correctly show/close associated_widget_panels

This resolves several open issues of displays with associated widgets (e.g. Camera and Image).
- when minimizing / unminimizing the main window, the enabled status of those displays changed
- tabbed DockWidgets were closed (and couldn't easily be reopened by enabling the display)

src/rviz/default_plugin/camera_display.cpp

@@ -127,11 +127,7 @@ CameraDisplay::~CameraDisplay()
     unsubscribe();
     caminfo_tf_filter_->clear();
 
-
-    //workaround. delete results in a later crash
-    render_panel_->hide();
-    //delete render_panel_;
-
+    delete render_panel_;
     delete bg_screen_rect_;
     delete fg_screen_rect_;
 

src/rviz/display.cpp

@@ -61,6 +61,7 @@ Display::Display()
   , visibility_bits_( 0xFFFFFFFF )
   , associated_widget_( NULL )
   , associated_widget_panel_( NULL )
+  , associated_widget_visible_( false )
 {
   // Needed for timeSignal (see header) to work across threads
   qRegisterMetaType<ros::Time>();
@@ -296,36 +297,42 @@ void Display::onEnableChanged()
 {
   QApplication::setOverrideCursor(QCursor(Qt::WaitCursor));
   queueRender();
+  /* We get here, by two different routes:
+   * - First, we might have disabled the display.
+   *   In this case we want to close/hide the associated widget.
+   *   But there is an exception: tabbed DockWidgets shouldn't be hidden, because then we would loose the tab.
+   * - Second, the corresponding widget changed visibility and we got here via associatedPanelVisibilityChange().
+   *   In this case, it's usually counterproductive to show/hide the widget here.
+   *   Typical cases are: main window was minimized/unminimized, tab was switched.
+   */
   if( isEnabled() )
   {
     scene_node_->setVisible( true );
 
     if( associated_widget_panel_ )
     {
-      associated_widget_panel_->show();
+      if (!associated_widget_visible_)
+        associated_widget_panel_->show();
+      else
+        associated_widget_panel_->setFocus();
     }
     else if( associated_widget_ )
-    {
       associated_widget_->show();
-    }
 
-    onEnable();
+    if( isEnabled() )  // status might have changed, e.g. if show() failed
+      onEnable();
   }
   else
   {
     onDisable();
 
     if( associated_widget_panel_ )
     {
-      if( associated_widget_panel_->isVisible() )
-      {
+      if( associated_widget_visible_ )
         associated_widget_panel_->hide();
-      }
     }
-    else if( associated_widget_ && associated_widget_->isVisible() )
-    {
+    else if( associated_widget_ )
       associated_widget_->hide();
-    }
 
     scene_node_->setVisible( false );
   }
@@ -359,6 +366,7 @@ void Display::setAssociatedWidget( QWidget* widget )
     if( wm )
     {
       associated_widget_panel_ = wm->addPane( getName(), associated_widget_ );
+      associated_widget_visible_ = true;
       connect( associated_widget_panel_, SIGNAL( visibilityChanged( bool ) ), this, SLOT( associatedPanelVisibilityChange( bool ) ));
       connect( associated_widget_panel_, SIGNAL( closed( ) ), this, SLOT( disable( )));
       associated_widget_panel_->setIcon( getIcon() );
@@ -377,15 +385,11 @@ void Display::setAssociatedWidget( QWidget* widget )
 
 void Display::associatedPanelVisibilityChange( bool visible )
 {
-  // if something external makes the panel visible, make sure we're enabled
-  if ( visible )
-  {
-    setEnabled( true );
-  }
-  else
-  {
-    setEnabled( false );
-  }
+  associated_widget_visible_ = visible;
+  // If something external makes the panel visible/invisible, make sure to enable/disable the display
+  setEnabled(visible);
+  // Remark: vice versa, in Display::onEnableChanged(),
+  //         the panel is made visible/invisible when the display is enabled/disabled
 }
 
 void Display::setIcon( const QIcon& icon )

src/rviz/display.h

@@ -298,6 +298,7 @@ private Q_SLOTS:
   uint32_t visibility_bits_;
   QWidget* associated_widget_;
   PanelDockWidget* associated_widget_panel_;
+  bool associated_widget_visible_;
 };
 
 } // end namespace rviz