The event queue now handles terminal resizing by calling the FApplication::onResize() method

Author: gansm

ChangeLog

@@ -1,3 +1,7 @@
+2026-10-14  Markus Gans  <guru.mail@muenster.de>
+	* The event queue now handles terminal resizing by calling 
+	  the FApplication::onResize() method
+
 2026-10-11  Markus Gans  <guru.mail@muenster.de>
 	* Optimize the FTermcap::hasDelay method
 

doc/event-processing.md

@@ -86,6 +86,7 @@ enum class Event : uInt8
   Show,              // Widget is shown
   Hide,              // Widget is hidden
   Close,             // Widget close
+  Log,               // Writes log changes
   Timer,             // Timer event occurred
   User               // User defined event
 };

final/fapplication.cpp

@@ -125,6 +125,9 @@ FApplication::~FApplication()  // destructor
   if ( eventInQueue() )
     event_queue.clear();
 
+  // Unset the resize handler
+  FTermData::getInstance().setResizeHandler(nullptr);
+
   resetLog();
 }
 
@@ -487,6 +490,39 @@ void FApplication::processExternalUserEvent()
   // This method can be overloaded and replaced by own code
 }
 
+//----------------------------------------------------------------------
+void FApplication::resize()
+{
+  auto foutput_ptr = FVTerm::getFOutput();
+  static auto& mouse = FMouseControl::getInstance();
+
+  // Detect and save the current terminal size
+  foutput_ptr->detectTerminalSize();
+  auto width = getDesktopWidth();
+  auto height = getDesktopHeight();
+  mouse.setMaxWidth (uInt16(width));
+  mouse.setMaxHeight (uInt16(height));
+
+  // The screen content is now unknown
+  foutput_ptr->clearTerminalState();
+  foutput_ptr->clearTerminalAttributes();
+
+  // Determine the new terminal size
+  const FRect old_term_geometry {getTermGeometry()};
+  setDesktopWidgetSize (width, height);
+  FRect term_geometry {getTermGeometry()};
+  term_geometry.move (-1, -1);
+
+  if ( old_term_geometry.getSize() == term_geometry.getSize() )
+    return;
+
+  resizeVTerm (term_geometry.getSize());
+  resizeRegion ({term_geometry, getShadow()}, getVirtualDesktop());
+  FVTerm::startDrawing();  // Avoid flickering - no update during adjustment
+  adjustSizeGlobal();
+  FVTerm::finishDrawing();
+}
+
 //----------------------------------------------------------------------
 auto FApplication::event (FEvent* ev) -> bool
 {
@@ -533,6 +569,16 @@ void FApplication::onLog (FEvent*)
   has_log_data = false;
 }
 
+//----------------------------------------------------------------------
+void FApplication::onResize (FResizeEvent* ev)
+{
+  // This event handler can be reimplemented in a subclass
+  // to receive resize events
+
+  processResizeEvent();
+  ev->accept();
+}
+
 //----------------------------------------------------------------------
 void FApplication::onClose (FCloseEvent*)
 {
@@ -596,6 +642,9 @@ void FApplication::init()
   // Initialize logging
   if ( ! getStartOptions().logfile_stream.is_open() )
     getLog()->setLineEnding(FLog::LineEnding::CRLF);
+
+  // Set the resize handler
+  FTermData::getInstance().setResizeHandler( [this] () { queueResize(); } );
 }
 
 //----------------------------------------------------------------------
@@ -1459,20 +1508,13 @@ auto FApplication::processParameters (const Args& args) -> FWidget*
 //----------------------------------------------------------------------
 void FApplication::processResizeEvent()
 {
-  if ( ! has_terminal_resized )  // A SIGWINCH signal was received
-    return;
+  // This method will be called when the terminal size changes
 
-  auto foutput_ptr = FVTerm::getFOutput();
-  foutput_ptr->detectTerminalSize();  // Detect and save the current terminal size
-  static auto& mouse = FMouseControl::getInstance();
-  mouse.setMaxWidth (uInt16(getDesktopWidth()));
-  mouse.setMaxHeight (uInt16(getDesktopHeight()));
-  FResizeEvent r_ev(Event::Resize);
-  sendEvent(internal::var::app_object, &r_ev);
-  has_terminal_resized = false;
+  resize();
+  redraw();
 
-  if ( r_ev.isAccepted() )
-    foutput_ptr->commitTerminalResize();
+  has_terminal_resized = false;
+  FVTerm::getFOutput()->commitTerminalResize();
 }
 
 //----------------------------------------------------------------------
@@ -1562,6 +1604,18 @@ void FApplication::queueLog()
   FApplication::queueEvent(this, std::move(ev));
 }
 
+//----------------------------------------------------------------------
+void FApplication::queueResize()
+{
+  if ( has_terminal_resized )  // A SIGWINCH signal was received
+    return;
+
+  has_terminal_resized = true;
+
+  auto ev = std::make_unique<FEvent>(Event::Resize);
+  FApplication::queueEvent(this, std::move(ev));
+}
+
 //----------------------------------------------------------------------
 void FApplication::processLogger() const
 {
@@ -1583,12 +1637,11 @@ auto FApplication::processNextEvent() -> bool
 {
   uInt num_events{0};
 
-  if ( hasDataInQueue() || hasTerminalResized() || isNextEventTimeout() )
+  if ( hasDataInQueue() || isNextEventTimeout() )
   {
     time_last_event = FObjectTimer::getCurrentTime();
     num_events += processTimerEvent();
     processInput();
-    processResizeEvent();  // when the terminal size has changed
     sendQueuedEvents();
     processTerminalScreenUpdate();
   }
@@ -1607,14 +1660,6 @@ void FApplication::performTimerAction (FObject* receiver, FEvent* event)
   sendEvent (receiver, event);
 }
 
-//----------------------------------------------------------------------
-inline auto FApplication::hasTerminalResized() -> bool
-{
-  auto foutput_ptr = FVTerm::getFOutput();
-  has_terminal_resized = foutput_ptr->hasTerminalResized();
-  return has_terminal_resized;
-}
-
 //----------------------------------------------------------------------
 auto FApplication::isEventProcessable ( FObject* receiver
                                       , const FEvent* event ) -> bool

final/fapplication.h

@@ -162,12 +162,15 @@ class FApplication : public FWidget
     void         cb_exitApp (FWidget*) const;
 
   protected:
+    // Methods
     virtual void processExternalUserEvent();
+    void         resize() override;
 
     // Event handlers
     auto         event (FEvent*) -> bool override;
     virtual void onDraw (FEvent*);
     virtual void onLog (FEvent*);
+    void         onResize (FResizeEvent*) override;
     void         onClose (FCloseEvent*) override;
 
   private:
@@ -244,10 +247,10 @@ class FApplication : public FWidget
     void         processTerminalScreenUpdate() const;
     void         processRedraw();
     void         queueLog();
+    void         queueResize();
     void         processLogger() const;
     auto         processNextEvent() -> bool;
     void         performTimerAction (FObject*, FEvent*) override;
-    auto         hasTerminalResized() -> bool;
     static auto  isEventProcessable (FObject*, const FEvent*) -> bool;
     static auto  isNextEventTimeout() -> bool;
 

final/fwidget.cpp

@@ -184,7 +184,7 @@ auto FWidget::getColorTheme() -> std::shared_ptr<FWidgetColors>&
 }
 
 //----------------------------------------------------------------------
-auto FWidget::doubleFlatLine_ref (Side side) -> std::vector<bool>&
+auto FWidget::mergingBorder_ref (Side side) -> std::vector<bool>&
 {
   auto& mask = merging_border_mask;
 
@@ -838,31 +838,9 @@ void FWidget::redraw (RedrawMode redraw_mode)
 //----------------------------------------------------------------------
 void FWidget::resize()
 {
-  if ( isRootWidget() )
-  {
-    // The screen content is now unknown
-    auto foutput_ptr = FVTerm::getFOutput();
-    foutput_ptr->clearTerminalState();
-    foutput_ptr->clearTerminalAttributes();
-    // Determine the new terminal size
-    const FRect old_term_geometry {getTermGeometry()};
-    determineDesktopSize();
-    FRect term_geometry {getTermGeometry()};
-    term_geometry.move (-1, -1);
-
-    if ( old_term_geometry.getSize() == term_geometry.getSize() )
-      return;
-
-    resizeVTerm (term_geometry.getSize());
-    resizeRegion ({term_geometry, getShadow()}, getVirtualDesktop());
-    FVTerm::startDrawing();  // Avoid flickering - no update during adjustment
-    adjustSizeGlobal();
-    FVTerm::finishDrawing();
-  }
-  else
-    adjustSize();
+  adjustSize();
 
-  // resize the four double-flatline-masks
+  // Resize the four merging border masks
   merging_border_mask.setSize (getWidth(), getHeight());
 }
 
@@ -1189,6 +1167,16 @@ void FWidget::setTermOffsetWithPadding()
   );
 }
 
+//----------------------------------------------------------------------
+void FWidget::setDesktopWidgetSize (std::size_t width, std::size_t height)
+{
+  wsize.setRect(1, 1, width, height);
+  adjust_wsize = wsize;
+  woffset.setRect(0, 0, width, height);
+  auto r = internal::var::root_widget;
+  wclient_offset.setRect(r->padding.left, r->padding.top, width, height);
+}
+
 //----------------------------------------------------------------------
 void FWidget::initTerminal()
 {
@@ -1442,12 +1430,10 @@ void FWidget::onAccel (FAccelEvent*)
 }
 
 //----------------------------------------------------------------------
-void FWidget::onResize (FResizeEvent* ev)
+void FWidget::onResize (FResizeEvent*)
 {
-  // The terminal was resized
-  internal::var::root_widget->resize();
-  internal::var::root_widget->redraw();
-  ev->accept();
+  // This event handler can be reimplemented in a subclass
+  // to receive a resized event
 }
 
 //----------------------------------------------------------------------
@@ -1482,11 +1468,7 @@ void FWidget::determineDesktopSize()
   detectTerminalSize();
   auto width = getDesktopWidth();
   auto height = getDesktopHeight();
-  wsize.setRect(1, 1, width, height);
-  adjust_wsize = wsize;
-  woffset.setRect(0, 0, width, height);
-  auto r = internal::var::root_widget;
-  wclient_offset.setRect(r->padding.left, r->padding.top, width, height);
+  setDesktopWidgetSize(width, height);
 }
 
 //----------------------------------------------------------------------

final/fwidget.h

@@ -172,7 +172,7 @@ class FWidget : public FVTerm
     auto  getStatusBarMessage() const -> FString;
     auto  getForegroundColor() const noexcept -> FColor;  // get the primary
     auto  getBackgroundColor() const noexcept -> FColor;  // widget colors
-    auto  doubleFlatLine_ref (Side) -> std::vector<bool>&;
+    auto  mergingBorder_ref (Side) -> std::vector<bool>&;
     // Positioning and sizes accessors...
     auto  getX() const -> int;
     auto  getY() const -> int;
@@ -328,6 +328,7 @@ class FWidget : public FVTerm
     void  setParentOffset();
     void  setTermOffset();
     void  setTermOffsetWithPadding();
+    void  setDesktopWidgetSize (std::size_t, std::size_t);
 
     // Methods
     void  initTerminal() override;
@@ -470,9 +471,7 @@ class FWidget : public FVTerm
     auto  sendFocusInEvent (FWidget*, FocusTypes) const -> bool;
     void  processDestroy() const;
     virtual void draw();
-  public:
     void  recursiveDraw();
-  private:
     void  drawChildren();
     void  adjustWidget();
     void  adjustSizeWithinRegion (FRect&) const;
@@ -530,6 +529,9 @@ class FWidget : public FVTerm
     static bool          init_terminal;
     static bool          init_desktop;
 
+    // Friend class
+    friend class FApplication;
+
     // Friend functions
     friend struct GenericBoxData;
     friend struct GenericBlockShadowData;

final/output/tty/ftermdata.h

@@ -149,6 +149,10 @@ class FTermData final
     // Using-declaration
     using EncodingMap = std::unordered_map<std::string, Encoding>;
 
+    // After switching to the new event loop implementation,
+    // this handler will no longer be necessary.
+    using ResizeHandler = std::function<void()>;
+
     // Constructors
     FTermData () = default;
 
@@ -208,6 +212,7 @@ class FTermData final
     void setVGAFont (bool = true) noexcept;
     void setMonochron (bool = true) noexcept;
     void setTermResized (bool = true);
+    void setResizeHandler (ResizeHandler&&);
     void setTermType (const std::string&);
     void setTermType (FTermType);
     void unsetTermType (FTermType);
@@ -221,6 +226,9 @@ class FTermData final
 #endif
 
   private:
+    // Method
+    void callResizeHandler();
+
     // Encoding-related fields
     struct EncodingInfo
     {
@@ -254,6 +262,10 @@ class FTermData final
       uInt          baudrate{0};
       std::string   termtype{};
       std::string   term_file_name{};
+
+      // After switching to the new event loop implementation,
+      // this handler will no longer be necessary.
+      ResizeHandler resize_handler;
     };
 
     // Synchronization and state
@@ -495,11 +507,22 @@ inline void FTermData::setTermResized (bool resize)
   std::lock_guard<std::mutex> resize_lock_guard(synchronization_state.resize_mutex);
 
   if ( resize )
+  {
     ++synchronization_state.resize_count;
+    callResizeHandler();
+  }
   else if ( synchronization_state.resize_count.load() > 0 )
     --synchronization_state.resize_count;
 }
 
+//----------------------------------------------------------------------
+inline void FTermData::setResizeHandler (ResizeHandler&& handler)
+{
+  // After switching to the new event loop implementation,
+  // this method will no longer be necessary.
+  terminal_settings.resize_handler = std::move(handler);
+}
+
 //----------------------------------------------------------------------
 inline void FTermData::setTermType (const std::string& name)
 {
@@ -547,6 +570,15 @@ inline void FTermData::setFramebufferBpp (int bpp) noexcept
 { terminal_settings.framebuffer_bpp = bpp; }
 #endif
 
+//----------------------------------------------------------------------
+inline void FTermData::callResizeHandler()
+{
+  // After switching to the new event loop implementation,
+  // this method will no longer be necessary.
+  if ( terminal_settings.resize_handler )
+    terminal_settings.resize_handler();
+}
+
 }  // namespace finalcut
 
 #endif  // FTERMDATA_H