js: Cleanup usage of StScrollView

Whilst you *can* use add_actor() with ScrollView, it's more idiomatic to
work on :child

Cleanup a few extras along the way

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/3010>

js/gdm/authList.js

@@ -84,20 +84,19 @@ export const AuthList = GObject.registerClass({
         this.label = new St.Label({style_class: 'login-dialog-auth-list-title'});
         this.add_child(this.label);
 
-        this._scrollView = new St.ScrollView({
-            style_class: 'login-dialog-auth-list-view',
-        });
-        this._scrollView.set_policy(
-            St.PolicyType.NEVER, St.PolicyType.AUTOMATIC);
-        this.add_child(this._scrollView);
-
         this._box = new St.BoxLayout({
             vertical: true,
             style_class: 'login-dialog-auth-list',
             pseudo_class: 'expanded',
         });
 
-        this._scrollView.add_child(this._box);
+        this._scrollView = new St.ScrollView({
+            style_class: 'login-dialog-auth-list-view',
+            hscrollbar_policy: St.PolicyType.NEVER,
+            child: this._box,
+        });
+        this.add_child(this._scrollView);
+
         this._items = new Map();
 
         this.connect('key-focus-in', this._moveFocusToItems.bind(this));
@@ -129,7 +128,7 @@ export const AuthList = GObject.registerClass({
     scrollToItem(item) {
         let box = item.get_allocation_box();
 
-        let adjustment = this._scrollView.get_vscroll_bar().get_adjustment();
+        const {adjustment} = this._scrollView.vscroll;
 
         let value = (box.y1 + adjustment.step_increment / 2.0) - (adjustment.page_size / 2.0);
         adjustment.ease(value, {

js/gdm/loginDialog.js

@@ -168,10 +168,8 @@ const UserList = GObject.registerClass({
             style_class: 'login-dialog-user-list-view',
             x_expand: true,
             y_expand: true,
+            hscrollbar_policy: St.PolicyType.NEVER,
         });
-        this.set_policy(
-            St.PolicyType.NEVER,
-            St.PolicyType.AUTOMATIC);
 
         this._box = new St.BoxLayout({
             vertical: true,
@@ -179,7 +177,7 @@ const UserList = GObject.registerClass({
             pseudo_class: 'expanded',
         });
 
-        this.add_child(this._box);
+        this.child = this._box;
         this._items = {};
     }
 
@@ -226,7 +224,7 @@ const UserList = GObject.registerClass({
     scrollToItem(item) {
         let box = item.get_allocation_box();
 
-        let adjustment = this.get_vscroll_bar().get_adjustment();
+        const {adjustment} = this.vscroll;
 
         let value = (box.y1 + adjustment.step_increment / 2.0) - (adjustment.page_size / 2.0);
         adjustment.ease(value, {
@@ -238,7 +236,7 @@ const UserList = GObject.registerClass({
     jumpToItem(item) {
         let box = item.get_allocation_box();
 
-        let adjustment = this.get_vscroll_bar().get_adjustment();
+        const {adjustment} = this.vscroll;
 
         let value = (box.y1 + adjustment.step_increment / 2.0) - (adjustment.page_size / 2.0);
 
@@ -487,17 +485,16 @@ export const LoginDialog = GObject.registerClass({
 
         this._userSelectionBox.add_child(this._notListedButton);
 
+        const bannerBox = new St.BoxLayout({vertical: true});
+
         this._bannerView = new St.ScrollView({
             style_class: 'login-dialog-banner-view',
             opacity: 0,
-            vscrollbar_policy: St.PolicyType.AUTOMATIC,
             hscrollbar_policy: St.PolicyType.NEVER,
+            child: bannerBox,
         });
         this.add_child(this._bannerView);
 
-        let bannerBox = new St.BoxLayout({vertical: true});
-
-        this._bannerView.add_child(bannerBox);
         this._bannerLabel = new St.Label({
             style_class: 'login-dialog-banner',
             text: '',

js/ui/appDisplay.js

@@ -520,15 +520,15 @@ var BaseAppView = GObject.registerClass({
             y_expand: true,
             reactive: true,
             enable_mouse_scrolling: false,
+            hscrollbar_policy: St.PolicyType.EXTERNAL,
+            vscrollbar_policy: St.PolicyType.NEVER,
+            child: this._grid,
         });
-        this._scrollView.set_policy(St.PolicyType.EXTERNAL, St.PolicyType.NEVER);
 
         this._canScroll = true; // limiting scrolling speed
         this._scrollTimeoutId = 0;
         this._scrollView.connect('scroll-event', this._onScroll.bind(this));
 
-        this._scrollView.add_child(this._grid);
-
         const scroll = this._scrollView.hscroll;
         this._adjustment = scroll.adjustment;
         this._adjustment.connect('notify::value', adj => {

js/ui/calendar.js

@@ -954,8 +954,8 @@ class CalendarMessageList extends St.Widget {
             style_class: 'vfade',
             overlay_scrollbars: true,
             x_expand: true, y_expand: true,
+            hscrollbar_policy: St.PolicyType.NEVER,
         });
-        this._scrollView.set_policy(St.PolicyType.NEVER, St.PolicyType.AUTOMATIC);
         box.add_child(this._scrollView);
 
         let hbox = new St.BoxLayout({style_class: 'message-list-controls'});
@@ -1008,7 +1008,7 @@ class CalendarMessageList extends St.Widget {
             'actor-added', this._sync.bind(this),
             'actor-removed', this._sync.bind(this),
             this);
-        this._scrollView.add_child(this._sectionList);
+        this._scrollView.child = this._sectionList;
 
         this._mediaSection = new Mpris.MediaSection();
         this._addSection(this._mediaSection);

js/ui/components/telepathyClient.js

@@ -870,17 +870,17 @@ class ChatNotificationBanner extends MessageTray.NotificationBanner {
             this.emit('unfocused');
         });
 
+        this._contentArea = new St.BoxLayout({
+            style_class: 'chat-body',
+            vertical: true,
+        });
         this._scrollArea = new St.ScrollView({
             style_class: 'chat-scrollview vfade',
             vscrollbar_policy: St.PolicyType.AUTOMATIC,
             hscrollbar_policy: St.PolicyType.NEVER,
             visible: this.expanded,
+            child: this._contentArea,
         });
-        this._contentArea = new St.BoxLayout({
-            style_class: 'chat-body',
-            vertical: true,
-        });
-        this._scrollArea.add_child(this._contentArea);
 
         this.setExpandedBody(this._scrollArea);
         this.setExpandedLines(CHAT_EXPAND_LINES);

js/ui/dateMenu.js

@@ -919,20 +919,21 @@ class DateMenuButton extends PanelMenu.Button {
         vbox.add_child(this._date);
         vbox.add_child(this._calendar);
 
-        this._displaysSection = new St.ScrollView({
-            style_class: 'datemenu-displays-section vfade',
-            x_expand: true,
-            overlay_scrollbars: true,
-        });
-        this._displaysSection.set_policy(St.PolicyType.NEVER, St.PolicyType.EXTERNAL);
-        vbox.add_child(this._displaysSection);
-
         const displaysBox = new St.BoxLayout({
             vertical: true,
             x_expand: true,
             style_class: 'datemenu-displays-box',
         });
-        this._displaysSection.add_child(displaysBox);
+
+        this._displaysSection = new St.ScrollView({
+            style_class: 'datemenu-displays-section vfade',
+            x_expand: true,
+            overlay_scrollbars: true,
+            hscrollbar_policy: St.PolicyType.NEVER,
+            vscrollbar_policy: St.PolicyType.EXTERNAL,
+            child: displaysBox,
+        });
+        vbox.add_child(this._displaysSection);
 
         this._eventsItem = new EventsSection();
         displaysBox.add_child(this._eventsItem);

js/ui/dialog.js

@@ -259,16 +259,16 @@ export const ListSection = GObject.registerClass({
     _init(params) {
         this._title = new St.Label({style_class: 'dialog-list-title'});
 
-        this._listScrollView = new St.ScrollView({
-            style_class: 'dialog-list-scrollview',
-            hscrollbar_policy: St.PolicyType.NEVER,
-        });
-
         this.list = new St.BoxLayout({
             style_class: 'dialog-list-box',
             vertical: true,
         });
-        this._listScrollView.add_child(this.list);
+
+        this._listScrollView = new St.ScrollView({
+            style_class: 'dialog-list-scrollview',
+            hscrollbar_policy: St.PolicyType.NEVER,
+            child: this.list,
+        });
 
         let defaultParams = {
             style_class: 'dialog-list',

js/ui/lookingGlass.js

@@ -162,9 +162,8 @@ const Notebook = GObject.registerClass({
         labelBox.add_child(label);
         this.tabControls.add_child(labelBox);
 
-        let scrollview = new St.ScrollView({y_expand: true});
+        const scrollview = new St.ScrollView({y_expand: true, child});
-        scrollview.get_hscroll_bar().hide();
+        scrollview.hscroll.hide();
-        scrollview.add_child(child);
 
         const tabData = {
             child,
@@ -395,7 +394,7 @@ class ObjInspector extends St.ScrollView {
 
         this._parentList = [];
 
-        this.get_hscroll_bar().hide();
+        this.hscroll.hide();
         this._container = new St.BoxLayout({
             name: 'LookingGlassPropertyInspector',
             style_class: 'lg-dialog',
@@ -403,7 +402,7 @@ class ObjInspector extends St.ScrollView {
             x_expand: true,
             y_expand: true,
         });
-        this.add_child(this._container);
+        this.child = this._container;
 
         this._lookingGlass = lookingGlass;
     }

js/ui/popupMenu.js

@@ -1016,9 +1016,9 @@ export class PopupSubMenu extends PopupMenuBase {
             style_class: 'popup-sub-menu',
             hscrollbar_policy: St.PolicyType.NEVER,
             vscrollbar_policy: St.PolicyType.NEVER,
+            child: this.box,
         });
 
-        this.actor.add_child(this.box);
         this.actor._delegate = this;
         this.actor.clip_to_allocation = true;
         this.actor.connect('key-press-event', this._onKeyPressEvent.bind(this));

js/ui/search.js

@@ -573,9 +573,9 @@ export const SearchResultsView = GObject.registerClass({
             style_class: 'search-display vfade',
             x_expand: true,
             y_expand: true,
+            hscrollbar_policy: St.PolicyType.NEVER,
+            child: this._content,
         });
-        this._scrollView.set_policy(St.PolicyType.NEVER, St.PolicyType.AUTOMATIC);
-        this._scrollView.add_child(this._content);
 
         let action = new Clutter.PanAction({interpolate: true});
         action.connect('pan', this._onPan.bind(this));

js/ui/switcherPopup.js

@@ -409,10 +409,11 @@ export const SwitcherList = GObject.registerClass({
         this._scrollView = new St.ScrollView({
             style_class: 'hfade',
             enable_mouse_scrolling: false,
+            hscrollbar_policy: St.PolicyType.NEVER,
+            vscrollbar_policy: St.PolicyType.NEVER,
+            child: this._list,
         });
-        this._scrollView.set_policy(St.PolicyType.NEVER, St.PolicyType.NEVER);
 
-        this._scrollView.add_child(this._list);
         this.add_child(this._scrollView);
 
         // Those arrows indicate whether scrolling in one direction is possible

js/ui/unlockDialog.js

@@ -43,13 +43,15 @@ const NotificationsBox = GObject.registerClass({
             name: 'unlockDialogNotifications',
         });
 
-        this._scrollView = new St.ScrollView({hscrollbar_policy: St.PolicyType.NEVER});
         this._notificationBox = new St.BoxLayout({
             vertical: true,
             style_class: 'unlock-dialog-notifications-container',
         });
-        this._scrollView.add_child(this._notificationBox);
 
+        this._scrollView = new St.ScrollView({
+            hscrollbar_policy: St.PolicyType.NEVER,
+            child: this._notificationBox,
+        });
         this.add_child(this._scrollView);
 
         this._settings = new Gio.Settings({