From d93b51e1354460be0ef9670013f7f06527af5f3c Mon Sep 17 00:00:00 2001
From: Georges Basile Stavracas Neto <georges.stavracas@gmail.com>
Date: Thu, 25 Jun 2020 16:51:30 -0300
Subject: [PATCH] appDisplay: Use a drag monitor to check for out-of-dialog
 drags

When the app folder dialog handles a drag hover, it starts a timeout
to popdown if dragging outside the "real" dialog area. However, when
dragging inside it, BaseAppView handles all drag hover events which
would disarm the popdown timeout. In cases like this, it's almost
impossible to prevent the timeout from triggering, which always pops
down the dialog.

Add a drag monitor when handling any drag hover (which only happens
when dragging outside the folder's icon grid); and eventually disarm
the popdown timeout from the monitor's motion event. Remove the drag
monitor when dragging over the folder dialog again.

https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1284
---
 js/ui/appDisplay.js | 67 +++++++++++++++++++++++++++++++++++----------
 1 file changed, 52 insertions(+), 15 deletions(-)

diff --git a/js/ui/appDisplay.js b/js/ui/appDisplay.js
index 44c4f3f5f..fdbfef677 100644
--- a/js/ui/appDisplay.js
+++ b/js/ui/appDisplay.js
@@ -2011,6 +2011,7 @@ var AppFolderDialog = GObject.registerClass({
         this._grabHelper.addActor(Main.layoutManager.overviewGroup);
         this.connect('destroy', this._onDestroy.bind(this));
 
+        this._dragMonitor = null;
         this._sourceMappedId = 0;
         this._popdownTimeoutId = 0;
         this._needsZoomAndFade = false;
@@ -2224,6 +2225,22 @@ var AppFolderDialog = GObject.registerClass({
         this._needsZoomAndFade = false;
     }
 
+    _removeDragMonitor() {
+        if (!this._dragMonitor)
+            return;
+
+        DND.removeDragMonitor(this._dragMonitor);
+        this._dragMonitor = null;
+    }
+
+    _removePopdownTimeout() {
+        if (this._popdownTimeoutId === 0)
+            return;
+
+        GLib.source_remove(this._popdownTimeoutId);
+        this._popdownTimeoutId = 0;
+    }
+
     _onDestroy() {
         if (this._isOpen) {
             this._isOpen = false;
@@ -2236,10 +2253,8 @@ var AppFolderDialog = GObject.registerClass({
             this._sourceMappedId = 0;
         }
 
-        if (this._popdownTimeoutId > 0) {
-            GLib.source_remove(this._popdownTimeoutId);
-            this._popdownTimeoutId = 0;
-        }
+        this._removePopdownTimeout();
+        this._removeDragMonitor();
     }
 
     vfunc_allocate(box) {
@@ -2306,19 +2321,41 @@ var AppFolderDialog = GObject.registerClass({
             y < childAllocation.y2;
     }
 
+    _setupDragMonitor() {
+        if (this._dragMonitor)
+            return;
+
+        this._dragMonitor = {
+            dragMotion: dragEvent => {
+                if (this._withinDialog(dragEvent.x, dragEvent.y)) {
+                    this._removePopdownTimeout();
+                    this._removeDragMonitor();
+                }
+                return DND.DragMotionResult.CONTINUE;
+            },
+        };
+        DND.addDragMonitor(this._dragMonitor);
+    }
+
+    _setupPopdownTimeout() {
+        if (this._popdownTimeoutId > 0)
+            return;
+
+        this._popdownTimeoutId =
+            GLib.timeout_add(GLib.PRIORITY_DEFAULT, POPDOWN_DIALOG_TIMEOUT, () => {
+                this._popdownTimeoutId = 0;
+                this.popdown();
+                return GLib.SOURCE_REMOVE;
+            });
+    }
+
     handleDragOver(source, actor, x, y) {
         if (this._withinDialog(x, y)) {
-            if (this._popdownTimeoutId > 0) {
-                GLib.source_remove(this._popdownTimeoutId);
-                this._popdownTimeoutId = 0;
-            }
-        } else if (this._popdownTimeoutId === 0) {
-            this._popdownTimeoutId =
-                GLib.timeout_add(GLib.PRIORITY_DEFAULT, POPDOWN_DIALOG_TIMEOUT, () => {
-                    this._popdownTimeoutId = 0;
-                    this.popdown();
-                    return GLib.SOURCE_REMOVE;
-                });
+            this._removePopdownTimeout();
+            this._removeDragMonitor();
+        } else {
+            this._setupPopdownTimeout();
+            this._setupDragMonitor();
         }
 
         return DND.DragMotionResult.NO_DROP;