[DropZone] Constrain drop zone height based on inherited wrapper height

UNRELEASED.md

@@ -12,6 +12,8 @@ Use [the changelog guidelines](https://git.io/polaris-changelog-guidelines) to f
 
 ### Bug fixes
 
+- Constrained `DropZone` height based on inherited wrapper height [#908](https://github.com/Shopify/polaris-react/pull/908)
+
 ### Documentation
 
 ### Development workflow

src/components/DropZone/DropZone.scss

@@ -15,12 +15,17 @@ $dropzone-overlay-border-color-error: color('red');
 $dropzone-overlay-background: color('indigo', 'lighter');
 $dropzone-overlay-background-error: color('red', 'lighter');
 
+.DropZoneWrapper {
+  height: inherit;
+}
+
 .DropZone {
   position: relative;
   display: flex;
   justify-content: center;
   background-color: $dropzone-background;
   border-radius: $dropzone-border-radius;
+  height: inherit;
 }
 
 .hasOutline {
@@ -36,6 +41,10 @@ $dropzone-overlay-background-error: color('red', 'lighter');
   cursor: not-allowed;
 }
 
+.isMeasuring {
+  visibility: hidden;
+}
+
 .sizeExtraLarge {
   min-height: $dropzone-min-height-extra-large;
 }
@@ -57,6 +66,9 @@ $dropzone-overlay-background-error: color('red', 'lighter');
 
 .Container {
   flex: 1;
+  display: flex;
+  justify-content: center;
+  align-items: center;
 }
 
 .Overlay {

src/components/DropZone/DropZone.tsx

@@ -21,21 +21,23 @@ import {FileUpload, Provider} from './components';
 import {dragDrop, alertCircle} from './icons';
 
 import {fileAccepted, getDataTransferFiles} from './utils';
-import {DropZoneContext} from './types';
+import {DropZoneContext, Size} from './types';
 
 import styles from './DropZone.scss';
 
 export type Type = 'file' | 'image';
 
 export interface State {
   id: string;
-  size: string;
+  height: Size;
+  width: Size;
   type?: string;
   error?: boolean;
   dragging: boolean;
   overlayText?: string;
   errorOverlayText?: string;
   numFiles: number;
+  measuring: boolean;
 }
 
 export interface Props {
@@ -108,7 +110,6 @@ export interface Props {
 export type CombinedProps = Props & WithAppProviderProps;
 
 const getUniqueID = createUniqueIDFactory('DropZone');
-
 export class DropZone extends React.Component<CombinedProps, State> {
   public static FileUpload: typeof FileUpload = FileUpload;
   public static defaultProps: Partial<CombinedProps> = {
@@ -170,19 +171,23 @@ export class DropZone extends React.Component<CombinedProps, State> {
     this.state = {
       type,
       id: props.id || getUniqueID(),
-      size: 'extraLarge',
+      height: Size.ExtraLarge,
       dragging: false,
       error: false,
       overlayText: translate(`Polaris.DropZone.overlayText${suffix}`),
       errorOverlayText: translate(`Polaris.DropZone.errorOverlayText${suffix}`),
       numFiles: 0,
+      width: Size.ExtraLarge,
+      measuring: true,
     };
   }
 
   get getContext(): DropZoneContext {
+    const {width, height, type = 'file'} = this.state;
     return {
-      size: this.state.size,
-      type: this.state.type || 'file',
+      width,
+      height,
+      type,
     };
   }
 
@@ -191,9 +196,11 @@ export class DropZone extends React.Component<CombinedProps, State> {
       id,
       dragging,
       error,
-      size,
+      height,
+      width,
       overlayText,
       errorOverlayText,
+      measuring,
     } = this.state;
     const {
       label,
@@ -223,61 +230,77 @@ export class DropZone extends React.Component<CombinedProps, State> {
       styles.DropZone,
       outline && styles.hasOutline,
       (active || dragging) && styles.isDragging,
+      measuring && styles.isMeasuring,
       error && styles.hasError,
-      size && size === 'extraLarge' && styles.sizeExtraLarge,
-      size && size === 'large' && styles.sizeLarge,
-      size && size === 'medium' && styles.sizeMedium,
-      size && size === 'small' && styles.sizeSmall,
+      height === Size.ExtraLarge && styles.sizeExtraLarge,
+      height === Size.Large && styles.sizeLarge,
+      height === Size.Medium && styles.sizeMedium,
+      height === Size.Small && styles.sizeSmall,
+    );
+
+    const extraLargeDropZoneSize =
+      width === Size.ExtraLarge && height !== Size.Small;
+
+    const mediumLargeDropZoneSize =
+      (width === Size.Medium || width === Size.Large) && height !== Size.Small;
+
+    const dragOverlayDisplayText = extraLargeDropZoneSize && (
+      <DisplayText size="small" element="p">
+        {overlayText}
+      </DisplayText>
+    );
+
+    const dragOverlayCaption = mediumLargeDropZoneSize && (
+      <Caption>{overlayText}</Caption>
     );
 
     const dragOverlay =
       (active || dragging) && !error && overlay ? (
         <div className={styles.Overlay}>
           <Stack vertical spacing="tight">
             <Icon source={dragDrop} color="indigo" />
-            {size === 'extraLarge' && (
-              <DisplayText size="small" element="p">
-                {overlayText}
-              </DisplayText>
-            )}
-            {(size === 'medium' || size === 'large') && (
-              <Caption>{overlayText}</Caption>
-            )}
+            {dragOverlayDisplayText}
+            {dragOverlayCaption}
           </Stack>
         </div>
       ) : null;
 
+    const dragErrorOverlayDisplayText = extraLargeDropZoneSize && (
+      <DisplayText size="small" element="p">
+        {errorOverlayText}
+      </DisplayText>
+    );
+
+    const dragErrorOverlayCaption = mediumLargeDropZoneSize && (
+      <Caption>{errorOverlayText}</Caption>
+    );
+
     const dragErrorOverlay =
       dragging && error ? (
         <div className={styles.Overlay}>
           <Stack vertical spacing="tight">
             <Icon source={alertCircle} color="red" />
-            {size === 'extraLarge' && (
-              <DisplayText size="small" element="p">
-                {errorOverlayText}
-              </DisplayText>
-            )}
-            {(size === 'medium' || size === 'large') && (
-              <Caption>{errorOverlayText}</Caption>
-            )}
+            {dragErrorOverlayDisplayText}
+            {dragErrorOverlayCaption}
           </Stack>
         </div>
       ) : null;
 
     const dropZoneMarkup = (
-      <div
-        ref={this.setNode}
-        className={classes}
-        aria-disabled={disabled}
-        onClick={this.handleClick}
-        onDragStart={handleDragStart}
-      >
-        {dragOverlay}
-        {dragErrorOverlay}
-        <div className={styles.Container}>{children}</div>
-        <VisuallyHidden>
-          <input {...inputAttributes} />
-        </VisuallyHidden>
+      <div ref={this.setNode} className={styles.DropZoneWrapper}>
+        <div
+          className={classes}
+          aria-disabled={disabled}
+          onClick={this.handleClick}
+          onDragStart={handleDragStart}
+        >
+          {dragOverlay}
+          {dragErrorOverlay}
+          <div className={styles.Container}>{children}</div>
+          <VisuallyHidden>
+            <input {...inputAttributes} />
+          </VisuallyHidden>
+        </div>
       </div>
     );
 
@@ -355,25 +378,35 @@ export class DropZone extends React.Component<CombinedProps, State> {
     this.fileInputNode.click();
   }
 
+  @autobind
+  private setWrapperSize(size: string, node: HTMLElement) {
+    let wrapperSize;
+    const getSize = size === 'height' ? 'height' : 'width';
+    const wrapper = node.getBoundingClientRect()[getSize];
+
+    if (wrapper < Size.Small) {
+      wrapperSize = Size.Small;
+    } else if (wrapper < Size.Medium) {
+      wrapperSize = Size.Medium;
+    } else if (wrapper < Size.Large) {
+      wrapperSize = Size.Large;
+    } else {
+      wrapperSize = Size.ExtraLarge;
+    }
+    return wrapperSize;
+  }
+
   @autobind
   @debounce(50, {trailing: true})
   private adjustSize() {
     if (!this.node) {
       return;
     }
 
-    let size = 'extraLarge';
-    const width = this.node.getBoundingClientRect().width;
-
-    if (width < 100) {
-      size = 'small';
-    } else if (width < 160) {
-      size = 'medium';
-    } else if (width < 300) {
-      size = 'large';
-    }
+    const height = this.setWrapperSize('height', this.node);
+    const width = this.setWrapperSize('width', this.node);
 
-    this.setState({size});
+    this.setState({height, width, measuring: false});
   }
 
   @autobind

src/components/DropZone/components/Context/Context.tsx

@@ -1,8 +1,9 @@
 import * as React from 'react';
-import {DropZoneContext} from '../../types';
+import {DropZoneContext, Size} from '../../types';
 
 const {Provider, Consumer} = React.createContext<DropZoneContext>({
-  size: 'extraLarge',
+  width: Size.ExtraLarge,
+  height: Size.ExtraLarge,
   type: 'file',
 });