topic edit modal: Add modal and functionality to perform topic name updates.

Fixes zulip#5365

Author: Leslie Ngo

src/topics/TopicEditModal.js

@@ -0,0 +1,181 @@
+// @flow
+import React, { useState, useContext, useMemo } from 'react';
+import { Modal, Text, Pressable, View, TextInput, Platform } from 'react-native';
+import type { JSX$Element } from 'tsflower/subst/react';
+import { ThemeContext, BRAND_COLOR, createStyleSheet } from '../styles';
+import { updateMessage } from '../api';
+import type { Auth, Stream, GetText } from '../types';
+
+type TopicEditModalArgs = {
+  topicModalState: {
+    visible: boolean,
+    topic: string,
+    fetchArgs: {
+      auth: Auth,
+      messageId: number,
+      zulipFeatureLevel: number
+    }
+  },
+  topicModalHandler: {
+    startEditTopic: (
+      streamId: number,
+      topic: string,
+      streamsById: Map<number, Stream>,
+      _: GetText,
+    ) => void,
+    closeEditTopicModal: () => void,
+  }
+};
+
+export default function TopicEditModal({ topicModalState, topicModalHandler }:TopicEditModalArgs): JSX$Element {
+  const { topic, fetchArgs } = topicModalState;
+  const [topicState, onChangeTopic] = useState(topic);
+  const { closeEditTopicModal } = topicModalHandler;
+  const { auth, messageId, zulipFeatureLevel } = fetchArgs;
+
+  const { backgroundColor } = useContext(ThemeContext);
+
+  const inputMarginPadding = useMemo(
+    () => ({
+      paddingHorizontal: 8,
+      paddingVertical: Platform.select({
+        ios: 8,
+        android: 2,
+      }),
+    }),
+    [],
+  );
+
+  const styles = createStyleSheet({
+    wrapper: {
+      flex: 1,
+      justifyContent: 'center',
+      alignItems: 'center',
+    },
+    modalView: {
+      margin: 10,
+      alignItems: 'center',
+      backgroundColor,
+      padding: 20,
+      borderStyle: 'solid',
+      borderWidth: 1,
+      borderColor: 'gray',
+      borderRadius: 20,
+      width: '90%',
+    },
+    buttonContainer: {
+      display: 'flex',
+      flexDirection: 'row',
+      justifyContent: 'space-between',
+      width: '60%',
+    },
+    input: {
+      width: '90%',
+      borderWidth: 1,
+      borderRadius: 5,
+      marginBottom: 16,
+      ...inputMarginPadding,
+      backgroundColor: 'white',
+      borderStyle: 'solid',
+      borderColor: 'black',
+    },
+    button: {
+      position: 'relative',
+      justifyContent: 'center',
+      alignItems: 'center',
+      borderRadius: 32,
+      padding: 8,
+    },
+    titleText: {
+      fontSize: 18,
+      lineHeight: 21,
+      fontWeight: 'bold',
+      color: BRAND_COLOR,
+      marginBottom: 12,
+    },
+    text: {
+      fontSize: 14,
+      lineHeight: 21,
+      fontWeight: 'bold',
+    },
+    submitButtonText: {
+      color: 'white',
+    },
+    cancelButtonText: {
+      color: BRAND_COLOR,
+    }
+  });
+
+  const handleSubmit = async () => {
+    await updateMessage(auth, messageId, {
+      propagate_mode: 'change_all',
+      subject: topicState,
+      ...(zulipFeatureLevel >= 9 && {
+        send_notification_to_old_thread: true,
+        send_notification_to_new_thread: true,
+      }),
+    });
+    closeEditTopicModal();
+  };
+  return (
+    <Modal
+      transparent
+      visible={topicModalState.visible}
+      animationType="slide"
+      onRequestClose={() => {
+        closeEditTopicModal();
+      }}
+    >
+      <View style={styles.wrapper}>
+        <View style={styles.modalView}>
+          <Text
+            style={styles.titleText}
+          >
+            Edit topic
+          </Text>
+          <TextInput
+            style={styles.input}
+            value={topicState}
+            onChangeText={onChangeTopic}
+            selectTextOnFocus
+          />
+          <View style={styles.buttonContainer}>
+            <Pressable
+              style={{
+                backgroundColor,
+                borderStyle: 'solid',
+                borderWidth: 2,
+                borderColor: BRAND_COLOR,
+                ...styles.button
+              }}
+              onPress={() => {
+                closeEditTopicModal();
+              }}
+            >
+              <Text
+                style={{ ...styles.text, ...styles.cancelButtonText }}
+              >
+                Cancel
+              </Text>
+            </Pressable>
+            <Pressable
+              style={{
+                opacity: !topicState ? 0.25 : 1,
+                backgroundColor: BRAND_COLOR,
+                ...styles.button
+              }}
+              onPress={handleSubmit}
+              disabled={!topicState}
+            >
+              <Text
+                style={{ ...styles.text, ...styles.submitButtonText }}
+              >
+                Submit
+              </Text>
+            </Pressable>
+          </View>
+        </View>
+      </View>
+    </Modal>
+  );
+}