Add MessageLoop to avoid 100% CPU in foreground windows.

src/ui/CMakeLists.txt

@@ -27,6 +27,7 @@ add_library(ui-lib
   manager.cpp
   menu.cpp
   message.cpp
+  message_loop.cpp
   paint_event.cpp
   popup_window.cpp
   preferred_size_event.cpp

src/ui/gui.h

@@ -32,6 +32,7 @@
 #include "ui/manager.h"
 #include "ui/menu.h"
 #include "ui/message.h"
+#include "ui/message_loop.h"
 #include "ui/paint_event.h"
 #include "ui/popup_window.h"
 #include "ui/preferred_size_event.h"

src/ui/manager.cpp

@@ -11,8 +11,6 @@
 
 #include "ui/manager.h"
 
-#include "base/chrono.h"
-#include "base/thread.h"
 #include "ui/gui.h"
 #include "ui/intern.h"
 
@@ -186,27 +184,10 @@ Manager::~Manager()
 
 void Manager::run()
 {
-  base::Chrono chrono;
+  MessageLoop loop(this);
 
-  while (!jlist_empty(this->children)) {
-    chrono.reset();
-
-    if (generateMessages()) {
-      dispatchMessages();
-    }
-    else if (!m_garbage.empty()) {
-      collectGarbage();
-    }
-
-    // If the dispatching of messages was faster than 10 milliseconds,
-    // it means that the process is not using a lot of CPU, so we can
-    // wait the difference to cover those 10 milliseconds
-    // sleeping. With this code we can avoid 100% CPU usage (a
-    // property of Allegro 4 polling nature).
-    double elapsedMSecs = chrono.elapsed() * 1000.0;
-    if (elapsedMSecs > 0.0 && elapsedMSecs < 10.0)
-      base::this_thread::sleep_for((10.0 - elapsedMSecs) / 1000.0);
-  }
+  while (!jlist_empty(this->children))
+    loop.pumpMessages();
 }
 
 bool Manager::generateMessages()
@@ -1196,6 +1177,9 @@ void Manager::invalidateDisplayRegion(const JRegion region)
 
 void Manager::collectGarbage()
 {
+  if (m_garbage.empty())
+    return;
+
   for (WidgetsList::iterator
          it = m_garbage.begin(),
          end = m_garbage.end(); it != end; ++it) {

src/ui/manager.h

@@ -28,12 +28,11 @@ namespace ui {
     // Returns true if there are messages in the queue to be
     // distpatched through jmanager_dispatch_messages().
     bool generateMessages();
-
     void dispatchMessages();
+    void enqueueMessage(Message* msg);
 
     void addToGarbage(Widget* widget);
-
-    void enqueueMessage(Message* msg);
+    void collectGarbage();
 
     Window* getTopWindow();
     Window* getForegroundWindow();
@@ -72,7 +71,6 @@ namespace ui {
   private:
     void layoutManager(JRect rect);
     void pumpQueue();
-    void collectGarbage();
     void generateSetCursorMessage();
     static void removeWidgetFromDests(Widget* widget, Message* msg);
     static bool someParentIsFocusStop(Widget* widget);

src/ui/message_loop.cpp

@@ -0,0 +1,43 @@
+// ASEPRITE gui library
+// Copyright (C) 2001-2012  David Capello
+//
+// This source file is ditributed under a BSD-like license, please
+// read LICENSE.txt for more information.
+
+#include "config.h"
+
+#include "ui/message_loop.h"
+
+#include "base/chrono.h"
+#include "base/thread.h"
+#include "ui/manager.h"
+
+namespace ui {
+
+MessageLoop::MessageLoop(Manager* manager)
+  : m_manager(manager)
+{
+}
+
+void MessageLoop::pumpMessages()
+{
+  base::Chrono chrono;
+
+  if (m_manager->generateMessages()) {
+    m_manager->dispatchMessages();
+  }
+  else {
+    m_manager->collectGarbage();
+  }
+
+  // If the dispatching of messages was faster than 10 milliseconds,
+  // it means that the process is not using a lot of CPU, so we can
+  // wait the difference to cover those 10 milliseconds
+  // sleeping. With this code we can avoid 100% CPU usage (a
+  // property of Allegro 4 polling nature).
+  double elapsedMSecs = chrono.elapsed() * 1000.0;
+  if (elapsedMSecs > 0.0 && elapsedMSecs < 10.0)
+    base::this_thread::sleep_for((10.0 - elapsedMSecs) / 1000.0);
+}
+
+} // namespace ui

src/ui/message_loop.h

@@ -0,0 +1,27 @@
+// ASEPRITE gui library
+// Copyright (C) 2001-2012  David Capello
+//
+// This source file is ditributed under a BSD-like license, please
+// read LICENSE.txt for more information.
+
+#ifndef UI_MESSAGE_LOOP_H_INCLUDED
+#define UI_MESSAGE_LOOP_H_INCLUDED
+
+namespace ui {
+
+  class Manager;
+
+  class MessageLoop
+  {
+  public:
+    MessageLoop(Manager* manager);
+
+    void pumpMessages();
+
+  private:
+    Manager* m_manager;
+  };
+
+} // namespace ui
+
+#endif

src/ui/window.cpp

@@ -233,14 +233,12 @@ void Window::openWindowInForeground()
 {
   openWindow();
 
-  Manager* manager = getManager();
+  MessageLoop loop(getManager());
 
   m_is_foreground = true;
 
-  while (!(this->flags & JI_HIDDEN)) {
-    if (manager->generateMessages())
-      manager->dispatchMessages();
-  }
+  while (!(this->flags & JI_HIDDEN))
+    loop.pumpMessages();
 
   m_is_foreground = false;
 }