[gnome-shell/gbsneto/pagination: 67/70] appDisplay: Factor out shared code into BaseAppView

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 3e2dd56fa82f231b5c8e17de1cf0f019c64aa3e1
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Fri May 22 13:20:40 2020 -0300

    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, as well as
    a new '_createGrid()' vfunc, so that FolderView can create
    its own FolderGrid instance.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1271

 js/ui/appDisplay.js | 367 +++++++++++++++++++++++++---------------------------
 1 file changed, 174 insertions(+), 193 deletions(-)
---
diff --git a/js/ui/appDisplay.js b/js/ui/appDisplay.js
index 0741f3f1d0..a729abcd0a 100644
--- a/js/ui/appDisplay.js
+++ b/js/ui/appDisplay.js
@@ -117,13 +117,64 @@ var BaseAppView = GObject.registerClass({
         'view-loaded': {},
     },
 }, class BaseAppView extends St.Widget {
-    _init(params = {}) {
+    _init(params = {}, orientation = Clutter.Orientation.VERTICAL) {
         super._init(params);
 
-        this._grid = new IconGrid.IconGrid();
+        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._items = new Map();
         this._orderedItems = [];
 
@@ -138,6 +189,66 @@ var BaseAppView = GObject.registerClass({
         });
     }
 
+    _createGrid() {
+        return new IconGrid.IconGrid();
+    }
+
+    _onScroll(actor, event) {
+        if (this._swipeTracker.canHandleScrollEvent(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;
+
+        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);
+
+        tracker.confirmSwipe(this._scrollView.height,
+            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);
@@ -268,7 +379,22 @@ 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();
     }
@@ -294,8 +420,44 @@ var BaseAppView = GObject.registerClass({
         this._grid.ease(params);
     }
 
-    adaptToSize(_width, _height) {
-        throw new GObject.NotImplementedError('adaptToSize in %s'.format(this.constructor.name));
+    goToPage(pageNumber, animate = true) {
+        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();
+        box.x1 = 0;
+        box.x2 = width;
+        box.y1 = 0;
+        box.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;
     }
 });
 
@@ -310,59 +472,24 @@ 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;
 
@@ -400,15 +527,6 @@ 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);
@@ -420,7 +538,6 @@ class AppDisplay extends BaseAppView {
         this._keyPressEventId =
             global.stage.connect('key-press-event',
                 this._onKeyPressEvent.bind(this));
-        this._swipeTracker.enabled = true;
         super.vfunc_map();
     }
 
@@ -429,7 +546,6 @@ class AppDisplay extends BaseAppView {
             global.stage.disconnect(this._keyPressEventId);
             this._keyPressEventId = 0;
         }
-        this._swipeTracker.enabled = false;
         super.vfunc_unmap();
     }
 
@@ -577,68 +693,14 @@ 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 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);
-            },
-        });
+        return super._onScroll(actor, event);
     }
 
     _onKeyPressEvent(actor, event) {
@@ -678,36 +740,6 @@ 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);
@@ -970,9 +1002,7 @@ class FolderView extends BaseAppView {
             layout_manager: new Clutter.BinLayout(),
             x_expand: true,
             y_expand: true,
-        });
-
-        this._grid = new FolderGrid();
+        }, 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"
@@ -982,14 +1012,6 @@ 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,
@@ -997,28 +1019,9 @@ class FolderView extends BaseAppView {
             y_expand: true,
         });
         box.add_actor(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_actor(this._pageIndicators);
         this.add_actor(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);
@@ -1026,16 +1029,8 @@ class FolderView extends BaseAppView {
         this._redisplay();
     }
 
-    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);
+    _createGrid() {
+        return new FolderGrid();
     }
 
     // Overridden from BaseAppView
@@ -1074,24 +1069,10 @@ 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);
-
-        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;
+        super.adaptToSize(width, height);
     }
 
     _loadApps() {