[FEATURE] Hide Deselected Layers action

Allows you to quickly hide all deselected layers. This is very handy
when you have a large project and want to quickly hide all except
for a couple of layers

python/gui/qgisinterface.sip

@@ -483,6 +483,11 @@ class QgisInterface : QObject
     virtual QAction *actionHideAllLayers() = 0;
     virtual QAction *actionShowAllLayers() = 0;
     virtual QAction *actionHideSelectedLayers() = 0;
+    /**
+     * Returns the Hide Deselected Layers action.
+     * @note added in QGIS 3.0
+     */
+    virtual QAction *actionHideDeselectedLayers() = 0;
     virtual QAction *actionShowSelectedLayers() = 0;
 
     // Plugin menu actions

src/app/qgisapp.cpp

@@ -1707,6 +1707,7 @@ void QgisApp::createActions()
   connect( mActionHideAllLayers, SIGNAL( triggered() ), this, SLOT( hideAllLayers() ) );
   connect( mActionShowSelectedLayers, SIGNAL( triggered() ), this, SLOT( showSelectedLayers() ) );
   connect( mActionHideSelectedLayers, SIGNAL( triggered() ), this, SLOT( hideSelectedLayers() ) );
+  connect( mActionHideDeselectedLayers, &QAction::triggered, this, &QgisApp::hideDeselectedLayers );
 
   // Plugin Menu Items
 
@@ -5783,6 +5784,17 @@ void QgisApp::hideSelectedLayers()
   }
 }
 
+void QgisApp::hideDeselectedLayers()
+{
+  QList<QgsLayerTreeLayer*> selectedLayerNodes = mLayerTreeView->selectedLayerNodes();
+
+  Q_FOREACH ( QgsLayerTreeLayer* nodeLayer, mLayerTreeView->layerTreeModel()->rootGroup()->findLayers() )
+  {
+    if ( selectedLayerNodes.contains( nodeLayer ) )
+      continue;
+    nodeLayer->setVisible( Qt::Unchecked );
+  }
+}
 
 // reimplements method from base (gui) class
 void QgisApp::showSelectedLayers()

src/app/qgisapp.h

@@ -411,6 +411,7 @@ class APP_EXPORT QgisApp : public QMainWindow, private Ui::MainWindow
     QAction *actionHideAllLayers() { return mActionHideAllLayers; }
     QAction *actionShowAllLayers() { return mActionShowAllLayers; }
     QAction *actionHideSelectedLayers() { return mActionHideSelectedLayers; }
+    QAction *actionHideDeselectedLayers() { return mActionHideDeselectedLayers; }
     QAction *actionShowSelectedLayers() { return mActionShowSelectedLayers; }
 
     QAction *actionManagePlugins() { return mActionManagePlugins; }
@@ -1027,6 +1028,8 @@ class APP_EXPORT QgisApp : public QMainWindow, private Ui::MainWindow
     void showAllLayers();
     //reimplements method from base (gui) class
     void hideSelectedLayers();
+    //! Hides any layers which are not selected
+    void hideDeselectedLayers();
     //reimplements method from base (gui) class
     void showSelectedLayers();
     //! Return pointer to the active layer

src/app/qgisappinterface.cpp

@@ -631,6 +631,7 @@ QAction *QgisAppInterface::actionRemoveAllFromOverview() { return qgis->actionRe
 QAction *QgisAppInterface::actionHideAllLayers() { return qgis->actionHideAllLayers(); }
 QAction *QgisAppInterface::actionShowAllLayers() { return qgis->actionShowAllLayers(); }
 QAction *QgisAppInterface::actionHideSelectedLayers() { return qgis->actionHideSelectedLayers(); }
+QAction*QgisAppInterface::actionHideDeselectedLayers() { return qgis->actionHideDeselectedLayers(); }
 QAction *QgisAppInterface::actionShowSelectedLayers() { return qgis->actionShowSelectedLayers(); }
 
 //! Plugin menu actions

src/app/qgisappinterface.h

@@ -445,6 +445,7 @@ class APP_EXPORT QgisAppInterface : public QgisInterface
     virtual QAction *actionHideAllLayers() override;
     virtual QAction *actionShowAllLayers() override;
     virtual QAction *actionHideSelectedLayers() override;
+    virtual QAction *actionHideDeselectedLayers() override;
     virtual QAction *actionShowSelectedLayers() override;
 
     //! Plugin menu actions

src/app/qgsmapthemes.cpp

@@ -42,6 +42,7 @@ QgsMapThemes::QgsMapThemes()
   mMenu->addAction( QgisApp::instance()->actionHideAllLayers() );
   mMenu->addAction( QgisApp::instance()->actionShowSelectedLayers() );
   mMenu->addAction( QgisApp::instance()->actionHideSelectedLayers() );
+  mMenu->addAction( QgisApp::instance()->actionHideDeselectedLayers() );
   mMenu->addSeparator();
 
   mReplaceMenu = new QMenu( tr( "Replace Theme" ) );

src/gui/qgisinterface.h

@@ -539,6 +539,12 @@ class GUI_EXPORT QgisInterface : public QObject
     virtual QAction *actionHideAllLayers() = 0;
     virtual QAction *actionShowAllLayers() = 0;
     virtual QAction *actionHideSelectedLayers() = 0;
+
+    /**
+     * Returns the Hide Deselected Layers action.
+     * @note added in QGIS 3.0
+     */
+    virtual QAction *actionHideDeselectedLayers() = 0;
     virtual QAction *actionShowSelectedLayers() = 0;
 
     // Plugin menu actions

src/ui/qgisapp.ui

@@ -118,6 +118,7 @@
     <addaction name="mActionHideAllLayers"/>
     <addaction name="mActionShowSelectedLayers"/>
     <addaction name="mActionHideSelectedLayers"/>
+    <addaction name="mActionHideDeselectedLayers"/>
     <addaction name="separator"/>
    </widget>
    <widget class="QMenu" name="mLayerMenu">
@@ -2425,6 +2426,15 @@ Acts on currently active editable layer</string>
     <string>Hide Selected Layers</string>
    </property>
   </action>
+  <action name="mActionHideDeselectedLayers">
+   <property name="icon">
+    <iconset resource="../../images/images.qrc">
+     <normaloff>:/images/themes/default/mActionHideSelectedLayers.png</normaloff>:/images/themes/default/mActionHideSelectedLayers.png</iconset>
+   </property>
+   <property name="text">
+    <string>Hide Deselected Layers</string>
+   </property>
+  </action>
   <action name="mActionNewMemoryLayer">
    <property name="icon">
     <iconset resource="../../images/images.qrc">