Merge PR #7435 by @wavexx (Shift+Tab shortcut to collapse sidebar):

The extra commit by lukasmatena fixes toolbar tooltip updating.

src/slic3r/GUI/GLCanvas3D.cpp

@@ -3214,6 +3214,10 @@ void GLCanvas3D::on_key(wxKeyEvent& evt)
                     // m_canvas->HandleAsNavigationKey(evt);   // XXX: Doesn't work in some cases / on Linux
                     post_event(SimpleEvent(EVT_GLCANVAS_TAB));
                 }
+                else if (keyCode == WXK_TAB && evt.ShiftDown()) {
+                    // Collapse side-panel with Shift+Tab
+                    post_event(SimpleEvent(EVT_GLCANVAS_COLLAPSE_SIDEBAR));
+                }
                 else if (keyCode == WXK_SHIFT)
                 {
                     translationProcessor.process(evt);

src/slic3r/GUI/KBShortcutsDialog.cpp

@@ -140,6 +140,8 @@ void KBShortcutsDialog::fill_shortcuts()
             // View
             { "0-6", L("Camera view") },
             { "E", L("Show/Hide object/instance labels") },
+            { "Tab", L("Switch between Editor/Preview") },
+            { "Shift+Tab", L("Collapse/Expand the sidebar") },
             // Configuration
             { ctrl + "P", L("Preferences") },
             // Help

src/slic3r/GUI/MainFrame.cpp

@@ -1295,7 +1295,7 @@ void MainFrame::init_menubar()
         append_menu_check_item(viewMenu, wxID_ANY, _L("Show &labels") + sep + "E", _L("Show object/instance labels in 3D scene"),
             [this](wxCommandEvent&) { m_plater->show_view3D_labels(!m_plater->are_view3D_labels_shown()); }, this,
             [this]() { return m_plater->is_view3D_shown(); }, [this]() { return m_plater->are_view3D_labels_shown(); }, this);
-        append_menu_check_item(viewMenu, wxID_ANY, _L("&Collapse sidebar"), _L("Collapse sidebar"),
+        append_menu_check_item(viewMenu, wxID_ANY, _L("&Collapse sidebar") + sep + "Shift+Tab", _L("Collapse sidebar"),
             [this](wxCommandEvent&) { m_plater->collapse_sidebar(!m_plater->is_sidebar_collapsed()); }, this,
             []() { return true; }, [this]() { return m_plater->is_sidebar_collapsed(); }, this);
     }

src/slic3r/GUI/Plater.cpp

@@ -1597,7 +1597,7 @@ struct Plater::priv
     void show_view3D_labels(bool show) { if (current_panel == view3D) view3D->get_canvas3d()->show_labels(show); }
 
     bool is_sidebar_collapsed() const   { return sidebar->is_collapsed(); }
-    void collapse_sidebar(bool show)    { sidebar->collapse(show); }
+    void collapse_sidebar(bool collapse);
 
     bool is_view3D_layers_editing_enabled() const { return (current_panel == view3D) && view3D->get_canvas3d()->is_layers_editing_enabled(); }
 
@@ -1952,6 +1952,7 @@ Plater::priv::priv(Plater *q, MainFrame *main_frame)
     preview->get_wxglcanvas()->Bind(EVT_GLCANVAS_QUESTION_MARK, [this](SimpleEvent&) { wxGetApp().keyboard_shortcuts(); });
     preview->get_wxglcanvas()->Bind(EVT_GLCANVAS_UPDATE_BED_SHAPE, [q](SimpleEvent&) { q->set_bed_shape(); });
     preview->get_wxglcanvas()->Bind(EVT_GLCANVAS_TAB, [this](SimpleEvent&) { select_next_view_3D(); });
+    preview->get_wxglcanvas()->Bind(EVT_GLCANVAS_COLLAPSE_SIDEBAR, [this](SimpleEvent&) { this->q->collapse_sidebar(!this->q->is_sidebar_collapsed());  });
 #if ENABLE_GCODE_VIEWER
     preview->get_wxglcanvas()->Bind(EVT_GLCANVAS_MOVE_LAYERS_SLIDER, [this](wxKeyEvent& evt) { preview->move_layers_slider(evt); });
     preview->get_wxglcanvas()->Bind(EVT_GLCANVAS_EDIT_COLOR_CHANGE, [this](wxKeyEvent& evt) { preview->edit_layers_slider(evt); });
@@ -2127,6 +2128,20 @@ void Plater::priv::select_next_view_3D()
         set_current_panel(view3D);
 }
 
+void Plater::priv::collapse_sidebar(bool collapse)
+{
+    sidebar->collapse(collapse);
+
+    // Now update the tooltip in the toolbar.
+    std::string new_tooltip = collapse
+                              ? _utf8(L("Expand sidebar"))
+                              : _utf8(L("Collapse sidebar"));
+    new_tooltip += " [Shift+Tab]";
+    int id = collapse_toolbar.get_item_id("collapse_sidebar");
+    collapse_toolbar.set_tooltip(id, new_tooltip);
+}
+
+
 void Plater::priv::reset_all_gizmos()
 {
     view3D->get_canvas3d()->reset_all_gizmos();
@@ -4076,21 +4091,17 @@ bool Plater::priv::init_collapse_toolbar()
 
     item.name = "collapse_sidebar";
     item.icon_filename = "collapse.svg";
-    item.tooltip = wxGetApp().plater()->is_sidebar_collapsed() ? _utf8(L("Expand right panel")) : _utf8(L("Collapse right panel"));
     item.sprite_id = 0;
-    item.left.action_callback = [this, item]() {
+    item.left.action_callback = []() {
-        std::string new_tooltip = wxGetApp().plater()->is_sidebar_collapsed() ?
-            _utf8(L("Collapse right panel")) : _utf8(L("Expand right panel"));
-
-        int id = collapse_toolbar.get_item_id("collapse_sidebar");
-        collapse_toolbar.set_tooltip(id, new_tooltip);
-
         wxGetApp().plater()->collapse_sidebar(!wxGetApp().plater()->is_sidebar_collapsed());
     };
 
     if (!collapse_toolbar.add_item(item))
         return false;
 
+    // Now "collapse" sidebar to current state. This is done so the tooltip
+    // is updated before the toolbar is first used.
+    wxGetApp().plater()->collapse_sidebar(wxGetApp().plater()->is_sidebar_collapsed());
     return true;
 }