appDisplay: Factor out shared code into BaseAppView

The two BaseAppView subclasses now share a lot in terms of
widgetry: they both have a scroll view, pagination dots, swipe
management, etc.

Move this shared code into BaseAppView. Notice, however, that
BaseAppView only creates the widgetry, but it doesn't add them
to any specific layout. FolderView arranges the widgetry in a
vertical box, while AppDisplay arranges it in a ShellStack.

Add a new 'orientation' parameter to BaseAppView and use it
to determine the orientation of the pagination dots, the swipe
tracker direction, and the scroll event handling.

It is worth noticing that the scroll event is a bit more
sophisticated now: when the orientation is horizontal, it
handles all directions since mice wheels usually only generate
up/down events.

https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1271

js/ui/appDisplay.js

@@ -117,13 +117,65 @@ var BaseAppView = GObject.registerClass({
         'view-loaded': {},
     },
 }, class BaseAppView extends St.Widget {
-    _init(params = {}) {
+    _init(params = {}, orientation = Clutter.Orientation.VERTICAL) {
         super._init(params);
 
         this._grid = this._createGrid();
         // Standard hack for ClutterBinLayout
         this._grid.x_expand = true;
 
+        const vertical = orientation === Clutter.Orientation.VERTICAL;
+
+        // Scroll View
+        this._scrollView = new St.ScrollView({
+            clip_to_allocation: true,
+            x_expand: true,
+            y_expand: true,
+            reactive: true,
+        });
+        this._scrollView.set_policy(
+            vertical ? St.PolicyType.NEVER : St.PolicyType.EXTERNAL,
+            vertical ? 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_actor(this._grid);
+
+        const scroll = vertical ?  this._scrollView.vscroll : this._scrollView.hscroll;
+        this._adjustment = scroll.adjustment;
+        this._adjustment.connect('notify::value', adj => {
+            this._pageIndicators.setCurrentPosition(adj.value / adj.page_size);
+        });
+
+        // Page Indicators
+        if (vertical)
+            this._pageIndicators = new PageIndicators.AnimatedPageIndicators();
+        else
+            this._pageIndicators = new PageIndicators.PageIndicators(orientation);
+
+        this._pageIndicators.y_expand = vertical;
+        this._pageIndicators.connect('page-activated',
+            (indicators, pageIndex) => {
+                this.goToPage(pageIndex);
+            });
+        this._pageIndicators.connect('scroll-event', (actor, event) => {
+            this._scrollView.event(event, false);
+        });
+
+        // Swipe
+        this._swipeTracker = new SwipeTracker.SwipeTracker(this._scrollView,
+            Shell.ActionMode.OVERVIEW | Shell.ActionMode.POPUP);
+        this._swipeTracker.orientation = orientation;
+        this._swipeTracker.connect('begin', this._swipeBegin.bind(this));
+        this._swipeTracker.connect('update', this._swipeUpdate.bind(this));
+        this._swipeTracker.connect('end', this._swipeEnd.bind(this));
+
+        this._availWidth = 0;
+        this._availHeight = 0;
+        this._orientation = orientation;
+
         this._items = new Map();
         this._orderedItems = [];
 
@@ -142,6 +194,86 @@ var BaseAppView = GObject.registerClass({
         return new IconGrid.IconGrid();
     }
 
+    _onScroll(actor, event) {
+        if (this._swipeTracker.canHandleScrollEvent(event))
+            return Clutter.EVENT_PROPAGATE;
+
+        if (!this._canScroll)
+            return Clutter.EVENT_STOP;
+
+        const rtl = this.get_text_direction() === Clutter.TextDirection.RTL;
+        const vertical = this._orientation === Clutter.Orientation.VERTICAL;
+
+        let nextPage = this._grid.currentPage;
+        switch (event.get_scroll_direction()) {
+        case Clutter.ScrollDirection.UP:
+            nextPage -= 1;
+            break;
+
+        case Clutter.ScrollDirection.DOWN:
+            nextPage += 1;
+            break;
+
+        case Clutter.ScrollDirection.LEFT:
+            if (vertical)
+                return Clutter.EVENT_STOP;
+            nextPage += rtl ? 1 : -1;
+            break;
+
+        case Clutter.ScrollDirection.RIGHT:
+            if (vertical)
+                return Clutter.EVENT_STOP;
+            nextPage += rtl ? -1 : 1;
+            break;
+
+        default:
+            return Clutter.EVENT_STOP;
+        }
+
+        this.goToPage(nextPage);
+
+        this._canScroll = false;
+        this._scrollTimeoutId = GLib.timeout_add(GLib.PRIORITY_DEFAULT,
+            SCROLL_TIMEOUT_TIME, () => {
+                this._canScroll = true;
+                this._scrollTimeoutId = 0;
+                return GLib.SOURCE_REMOVE;
+            });
+
+        return Clutter.EVENT_STOP;
+    }
+
+    _swipeBegin(tracker, monitor) {
+        if (monitor !== Main.layoutManager.primaryIndex)
+            return;
+
+        const adjustment = this._adjustment;
+        adjustment.remove_transition('value');
+
+        const progress = adjustment.value / adjustment.page_size;
+        const points = Array.from({ length: this._grid.nPages }, (v, i) => i);
+        const size = tracker.orientation === Clutter.Orientation.VERTICAL
+            ? this._scrollView.height : this._scrollView.width;
+
+        tracker.confirmSwipe(size, points, progress, Math.round(progress));
+    }
+
+    _swipeUpdate(tracker, progress) {
+        const adjustment = this._adjustment;
+        adjustment.value = progress * adjustment.page_size;
+    }
+
+    _swipeEnd(tracker, duration, endProgress) {
+        const adjustment = this._adjustment;
+        const value = endProgress * adjustment.page_size;
+
+        adjustment.ease(value, {
+            mode: Clutter.AnimationMode.EASE_OUT_CUBIC,
+            duration,
+            onComplete: () => this.goToPage(endProgress, false),
+        });
+    }
+
     _redisplay() {
         let oldApps = this._orderedItems.slice();
         let oldAppIds = oldApps.map(icon => icon.id);
@@ -272,7 +404,22 @@ var BaseAppView = GObject.registerClass({
         }
     }
 
+    vfunc_allocate(box) {
+        const width = box.get_width();
+        const height = box.get_height();
+
+        this.adaptToSize(width, height);
+
+        super.vfunc_allocate(box);
+    }
+
+    vfunc_map() {
+        this._swipeTracker.enabled = true;
+        super.vfunc_map();
+    }
+
     vfunc_unmap() {
+        this._swipeTracker.enabled = false;
         this._clearAnimateLater();
         super.vfunc_unmap();
     }
@@ -298,8 +445,43 @@ var BaseAppView = GObject.registerClass({
         this._grid.ease(params);
     }
 
-    adaptToSize(_width, _height) {
+    goToPage(pageNumber, animate = true) {
-        throw new GObject.NotImplementedError('adaptToSize in %s'.format(this.constructor.name));
+        pageNumber = Math.clamp(pageNumber, 0, this._grid.nPages - 1);
+
+        if (this._grid.currentPage === pageNumber)
+            return;
+
+        this._grid.goToPage(pageNumber, animate);
+    }
+
+    adaptToSize(width, height) {
+        let box = new Clutter.ActorBox({
+            x2: width,
+            y2: height,
+        });
+        box = this._scrollView.get_theme_node().get_content_box(box);
+        box = this._grid.get_theme_node().get_content_box(box);
+
+        const availWidth = box.get_width();
+        const availHeight = box.get_height();
+        const oldNPages = this._grid.nPages;
+
+        this._grid.adaptToSize(availWidth, availHeight);
+
+        if (this._availWidth !== availWidth ||
+            this._availHeight !== availHeight ||
+            oldNPages !== this._grid.nPages) {
+            Meta.later_add(Meta.LaterType.BEFORE_REDRAW, () => {
+                this._adjustment.value = 0;
+                this._grid.currentPage = 0;
+                this._pageIndicators.setNPages(this._grid.nPages);
+                this._pageIndicators.setCurrentPosition(0);
+                return GLib.SOURCE_REMOVE;
+            });
+        }
+
+        this._availWidth = availWidth;
+        this._availHeight = availHeight;
     }
 });
 
@@ -314,59 +496,24 @@ class AppDisplay extends BaseAppView {
 
         this._grid._delegate = this;
 
+        this._scrollView.add_style_class_name('all-apps');
+
         this._stack = new St.Widget({
             layout_manager: new Clutter.BinLayout(),
             x_expand: true,
             y_expand: true,
         });
         this.add_actor(this._stack);
-
-        this._scrollView = new St.ScrollView({
-            style_class: 'all-apps',
-            x_expand: true,
-            y_expand: true,
-            reactive: true,
-        });
-        this._scrollView.add_actor(this._grid);
         this._stack.add_actor(this._scrollView);
 
-        this._scrollView.set_policy(St.PolicyType.NEVER,
-                                    St.PolicyType.EXTERNAL);
-        this._adjustment = this._scrollView.vscroll.adjustment;
-        this._adjustment.connect('notify::value', adj => {
-            this._pageIndicators.setCurrentPosition(adj.value / adj.page_size);
-        });
-
-        this._pageIndicators = new PageIndicators.AnimatedPageIndicators();
-        this._pageIndicators.connect('page-activated',
-            (indicators, pageIndex) => {
-                this.goToPage(pageIndex);
-            });
-        this._pageIndicators.connect('scroll-event', (actor, event) => {
-            this._scrollView.event(event, false);
-        });
         this.add_actor(this._pageIndicators);
 
         this._folderIcons = [];
 
-        this._scrollView.connect('scroll-event', this._onScroll.bind(this));
-
-        this._swipeTracker = new SwipeTracker.SwipeTracker(
-            this._scrollView, Shell.ActionMode.OVERVIEW);
-        this._swipeTracker.connect('begin', this._swipeBegin.bind(this));
-        this._swipeTracker.connect('update', this._swipeUpdate.bind(this));
-        this._swipeTracker.connect('end', this._swipeEnd.bind(this));
-
         this._currentDialog = null;
         this._displayingDialog = false;
         this._currentDialogDestroyId = 0;
 
-        this._canScroll = true; // limiting scrolling speed
-        this._scrollTimeoutId = 0;
-
-        this._availWidth = 0;
-        this._availHeight = 0;
-
         this._lastOvershootY = -1;
         this._lastOvershootTimeoutId = 0;
 
@@ -404,15 +551,6 @@ class AppDisplay extends BaseAppView {
         }
     }
 
-    vfunc_allocate(box) {
-        box = this.get_theme_node().get_content_box(box);
-        let availWidth = box.get_width();
-        let availHeight = box.get_height();
-        this.adaptToSize(availWidth, availHeight);
-
-        super.vfunc_allocate(box);
-    }
-
     _onDestroy() {
         if (this._scrollTimeoutId !== 0) {
             GLib.source_remove(this._scrollTimeoutId);
@@ -424,7 +562,6 @@ class AppDisplay extends BaseAppView {
         this._keyPressEventId =
             global.stage.connect('key-press-event',
                 this._onKeyPressEvent.bind(this));
-        this._swipeTracker.enabled = true;
         super.vfunc_map();
     }
 
@@ -433,7 +570,6 @@ class AppDisplay extends BaseAppView {
             global.stage.disconnect(this._keyPressEventId);
             this._keyPressEventId = 0;
         }
-        this._swipeTracker.enabled = false;
         super.vfunc_unmap();
     }
 
@@ -581,68 +717,14 @@ class AppDisplay extends BaseAppView {
         if (this._displayingDialog && this._currentDialog)
             this._currentDialog.popdown();
 
-        this._grid.goToPage(pageNumber, animate);
+        super.goToPage(pageNumber, animate);
     }
 
     _onScroll(actor, event) {
         if (this._displayingDialog || !this._scrollView.reactive)
             return Clutter.EVENT_STOP;
 
-        if (this._swipeTracker.canHandleScrollEvent(event))
+        return super._onScroll(actor, event);
-            return Clutter.EVENT_PROPAGATE;
-
-        if (!this._canScroll)
-            return Clutter.EVENT_STOP;
-
-        let direction = event.get_scroll_direction();
-        if (direction == Clutter.ScrollDirection.UP)
-            this.goToPage(this._grid.currentPage - 1);
-        else if (direction == Clutter.ScrollDirection.DOWN)
-            this.goToPage(this._grid.currentPage + 1);
-        else
-            return Clutter.EVENT_STOP;
-
-        this._canScroll = false;
-        this._scrollTimeoutId = GLib.timeout_add(GLib.PRIORITY_DEFAULT,
-            SCROLL_TIMEOUT_TIME, () => {
-                this._canScroll = true;
-                this._scrollTimeoutId = 0;
-                return GLib.SOURCE_REMOVE;
-            });
-
-        return Clutter.EVENT_STOP;
-    }
-
-    _swipeBegin(tracker, monitor) {
-        if (monitor !== Main.layoutManager.primaryIndex)
-            return;
-
-        let adjustment = this._adjustment;
-        adjustment.remove_transition('value');
-
-        let progress = adjustment.value / adjustment.page_size;
-        let points = Array.from({ length: this._grid.nPages }, (v, i) => i);
-
-        tracker.confirmSwipe(this._scrollView.height,
-            points, progress, Math.round(progress));
-    }
-
-    _swipeUpdate(tracker, progress) {
-        let adjustment = this._adjustment;
-        adjustment.value = progress * adjustment.page_size;
-    }
-
-    _swipeEnd(tracker, duration, endProgress) {
-        let adjustment = this._adjustment;
-        let value = endProgress * adjustment.page_size;
-
-        adjustment.ease(value, {
-            mode: Clutter.AnimationMode.EASE_OUT_CUBIC,
-            duration,
-            onComplete: () => {
-                this.goToPage(endProgress, false);
-            },
-        });
     }
 
     _onKeyPressEvent(actor, event) {
@@ -682,36 +764,6 @@ class AppDisplay extends BaseAppView {
     }
 
 
-    // Called before allocation to calculate dynamic spacing
-    adaptToSize(width, height) {
-        let box = new Clutter.ActorBox();
-        box.x1 = 0;
-        box.x2 = width;
-        box.y1 = 0;
-        box.y2 = height;
-        box = this.get_theme_node().get_content_box(box);
-        box = this._scrollView.get_theme_node().get_content_box(box);
-        box = this._grid.get_theme_node().get_content_box(box);
-        let availWidth = box.x2 - box.x1;
-        let availHeight = box.y2 - box.y1;
-        let oldNPages = this._grid.nPages;
-
-        this._grid.adaptToSize(availWidth, availHeight);
-
-        if (this._availWidth != availWidth || this._availHeight != availHeight || oldNPages != this._grid.nPages) {
-            Meta.later_add(Meta.LaterType.BEFORE_REDRAW, () => {
-                this._adjustment.value = 0;
-                this._grid.currentPage = 0;
-                this._pageIndicators.setNPages(this._grid.nPages);
-                this._pageIndicators.setCurrentPosition(0);
-                return GLib.SOURCE_REMOVE;
-            });
-        }
-
-        this._availWidth = availWidth;
-        this._availHeight = availHeight;
-    }
-
     _resetOvershoot() {
         if (this._lastOvershootTimeoutId)
             GLib.source_remove(this._lastOvershootTimeoutId);
@@ -974,7 +1026,7 @@ class FolderView extends BaseAppView {
             layout_manager: new Clutter.BinLayout(),
             x_expand: true,
             y_expand: true,
-        });
+        }, Clutter.Orientation.HORIZONTAL);
 
         // If it not expand, the parent doesn't take into account its preferred_width when allocating
         // the second time it allocates, so we apply the "Standard hack for ClutterBinLayout"
@@ -984,14 +1036,6 @@ class FolderView extends BaseAppView {
         this._parentView = parentView;
         this._grid._delegate = this;
 
-        this._scrollView = new St.ScrollView({
-            overlay_scrollbars: true,
-            x_expand: true,
-            y_expand: true,
-        });
-        this._scrollView.set_policy(St.PolicyType.EXTERNAL, St.PolicyType.NEVER);
-        this._scrollView.add_actor(this._grid);
-
         const box = new St.BoxLayout({
             vertical: true,
             reactive: true,
@@ -999,28 +1043,9 @@ class FolderView extends BaseAppView {
             y_expand: true,
         });
         box.add_child(this._scrollView);
-
-        // Page Dots
-        this._adjustment = this._scrollView.hscroll.adjustment;
-        this._adjustment.connect('notify::value', adj => {
-            this._pageIndicators.setCurrentPosition(adj.value / adj.page_size);
-        });
-
-        this._pageIndicators = new PageIndicators.PageIndicators(Clutter.Orientation.HORIZONTAL);
-        this._pageIndicators.y_expand = false;
-        this._pageIndicators.connect('page-activated',
-            (indicators, pageIndex) => {
-                this._grid.goToPage(pageIndex);
-            });
-        this._pageIndicators.connect('scroll-event', (actor, event) => {
-            this._scrollView.event(event, false);
-        });
         box.add_child(this._pageIndicators);
         this.add_child(box);
 
-        this._availWidth = 0;
-        this._availHeight = 0;
-
         let action = new Clutter.PanAction({ interpolate: true });
         action.connect('pan', this._onPan.bind(this));
         this._scrollView.add_action(action);
@@ -1032,18 +1057,6 @@ class FolderView extends BaseAppView {
         return new FolderGrid();
     }
 
-    vfunc_allocate(box) {
-        const node = this.get_theme_node();
-        const contentBox = node.get_content_box(box);
-
-        const [width, height] = contentBox.get_size();
-        this.adaptToSize(width, height);
-
-        this._grid.topPadding = 0;
-
-        super.vfunc_allocate(box);
-    }
-
     // Overridden from BaseAppView
     animate(animationDirection) {
         this._grid.animatePulse(animationDirection);
@@ -1080,26 +1093,10 @@ class FolderView extends BaseAppView {
     }
 
     adaptToSize(width, height) {
-        const oldNPages = this._grid.nPages;
         const [, indicatorHeight] = this._pageIndicators.get_preferred_height(-1);
         height -= indicatorHeight;
 
-        this._grid.adaptToSize(width, height);
+        super.adaptToSize(width, height);
-
-        if (this._availWidth !== width ||
-            this._availHeight !== height ||
-            oldNPages !== this._grid.nPages) {
-            Meta.later_add(Meta.LaterType.BEFORE_REDRAW, () => {
-                this._adjustment.value = 0;
-                this._grid.currentPage = 0;
-                this._pageIndicators.setNPages(this._grid.nPages);
-                this._pageIndicators.setCurrentPosition(0);
-                return GLib.SOURCE_REMOVE;
-            });
-        }
-
-        this._availWidth = width;
-        this._availHeight = height;
     }
 
     _loadApps() {