[gnome-shell] appDisplay: Simplify event blocking while folder is opened

[Florian Müllner <fmuellner src gnome org>]

commit 0897915b05c39011532adac25206d5f78bc3bb02
Author: Jonas Dreßler <verdre v0yd nl>
Date:   Sat Nov 23 21:11:14 2019 +0100

    appDisplay: Simplify event blocking while folder is opened
    
    There's no need for a `inhibitEventBlocker` interface. Since we connect
    to "open-state-changed" of our folders in the AllView anyway, we can
    just make the event blocker visible while a folder is opened, and hide
    the event blocker during DnD.
    
    This allows keeping the eventBlocker reactive at all times and fixes an
    issue where DnD to create a new folder is impossible if no folders are
    present because the eventBlocker would not get inhibited.
    
    Fixes https://gitlab.gnome.org/GNOME/gnome-shell/issues/1652

 js/ui/appDisplay.js | 35 +++++++++++++----------------------
 1 file changed, 13 insertions(+), 22 deletions(-)
---
diff --git a/js/ui/appDisplay.js b/js/ui/appDisplay.js
index 6221eb2b41..2b60bc9a57 100644
--- a/js/ui/appDisplay.js
+++ b/js/ui/appDisplay.js
@@ -337,7 +337,12 @@ var AllView = GObject.registerClass({
 
         this._grid.currentPage = 0;
         this._stack.add_actor(this._grid);
-        this._eventBlocker = new St.Widget({ x_expand: true, y_expand: true });
+        this._eventBlocker = new St.Widget({
+            x_expand: true,
+            y_expand: true,
+            reactive: true,
+            visible: false,
+        });
         this._stack.add_actor(this._eventBlocker);
 
         box.add_actor(this._stack);
@@ -364,6 +369,7 @@ var AllView = GObject.registerClass({
         });
         this._eventBlocker.add_action(this._clickAction);
 
+        this._currentPopup = null;
         this._displayingPopup = false;
         this._currentPopupDestroyId = 0;
 
@@ -394,8 +400,6 @@ var AllView = GObject.registerClass({
 
         Main.overview.connect('item-drag-begin', this._onDragBegin.bind(this));
         Main.overview.connect('item-drag-end', this._onDragEnd.bind(this));
-
-        this._nEventBlockerInhibits = 0;
     }
 
     vfunc_map() {
@@ -610,7 +614,6 @@ var AllView = GObject.registerClass({
     openSpaceForPopup(item, side, nRows) {
         this._updateIconOpacities(true);
         this._displayingPopup = true;
-        this._eventBlocker.reactive = true;
         this._grid.openExtraSpace(item, side, nRows);
     }
 
@@ -685,7 +688,7 @@ var AllView = GObject.registerClass({
     addFolderPopup(popup) {
         this._stack.add_actor(popup);
         popup.connect('open-state-changed', (o, isOpen) => {
-            this._eventBlocker.reactive = isOpen;
+            this._eventBlocker.visible = isOpen;
 
             if (this._currentPopup) {
                 this._currentPopup.disconnect(this._currentPopupDestroyId);
@@ -699,7 +702,7 @@ var AllView = GObject.registerClass({
                 this._currentPopupDestroyId = popup.connect('destroy', () => {
                     this._currentPopup = null;
                     this._currentPopupDestroyId = 0;
-                    this._eventBlocker.reactive = false;
+                    this._eventBlocker.visible = false;
                 });
             }
             this._updateIconOpacities(isOpen);
@@ -795,6 +798,8 @@ var AllView = GObject.registerClass({
             dragMotion: this._onDragMotion.bind(this),
         };
         DND.addDragMonitor(this._dragMonitor);
+
+        this._eventBlocker.visible = false;
     }
 
     _onDragMotion(dragEvent) {
@@ -817,6 +822,8 @@ var AllView = GObject.registerClass({
             DND.removeDragMonitor(this._dragMonitor);
             this._dragMonitor = null;
         }
+
+        this._eventBlocker.visible = this._currentPopup !== null;
     }
 
     _canAccept(source) {
@@ -850,19 +857,6 @@ var AllView = GObject.registerClass({
         return true;
     }
 
-    inhibitEventBlocker() {
-        this._nEventBlockerInhibits++;
-        this._eventBlocker.visible = this._nEventBlockerInhibits == 0;
-    }
-
-    uninhibitEventBlocker() {
-        if (this._nEventBlockerInhibits === 0)
-            throw new Error('Not inhibited');
-
-        this._nEventBlockerInhibits--;
-        this._eventBlocker.visible = this._nEventBlockerInhibits == 0;
-    }
-
     createFolder(apps) {
         let newFolderId = GLib.uuid_string_random();
 
@@ -1566,8 +1560,6 @@ var FolderIcon = GObject.registerClass({
             dragMotion: this._onDragMotion.bind(this),
         };
         DND.addDragMonitor(this._dragMonitor);
-
-        this._parentView.inhibitEventBlocker();
     }
 
     _onDragMotion(dragEvent) {
@@ -1583,7 +1575,6 @@ var FolderIcon = GObject.registerClass({
 
     _onDragEnd() {
         this.remove_style_pseudo_class('drop');
-        this._parentView.uninhibitEventBlocker();
         DND.removeDragMonitor(this._dragMonitor);
     }