Added Engine::pauseEngine method (allows outside code, like the backend, to pause/resume the active engine); made the global 'confirm exit' dialog use that feature; implemented ScummEngine::pauseEngine

svn-id: r27797

2 files changed, 56 insertions, 27 deletions

diff --git a/engines/scumm/scumm.cpp b/engines/scumm/scumm.cpp
index 4b3a365394..aa6bea45bf 100644
--- a/engines/scumm/scumm.cpp
+++ b/engines/scumm/scumm.cpp
@@ -120,6 +120,8 @@ ScummEngine::ScummEngine(OSystem *syst, const DetectorResult &dr)
 		_gdi = new Gdi(this);
 	}
 	_res = new ResourceManager(this);
+	
+	_pauseLevel = 0;
 
 	// Convert MD5 checksum back into a digest
 	for (int i = 0; i < 16; ++i) {
@@ -2236,31 +2238,50 @@ void ScummEngine::startManiac() {
 #pragma mark --- GUI ---
 #pragma mark -
 
-int ScummEngine::runDialog(Dialog &dialog) {
-	_dialogStartTime = _system->getMillis() / 1000;
+void ScummEngine::pauseEngine(bool pause) {
+	assert((pause && _pauseLevel >= 0) || (!pause && _pauseLevel));
 
-	// Pause sound & video
-	bool old_soundsPaused = _sound->_soundsPaused;
-	_sound->pauseSounds(true);
+	if (pause)
+		_pauseLevel++;
+	else
+		_pauseLevel--;
 
-	bool visible = CursorMan.isVisible();
+	if (_pauseLevel == 1) {
+		_pauseStartTime = _system->getMillis();
 
-	// Open & run the dialog
-	int result = dialog.runModal();
+		// Pause sound & video
+		_oldSoundsPaused = _sound->_soundsPaused;
+		_sound->pauseSounds(true);
+	
+		//bool visible = CursorMan.isVisible();
+	
+	} else if (_pauseLevel == 0) {
+		// Restore old cursor -- FIXME: Should be obsolete thanks to CursorMan
+		//updateCursor();
+		//CursorMan.showMouse(visible);
 
-	// Restore old cursor
-	updateCursor();
-	CursorMan.showMouse(visible);
+		// Update the screen to make it less likely that the player will see a
+		// brief cursor palette glitch when the GUI is disabled.
+		_system->updateScreen();
 
-	// Update the screen to make it less likely that the player will see a
-	// brief cursor palette glitch when the GUI is disabled.
-	_system->updateScreen();
+		// Resume sound & video
+		_sound->pauseSounds(_oldSoundsPaused);
 
-	// Resume sound & video
-	_sound->pauseSounds(old_soundsPaused);
+		// Adjust engine start time
+		_engineStartTime += (_system->getMillis() - _pauseStartTime) / 1000;
+		_pauseStartTime = 0;
+	}
+}
+
+int ScummEngine::runDialog(Dialog &dialog) {
+	// Pause engine
+	pauseEngine(true);
+
+	// Open & run the dialog
+	int result = dialog.runModal();
 
-	_engineStartTime += (_system->getMillis() / 1000) - _dialogStartTime;
-	_dialogStartTime = 0;
+	// Resume engine
+	pauseEngine(false);
 
 	// Return the result
 	return result;
diff --git a/engines/scumm/scumm.h b/engines/scumm/scumm.h
index 3a5e9fb1ba..5c2249d198 100644
--- a/engines/scumm/scumm.h
+++ b/engines/scumm/scumm.h
@@ -406,9 +406,6 @@ class ScummEngine : public Engine {
 	friend class CharsetRenderer;
 	friend class ResourceManager;
 
-	GUI::Debugger *getDebugger();
-	void errorString(const char *buf_input, char *buf_output);
-
 public:
 	/* Put often used variables at the top.
 	 * That results in a shorter form of the opcode
@@ -437,17 +434,28 @@ public:
 
 protected:
 	VirtualMachineState vm;
+	
+	/**
+	 * The pause level, 0 means 'running', a positive value indicates
+	 * how often the engine has been paused (and hence how often it has
+	 * to be un-paused before it resumes running). This makes it possible
+	 * to nest code which pauses the engine.
+	 */
+	int _pauseLevel;
+	
+	bool _oldSoundsPaused;
 
 public:
 	// Constructor / Destructor
 	ScummEngine(OSystem *syst, const DetectorResult &dr);
 	virtual ~ScummEngine();
 
-	/** Startup function, main loop. */
-	int go();
-
-	// Init functions
-	int init();
+	// Engine APIs
+	virtual int init();
+	virtual int go();
+	virtual void errorString(const char *buf_input, char *buf_output);
+	virtual GUI::Debugger *getDebugger();
+	virtual void pauseEngine(bool pause);
 
 protected:
 	virtual void setupScumm();
@@ -638,7 +646,7 @@ protected:
 	void saveInfos(Common::OutSaveFile* file);
 
 	int32 _engineStartTime;
-	int32 _dialogStartTime;
+	int32 _pauseStartTime;
 
 protected:
 	/* Script VM - should be in Script class */