Move the dial pad button next to Explore button from Create Room context menu (#6237)

This commit moves the dial pad from a context menu to sit right by the explore button, in line with the designs in the linked issue. The dial pad button is only shown when PSTN support is detected.

src/components/structures/LeftPanel.tsx

@@ -24,6 +24,7 @@ import CustomRoomTagPanel from "./CustomRoomTagPanel";
 import dis from "../../dispatcher/dispatcher";
 import { _t } from "../../languageHandler";
 import RoomList from "../views/rooms/RoomList";
+import CallHandler from "../../CallHandler";
 import { HEADER_HEIGHT } from "../views/rooms/RoomSublist";
 import { Action } from "../../dispatcher/actions";
 import UserMenu from "./UserMenu";
@@ -124,6 +125,10 @@ export default class LeftPanel extends React.Component<IProps, IState> {
         this.setState({ activeSpace });
     };
 
+    private onDialPad = () => {
+        dis.fire(Action.OpenDialPad);
+    }
+
     private onExplore = () => {
         dis.fire(Action.ViewRoomDirectory);
     };
@@ -397,7 +402,20 @@ export default class LeftPanel extends React.Component<IProps, IState> {
         }
     }
 
-    private renderSearchExplore(): React.ReactNode {
+    private renderSearchDialExplore(): React.ReactNode {
+        let dialPadButton = null;
+
+        // If we have dialer support, show a button to bring up the dial pad
+        // to start a new call
+        if (CallHandler.sharedInstance().getSupportsPstnProtocol()) {
+            dialPadButton =
+                <AccessibleTooltipButton
+                    className={classNames("mx_LeftPanel_dialPadButton", {})}
+                    onClick={this.onDialPad}
+                    title={_t("Open dial pad")}
+                />;
+        }
+
         return (
             <div
                 className="mx_LeftPanel_filterContainer"
@@ -410,6 +428,9 @@ export default class LeftPanel extends React.Component<IProps, IState> {
                     onKeyDown={this.onKeyDown}
                     onSelectRoom={this.selectRoom}
                 />
+
+                {dialPadButton}
+
                 <AccessibleTooltipButton
                     className={classNames("mx_LeftPanel_exploreButton", {
                         mx_LeftPanel_exploreButton_space: !!this.state.activeSpace,
@@ -458,7 +479,7 @@ export default class LeftPanel extends React.Component<IProps, IState> {
                 {leftLeftPanel}
                 <aside className="mx_LeftPanel_roomListContainer">
                     {this.renderHeader()}
-                    {this.renderSearchExplore()}
+                    {this.renderSearchDialExplore()}
                     {this.renderBreadcrumbs()}
                     <RoomListNumResults onVisibilityChange={this.refreshStickyHeaders} />
                     <div className="mx_LeftPanel_roomListWrapper">