Move in ui-qr as react-qr (from apps) (#164)

packages/react-qr/src/ScanAddress.tsx

@@ -0,0 +1,48 @@
+// Copyright 2017-2019 @polkadot/react-qr authors & contributors
+// This software may be modified and distributed under the terms
+// of the Apache-2.0 license. See the LICENSE file for details.
+
+import { BaseProps } from './types';
+
+import React from 'react';
+
+import { ADDRESS_PREFIX } from './constants';
+import QrScan from './Scan';
+import { decodeAddress } from '@polkadot/util-crypto';
+
+interface Props extends BaseProps {
+  onError?: (error: Error) => void;
+  onScan?: (data: string) => void;
+}
+
+export default class ScanAddress extends React.PureComponent<Props> {
+  public render (): React.ReactNode {
+    const { className, onError, style } = this.props;
+
+    return (
+      <QrScan
+        className={className}
+        onError={onError}
+        onScan={this.onScan}
+        style={style}
+      />
+    );
+  }
+
+  private onScan = (data: string | null): void => {
+    const { onScan } = this.props;
+
+    if (!data || !onScan || !data.startsWith(ADDRESS_PREFIX)) {
+      return;
+    }
+
+    const address = data.substr(ADDRESS_PREFIX.length);
+
+    try {
+      decodeAddress(address);
+      onScan(address);
+    } catch (error) {
+      console.error('@polkadot/react-qr:QrScanAddress', error.message);
+    }
+  }
+}