From cd506d45ef448d318c042b6901c4da57634c2b28 Mon Sep 17 00:00:00 2001
From: Carlos Garnacho <carlosg@gnome.org>
Date: Mon, 4 Jan 2021 16:23:45 +0100
Subject: [PATCH] overview: Make 3fg 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.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1643>
---
 js/ui/overview.js         | 52 +++++++++++++++++++++++++++++++++++++++
 js/ui/overviewControls.js | 41 ++++++++++++++++++++++++++++++
 2 files changed, 93 insertions(+)

diff --git a/js/ui/overview.js b/js/ui/overview.js
index 136b69c1d..af3e5be2b 100644
--- a/js/ui/overview.js
+++ b/js/ui/overview.js
@@ -14,6 +14,7 @@ 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;
 const WorkspaceThumbnail = imports.ui.workspaceThumbnail;
 
@@ -117,6 +118,10 @@ class OverviewActor extends St.BoxLayout {
     get viewSelector() {
         return this._controls.viewSelector;
     }
+
+    get controls() {
+        return this._controls;
+    }
 });
 
 var Overview = class {
@@ -233,6 +238,15 @@ var Overview = class {
             Meta.KeyBindingFlags.IGNORE_AUTOREPEAT,
             Shell.ActionMode.NORMAL | Shell.ActionMode.OVERVIEW,
             this.toggle.bind(this));
+
+        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) {
@@ -365,6 +379,44 @@ 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 f43d8e236..14f247b09 100644
--- a/js/ui/overviewControls.js
+++ b/js/ui/overviewControls.js
@@ -583,6 +583,47 @@ class ControlsManager extends St.Widget {
         return this.layoutManager.getWorkspacesBoxForState(state);
     }
 
+    gestureBegin(tracker) {
+        const baseDistance = global.screen_height;
+        const progress = this._stateAdjustment.value;
+        const points = [
+            ControlsState.HIDDEN,
+            ControlsState.WINDOW_PICKER,
+            ControlsState.APP_GRID,
+        ];
+
+        const transition = this._stateAdjustment.get_transition('value');
+        const cancelProgress = transition
+            ? transition.get_interval().peek_final_value()
+            : Math.round(progress);
+
+        tracker.confirmSwipe(baseDistance, points, progress, cancelProgress);
+        this._workspacesDisplay.prepareToEnterOverview();
+        this._searchController.prepareToEnterOverview();
+        this._stateAdjustment.gestureInProgress = true;
+    }
+
+    gestureProgress(progress) {
+        this._stateAdjustment.value = progress;
+    }
+
+    gestureEnd(target, duration, onComplete) {
+        if (target === ControlsState.HIDDEN)
+            this._workspacesDisplay.prepareToLeaveOverview();
+
+        this.dash.showAppsButton.checked =
+            target === ControlsState.APP_GRID;
+
+        this._stateAdjustment.remove_transition('value');
+        this._stateAdjustment.ease(target, {
+            duration,
+            mode: Clutter.AnimationMode.EASE_OUT_QUAD,
+            onComplete,
+        });
+
+        this._stateAdjustment.gestureInProgress = false;
+    }
+
     get searchEntry() {
         return this._searchEntry;
     }