../util/asset';
+import { BigNumberInput } from '../util/big_number_input';
+import { util } from '../util/util';
+
+import { ScalingAmountInput } from './scaling_amount_input';
+import { Container, Text } from './ui';
+
+// Asset amounts only apply to ERC20 assets
+export interface ERC20AssetAmountInputProps {
+    asset?: ERC20Asset;
+    value?: BigNumberInput;
+    onChange: (value?: BigNumberInput, asset?: ERC20Asset) => void;
+    startingFontSizePx: number;
+    fontColor?: ColorOption;
+}
+
+export interface ERC20AssetAmountInputState {
+    currentFontSizePx: number;
+}
+
+export class ERC20AssetAmountInput extends React.Component<ERC20AssetAmountInputProps, ERC20AssetAmountInputState> {
+    public static defaultProps = {
+        onChange: util.boundNoop,
+    };
+    constructor(props: ERC20AssetAmountInputProps) {
+        super(props);
+        this.state = {
+            currentFontSizePx: props.startingFontSizePx,
+        };
+    }
+    public render(): React.ReactNode {
+        const { asset, onChange, ...rest } = this.props;
+        return (
+            <Container whiteSpace="nowrap">
+                <Container borderBottom={`1px solid ${transparentWhite}`} display="inline-block">
+                    <ScalingAmountInput
+                        {...rest}
+                        textLengthThreshold={this._textLengthThresholdForAsset(asset)}
+                        maxFontSizePx={this.props.startingFontSizePx}
+                        onChange={this._handleChange}
+                        onFontSizeChange={this._handleFontSizeChange}
+                    />
+                </Container>
+                <Container display="inline-flex" marginLeft="10px" title={assetUtils.bestNameForAsset(asset)}>
+                    <Text
+                        fontSize={`${this.state.currentFontSizePx}px`}
+                        fontColor={ColorOption.white}
+                        textTransform="uppercase"
+                    >
+                        {assetUtils.formattedSymbolForAsset(asset)}
+                    </Text>
+                </Container>
+            </Container>
+        );
+    }
+    private readonly _handleChange = (value?: BigNumberInput): void => {
+        this.props.onChange(value, this.props.asset);
+    };
+    private readonly _handleFontSizeChange = (fontSizePx: number): void => {
+        this.setState({
+            currentFontSizePx: fontSizePx,
+        });
+    };
+    // For assets with symbols of different length,
+    // start scaling the input at different character lengths
+    private readonly _textLengthThresholdForAsset = (asset?: ERC20Asset): number => {
+        if (_.isUndefined(asset)) {
+            return 3;
+        }
+        const symbol = asset.metaData.symbol;
+        if (symbol.length <= 3) {
+            return 5;
+        }
+        if (symbol.length === 5) {
+            return 3;
+        }
+        return 4;
+    };
+}
diff --git a/packages/instant/src/components/instant_heading.tsx b/packages/instant/src/components/instant_heading.tsx
index 17ac65429..1ef276ff3 100644
--- a/packages/instant/src/components/instant_heading.tsx
+++ b/packages/instant/src/components/instant_heading.tsx
@@ -2,7 +2,7 @@ import { BigNumber } from '@0x/utils';
 import * as _ from 'lodash';
 import * as React from 'react';
 
-import { SelectedAssetAmountInput } from '../containers/selected_asset_amount_input';
+import { SelectedERC20AssetAmountInput } from '../containers/selected_erc20_asset_amount_input';
 import { ColorOption } from '../style/theme';
 import { AsyncProcessState, OrderProcessState, OrderState } from '../types';
 import { format } from '../util/format';
@@ -48,7 +48,9 @@ export class InstantHeading extends React.Component<InstantHeadingProps, {}> {
                     </Text>
                 </Container>
                 <Flex direction="row" justify="space-between">
-                    <SelectedAssetAmountInput fontSize="45px" />
+                    <Flex height="60px">
+                        <SelectedERC20AssetAmountInput startingFontSizePx={38} />
+                    </Flex>
                     <Flex direction="column" justify="space-between">
                         {iconOrAmounts}
                     </Flex>
diff --git a/packages/instant/src/components/scaling_amount_input.tsx b/packages/instant/src/components/scaling_amount_input.tsx
new file mode 100644
index 000000000..655ae2b74
--- /dev/null
+++ b/packages/instant/src/components/scaling_amount_input.tsx
@@ -0,0 +1,52 @@
+import * as _ from 'lodash';
+import * as React from 'react';
+
+import { ColorOption } from '../style/theme';
+import { BigNumberInput } from '../util/big_number_input';
+import { util } from '../util/util';
+
+import { ScalingInput } from './scaling_input';
+
+export interface ScalingAmountInputProps {
+    maxFontSizePx: number;
+    textLengthThreshold: number;
+    fontColor?: ColorOption;
+    value?: BigNumberInput;
+    onChange: (value?: BigNumberInput) => void;
+    onFontSizeChange: (fontSizePx: number) => void;
+}
+
+export class ScalingAmountInput extends React.Component<ScalingAmountInputProps> {
+    public static defaultProps = {
+        onChange: util.boundNoop,
+        onFontSizeChange: util.boundNoop,
+    };
+    public render(): React.ReactNode {
+        const { textLengthThreshold, fontColor, maxFontSizePx, value, onFontSizeChange } = this.props;
+        return (
+            <ScalingInput
+                maxFontSizePx={maxFontSizePx}
+                textLengthThreshold={textLengthThreshold}
+                onFontSizeChange={onFontSizeChange}
+                fontColor={fontColor}
+                onChange={this._handleChange}
+                value={!_.isUndefined(value) ? value.toDisplayString() : ''}
+                placeholder="0.00"
+                emptyInputWidthCh={3.5}
+            />
+        );
+    }
+    private readonly _handleChange = (event: React.ChangeEvent<HTMLInputElement>): void => {
+        const value = event.target.value;
+        let bigNumberValue;
+        if (!_.isEmpty(value)) {
+            try {
+                bigNumberValue = new BigNumberInput(value);
+            } catch {
+                // We don't want to allow values that can't be a BigNumber, so don't even call onChange.
+                return;
+            }
+        }
+        this.props.onChange(bigNumberValue);
+    };
+}
diff --git a/packages/instant/src/components/scaling_input.tsx b/packages/instant/src/components/scaling_input.tsx
new file mode 100644
index 000000000..34cb0b5fd
--- /dev/null
+++ b/packages/instant/src/components/scaling_input.tsx
@@ -0,0 +1,170 @@
+import * as _ from 'lodash';
+import * as React from 'react';
+
+import { ColorOption } from '../style/theme';
+import { util } from '../util/util';
+
+import { Input } from './ui';
+
+export enum ScalingInputPhase {
+    FixedFontSize,
+    ScalingFontSize,
+}
+
+export interface ScalingSettings {
+    percentageToReduceFontSizePerCharacter: number;
+    constantPxToIncreaseWidthPerCharacter: number;
+}
+
+export interface ScalingInputProps {
+    textLengthThreshold: number;
+    maxFontSizePx: number;
+    value: string;
+    emptyInputWidthCh: number;
+    onChange: (event: React.ChangeEvent<HTMLInputElement>) => void;
+    onFontSizeChange: (fontSizePx: number) => void;
+    fontColor?: ColorOption;
+    placeholder?: string;
+    maxLength?: number;
+    scalingSettings: ScalingSettings;
+}
+
+export interface ScalingInputState {
+    inputWidthPxAtPhaseChange?: number;
+}
+
+export interface ScalingInputSnapshot {
+    inputWidthPx: number;
+}
+
+// These are magic numbers that were determined experimentally.
+const defaultScalingSettings: ScalingSettings = {
+    percentageToReduceFontSizePerCharacter: 0.125,
+    constantPxToIncreaseWidthPerCharacter: 4,
+};
+
+export class ScalingInput extends React.Component<ScalingInputProps, ScalingInputState> {
+    public static defaultProps = {
+        onChange: util.boundNoop,
+        onFontSizeChange: util.boundNoop,
+        maxLength: 7,
+        scalingSettings: defaultScalingSettings,
+    };
+    public state: ScalingInputState = {
+        inputWidthPxAtPhaseChange: undefined,
+    };
+    private readonly _inputRef = React.createRef<HTMLInputElement>();
+    public static getPhase(textLengthThreshold: number, value: string): ScalingInputPhase {
+        if (value.length <= textLengthThreshold) {
+            return ScalingInputPhase.FixedFontSize;
+        }
+        return ScalingInputPhase.ScalingFontSize;
+    }
+    public static getPhaseFromProps(props: ScalingInputProps): ScalingInputPhase {
+        const { value, textLengthThreshold } = props;
+        return ScalingInput.getPhase(textLengthThreshold, value);
+    }
+    public static calculateFontSize(
+        textLengthThreshold: number,
+        maxFontSizePx: number,
+        phase: ScalingInputPhase,
+        value: string,
+        percentageToReduceFontSizePerCharacter: number,
+    ): number {
+        if (phase !== ScalingInputPhase.ScalingFontSize) {
+            return maxFontSizePx;
+        }
+        const charactersOverMax = value.length - textLengthThreshold;
+        const scalingFactor = (1 - percentageToReduceFontSizePerCharacter) ** charactersOverMax;
+        const fontSize = scalingFactor * maxFontSizePx;
+        return fontSize;
+    }
+    public static calculateFontSizeFromProps(props: ScalingInputProps, phase: ScalingInputPhase): number {
+        const { textLengthThreshold, value, maxFontSizePx, scalingSettings } = props;
+        return ScalingInput.calculateFontSize(
+            textLengthThreshold,
+            maxFontSizePx,
+            phase,
+            value,
+            scalingSettings.percentageToReduceFontSizePerCharacter,
+        );
+    }
+    public getSnapshotBeforeUpdate(): ScalingInputSnapshot {
+        return {
+            inputWidthPx: this._getInputWidthInPx(),
+        };
+    }
+    public componentDidUpdate(
+        prevProps: ScalingInputProps,
+        prevState: ScalingInputState,
+        snapshot: ScalingInputSnapshot,
+    ): void {
+        const prevPhase = ScalingInput.getPhaseFromProps(prevProps);
+        const curPhase = ScalingInput.getPhaseFromProps(this.props);
+        // if we went from fixed to scaling, save the width from the transition
+        if (prevPhase !== ScalingInputPhase.ScalingFontSize && curPhase === ScalingInputPhase.ScalingFontSize) {
+            this.setState({
+                inputWidthPxAtPhaseChange: snapshot.inputWidthPx,
+            });
+        }
+        // if we went from scaling to fixed, revert back to scaling using `ch`
+        if (prevPhase === ScalingInputPhase.ScalingFontSize && curPhase !== ScalingInputPhase.ScalingFontSize) {
+            this.setState({
+                inputWidthPxAtPhaseChange: undefined,
+            });
+        }
+        const prevFontSize = ScalingInput.calculateFontSizeFromProps(prevProps, prevPhase);
+        const curFontSize = ScalingInput.calculateFontSizeFromProps(this.props, curPhase);
+        // If font size has changed, notify.
+        if (prevFontSize !== curFontSize) {
+            this.props.onFontSizeChange(curFontSize);
+        }
+    }
+    public render(): React.ReactNode {
+        const { fontColor, onChange, placeholder, value, maxLength } = this.props;
+        const phase = ScalingInput.getPhaseFromProps(this.props);
+        return (
+            <Input
+                ref={this._inputRef as any}
+                fontColor={fontColor}
+                onChange={onChange}
+                value={value}
+                placeholder={placeholder}
+                fontSize={`${this._calculateFontSize(phase)}px`}
+                width={this._calculateWidth(phase)}
+                maxLength={maxLength}
+            />
+        );
+    }
+    private readonly _calculateWidth = (phase: ScalingInputPhase): string => {
+        const { value, textLengthThreshold, scalingSettings } = this.props;
+        if (_.isEmpty(value)) {
+            return `${this.props.emptyInputWidthCh}ch`;
+        }
+        switch (phase) {
+            case ScalingInputPhase.FixedFontSize:
+                return `${value.length}ch`;
+            case ScalingInputPhase.ScalingFontSize:
+                const { inputWidthPxAtPhaseChange } = this.state;
+                if (!_.isUndefined(inputWidthPxAtPhaseChange)) {
+                    const charactersOverMax = value.length - textLengthThreshold;
+                    const scalingAmount = scalingSettings.constantPxToIncreaseWidthPerCharacter * charactersOverMax;
+                    const width = inputWidthPxAtPhaseChange + scalingAmount;
+                    return `${width}px`;
+                }
+                return `${textLengthThreshold}ch`;
+            default:
+                return '1ch';
+        }
+    };
+    private readonly _calculateFontSize = (phase: ScalingInputPhase): number => {
+        return ScalingInput.calculateFontSizeFromProps(this.props, phase);
+    };
+    private readonly _getInputWidthInPx = (): number => {
+        const ref = this._inputRef.current;
+        if (!ref) {
+            return 0;
+        }
+        return ref.getBoundingClientRect().width;
+    };
+}
diff --git a/packages/instant/src/components/ui/container.tsx b/packages/instant/src/components/ui/container.tsx
index 5e2218c68..76b570de7 100644
--- a/packages/instant/src/components/ui/container.tsx
+++ b/packages/instant/src/components/ui/container.tsx
@@ -1,5 +1,3 @@
-import * as React from 'react';
-
 import { ColorOption, styled } from '../../style/theme';
 import { cssRuleIfExists } from '../../style/util';
 
@@ -11,6 +9,7 @@ export interface ContainerProps {
     bottom?: string;
     left?: string;
     width?: string;
+    height?: string;
     maxWidth?: string;
     margin?: string;
     marginTop?: string;
@@ -27,14 +26,14 @@ export interface ContainerProps {
     backgroundColor?: ColorOption;
     hasBoxShadow?: boolean;
     zIndex?: number;
+    whiteSpace?: string;
     opacity?: number;
 }
 
-const PlainContainer: React.StatelessComponent<ContainerProps> = ({ children, className }) => (
-    <div className={className}>{children}</div>
-);
-
-export const Container = styled(PlainContainer)`
+export const Container =
+    styled.div <
+    ContainerProps >
+    `
     box-sizing: border-box;
     ${props => cssRuleIfExists(props, 'display')}
     ${props => cssRuleIfExists(props, 'position')}
@@ -43,6 +42,7 @@ export const Container = styled(PlainContainer)`
     ${props => cssRuleIfExists(props, 'bottom')}
     ${props => cssRuleIfExists(props, 'left')}
     ${props => cssRuleIfExists(props, 'width')}
+    ${props => cssRuleIfExists(props, 'height')}
     ${props => cssRuleIfExists(props, 'max-width')}
     ${props => cssRuleIfExists(props, 'margin')}
     ${props => cssRuleIfExists(props, 'margin-top')}
@@ -55,6 +55,7 @@ export const Container = styled(PlainContainer)`
     ${props => cssRuleIfExists(props, 'border-top')}
     ${props => cssRuleIfExists(props, 'border-bottom')}
     ${props => cssRuleIfExists(props, 'z-index')}
+    ${props => cssRuleIfExists(props, 'white-space')}
     ${props => cssRuleIfExists(props, 'opacity')}
     ${props => (props.hasBoxShadow ? `box-shadow: 0px 2px 10px rgba(0, 0, 0, 0.1)` : '')};
     background-color: ${props => (props.backgroundColor ? props.theme[props.backgroundColor] : 'none')};
diff --git a/packages/instant/src/components/ui/flex.tsx b/packages/instant/src/components/ui/flex.tsx
index 327e91926..5fa3fc95b 100644
--- a/packages/instant/src/components/ui/flex.tsx
+++ b/packages/instant/src/components/ui/flex.tsx
@@ -1,5 +1,3 @@
-import * as React from 'react';
-
 import { ColorOption, styled } from '../../style/theme';
 import { cssRuleIfExists } from '../../style/util';
 
@@ -9,21 +7,22 @@ export interface FlexProps {
     justify?: 'flex-start' | 'center' | 'space-around' | 'space-between' | 'space-evenly' | 'flex-end';
     align?: 'flex-start' | 'center' | 'space-around' | 'space-between' | 'space-evenly' | 'flex-end';
     width?: string;
+    height?: string;
     backgroundColor?: ColorOption;
     className?: string;
 }
 
-const PlainFlex: React.StatelessComponent<FlexProps> = ({ children, className }) => (
-    <div className={className}>{children}</div>
-);
-
-export const Flex = styled(PlainFlex)`
+export const Flex =
+    styled.div <
+    FlexProps >
+    `
     display: flex;
     flex-direction: ${props => props.direction};
     flex-wrap: ${props => props.flexWrap};
     justify-content: ${props => props.justify};
     align-items: ${props => props.align};
     ${props => cssRuleIfExists(props, 'width')}
+    ${props => cssRuleIfExists(props, 'height')}
     background-color: ${props => (props.backgroundColor ? props.theme[props.backgroundColor] : 'none')};
 `;
 
diff --git a/packages/instant/src/components/ui/input.tsx b/packages/instant/src/components/ui/input.tsx
index f8c6b6ef6..a884ff7cb 100644
--- a/packages/instant/src/components/ui/input.tsx
+++ b/packages/instant/src/components/ui/input.tsx
@@ -12,11 +12,10 @@ export interface InputProps {
     onChange?: (event: React.ChangeEvent<HTMLInputElement>) => void;
 }
 
-const PlainInput: React.StatelessComponent<InputProps> = ({ value, className, placeholder, onChange }) => (
-    <input className={className} value={value} onChange={onChange} placeholder={placeholder} />
-);
-
-export const Input = styled(PlainInput)`
+export const Input =
+    styled.input <
+    InputProps >
+    `
     font-size: ${props => props.fontSize};
     width: ${props => props.width};
     padding: 0.1em 0em;
diff --git a/packages/instant/src/components/ui/text.tsx b/packages/instant/src/components/ui/text.tsx
index 9fb8ea26f..fd72f6cc8 100644
--- a/packages/instant/src/components/ui/text.tsx
+++ b/packages/instant/src/components/ui/text.tsx
@@ -23,14 +23,11 @@ export interface TextProps {
     display?: string;
 }
 
-const PlainText: React.StatelessComponent<TextProps> = ({ children, className, onClick }) => (
-    <div className={className} onClick={onClick}>
-        {children}
-    </div>
-);
-
 const darkenOnHoverAmount = 0.3;
-export const Text = styled(PlainText)`
+export const Text =
+    styled.div <
+    TextProps >
+    `
     font-family: ${props => props.fontFamily};
     font-style: ${props => props.fontStyle};
     font-weight: ${props => props.fontWeight};
diff --git a/packages/instant/src/containers/selected_asset_amount_input.ts b/packages/instant/src/containers/selected_erc20_asset_amount_input.ts
index e9dbc61ce..ee76e9d66 100644
--- a/packages/instant/src/containers/selected_asset_amount_input.ts
+++ b/packages/instant/src/containers/selected_erc20_asset_amount_input.ts
@@ -11,34 +11,35 @@ import { Action, actions } from '../redux/actions';
 import { State } from '../redux/reducer';
 import { ColorOption } from '../style/theme';
 import { ERC20Asset, OrderProcessState } from '../types';
+import { BigNumberInput } from '../util/big_number_input';
 import { errorUtil } from '../util/error';
 
-import { AssetAmountInput } from '../components/asset_amount_input';
+import { ERC20AssetAmountInput } from '../components/erc20_asset_amount_input';
 
-export interface SelectedAssetAmountInputProps {
+export interface SelectedERC20AssetAmountInputProps {
     fontColor?: ColorOption;
-    fontSize?: string;
+    startingFontSizePx: number;
 }
 
 interface ConnectedState {
     assetBuyer?: AssetBuyer;
-    value?: BigNumber;
+    value?: BigNumberInput;
     asset?: ERC20Asset;
 }
 
 interface ConnectedDispatch {
-    updateBuyQuote: (assetBuyer?: AssetBuyer, value?: BigNumber, asset?: ERC20Asset) => void;
+    updateBuyQuote: (assetBuyer?: AssetBuyer, value?: BigNumberInput, asset?: ERC20Asset) => void;
 }
 
 interface ConnectedProps {
-    value?: BigNumber;
+    value?: BigNumberInput;
     asset?: ERC20Asset;
-    onChange: (value?: BigNumber, asset?: ERC20Asset) => void;
+    onChange: (value?: BigNumberInput, asset?: ERC20Asset) => void;
 }
 
-type FinalProps = ConnectedProps & SelectedAssetAmountInputProps;
+type FinalProps = ConnectedProps & SelectedERC20AssetAmountInputProps;
 
-const mapStateToProps = (state: State, _ownProps: SelectedAssetAmountInputProps): ConnectedState => {
+const mapStateToProps = (state: State, _ownProps: SelectedERC20AssetAmountInputProps): ConnectedState => {
     const selectedAsset = state.selectedAsset;
     if (_.isUndefined(selectedAsset) || selectedAsset.metaData.assetProxyId !== AssetProxyId.ERC20) {
         return {
@@ -82,7 +83,7 @@ const debouncedUpdateBuyQuoteAsync = _.debounce(updateBuyQuoteAsync, 200, { trai
 
 const mapDispatchToProps = (
     dispatch: Dispatch<Action>,
-    _ownProps: SelectedAssetAmountInputProps,
+    _ownProps: SelectedERC20AssetAmountInputProps,
 ): ConnectedDispatch => ({
     updateBuyQuote: (assetBuyer, value, asset) => {
         // Update the input
@@ -104,7 +105,7 @@ const mapDispatchToProps = (
 const mergeProps = (
     connectedState: ConnectedState,
     connectedDispatch: ConnectedDispatch,
-    ownProps: SelectedAssetAmountInputProps,
+    ownProps: SelectedERC20AssetAmountInputProps,
 ): FinalProps => {
     return {
         ...ownProps,
@@ -116,8 +117,8 @@ const mergeProps = (
     };
 };
 
-export const SelectedAssetAmountInput: React.ComponentClass<SelectedAssetAmountInputProps> = connect(
+export const SelectedERC20AssetAmountInput: React.ComponentClass<SelectedERC20AssetAmountInputProps> = connect(
     mapStateToProps,
     mapDispatchToProps,
     mergeProps,
-)(AssetAmountInput);
+)(ERC20AssetAmountInput);
diff --git a/packages/instant/src/redux/actions.ts b/packages/instant/src/redux/actions.ts
index 5a4099f15..46045024b 100644
--- a/packages/instant/src/redux/actions.ts
+++ b/packages/instant/src/redux/actions.ts
@@ -2,6 +2,8 @@ import { BuyQuote } from '@0x/asset-buyer';
 import { BigNumber } from '@0x/utils';
 import * as _ from 'lodash';
 
+import { BigNumberInput } from '../util/big_number_input';
+
 import { ActionsUnion, OrderState } from '../types';
 
 export interface PlainAction<T extends string> {
@@ -36,7 +38,8 @@ export enum ActionTypes {
 
 export const actions = {
     updateEthUsdPrice: (price?: BigNumber) => createAction(ActionTypes.UPDATE_ETH_USD_PRICE, price),
-    updateSelectedAssetAmount: (amount?: BigNumber) => createAction(ActionTypes.UPDATE_SELECTED_ASSET_AMOUNT, amount),
+    updateSelectedAssetAmount: (amount?: BigNumberInput) =>
+        createAction(ActionTypes.UPDATE_SELECTED_ASSET_AMOUNT, amount),
     updateBuyOrderState: (orderState: OrderState) => createAction(ActionTypes.UPDATE_BUY_ORDER_STATE, orderState),
     updateLatestBuyQuote: (buyQuote?: BuyQuote) => createAction(ActionTypes.UPDATE_LATEST_BUY_QUOTE, buyQuote),
     updateSelectedAsset: (assetData?: string) => createAction(ActionTypes.UPDATE_SELECTED_ASSET, assetData),
diff --git a/packages/instant/src/redux/reducer.ts b/packages/instant/src/redux/reducer.ts
index 25d0092b2..d7e5bdfb5 100644
--- a/packages/instant/src/redux/reducer.ts
+++ b/packages/instant/src/redux/reducer.ts
@@ -14,6 +14,7 @@ import {
     OrderState,
 } from '../types';
 import { assetUtils } from '../util/asset';
+import { BigNumberInput } from '../util/big_number_input';
 
 import { Action, ActionTypes } from './actions';
 
@@ -22,7 +23,7 @@ export interface State {
     assetBuyer?: AssetBuyer;
     assetMetaDataMap: ObjectMap<AssetMetaData>;
     selectedAsset?: Asset;
-    selectedAssetAmount?: BigNumber;
+    selectedAssetAmount?: BigNumberInput;
     buyOrderState: OrderState;
     ethUsdPrice?: BigNumber;
     latestBuyQuote?: BuyQuote;
diff --git a/packages/instant/src/style/fonts.ts b/packages/instant/src/style/fonts.ts
index 975a30a61..92450502d 100644
--- a/packages/instant/src/style/fonts.ts
+++ b/packages/instant/src/style/fonts.ts
@@ -1,10 +1,10 @@
-import { injectGlobal } from './theme';
-
 export const fonts = {
     include: () => {
         // Inject the inter-ui font into the page
-        return injectGlobal`
-            @import url('https://rsms.me/inter/inter-ui.css');
-        `;
+        const appendTo = document.head || document.getElementsByTagName('head')[0] || document.body;
+        const style = document.createElement('style');
+        style.type = 'text/css';
+        style.appendChild(document.createTextNode(`@import url('https://rsms.me/inter/inter-ui.css')`));
+        appendTo.appendChild(style);
     },
 };
diff --git a/packages/instant/src/style/theme.ts b/packages/instant/src/style/theme.ts
index d26c816c1..6575ff9f4 100644
--- a/packages/instant/src/style/theme.ts
+++ b/packages/instant/src/style/theme.ts
@@ -1,6 +1,6 @@
 import * as styledComponents from 'styled-components';
 
-const { default: styled, css, injectGlobal, keyframes, ThemeProvider } = styledComponents;
+const { default: styled, css, keyframes, ThemeProvider } = styledComponents;
 
 export type Theme = { [key in ColorOption]: string };
 
@@ -28,4 +28,6 @@ export const theme: Theme = {
     darkOrange: '#F2994C',
 };
 
-export { styled, css, injectGlobal, keyframes, ThemeProvider };
+export const transparentWhite = 'rgba(255,255,255,0.3)';
+
+export { styled, css, keyframes, ThemeProvider };
diff --git a/packages/instant/src/util/asset.ts b/packages/instant/src/util/asset.ts
index 4e3b2b946..2c5b6325d 100644
--- a/packages/instant/src/util/asset.ts
+++ b/packages/instant/src/util/asset.ts
@@ -2,7 +2,7 @@ import { AssetProxyId, ObjectMap } from '@0x/types';
 import * as _ from 'lodash';
 
 import { assetDataNetworkMapping } from '../data/asset_data_network_mapping';
-import { Asset, AssetMetaData, Network, ZeroExInstantError } from '../types';
+import { Asset, AssetMetaData, ERC20Asset, Network, ZeroExInstantError } from '../types';
 
 export const assetUtils = {
     createAssetFromAssetData: (
@@ -43,6 +43,16 @@ export const assetUtils = {
                 return defaultName;
         }
     },
+    formattedSymbolForAsset: (asset?: ERC20Asset, defaultName: string = '???'): string => {
+        if (_.isUndefined(asset)) {
+            return defaultName;
+        }
+        const symbol = asset.metaData.symbol;
+        if (symbol.length <= 5) {
+            return symbol;
+        }
+        return `${symbol.slice(0, 3)}…`;
+    },
     getAssociatedAssetDataIfExists: (assetData: string, network: Network): string | undefined => {
         const assetDataGroupIfExists = _.find(assetDataNetworkMapping, value => value[network] === assetData);
         if (_.isUndefined(assetDataGroupIfExists)) {
diff --git a/packages/instant/src/util/big_number_input.ts b/packages/instant/src/util/big_number_input.ts
new file mode 100644
index 000000000..d2a9a8dc5
--- /dev/null
+++ b/packages/instant/src/util/big_number_input.ts
@@ -0,0 +1,29 @@
+import { BigNumber } from '@0x/utils';
+import * as _ from 'lodash';
+
+/**
+ *  A BigNumber extension that is more flexible about decimal strings.
+ *  Such as allowing:
+ *  new BigNumberInput('0.') => 0
+ *  new BigNumberInput('1.') => 1
+ *  new BigNumberInput('1..') => still throws
+ */
+export class BigNumberInput extends BigNumber {
+    private readonly _isEndingWithDecimal: boolean;
+    constructor(bigNumberString: string) {
+        const hasDecimalPeriod = _.endsWith(bigNumberString, '.');
+        let internalString = bigNumberString;
+        if (hasDecimalPeriod) {
+            internalString = bigNumberString.slice(0, -1);
+        }
+        super(internalString);
+        this._isEndingWithDecimal = hasDecimalPeriod;
+    }
+    public toDisplayString(): string {
+        const internalString = super.toString();
+        if (this._isEndingWithDecimal) {
+            return `${internalString}.`;
+        }
+        return internalString;
+    }
+}
diff --git a/packages/instant/src/util/format.ts b/packages/instant/src/util/format.ts
index 8482b1526..ca7c01359 100644
--- a/packages/instant/src/util/format.ts
+++ b/packages/instant/src/util/format.ts
@@ -24,7 +24,7 @@ export const format = {
         if (_.isUndefined(ethUnitAmount)) {
             return defaultText;
         }
-        const roundedAmount = ethUnitAmount.round(decimalPlaces);
+        const roundedAmount = ethUnitAmount.round(decimalPlaces).toDigits(decimalPlaces);
         return `${roundedAmount} ETH`;
     },
     ethBaseAmountInUsd: (
diff --git a/packages/instant/test/util/format.test.ts b/packages/instant/test/util/format.test.ts
index 141df9275..2c9294c78 100644
--- a/packages/instant/test/util/format.test.ts
+++ b/packages/instant/test/util/format.test.ts
@@ -20,8 +20,8 @@ describe('format', () => {
         it('converts .432414 ETH in base units to the string `.4324 ETH`', () => {
             expect(format.ethBaseAmount(DECIMAL_ETH_IN_BASE_UNITS)).toBe('0.4324 ETH');
         });
-        it('converts 5.3014059295032 ETH in base units to the string `5.3014 ETH`', () => {
-            expect(format.ethBaseAmount(IRRATIONAL_ETH_IN_BASE_UNITS)).toBe('5.3014 ETH');
+        it('converts 5.3014059295032 ETH in base units to the string `5.301 ETH`', () => {
+            expect(format.ethBaseAmount(IRRATIONAL_ETH_IN_BASE_UNITS)).toBe('5.301 ETH');
         });
         it('returns defaultText param when ethBaseAmount is not defined', () => {
             const defaultText = 'defaultText';
@@ -38,8 +38,8 @@ describe('format', () => {
         it('converts BigNumer(.432414) to the string `.4324 ETH`', () => {
             expect(format.ethUnitAmount(BIG_NUMBER_DECIMAL)).toBe('0.4324 ETH');
         });
-        it('converts BigNumber(5.3014059295032) to the string `5.3014 ETH`', () => {
-            expect(format.ethUnitAmount(BIG_NUMBER_IRRATIONAL)).toBe('5.3014 ETH');
+        it('converts BigNumber(5.3014059295032) to the string `5.301 ETH`', () => {
+            expect(format.ethUnitAmount(BIG_NUMBER_IRRATIONAL)).toBe('5.301 ETH');
         });
         it('returns defaultText param when ethUnitAmount is not defined', () => {
             const defaultText = 'defaultText';
diff --git a/yarn.lock b/yarn.lock
index 8b9fd53cb..1ea799433 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -484,6 +484,12 @@
   dependencies:
     "@babel/highlight" "^7.0.0"
 
+"@babel/helper-annotate-as-pure@^7.0.0":
+  version "7.0.0"
+  resolved "https://registry.npmjs.org/@babel/helper-annotate-as-pure/-/helper-annotate-as-pure-7.0.0.tgz#323d39dd0b50e10c7c06ca7d7638e6864d8c5c32"
+  dependencies:
+    "@babel/types" "^7.0.0"
+
 "@babel/highlight@^7.0.0":
   version "7.0.0"
   resolved "https://registry.npmjs.org/@babel/highlight/-/highlight-7.0.0.tgz#f710c38c8d458e6dd9a201afb637fcb781ce99e4"
@@ -504,6 +510,24 @@
   dependencies:
     regenerator-runtime "^0.12.0"
 
+"@babel/types@^7.0.0":
+  version "7.1.3"
+  resolved "https://registry.npmjs.org/@babel/types/-/types-7.1.3.tgz#3a767004567060c2f40fca49a304712c525ee37d"
+  dependencies:
+    esutils "^2.0.2"
+    lodash "^4.17.10"
+    to-fast-properties "^2.0.0"
+
+"@emotion/is-prop-valid@^0.6.8":
+  version "0.6.8"
+  resolved "https://registry.npmjs.org/@emotion/is-prop-valid/-/is-prop-valid-0.6.8.tgz#68ad02831da41213a2089d2cab4e8ac8b30cbd85"
+  dependencies:
+    "@emotion/memoize" "^0.6.6"
+
+"@emotion/memoize@^0.6.6":
+  version "0.6.6"
+  resolved "https://registry.npmjs.org/@emotion/memoize/-/memoize-0.6.6.tgz#004b98298d04c7ca3b4f50ca2035d4f60d2eed1b"
+
 "@ledgerhq/hw-app-eth@^4.3.0":
   version "4.7.3"
   resolved "https://registry.yarnpkg.com/@ledgerhq/hw-app-eth/-/hw-app-eth-4.7.3.tgz#d352e19658ae296532e522c53c8ec2a1a77b64e5"
@@ -1579,6 +1603,13 @@
     "@types/node" "*"
     "@types/react" "*"
 
+"@types/styled-components@^4.0.1":
+  version "4.0.1"
+  resolved "https://registry.npmjs.org/@types/styled-components/-/styled-components-4.0.1.tgz#5eb9a5474dbde3becab2bcc8f04e0b8e8dcf8c06"
+  dependencies:
+    "@types/node" "*"
+    "@types/react" "*"
+
 "@types/tmp@^0.0.33":
   version "0.0.33"
   resolved "https://registry.yarnpkg.com/@types/tmp/-/tmp-0.0.33.tgz#1073c4bc824754ae3d10cfab88ab0237ba964e4d"
@@ -2532,6 +2563,13 @@ babel-plugin-jest-hoist@^23.2.0:
   version "23.2.0"
   resolved "https://registry.npmjs.org/babel-plugin-jest-hoist/-/babel-plugin-jest-hoist-23.2.0.tgz#e61fae05a1ca8801aadee57a6d66b8cefaf44167"
 
+"babel-plugin-styled-components@>= 1":
+  version "1.8.0"
+  resolved "https://registry.npmjs.org/babel-plugin-styled-components/-/babel-plugin-styled-components-1.8.0.tgz#9dd054c8e86825203449a852a5746f29f2dab857"
+  dependencies:
+    "@babel/helper-annotate-as-pure" "^7.0.0"
+    lodash "^4.17.10"
+
 babel-plugin-syntax-async-functions@^6.8.0:
   version "6.13.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-syntax-async-functions/-/babel-plugin-syntax-async-functions-6.13.0.tgz#cad9cad1191b5ad634bf30ae0872391e0647be95"
@@ -4581,6 +4619,14 @@ css-to-react-native@^2.0.3:
     fbjs "^0.8.5"
     postcss-value-parser "^3.3.0"
 
+css-to-react-native@^2.2.2:
+  version "2.2.2"
+  resolved "https://registry.npmjs.org/css-to-react-native/-/css-to-react-native-2.2.2.tgz#c077d0f7bf3e6c915a539e7325821c9dd01f9965"
+  dependencies:
+    css-color-keywords "^1.0.0"
+    fbjs "^0.8.5"
+    postcss-value-parser "^3.3.0"
+
 css-vendor@^0.3.8:
   version "0.3.8"
   resolved "https://registry.npmjs.org/css-vendor/-/css-vendor-0.3.8.tgz#6421cfd3034ce664fe7673972fd0119fc28941fa"
@@ -6705,7 +6751,7 @@ ganache-core@0xProject/ganache-core#monorepo-dep:
     ethereumjs-tx "0xProject/ethereumjs-tx#fake-tx-include-signature-by-default"
     ethereumjs-util "^5.2.0"
     ethereumjs-vm "2.3.5"
-    ethereumjs-wallet "0.6.0"
+    ethereumjs-wallet "~0.6.0"
     fake-merkle-patricia-tree "~1.0.1"
     heap "~0.2.6"
     js-scrypt "^0.2.0"
@@ -14394,19 +14440,18 @@ styled-components@^3.3.3:
     stylis-rule-sheet "^0.0.10"
     supports-color "^3.2.3"
 
-styled-components@^3.4.9:
-  version "3.4.10"
-  resolved "https://registry.npmjs.org/styled-components/-/styled-components-3.4.10.tgz#9a654c50ea2b516c36ade57ddcfa296bf85c96e1"
+styled-components@^4.0.2:
+  version "4.0.2"
+  resolved "https://registry.npmjs.org/styled-components/-/styled-components-4.0.2.tgz#7d4409ada019cdd34c25ba68c4577ea95dbcf0c5"
   dependencies:
-    buffer "^5.0.3"
-    css-to-react-native "^2.0.3"
-    fbjs "^0.8.16"
-    hoist-non-react-statics "^2.5.0"
+    "@emotion/is-prop-valid" "^0.6.8"
+    babel-plugin-styled-components ">= 1"
+    css-to-react-native "^2.2.2"
+    memoize-one "^4.0.0"
     prop-types "^15.5.4"
     react-is "^16.3.1"
     stylis "^3.5.0"
     stylis-rule-sheet "^0.0.10"
-    supports-color "^3.2.3"
 
 stylis-rule-sheet@^0.0.10:
   version "0.0.10"
@@ -14849,6 +14894,10 @@ to-fast-properties@^1.0.3:
   version "1.0.3"
   resolved "https://registry.yarnpkg.com/to-fast-properties/-/to-fast-properties-1.0.3.tgz#b83571fa4d8c25b82e231b06e3a3055de4ca1a47"
 
+to-fast-properties@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.npmjs.org/to-fast-properties/-/to-fast-properties-2.0.0.tgz#dc5e698cbd079265bc73e0377681a4e4e83f616e"
+
 to-no-case@^1.0.0:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/to-no-case/-/to-no-case-1.0.2.tgz#c722907164ef6b178132c8e69930212d1b4aa16a"