Launch application after destructing menu

This allows all destructors to do their job before we pass control to
a new process.

src/gmenu2x.cpp

@@ -126,6 +126,7 @@ static const char *colorToString(enum color c)
 
 static void quit_all(int err) {
 	delete app;
+	SDL_Quit();
 	exit(err);
 }
 
@@ -163,11 +164,31 @@ int main(int /*argc*/, char * /*argv*/[]) {
 
 	DEBUG("Home path: %s.\n", gmenu2x_home.c_str());
 
-	app = new GMenu2X();
+	GMenu2X::run();
-	DEBUG("Starting main()\n");
-	app->main();
 
-	return 0;
+	return EXIT_FAILURE;
+}
+
+void GMenu2X::run() {
+	auto menu = new GMenu2X();
+	app = menu;
+	DEBUG("Starting main()\n");
+	menu->mainLoop();
+
+	app = nullptr;
+	Launcher *toLaunch = menu->toLaunch.release();
+	delete menu;
+
+	SDL_Quit();
+	unsetenv("SDL_FBCON_DONT_CLEAR");
+
+	if (toLaunch) {
+		toLaunch->exec();
+		// If control gets here, execution failed. Since we already destructed
+		// everything, the easiest solution is to exit and let the system
+		// respawn the menu.
+		delete toLaunch;
+	}
 }
 
 #ifdef ENABLE_CPUFREQ
@@ -194,7 +215,6 @@ void GMenu2X::initCPULimits() {
 #endif
 
 GMenu2X::GMenu2X()
-	: appToLaunch(nullptr)
 {
 	usbnet = samba = inet = web = false;
 	useSelectionPng = false;
@@ -219,7 +239,9 @@ GMenu2X::GMenu2X()
 
 	if( SDL_Init(SDL_INIT_TIMER) < 0) {
 		ERROR("Could not initialize SDL: %s\n", SDL_GetError());
-		quit();
+		// TODO: We don't use exceptions, so don't put things that can fail
+		//       in a constructor.
+		exit(EXIT_FAILURE);
 	}
 
 	bg = NULL;
@@ -232,7 +254,9 @@ GMenu2X::GMenu2X()
 	 * a black screen for a couple of seconds. */
 	if( SDL_InitSubSystem(SDL_INIT_VIDEO) < 0) {
 		ERROR("Could not initialize SDL: %s\n", SDL_GetError());
-		quit();
+		// TODO: We don't use exceptions, so don't put things that can fail
+		//       in a constructor.
+		exit(EXIT_FAILURE);
 	}
 
 	s = Surface::openOutputSurface(resX, resY, confInt["videoBpp"]);
@@ -275,22 +299,17 @@ GMenu2X::GMenu2X()
 }
 
 GMenu2X::~GMenu2X() {
-	if (PowerSaver::isRunning())
+	if (PowerSaver::isRunning()) {
 		delete PowerSaver::getInstance();
-	quit();
+	}
 
-#ifdef ENABLE_INOTIFY
-	delete monitor;
-#endif
-}
-
-void GMenu2X::quit() {
 	fflush(NULL);
 	sc.clear();
 	delete s;
 
-	SDL_Quit();
+#ifdef ENABLE_INOTIFY
-	unsetenv("SDL_FBCON_DONT_CLEAR");
+	delete monitor;
+#endif
 }
 
 void GMenu2X::initBG() {
@@ -567,12 +586,10 @@ void GMenu2X::writeTmp(int selelem, const string &selectordir) {
 	}
 }
 
-void GMenu2X::main() {
+void GMenu2X::mainLoop() {
 	if (!fileExists(CARD_ROOT))
 		CARD_ROOT = "";
 
-	appToLaunch = nullptr;
-
 	// Recover last session
 	readTmp();
 	if (lastSelectorElement > -1 && menu->selLinkApp() &&
@@ -600,10 +617,12 @@ void GMenu2X::main() {
 		for (auto layer : layers) {
 			layer->paint(*s);
 		}
-		if (appToLaunch) {
+		s->flip();
+
+		// Exit main loop once we have something to launch.
+		if (toLaunch) {
 			break;
 		}
-		s->flip();
 
 		// Handle touchscreen events.
 		if (ts.available()) {
@@ -630,11 +649,6 @@ void GMenu2X::main() {
 			}
 		}
 	}
-
-	if (appToLaunch) {
-		appToLaunch->drawRun();
-		appToLaunch->launch(fileToLaunch);
-	}
 }
 
 void GMenu2X::explorer() {
@@ -645,24 +659,20 @@ void GMenu2X::explorer() {
 
 		string command = cmdclean(fd.getPath()+"/"+fd.getFile());
 		chdir(fd.getPath().c_str());
-		quit();
 #ifdef ENABLE_CPUFREQ
 		setClock(cpuFreqAppDefault);
 #endif
 
-		Launcher launcher(vector<string> { "/bin/sh", "-c", command });
+		toLaunch.reset(new Launcher(
-		launcher.exec();
+				vector<string> { "/bin/sh", "-c", command }));
-
-		//if execution continues then something went wrong and as we already called SDL_Quit we cannot continue
-		//try relaunching gmenu2x
-		ERROR("Error executing selected application, re-launching gmenu2x\n");
-		main();
 	}
 }
 
-void GMenu2X::queueLaunch(LinkApp *app, const std::string &file) {
+void GMenu2X::queueLaunch(
-	appToLaunch = app;
+	unique_ptr<Launcher>&& launcher, shared_ptr<Layer> launchLayer
-	fileToLaunch = file;
+) {
+	toLaunch = move(launcher);
+	layers.push_back(launchLayer);
 }
 
 void GMenu2X::showHelpPopup() {

src/gmenu2x.h

@@ -38,8 +38,8 @@ class Button;
 class Font;
 class HelpPopup;
 class IconButton;
+class Launcher;
 class Layer;
-class LinkApp;
 class MediaMonitor;
 class Menu;
 class Surface;
@@ -76,8 +76,7 @@ private:
 	MediaMonitor *monitor;
 #endif
 
-	LinkApp *appToLaunch;
+	std::unique_ptr<Launcher> toLaunch;
-	std::string fileToLaunch;
 
 	std::vector<std::shared_ptr<Layer>> layers;
 
@@ -120,9 +119,10 @@ private:
 	void initBG();
 
 public:
+	static void run();
+
 	GMenu2X();
 	~GMenu2X();
-	void quit();
 
 	/* Returns the home directory of gmenu2x, usually
 	 * ~/.gmenu2x */
@@ -162,7 +162,7 @@ public:
 	std::unique_ptr<Font> font;
 
 	//Status functions
-	void main();
+	void mainLoop();
 	void showContextMenu();
 	void showHelpPopup();
 	void showManual();
@@ -184,7 +184,9 @@ public:
 	 * The launch won't happen immediately; it will happen after control
 	 * returns to the main loop.
 	 */
-	void queueLaunch(LinkApp *app, const std::string &file);
+	void queueLaunch(std::unique_ptr<Launcher>&& launcher,
+					 std::shared_ptr<Layer> launchLayer);
+
 	void saveSelection();
 	void writeConfig();
 	void writeSkinConfig();

src/linkapp.cpp

@@ -24,6 +24,7 @@
 #include "delegate.h"
 #include "gmenu2x.h"
 #include "launcher.h"
+#include "layer.h"
 #include "menu.h"
 #include "selector.h"
 #include "surface.h"
@@ -55,6 +56,31 @@ using namespace std;
 
 static array<const char *, 4> tokens = { "%f", "%F", "%u", "%U", };
 
+
+/**
+ * Displays the launch message (loading screen).
+ */
+class LaunchLayer: public Layer {
+public:
+	LaunchLayer(LinkApp& app) : app(app) {}
+
+	void paint(Surface &s) override {
+		app.drawLaunch(s);
+	}
+
+	bool handleButtonPress(InputManager::Button) override {
+		return true;
+	}
+
+	bool handleTouchscreen(Touchscreen&) override {
+		return true;
+	}
+
+private:
+	LinkApp& app;
+};
+
+
 #ifdef HAVE_LIBOPK
 LinkApp::LinkApp(GMenu2X *gmenu2x_, const char* linkfile,
 			struct OPK *opk, const char *metadata_)
@@ -323,9 +349,9 @@ bool LinkApp::save() {
 	return false;
 }
 
-void LinkApp::drawRun() {
+void LinkApp::drawLaunch(Surface& s) {
 	//Darkened background
-	gmenu2x->s->box(0, 0, gmenu2x->resX, gmenu2x->resY, 0,0,0,150);
+	s.box(0, 0, gmenu2x->resX, gmenu2x->resY, 0,0,0,150);
 
 	string text = getLaunchMsg().empty()
 		? gmenu2x->tr.translate("Launching $1", getTitle().c_str(), nullptr)
@@ -336,25 +362,25 @@ void LinkApp::drawRun() {
 	int halfBoxW = boxW/2;
 
 	//outer box
-	gmenu2x->s->box(gmenu2x->halfX-2-halfBoxW, gmenu2x->halfY-23, halfBoxW*2+5, 47, gmenu2x->skinConfColors[COLOR_MESSAGE_BOX_BG]);
+	s.box(gmenu2x->halfX-2-halfBoxW, gmenu2x->halfY-23, halfBoxW*2+5, 47, gmenu2x->skinConfColors[COLOR_MESSAGE_BOX_BG]);
 	//inner rectangle
-	gmenu2x->s->rectangle(gmenu2x->halfX-halfBoxW, gmenu2x->halfY-21, boxW, 42, gmenu2x->skinConfColors[COLOR_MESSAGE_BOX_BORDER]);
+	s.rectangle(gmenu2x->halfX-halfBoxW, gmenu2x->halfY-21, boxW, 42, gmenu2x->skinConfColors[COLOR_MESSAGE_BOX_BORDER]);
 
 	int x = gmenu2x->halfX+10-halfBoxW;
 	/*if (!getIcon().empty())
 		gmenu2x->sc[getIcon()]->blit(gmenu2x->s,x,104);
 	else
 		gmenu2x->sc["icons/generic.png"]->blit(gmenu2x->s,x,104);*/
-	iconSurface->blit(gmenu2x->s,x,gmenu2x->halfY-16);
+	iconSurface->blit(&s, x, gmenu2x->halfY - 16);
-	gmenu2x->font->write(gmenu2x->s, text, x+42, gmenu2x->halfY+1, Font::HAlignLeft, Font::VAlignMiddle );
+	gmenu2x->font->write(&s, text, x + 42, gmenu2x->halfY + 1, Font::HAlignLeft, Font::VAlignMiddle);
-	gmenu2x->s->flip();
 }
 
 void LinkApp::start() {
-	if (!selectordir.empty())
+	if (selectordir.empty()) {
+		gmenu2x->queueLaunch(prepareLaunch(""), make_shared<LaunchLayer>(*this));
+	} else {
 		selector();
-	else
+	}
-		gmenu2x->queueLaunch(this, "");
 }
 
 void LinkApp::showManual() {
@@ -510,11 +536,13 @@ void LinkApp::selector(int startSelection, const string &selectorDir) {
 			selectordir = selectedDir;
 		}
 		gmenu2x->writeTmp(selection, selectedDir);
-		gmenu2x->queueLaunch(this, selectedDir + sel.getFile());
+		gmenu2x->queueLaunch(
+				prepareLaunch(selectedDir + sel.getFile()),
+				make_shared<LaunchLayer>(*this));
 	}
 }
 
-void LinkApp::launch(const string &selectedFile) {
+unique_ptr<Launcher> LinkApp::prepareLaunch(const string &selectedFile) {
 	save();
 
 	if (!isOpk()) {
@@ -568,7 +596,6 @@ void LinkApp::launch(const string &selectedFile) {
 		gmenu2x->setClock(clock());
 	}
 #endif
-	gmenu2x->quit();
 
 	vector<string> commandLine;
 	if (isOpk()) {
@@ -582,12 +609,8 @@ void LinkApp::launch(const string &selectedFile) {
 		commandLine = { "/bin/sh", "-c", exec + " " + params };
 	}
 
-	Launcher launcher(move(commandLine), consoleApp);
+	return std::unique_ptr<Launcher>(new Launcher(
-	launcher.exec();
+			move(commandLine), consoleApp));
-
-	//if execution continues then something went wrong and as we already called SDL_Quit we cannot continue
-	//try relaunching gmenu2x
-	gmenu2x->main();
 }
 
 const string &LinkApp::getExec() {

src/linkapp.h

@@ -23,9 +23,11 @@
 
 #include "link.h"
 
+#include <memory>
 #include <string>
 
 class GMenu2X;
+class Launcher;
 
 /**
 Parses links files.
@@ -95,8 +97,11 @@ public:
 	const std::string &getFile() { return file; }
 	void renameFile(const std::string &name);
 
-	void drawRun();
+private:
-	void launch(const std::string &selectedFile);
+	void drawLaunch(Surface& s);
+	std::unique_ptr<Launcher> prepareLaunch(const std::string &selectedFile);
+
+	friend class LaunchLayer;
 };
 
 #endif