editor: delete viewport widgets immediately

I don't know why the viewports are deleted with deleteLater(), but it leads
to an OpenGL context getting deselected behind our back, and so we don't know
when is a good time to re-select it. This leads to termination of the engine
when selecting File->Close (Ctrl+W) in the editor, because the graphics
re-initialization fails with no GL context active.

Instead, just delete the viewport widget immediately, which works fine at
least on Linux. This is also recommended by the Qt documentation at
http://doc.qt.io/qt-5/qopenglwidget.html.

src/editor/C4Console.cpp

@@ -62,7 +62,9 @@ C4Console::~C4Console()
 
 C4Window * C4Console::Init(C4AbstractApp * pApp)
 {
-	return C4ConsoleGUI::CreateConsoleWindow(pApp);
+	if (!C4ConsoleGUI::CreateConsoleWindow(pApp))
+		return NULL;
+	return this;
 }
 
 bool C4Console::In(const char *szText)
@@ -366,15 +368,18 @@ void C4Console::Default()
 
 void C4Console::Clear()
 {
+	if (pSurface) delete pSurface;
+	pSurface = 0;
+
 	C4Window::Clear();
+	C4ConsoleGUI::DeleteConsoleWindow();
+
 	EditCursor.Clear();
 	ToolsDlg.Clear();
 	PropertyDlgClose();
 	ClearViewportMenu();
 	ClearPlayerMenu();
 	ClearNetMenu();
-	if (pSurface) delete pSurface;
-	pSurface = 0;
 #ifndef _WIN32
 	Application.Quit();
 #endif
@@ -613,11 +618,14 @@ bool C4ConsoleGUI::ClearLog() {return 0;}
 void C4ConsoleGUI::ClearNetMenu() {}
 void C4ConsoleGUI::ClearPlayerMenu() {}
 void C4ConsoleGUI::ClearViewportMenu() {}
-C4Window * C4ConsoleGUI::CreateConsoleWindow(C4AbstractApp * pApp)
+bool C4ConsoleGUI::CreateConsoleWindow(C4AbstractApp * pApp)
 {
 	C4Rect r(0, 0, 400, 350);
-	return C4Window::Init(C4Window::W_Console, pApp, LoadResStr("IDS_CNS_CONSOLE"), &r);
+	if (!C4Window::Init(C4Window::W_Console, pApp, LoadResStr("IDS_CNS_CONSOLE"), &r))
+		return false;
+	return true;
 }
+void C4ConsoleGUI::DeleteConsoleWindow() {}
 void C4ConsoleGUI::DisplayInfoText(C4ConsoleGUI::InfoTextType, StdStrBuf&) {}
 void C4ConsoleGUI::DoEnableControls(bool) {}
 bool C4ConsoleGUI::DoUpdateHaltCtrls(bool) {return 0;}

src/editor/C4ConsoleCocoa.mm

@@ -63,14 +63,18 @@ public:
 	void Clear() {}
 };
 
-C4Window* C4ConsoleGUI::CreateConsoleWindow(C4AbstractApp *application)
+bool C4ConsoleGUI::CreateConsoleWindow(C4AbstractApp *application)
 {
 	C4WindowController* controller = [C4EditorWindowController new];
 	setObjectiveCObject(controller);
 	[NSBundle loadNibNamed:@"Editor" owner:controller];
 	[controller setStdWindow:this];
 	this->Active = true;
-	return this;
+	return true;
+}
+
+void C4ConsoleGUI::DeleteConsoleWindow()
+{
 }
 
 void C4ConsoleGUI::Out(const char* message)

src/editor/C4ConsoleGUI.h

@@ -122,7 +122,8 @@ public:
 	void ClearPlayerMenu();
 	void SetInputFunctions(std::list<const char*> &functions);
 	
-	C4Window* CreateConsoleWindow(C4AbstractApp *application);
+	bool CreateConsoleWindow(C4AbstractApp *application);
+	void DeleteConsoleWindow();
 	void Out(const char* message);
 	bool ClearLog();
 	void DisplayInfoText(InfoTextType type, StdStrBuf& text);

src/editor/C4ConsoleQt.cpp

@@ -82,12 +82,21 @@ void C4ConsoleGUI::SetInputFunctions(std::list<const char*> &functions)
 	if (Active) state->SetInputFunctions(functions);
 }
 
-C4Window* C4ConsoleGUI::CreateConsoleWindow(C4AbstractApp *application)
+bool C4ConsoleGUI::CreateConsoleWindow(C4AbstractApp *application)
 {
-	if (!state->CreateConsoleWindow(application)) return NULL;
+	if (!state->CreateConsoleWindow(application)) return false;
 	Active = true;
 	EnableControls(fGameOpen);
-	return this;
+	return true;
+}
+
+void C4ConsoleGUI::DeleteConsoleWindow()
+{
+	if (Active)
+	{
+		Active = false;
+		state->DeleteConsoleWindow();
+	}
 }
 
 void C4ConsoleGUI::Out(const char* message)

src/editor/C4ConsoleQtState.cpp

@@ -734,6 +734,46 @@ bool C4ConsoleGUIState::CreateConsoleWindow(C4AbstractApp *app)
 	return true;
 }
 
+void C4ConsoleGUIState::DeleteConsoleWindow()
+{
+	// Reset to a state before CreateConsoleWindow was called
+	action_object = C4VNull;
+	is_object_selection_updating = false;
+
+	editcursor_mode = C4CNS_ModePlay;
+	drawing_tool = C4TLS_Brush;
+	landscape_mode = LandscapeMode::Dynamic;
+	net_enabled = false;
+	recording = false;
+	enabled = false;
+	
+	window_menu_separator = nullptr;
+	status_cursor = status_framecounter = status_timefps = nullptr;
+
+	while (!viewports.empty())
+	{
+		auto vp = viewports.front();
+		viewports.erase(viewports.begin());
+
+		viewport_area->removeDockWidget(vp);
+		delete vp;
+	}
+
+	client_actions.clear();
+	player_actions.clear();
+	viewport_actions.clear();
+	viewport_area = nullptr;
+
+	disable_shortcut_filter.reset(nullptr);
+	definition_list_model.reset(nullptr);
+	object_list_model.reset(nullptr);
+	property_name_delegate.reset(nullptr);
+	property_delegate_factory.reset(nullptr);
+	property_model.reset(nullptr);
+	window.reset(nullptr);
+	application.reset(nullptr);
+}
+
 void C4ConsoleGUIState::Execute(bool redraw_only)
 {
 	// Nothing to do - Qt's event loop is handling everything.
@@ -875,12 +915,26 @@ void C4ConsoleGUIState::AddViewport(C4ViewportWindow *cvp)
 void C4ConsoleGUIState::RemoveViewport(C4ViewportWindow *cvp)
 {
 	if (!viewport_area) return;
-	for (auto vp : viewports)
+
+	for (auto iter = viewports.begin(); iter != viewports.end(); )
 	{
+		auto vp = *iter;
 		if (vp->GetViewportWindow() == cvp)
 		{
 			viewport_area->removeDockWidget(vp);
-			vp->deleteLater();
+			iter = viewports.erase(iter);
+
+			// cannot use deleteLater here because Qt will then
+			// still select/deselect the viewport's GL context
+			// behind the scenes, leaving us with an unselected
+			// GL context.
+			// Documented at http://doc.qt.io/qt-5/qopenglwidget.html
+			// Instead, delete the viewport widget directly.
+			delete vp;
+		}
+		else
+		{
+			++iter;
 		}
 	}
 }

src/editor/C4ConsoleQtState.h

@@ -220,6 +220,7 @@ public:
 
 	void AddToolbarSpacer(int space);
 	bool CreateConsoleWindow(C4AbstractApp *app);
+	void DeleteConsoleWindow();
 	void Execute(bool redraw_only=false);
 	void Redraw() { Execute(true); }
 	void UpdateActionStates();

src/editor/C4ConsoleQtViewport.cpp

@@ -524,9 +524,15 @@ void C4ConsoleQtViewportDockWidget::closeEvent(QCloseEvent * event)
 	QDockWidget::closeEvent(event);
 	if (event->isAccepted())
 	{
-		if (cvp) cvp->Close();
-		cvp = NULL;
-		deleteLater();
+		if (cvp)
+		{
+			// This causes "this" to be deleted:
+			cvp->Close();
+		}
+		else
+		{
+			deleteLater();
+		}
 	}
 }
 

src/editor/C4ConsoleWin32.cpp

@@ -783,7 +783,7 @@ bool C4ConsoleGUI::UpdateModeCtrls(int iMode)
 	return true;
 }
 
-C4Window* C4ConsoleGUI::CreateConsoleWindow(C4AbstractApp *application)
+bool C4ConsoleGUI::CreateConsoleWindow(C4AbstractApp *application)
 {
 	hWindow = CreateDialog(application->GetInstance(), MAKEINTRESOURCE(IDD_CONSOLE), NULL, ConsoleDlgProc);
 	if (!hWindow)
@@ -802,7 +802,7 @@ C4Window* C4ConsoleGUI::CreateConsoleWindow(C4AbstractApp *application)
 		Log(FormatString("Error creating dialog window: %s", StdStrBuf(lpMsgBuf).getData()).getData());
 		// Free the buffer.
 		LocalFree(lpMsgBuf);
-		return NULL;
+		return false;
 	}
 	// Remember metrics
 	state->console_handle = hWindow;
@@ -827,7 +827,11 @@ C4Window* C4ConsoleGUI::CreateConsoleWindow(C4AbstractApp *application)
 	ShowCursor(true);
 	renderwnd = hWindow;
 	// Success
-	return this;
+	return true;
+}
+
+void C4ConsoleGUI::DeleteConsoleWindow()
+{
 }
 
 void C4ConsoleGUI::DoEnableControls(bool fEnable)