panel: Remove panel translucency

Since commit 447bf55e45 we turn the top bar translucent when
free-floating. While this looks fancy and reduces the appearance
of cutting into the available screen space, it has also had a
negative effect on legibility.

Nobody stepped up to address those issues in two years, so revert
back to the fully opaque top bar.

https://gitlab.gnome.org/GNOME/gnome-shell/issues/408

data/theme/gnome-shell-sass/_common.scss

@@ -729,9 +729,7 @@ StScrollBar {
 /* TOP BAR */
 
 #panel {
-  background-color: rgba(0, 0, 0, 0.35);
+  background-color: black;
-  /* transition from solid to transparent */
-  transition-duration: 500ms;
   font-weight: bold;
   height: 1.86em;
   font-feature-settings: "tnum";
@@ -748,7 +746,7 @@ StScrollBar {
 
   .panel-corner {
     -panel-corner-radius: $panel-corner-radius;
-    -panel-corner-background-color: rgba(0, 0, 0, 0.35);
+    -panel-corner-background-color: black;
     -panel-corner-border-width: 2px;
     -panel-corner-border-color: transparent;
 
@@ -767,9 +765,7 @@ StScrollBar {
     -natural-hpadding: 12px;
     -minimum-hpadding: 6px;
     font-weight: bold;
-    color: #eee;
+    color: #ccc;
-    text-shadow: 0px 1px 2px rgba(0, 0, 0, 0.9);
-    transition-duration: 100ms;
 
     .app-menu-icon {
       -st-icon-style: symbolic;
@@ -778,21 +774,8 @@ StScrollBar {
       //dimensions of the icon are hardcoded
     }
 
-    .system-status-icon,
-    .app-menu-icon > StIcon,
-    .popup-menu-arrow {
-      icon-shadow: 0px 1px 2px rgba(0, 0, 0, 0.9);
-    }
-
     &:hover {
       color: lighten($fg_color, 10%);
-      text-shadow: 0px 1px 6px rgba(0, 0, 0, 1);
-
-      .system-status-icon,
-      .app-menu-icon > StIcon,
-      .popup-menu-arrow {
-        icon-shadow: 0px 1px 6px rgba(0, 0, 0, 1);
-      }
     }
 
     &:active, &:overview, &:focus, &:checked {
@@ -801,8 +784,6 @@ StScrollBar {
       background-color: rgba(0, 0, 0, 0.01);
       box-shadow: inset 0 -2px 0px lighten($selected_bg_color,5%);
       color: lighten($fg_color,10%);
-
-      & > .system-status-icon { icon-shadow: black 0 2px 2px; }
     }
 
     .system-status-icon { icon-size: 1.09em; padding: 0 5px; }
@@ -827,31 +808,6 @@ StScrollBar {
   .screencast-indicator { color: $warning_color; }
 
   .remote-access-indicator { color: $warning_color; }
-
-  &.solid {
-    background-color: black;
-    /* transition from transparent to solid */
-    transition-duration: 300ms;
-
-    .panel-corner {
-      -panel-corner-background-color: black;
-    }
-
-    .panel-button {
-      color: #ccc;
-      text-shadow: none;
-
-      &:hover, &:active, &:overview, &:focus, &:checked {
-        color: lighten($fg_color, 10%);
-      }
-    }
-
-    .system-status-icon,
-    .app-menu-icon > StIcon,
-    .popup-menu-arrow {
-      icon-shadow: none;
-    }
-  }
 }
 
   // calendar popover

js/ui/panel.js

@@ -797,11 +797,9 @@ class Panel extends St.Widget {
 
         Main.overview.connect('showing', () => {
             this.add_style_pseudo_class('overview');
-            this._updateSolidStyle();
         });
         Main.overview.connect('hiding', () => {
             this.remove_style_pseudo_class('overview');
-            this._updateSolidStyle();
         });
 
         Main.layoutManager.panelBox.add(this);
@@ -810,31 +808,10 @@ class Panel extends St.Widget {
 
         Main.sessionMode.connect('updated', this._updatePanel.bind(this));
 
-        this._trackedWindows = new Map();
-        global.window_group.connect('actor-added', this._onWindowActorAdded.bind(this));
-        global.window_group.connect('actor-removed', this._onWindowActorRemoved.bind(this));
-        global.window_manager.connect('switch-workspace', this._updateSolidStyle.bind(this));
-
         global.display.connect('workareas-changed', () => { this.queue_relayout(); });
         this._updatePanel();
     }
 
-    _onWindowActorAdded(container, metaWindowActor) {
-        let signalIds = [];
-        ['allocation-changed', 'notify::visible'].forEach(s => {
-            signalIds.push(metaWindowActor.connect(s, this._updateSolidStyle.bind(this)));
-        });
-        this._trackedWindows.set(metaWindowActor, signalIds);
-    }
-
-    _onWindowActorRemoved(container, metaWindowActor) {
-        this._trackedWindows.get(metaWindowActor).forEach(id => {
-            metaWindowActor.disconnect(id);
-        });
-        this._trackedWindows.delete(metaWindowActor);
-        this._updateSolidStyle();
-    }
-
     vfunc_get_preferred_width(forHeight) {
         let primaryMonitor = Main.layoutManager.primaryMonitor;
 
@@ -1042,8 +1019,6 @@ class Panel extends St.Widget {
         else
             Main.messageTray.bannerAlignment = Clutter.ActorAlign.CENTER;
 
-        this._updateSolidStyle();
-
         if (this._sessionStyle)
             this._removeStyleClassName(this._sessionStyle);
 
@@ -1060,41 +1035,6 @@ class Panel extends St.Widget {
         }
     }
 
-    _updateSolidStyle() {
-        if (this.has_style_pseudo_class('overview') || !Main.sessionMode.hasWindows) {
-            this._removeStyleClassName('solid');
-            return;
-        }
-
-        if (!Main.layoutManager.primaryMonitor)
-            return;
-
-        /* Get all the windows in the active workspace that are in the primary monitor and visible */
-        let workspaceManager = global.workspace_manager;
-        let activeWorkspace = workspaceManager.get_active_workspace();
-        let windows = activeWorkspace.list_windows().filter(metaWindow => {
-            return metaWindow.is_on_primary_monitor() &&
-                   metaWindow.showing_on_its_workspace() &&
-                   !metaWindow.is_hidden() &&
-                   metaWindow.get_window_type() != Meta.WindowType.DESKTOP;
-        });
-
-        /* Check if at least one window is near enough to the panel */
-        let [, panelTop] = this.get_transformed_position();
-        let panelBottom = panelTop + this.get_height();
-        let scale = St.ThemeContext.get_for_stage(global.stage).scale_factor;
-        let isNearEnough = windows.some(metaWindow => {
-            let verticalPosition = metaWindow.get_frame_rect().y;
-            return verticalPosition < panelBottom + 5 * scale;
-        });
-
-        if (isNearEnough)
-            this._addStyleClassName('solid');
-        else
-            this._removeStyleClassName('solid');
-
-    }
-
     _hideIndicators() {
         for (let role in PANEL_ITEM_IMPLEMENTATIONS) {
             let indicator = this.statusArea[role];