screensheild.js: Listen to changes to allow floating setting (#13624)

We were only reading this setting at creation time. Instead read it on each
activation in case the value changed. The timer to start widgets floating
also wasn't getting started on first show.

Author: JosephMcc

js/ui/screensaver/screenShield.js

@@ -22,7 +22,7 @@ const POWER_SCHEMA = 'org.cinnamon.settings-daemon.plugins.power';
 const FADE_TIME = 200;
 const MOTION_THRESHOLD = 100;
 
-const FLOAT_TIMER_INTERVAL = 30;
+const FLOAT_TIMER_INTERVAL = 5;
 const DEBUG_FLOAT = false;  // Set to true for 5-second intervals during development
 
 const MAX_SCREENSAVER_WIDGETS = 3;
@@ -136,7 +136,6 @@ var ScreenShield = GObject.registerClass({
         this._settings = new Gio.Settings({ schema_id: SCREENSAVER_SCHEMA });
         this._settings.connect('changed::lock-enabled', this._syncInhibitor.bind(this));
         this._powerSettings = new Gio.Settings({ schema_id: POWER_SCHEMA });
-        this._allowFloating = this._settings.get_boolean('floating-widgets');
 
         let constraint = new Clutter.BindConstraint({
             source: global.stage,
@@ -416,6 +415,7 @@ var ScreenShield = GObject.registerClass({
         this._lastMotionX = -1;
         this._lastMotionY = -1;
         this._activationTime = GLib.get_monotonic_time();
+        this._allowFloating = this._settings.get_boolean('floating-widgets');
 
         this._activationPending = true;
         _log('ScreenShield: requesting screensaver modal grab');
@@ -934,7 +934,7 @@ var ScreenShield = GObject.registerClass({
             this._assignRandomPositionToWidget(widget);
             widget.applyNextPosition();
 
-            if (this._widgets.length === 0) {
+            if (this._widgets.length !== 0) {
                 this._startFloatTimer();
             }
         }