Add C++ client

README.md

@@ -59,3 +59,7 @@ ERROR: API_EventTimeout
 2020-02-14 23:48:36.249320 TEST/DEVICE2/1 ATTR1 IDL5_CHANGE [ATTR_VALID] 0.0
 ERROR: API_EventTimeout
 ```
+
+Alternatively build and run the C++ client:
+1. `g++ client1.cpp -o client1 -I/usr/include/tango -ltango -lzmq -lomniORB4 -lomnithread -lCOS4 -lomniDynamic4 -g`
+2. `./client1`

client1.cpp

@@ -0,0 +1,59 @@
+#include <tango.h>
+#include <unistd.h>
+
+using namespace Tango;
+
+class EventCallBack: public Tango::CallBack {
+    public: 
+    void push_event(Tango::EventData* event) {
+        if (event->err) {
+            Tango::Except::print_error_stack(event->errors);
+        } else {
+            std::cout << "event: " << event->attr_name << " " << event->event << std::endl; 
+        }
+
+    };
+};
+
+class CB: public Tango::CallBack {
+    public: 
+    CB(DeviceProxy* dev, int id):
+        dev(dev), id(id) 
+    {};
+
+    void push_event(Tango::EventData* event) {
+        if (event->err) {
+            Tango::Except::print_error_stack(event->errors);
+        } else {
+            dev->unsubscribe_event(id);
+            std::cout << "unsubscribed " << id << std::endl;
+        }
+
+    };
+    int id;
+    Tango::DeviceProxy * dev;
+};
+
+int main(unsigned int argc, char **argv)
+{
+
+    Tango::DeviceProxy *dev1 = new Tango::DeviceProxy("test/device1/1");
+    Tango::DeviceProxy *dev2 = new Tango::DeviceProxy("test/device2/1");
+
+    sleep(1);
+    int id = dev1->subscribe_event(
+        "attr1", Tango::EventType::ATTR_CONF_EVENT, new EventCallBack()
+    );
+    sleep(1);
+
+    dev2->subscribe_event(
+        "attr1", Tango::EventType::CHANGE_EVENT, new EventCallBack()
+    );
+
+    CB * cb = new CB(dev1, id);
+    dev2->subscribe_event(
+        "attr2", Tango::EventType::CHANGE_EVENT, cb
+    );
+
+    sleep(30);
+};