Linux: Allow the event bit mask to be specified in LinuxEventLoop::registerFdCallback()

modules/juce_events/native/juce_linux_EventLoop.h

@@ -34,8 +34,11 @@ namespace LinuxEventLoop
         @param fd            the file descriptor to be monitored
         @param readCallback  a callback that will be called when the file descriptor has
                              data to read. The file descriptor will be passed as an argument
+        @param eventMask     a bit mask specifying the events you are interested in for the
+                             file descriptor. The possible values for this are defined in
+                             <poll.h>
     */
-    void registerFdCallback (int fd, std::function<void(int)> readCallback);
+    void registerFdCallback (int fd, std::function<void(int)> readCallback, short eventMask = 1 /*POLLIN*/);
 
     /** Unregisters a previously registered file descriptor.
 

modules/juce_events/native/juce_linux_Messaging.cpp

@@ -119,12 +119,12 @@ public:
         fdReadCallbacks.reserve (8);
     }
 
-    void registerFdCallback (int fd, std::function<void(int)>&& cb)
+    void registerFdCallback (int fd, std::function<void(int)>&& cb, short eventMask)
     {
         const ScopedLock sl (lock);
 
         fdReadCallbacks.push_back ({ fd, std::move (cb) });
-        pfds.push_back ({ fd, POLLIN, 0 });
+        pfds.push_back ({ fd, eventMask, 0 });
     }
 
     void unregisterFdCallback (int fd)
@@ -273,10 +273,10 @@ bool MessageManager::dispatchNextMessageOnSystemQueue (bool returnIfNoPendingMes
 }
 
 //==============================================================================
-void LinuxEventLoop::registerFdCallback (int fd, std::function<void(int)> readCallback)
+void LinuxEventLoop::registerFdCallback (int fd, std::function<void(int)> readCallback, short eventMask)
 {
     if (auto* runLoop = InternalRunLoop::getInstanceWithoutCreating())
-        runLoop->registerFdCallback (fd, std::move (readCallback));
+        runLoop->registerFdCallback (fd, std::move (readCallback), eventMask);
 }
 
 void LinuxEventLoop::unregisterFdCallback (int fd)