[gnome-shell/gbsneto/40-stuff: 50/68] overview: Make 4fg vertical swipes bring overview and app grid

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

commit 299b81e6217d202c7d76f89d0463f2b3a9f9c08b
Author: Carlos Garnacho <carlosg gnome org>
Date:   Mon Jan 4 16:23:45 2021 +0100

    overview: Make 4fg vertical swipes bring overview and app grid
    
    The gesture internally manipulates the main adjustment so one swipe
    up brings up the overview, and a second swipe up brings the app
    grid. The gesture also works in the other direction to get out of
    the overview.
    
    Internally, this is delegated on the OverviewControls, so the
    adjustment is not leaked out of there. This however meant open
    coding the gesture interaction so it can be directed from
    overview.js code.

 js/ui/overview.js         | 53 ++++++++++++++++++++++++++++++++++++++++++++++-
 js/ui/overviewControls.js | 39 ++++++++++++++++++++++++++++++++++
 2 files changed, 91 insertions(+), 1 deletion(-)
---
diff --git a/js/ui/overview.js b/js/ui/overview.js
index 835665003c..5f98ed59a7 100644
--- a/js/ui/overview.js
+++ b/js/ui/overview.js
@@ -15,6 +15,7 @@ const Main = imports.ui.main;
 const MessageTray = imports.ui.messageTray;
 const OverviewControls = imports.ui.overviewControls;
 const Params = imports.misc.params;
+const SwipeTracker = imports.ui.swipeTracker;
 const WindowManager = imports.ui.windowManager;
 
 var DND_WINDOW_SWITCH_TIMEOUT = 750;
@@ -117,6 +118,10 @@ class OverviewActor extends St.BoxLayout {
     get viewSelector() {
         return this._controls.viewSelector;
     }
+
+    get controls() {
+        return this._controls;
+    }
 });
 
 var Overview = class {
@@ -238,7 +243,6 @@ var Overview = class {
             Shell.ActionMode.NORMAL | Shell.ActionMode.OVERVIEW,
             this.toggle.bind(this));
 
-
         let side;
         if (Clutter.get_default_text_direction() === Clutter.TextDirection.RTL)
             side = St.Side.RIGHT;
@@ -255,6 +259,15 @@ var Overview = class {
                 this.showApps();
         });
         global.stage.add_action(gesture);
+
+        const swipeTracker = new SwipeTracker.SwipeTracker(global.stage,
+            Shell.ActionMode.NORMAL | Shell.ActionMode.OVERVIEW,
+            { allowDrag: false, allowScroll: false });
+        swipeTracker.orientation = Clutter.Orientation.VERTICAL;
+        swipeTracker.connect('begin', this._gestureBegin.bind(this));
+        swipeTracker.connect('update', this._gestureUpdate.bind(this));
+        swipeTracker.connect('end', this._gestureEnd.bind(this));
+        this._swipeTracker = swipeTracker;
     }
 
     addSearchProvider(provider) {
@@ -386,6 +399,44 @@ var Overview = class {
         this.emit('windows-restacked', stackIndices);
     }
 
+    _gestureBegin(tracker) {
+        this._overview.controls.gestureBegin(tracker);
+    }
+
+    _gestureUpdate(tracker, progress) {
+        if (!this._shown) {
+            Meta.disable_unredirect_for_display(global.display);
+
+            this._shown = true;
+            this._visible = true;
+            this._visibleTarget = true;
+            this._animationInProgress = true;
+
+            Main.layoutManager.overviewGroup.set_child_above_sibling(
+                this._coverPane, null);
+            this._coverPane.show();
+            this.emit('showing');
+
+            Main.layoutManager.showOverview();
+            this._syncGrab();
+        }
+
+        this._overview.controls.gestureProgress(progress);
+    }
+
+    _gestureEnd(tracker, duration, endProgress) {
+        let onComplete;
+        if (endProgress === 0) {
+            this._shown = false;
+            this.emit('hiding');
+            onComplete = () => this._hideDone();
+        } else {
+            onComplete = () => this._showDone();
+        }
+
+        this._overview.controls.gestureEnd(endProgress, duration, onComplete);
+    }
+
     beginItemDrag(source) {
         this.emit('item-drag-begin', source);
         this._inItemDrag = true;
diff --git a/js/ui/overviewControls.js b/js/ui/overviewControls.js
index 3ab4ab192f..7b70872322 100644
--- a/js/ui/overviewControls.js
+++ b/js/ui/overviewControls.js
@@ -270,4 +270,43 @@ class ControlsManager extends St.Widget {
     get searchEntry() {
         return this._searchEntry;
     }
+
+    gestureBegin(tracker) {
+        const baseDistance = global.screen_height;
+        const progress = this._adjustment.value;
+        const points = [
+            ControlsState.HIDDEN,
+            ControlsState.WINDOW_PICKER,
+            ControlsState.APP_GRID,
+        ];
+
+        const transition = this._adjustment.get_transition('value');
+        const cancelProgress = transition
+            ? transition.get_interval().peek_final_value()
+            : Math.round(progress);
+
+        tracker.confirmSwipe(baseDistance, points, progress, cancelProgress);
+        this.viewSelector.prepareToEnterOverview();
+    }
+
+    gestureProgress(progress) {
+        this._adjustment.value = progress;
+    }
+
+    gestureEnd(target, duration, onComplete) {
+        this._animating = true;
+
+        if (target === ControlsState.HIDDEN)
+            this.viewSelector.prepareToLeaveOverview();
+
+        this._adjustment.ease(target, {
+            duration,
+            mode: Clutter.AnimationMode.EASE_OUT_QUAD,
+            onComplete,
+        });
+
+        this.dash.showAppsButton.checked =
+            target === ControlsState.APP_GRID;
+        this._animating = false;
+    }
 });