From 35ee984d7239244a757f77e8621d4983d08fbc6c Mon Sep 17 00:00:00 2001 From: Vlad Pyatnichenko Date: Fri, 4 Mar 2016 20:15:13 +0200 Subject: [PATCH 1/4] Adaptation to Qt's pimpl idiom design. Improved inheritance safety. Details: * Improved unsafe C-style macros inheritance approach to the project-wide DEFINES: it is unspecified in which order source files are being preprocessed ones, so in singleapplication.cpp the class might be inherent of default-specified base, while in main.cpp this can be a user-provided QAPPLICATION_CLASS definition. * Replace Qt's pseudo-keywords to more library-independent counterparts ('emit -> Q_EMIT', etc) * Indentation fixes (80 character column-width) * Rearragned #include statements: from most platform-independen to more app-specific. * Fixed some grammar typos. * README.md updated respectively. --- README.md | 25 ++++++++-------- singleapplication.cpp | 66 ++++++++++++++++++++++++++----------------- singleapplication.h | 32 ++++++++++----------- 3 files changed, 68 insertions(+), 55 deletions(-) diff --git a/README.md b/README.md index 7cf1f9e..754e6b4 100644 --- a/README.md +++ b/README.md @@ -3,11 +3,11 @@ SingleApplication This is a replacement of the QSingleApplication for `Qt5`. -Keeps the Primary Instance of your Application and kills each subsequent instance. +Keeps the Primary Instance of your Application and kills each subsequent instances. Usage ----- -The `SingleApplication` class inherits from `QApplication`. Use it as if you are using the `QApplication` class. +The `SingleApplication` class inherits from whatever `Q[Core|Gui]Application` class you specify in the `*.pro` file. Further usage is similar to use one of the `Q[Core|Gui]Application` classes. The library uses your `Organization Name` and `Application Name` to set up a `QLocalServer` and a `QSharedMemory` block. The first instance of your Application would check if the shared memory block exists and if not it will start a `QLocalServer` and then listen for connections on it. Each subsequent instance of your application would check if the shared memory block exists and if it does, it will connect to the QLocalServer to notify it that a new instance had been started, after which would terminate the new instance with status code `0`. The Primary Instance, `SingleApplication` would emmit the `showUp()` signal upon detecting that a new instance had been started. @@ -15,6 +15,10 @@ The library uses `stdlib` to terminate the program with the `exit()` function. Here is an example usage of the library: ```cpp +// project.pro +DEFINES += QAPPLICATION_CLASS=QApplication # or whatever app class you want + +// main.cpp #include "singleapplication.h" int main(int argc, char *argv[]) @@ -34,21 +38,16 @@ The SingleApplication class implements a `showUp()` signal. You can bind to that Note that since `SingleApplication` extends the `QApplication` class you can do the following: ```cpp -QObject::connect(QApplication::instance(), SIGNAL(showUp()), window, SLOT(raise())); // window is your QWindow instance +// Truly raise your window. +QObject::connect(&app, &SingleApplication::showUp, [&]{ + window.show(); + window.raise(); + window.activateWindow(); + }); // 'window' is your QWindow instance ``` Using `QApplication::instance()` is a neat way to get the `SingleApplication` instance at any place in your program. -Extending from other application classes ------------------------ - -`SingleApplication` extends from the `QApplication` class by default , but you can easily change that to `QGuiApplication` or `QCoreApplication` with the `QAPPLICATION_CLASS` macro. Define it before the include statement of `singleapplication.h` or change the default value in the file. - -__Example:__ - -```cpp -#define QAPPLICATION_CLASS QCoreApplication -``` Implementation -------------- diff --git a/singleapplication.cpp b/singleapplication.cpp index 0bcbc12..451857d 100644 --- a/singleapplication.cpp +++ b/singleapplication.cpp @@ -1,16 +1,21 @@ -#include "singleapplication.h" +#include + #include #include #include #include -#include #ifdef Q_OS_UNIX #include #include #endif +#include "singleapplication.h" + + class SingleApplicationPrivate { + Q_DECLARE_PUBLIC(SingleApplication) + public: SingleApplicationPrivate(SingleApplication *q_ptr) : q_ptr(q_ptr) { } @@ -18,7 +23,7 @@ class SingleApplicationPrivate { { // Start a QLocalServer to listen for connections server = new QLocalServer(); - server->removeServer(serverName); + QLocalServer::removeServer(serverName); server->listen(serverName); QObject::connect(server, SIGNAL(newConnection()), q_ptr, SLOT(slotConnectionEstablished())); } @@ -27,8 +32,8 @@ class SingleApplicationPrivate { void crashHandler() { // This guarantees the program will work even with multiple - // instances of SingleApplication in different threads - // Which in my opinion is idiotic, but lets handle that too + // instances of SingleApplication in different threads. + // Which in my opinion is idiotic, but lets handle that too. { sharedMemMutex.lock(); sharedMem.append(memory); @@ -38,9 +43,9 @@ class SingleApplicationPrivate { // QSharedMemory block is deleted even if the process crashes signal(SIGSEGV, SingleApplicationPrivate::terminate); signal(SIGABRT, SingleApplicationPrivate::terminate); - signal(SIGFPE, SingleApplicationPrivate::terminate); - signal(SIGILL, SingleApplicationPrivate::terminate); - signal(SIGINT, SingleApplicationPrivate::terminate); + signal(SIGFPE, SingleApplicationPrivate::terminate); + signal(SIGILL, SingleApplicationPrivate::terminate); + signal(SIGINT, SingleApplicationPrivate::terminate); signal(SIGTERM, SingleApplicationPrivate::terminate); } @@ -75,38 +80,43 @@ class SingleApplicationPrivate { * @param argv */ SingleApplication::SingleApplication(int &argc, char *argv[]) - : QAPPLICATION_CLASS(argc, argv), d_ptr(new SingleApplicationPrivate(this)) + : app_t(argc, argv), d_ptr(new SingleApplicationPrivate(this)) { - QString serverName = QAPPLICATION_CLASS::organizationName() + QAPPLICATION_CLASS::applicationName(); + Q_D(SingleApplication); + + QString serverName = app_t::organizationName() + app_t::applicationName(); serverName.replace(QRegExp("[^\\w\\-. ]"), ""); - // Garantee thread safe behaviour with a shared memory block - d_ptr->memory = new QSharedMemory(serverName); + // Guarantee thread safe behaviour with a shared memory block + d->memory = new QSharedMemory(serverName); // Create a shared memory block with a minimum size of 1 byte - if( d_ptr->memory->create(1, QSharedMemory::ReadOnly) ) + if( d->memory->create(1, QSharedMemory::ReadOnly) ) { #ifdef Q_OS_UNIX // Handle any further termination signals to ensure the // QSharedMemory block is deleted even if the process crashes - d_ptr->crashHandler(); + d->crashHandler(); #endif // Successful creation means that no main process exists // So we start a Local Server to listen for connections - d_ptr->startServer(serverName); + d->startServer(serverName); } else { // Connect to the Local Server of the main process to notify it // that a new process had been started - d_ptr->socket = new QLocalSocket(); - d_ptr->socket->connectToServer(serverName); + d->socket = new QLocalSocket(); + d->socket->connectToServer(serverName); - // Even though a shared memory block exists, the original application might have crashed - // So only after a successful connection is the second instance terminated - if( d_ptr->socket->waitForConnected(100) ) + // Even though a shared memory block exists, the original application + // might have crashed. + // So only after a successful connection is the second instance + // terminated. + if( d->socket->waitForConnected(100) ) { - ::exit(EXIT_SUCCESS); // Terminate the program using STDLib's exit function + // Terminate the program using STDLib's exit function. + ::exit(EXIT_SUCCESS); } else { - delete d_ptr->memory; + delete d->memory; ::exit(EXIT_SUCCESS); } } @@ -117,8 +127,10 @@ SingleApplication::SingleApplication(int &argc, char *argv[]) */ SingleApplication::~SingleApplication() { - delete d_ptr->memory; - d_ptr->server->close(); + Q_D(SingleApplication); + + delete d->memory; + d->server->close(); } /** @@ -126,8 +138,10 @@ SingleApplication::~SingleApplication() */ void SingleApplication::slotConnectionEstablished() { - QLocalSocket *socket = d_ptr->server->nextPendingConnection(); + Q_D(SingleApplication); + + QLocalSocket *socket = d->server->nextPendingConnection(); socket->close(); delete socket; - emit showUp(); + Q_EMIT showUp(); } diff --git a/singleapplication.h b/singleapplication.h index 1fe5c12..dc6beb3 100644 --- a/singleapplication.h +++ b/singleapplication.h @@ -1,14 +1,8 @@ #ifndef SINGLE_APPLICATION_H #define SINGLE_APPLICATION_H +#include -// Change this to inherit from QGuiApplication or QCoreApplication -#ifndef QAPPLICATION_CLASS - #define QAPPLICATION_CLASS QCoreApplication -#endif - -#define QUOTE(C) #C -#define INCLUDE_FILE(C) QUOTE(C) -#include INCLUDE_FILE(QAPPLICATION_CLASS) +#include QT_STRINGIFY(QAPPLICATION_CLASS) class SingleApplicationPrivate; @@ -18,19 +12,25 @@ class SingleApplicationPrivate; */ class SingleApplication : public QAPPLICATION_CLASS { - Q_OBJECT + Q_OBJECT + Q_DECLARE_PRIVATE(SingleApplication) + + typedef QAPPLICATION_CLASS app_t; + public: - explicit SingleApplication(int&, char *[]); - ~SingleApplication(); + explicit SingleApplication(int&, char *[]); + ~SingleApplication(); -signals: - void showUp(); +Q_SIGNALS: + void showUp(); -private slots: - void slotConnectionEstablished(); +private Q_SLOTS: + void slotConnectionEstablished(); private: - SingleApplicationPrivate *d_ptr; + SingleApplicationPrivate *d_ptr; + + }; #endif // SINGLE_APPLICATION_H From 27df0ec8d012dca64dc0937649c39015f5d421f8 Mon Sep 17 00:00:00 2001 From: Vlad Pyatnichenko Date: Sun, 6 Mar 2016 01:09:04 +0200 Subject: [PATCH 2/4] HOTFIX: added Qt's modules prefixes to #include statements. --- singleapplication.cpp | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/singleapplication.cpp b/singleapplication.cpp index 451857d..32269d4 100644 --- a/singleapplication.cpp +++ b/singleapplication.cpp @@ -1,9 +1,9 @@ #include -#include -#include -#include -#include +#include +#include +#include +#include #ifdef Q_OS_UNIX #include From 7a3858a2148b60500f7a8ce26b5047ff34bee42c Mon Sep 17 00:00:00 2001 From: Vlad Pyatnichenko Date: Tue, 22 Mar 2016 01:32:20 +0200 Subject: [PATCH 3/4] HOTFIX: use Q_Q instead of q_ptr directly. --- singleapplication.cpp | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/singleapplication.cpp b/singleapplication.cpp index 32269d4..1c0d921 100644 --- a/singleapplication.cpp +++ b/singleapplication.cpp @@ -21,11 +21,13 @@ class SingleApplicationPrivate { void startServer(QString &serverName) { + Q_Q(SingleApplication); + // Start a QLocalServer to listen for connections server = new QLocalServer(); QLocalServer::removeServer(serverName); server->listen(serverName); - QObject::connect(server, SIGNAL(newConnection()), q_ptr, SLOT(slotConnectionEstablished())); + QObject::connect(server, SIGNAL(newConnection()), q, SLOT(slotConnectionEstablished())); } #ifdef Q_OS_UNIX From 8eb993a7f81428b816d47887cd60139d1dfa7fff Mon Sep 17 00:00:00 2001 From: Vlad Pyatnichenko Date: Tue, 5 Apr 2016 20:31:05 +0300 Subject: [PATCH 4/4] Ensure backward compatibility and some cosmetic changes. --- README.md | 11 ++++++----- singleapplication.cpp | 2 +- singleapplication.h | 4 ++++ 3 files changed, 11 insertions(+), 6 deletions(-) diff --git a/README.md b/README.md index 754e6b4..f677ba6 100644 --- a/README.md +++ b/README.md @@ -39,11 +39,12 @@ The SingleApplication class implements a `showUp()` signal. You can bind to that Note that since `SingleApplication` extends the `QApplication` class you can do the following: ```cpp // Truly raise your window. -QObject::connect(&app, &SingleApplication::showUp, [&]{ - window.show(); - window.raise(); - window.activateWindow(); - }); // 'window' is your QWindow instance +QObject::connect(&app, &SingleApplication::showUp, [&] +{ + window.show(); + window.raise(); + window.activateWindow(); +}); // 'window' is your QWindow instance ``` Using `QApplication::instance()` is a neat way to get the `SingleApplication` instance at any place in your program. diff --git a/singleapplication.cpp b/singleapplication.cpp index 1c0d921..27e2bb1 100644 --- a/singleapplication.cpp +++ b/singleapplication.cpp @@ -115,7 +115,7 @@ SingleApplication::SingleApplication(int &argc, char *argv[]) // terminated. if( d->socket->waitForConnected(100) ) { - // Terminate the program using STDLib's exit function. + // Terminate the program using STDLib's exit function ::exit(EXIT_SUCCESS); } else { delete d->memory; diff --git a/singleapplication.h b/singleapplication.h index dc6beb3..91f5b11 100644 --- a/singleapplication.h +++ b/singleapplication.h @@ -2,6 +2,10 @@ #define SINGLE_APPLICATION_H #include +#ifndef QAPPLICATION_CLASS + #define QAPPLICATION_CLASS QApplication +#endif + #include QT_STRINGIFY(QAPPLICATION_CLASS) class SingleApplicationPrivate;