added option for automatic pause/continue of emulation depending on focus (resolves #870)

Changes.txt

@@ -25,6 +25,8 @@
     - Added option to show/hide file extensions.
     - Extended context menu and shortcuts.
 
+  * Added option to automatically pause emulation when focus is lost.
+
   * Added option to toggle autofire mode.
 
   * Added another oddball TIA glitch option for score mode color.

docs/index.html

@@ -2854,6 +2854,11 @@
         indicating serious errors override this setting, and are always
         shown.</td>
     </tr>
+    <tr>
+      <td><pre>-autopause &lt;1|0&gt;</pre></td>
+      <td>Enable or disable automatic pause/continue of emulation, when
+        Stella loses/gains focus.</td>
+    </tr>
     <tr>
       <td><pre>-pausedim &lt;1|0&gt;</pre></td>
       <td>Enable or disable emulation dimming in pause mode.</td>
@@ -3966,6 +3971,10 @@
           <tr><td>Multi-threading</td><td>Enable multi-threaded rendering</td><td>-threads</td></tr>
           <tr><td>Fast SuperCharger load</td><td>Skip progress loading bars for SuperCharger ROMs</td><td>-fastscbios</td></tr>
           <tr><td>Show UI messages</td><td>Overlay UI messages onscreen</td><td>-uimessages</td></tr>
+          <tr><td>
+            Automatic pause</td><td>Enable or disable automatic pause/continue of emulation,
+            when Stella loses/gains focus.</td><td>-autopause
+          </td></tr>
           <tr><td>Confirm exiting...</td><td>Display a popup when emulation is exited</td><td>-confirmexit</td></tr>
           <tr>
             <td>When entering/exiting emulation:</td>

src/emucore/EventHandler.cxx

@@ -376,6 +376,15 @@ void EventHandler::handleSystemEvent(SystemEvent e, int, int)
         enterMenuMode(EventHandlerState::OPTIONSMENU);
       break;
 #endif
+    case SystemEvent::WINDOW_FOCUS_GAINED:
+      if(myOSystem.settings().getBool("autopause") && myState == EventHandlerState::PAUSE)
+        setState(EventHandlerState::EMULATION);
+      break;
+    case SystemEvent::WINDOW_FOCUS_LOST:
+      if(myOSystem.settings().getBool("autopause") && myState == EventHandlerState::EMULATION)
+        setState(EventHandlerState::PAUSE);
+      break;
+
     default:  // handle other events as testing requires
       // cerr << "handleSystemEvent: " << e << endl;
       break;

src/emucore/Settings.cxx

@@ -184,6 +184,8 @@ Settings::Settings()
   setPermanent("dialogfont", "medium");
   setPermanent("dialogpos", 0);
   setPermanent("confirmexit", false);
+  setPermanent("autopause", false);
+
 
   // Misc options
   setPermanent("loglevel", int(Logger::Level::INFO));
@@ -624,6 +626,7 @@ void Settings::usage() const
     << "                 large16>\n"
     << "  -dialogpos    <0..4>         Display all dialogs at given positions\n"
     << "  -confirmexit  <0|1>          Display a confirm dialog when exiting emulation\n"
+    << "  -autopause    <0|1>          Pause/continue emulation when focus is lost/gained\n"
     << "  -listdelay    <delay>        Time to wait between keypresses in list widgets\n"
     << "                                (300-1000)\n"
     << "  -mwheel       <lines>        Number of lines the mouse wheel will scroll in\n"

src/gui/EmulationDialog.cxx

@@ -81,7 +81,7 @@ EmulationDialog::EmulationDialog(OSystem& osystem, DialogContainer& parent,
 
   // Set real dimensions
   _w = 37 * fontWidth + HBORDER * 2 + CheckboxWidget::prefixSize(_font);
-  _h = 12 * (lineHeight + VGAP) + VGAP * 7 + VBORDER * 3 + _th + buttonHeight;
+  _h = 13 * (lineHeight + VGAP) + VGAP * 7 + VBORDER * 3 + _th + buttonHeight;
 
   xpos = HBORDER;  ypos = VBORDER + _th;
 
@@ -122,8 +122,14 @@ EmulationDialog::EmulationDialog(OSystem& osystem, DialogContainer& parent,
   wid.push_back(myUIMessages);
   ypos += lineHeight + VGAP;
 
-  // Confirm dialog when exiting emulation
+  // Automatically pause emulation when focus is lost
   xpos = HBORDER; ypos += VGAP * 3;
+  myAutoPauseWidget = new CheckboxWidget(this, _font, xpos, ypos, "Automatic pause");
+  myAutoPauseWidget->setToolTip("Check for automatic pause/continue of\nemulation when Stella loses/gains focus.");
+  wid.push_back(myAutoPauseWidget);
+
+  // Confirm dialog when exiting emulation
+  ypos += lineHeight + VGAP;
   myConfirmExitWidget = new CheckboxWidget(this, _font, xpos, ypos, "Confirm exiting emulation");
   wid.push_back(myConfirmExitWidget);
 
@@ -186,6 +192,9 @@ void EmulationDialog::loadConfig()
   // Multi-threaded rendering
   myUseThreads->setState(settings.getBool("threads"));
 
+  // Automatically pause emulation when focus is lost
+  myAutoPauseWidget->setState(settings.getBool("autopause"));
+
   // Confirm dialog when exiting emulation
   myConfirmExitWidget->setState(settings.getBool("confirmexit"));
 
@@ -222,6 +231,9 @@ void EmulationDialog::saveConfig()
   // Multi-threaded rendering
   settings.setValue("threads", myUseThreads->getState());
 
+  // Automatically pause emulation when focus is lost
+  settings.setValue("autopause", myAutoPauseWidget->getState());
+
   // Confirm dialog when exiting emulation
   settings.setValue("confirmexit", myConfirmExitWidget->getState());
 
@@ -254,6 +266,7 @@ void EmulationDialog::setDefaults()
   myUIMessages->setState(true);
   myFastSCBios->setState(true);
   myUseThreads->setState(false);
+  myAutoPauseWidget->setState(false);
   myConfirmExitWidget->setState(false);
 
   mySaveOnExitGroup->setSelected(0);

src/gui/EmulationDialog.hxx

@@ -43,6 +43,7 @@ class EmulationDialog : public Dialog
     CheckboxWidget*   myUIMessages{nullptr};
     CheckboxWidget*   myFastSCBios{nullptr};
     CheckboxWidget*   myUseThreads{nullptr};
+    CheckboxWidget*   myAutoPauseWidget{nullptr};
     CheckboxWidget*   myConfirmExitWidget{nullptr};
     RadioButtonGroup* mySaveOnExitGroup{nullptr};
     CheckboxWidget*   myAutoSlotWidget{nullptr};