Avoids flickering when redrawing a focused widget

ChangeLog

@@ -1,3 +1,6 @@
+2017-02-02  Markus Gans  <guru.mail@muenster.de>
+	* Avoids flickering when redrawing a focused widget
+
 2017-01-31  Markus Gans  <guru.mail@muenster.de>
 	* Refactoring FSwitch::drawCheckButton
 	* Refactoring FWidget::redraw

include/final/fvterm.h

@@ -102,6 +102,13 @@ class FVTerm : public FTerm
       fully_covered
     };
 
+    enum terminal_update
+    {
+      stop_refresh,
+      continue_refresh,
+      start_refresh
+    };
+
     // Constructor
     explicit FVTerm (bool, bool = false);
 
@@ -220,7 +227,7 @@ class FVTerm : public FTerm
     static void         resizeVTerm (const FRect&);
     static void         resizeVTerm (int, int);
     static void         putVTerm();
-    static void         updateTerminal (bool);
+    static void         updateTerminal (terminal_update);
     static void         updateTerminal();
     virtual void        addPreprocessingHandler ( FVTerm*
                                                 , FPreprocessingHandler );

src/fapplication.cpp

@@ -1542,7 +1542,7 @@ int FApplication::processTimerEvent()
 //----------------------------------------------------------------------
 void FApplication::processCloseWidget()
 {
-  updateTerminal(false);
+  updateTerminal (FVTerm::stop_refresh);
 
   if ( close_widget && ! close_widget->empty() )
   {
@@ -1558,7 +1558,7 @@ void FApplication::processCloseWidget()
     close_widget->clear();
   }
 
-  updateTerminal(true);
+  updateTerminal (FVTerm::start_refresh);
 }
 
 //----------------------------------------------------------------------

src/fmenu.cpp

@@ -78,7 +78,7 @@ FMenu::~FMenu()  // destructor
   FApplication* fapp = static_cast<FApplication*>(getRootWidget());
 
   if ( ! fapp->isQuit() )
-    switchToPrevWindow();
+    switchToPrevWindow();  // Switch to previous window
 }
 
 
@@ -118,8 +118,9 @@ void FMenu::show()
 //----------------------------------------------------------------------
 void FMenu::hide()
 {
-  if ( isVisible() )
+  if ( ! isVisible() )
-  {
+    return;
+
   FWindow::hide();
   const FRect& t_geometry = getTermGeometryWithShadow();
   restoreVTerm (t_geometry);
@@ -138,7 +139,6 @@ void FMenu::hide()
 
   mouse_down = false;
 }
-}
 
 //----------------------------------------------------------------------
 void FMenu::onKeyPress (FKeyEvent* ev)

src/fmenubar.cpp

@@ -3,7 +3,7 @@
 *                                                                      *
 * This file is part of the Final Cut widget toolkit                    *
 *                                                                      *
-* Copyright 2015-2017 Markus Gans                                      *
+* Copyright 2015-2018 Markus Gans                                      *
 *                                                                      *
 * The Final Cut is free software; you can redistribute it and/or       *
 * modify it under the terms of the GNU Lesser General Public License   *
@@ -330,7 +330,7 @@ bool FMenuBar::selectNextItem()
       if ( next == *iter )
         return false;
 
-      updateTerminal(false);
+      updateTerminal (FVTerm::stop_refresh);
       unselectItem();
       next->setSelected();
       setSelectedItem(next);
@@ -354,7 +354,7 @@ bool FMenuBar::selectNextItem()
         getStatusBar()->drawMessage();
 
       redraw();
-      updateTerminal(true);
+      updateTerminal (FVTerm::start_refresh);
       break;
     }
 
@@ -397,7 +397,7 @@ bool FMenuBar::selectPrevItem()
       if ( prev == *iter )
         return false;
 
-      updateTerminal(false);
+      updateTerminal (FVTerm::stop_refresh);
       unselectItem();
       prev->setSelected();
       prev->setFocus();
@@ -421,7 +421,7 @@ bool FMenuBar::selectPrevItem()
 
       setSelectedItem(prev);
       redraw();
-      updateTerminal(true);
+      updateTerminal (FVTerm::stop_refresh);
       break;
     }
   }

src/fvterm.cpp

@@ -230,11 +230,20 @@ void FVTerm::putVTerm()
 }
 
 //----------------------------------------------------------------------
-void FVTerm::updateTerminal (bool on)
+void FVTerm::updateTerminal (terminal_update refresh_state)
 {
-  stop_terminal_updates = bool(! on);
+  switch ( refresh_state )
+  {
+    case stop_refresh:
+      stop_terminal_updates = true;
+      break;
 
-  if ( on )
+    case continue_refresh:
+    case start_refresh:
+      stop_terminal_updates = false;
+  }
+
+  if ( refresh_state == start_refresh )
     updateTerminal();
 }
 

src/fwindow.cpp

@@ -3,7 +3,7 @@
 *                                                                      *
 * This file is part of the Final Cut widget toolkit                    *
 *                                                                      *
-* Copyright 2015-2017 Markus Gans                                      *
+* Copyright 2015-2018 Markus Gans                                      *
 *                                                                      *
 * The Final Cut is free software; you can redistribute it and/or       *
 * modify it under the terms of the GNU Lesser General Public License   *
@@ -719,6 +719,11 @@ bool FWindow::zoomWindow()
 void FWindow::switchToPrevWindow()
 {
   // switch to previous window
+
+  // Disable terminal updates to avoid flickering
+  // when redrawing the focused widget
+  updateTerminal (FVTerm::stop_refresh);
+
   bool is_activated = activatePrevWindow();
   FWindow* active_window = getActiveWindow();
 
@@ -765,6 +770,9 @@ void FWindow::switchToPrevWindow()
         focus_widget->redraw();
     }
   }
+
+  // Enable terminal updates again
+  updateTerminal (FVTerm::continue_refresh);
 }
 
 //----------------------------------------------------------------------