[Go] Updated the 'callback' and 'extend' examples to match the 'director' one.

After the documentation update on how to utilize the director feature with
commit @17b1c1c the 'callback' and 'extend' examples needed an update as well.

Examples/go/callback/Makefile

@@ -1,6 +1,7 @@
 TOP        = ../..
 SWIG       = $(TOP)/../preinst-swig
 CXXSRCS    = callback.cxx
+GOSRCS     = gocallback.go
 TARGET     = example
 INTERFACE  = example.i
 SWIGOPT    =
@@ -9,8 +10,15 @@ check: build
 	$(MAKE) -f $(TOP)/Makefile SRCDIR='$(SRCDIR)' CXXSRCS='$(CXXSRCS)' TARGET='$(TARGET)' INTERFACE='$(INTERFACE)' go_run
 
 build:
-	$(MAKE) -f $(TOP)/Makefile SRCDIR='$(SRCDIR)' CXXSRCS='$(CXXSRCS)' SWIG='$(SWIG)' \
+	if [ -n '$(SRCDIR)' ]; then \
-	SWIGOPT='$(SWIGOPT)' TARGET='$(TARGET)' INTERFACE='$(INTERFACE)' go_cpp
+		cp $(GOSRCS:%=$(SRCDIR)/%) .; \
+	fi
+	@# Note: example.go gets generated by SWIG
+	$(MAKE) -f $(TOP)/Makefile SRCDIR='$(SRCDIR)' CXXSRCS='$(CXXSRCS)' GOSRCS='example.go $(GOSRCS)' \
+	SWIG='$(SWIG)' SWIGOPT='$(SWIGOPT)' TARGET='$(TARGET)' INTERFACE='$(INTERFACE)' go_cpp
 
 clean:
+	if [ -n '$(SRCDIR)' ]; then \
+		rm $(GOSRCS) || true; \
+	fi
 	$(MAKE) -f $(TOP)/Makefile SRCDIR='$(SRCDIR)' INTERFACE='$(INTERFACE)' go_clean

Examples/go/callback/example.h

@@ -20,4 +20,3 @@ public:
 	void setCallback(Callback *cb) { delCallback(); _callback = cb; }
 	void call() { if (_callback) _callback->run(); }
 };
-

Examples/go/callback/gocallback.go

@@ -0,0 +1,41 @@
+package example
+
+import (
+	"fmt"
+)
+
+type GoCallback interface {
+	Callback
+	deleteCallback()
+	IsGoCallback()
+}
+
+type goCallback struct {
+	Callback
+}
+
+func (p *goCallback) deleteCallback() {
+	DeleteDirectorCallback(p.Callback)
+}
+
+func (p *goCallback) IsGoCallback() {}
+
+type overwrittenMethodsOnCallback struct {
+	p Callback
+}
+
+func NewGoCallback() GoCallback {
+	om := &overwrittenMethodsOnCallback{}
+	p := NewDirectorCallback(om)
+	om.p = p
+
+	return &goCallback{Callback: p}
+}
+
+func DeleteGoCallback(p GoCallback) {
+	p.deleteCallback()
+}
+
+func (p *goCallback) Run() {
+	fmt.Println("GoCallback.Run")
+}

Examples/go/callback/index.html

@@ -12,67 +12,17 @@
 <H2>Implementing C++ callbacks in Go</H2>
 
 <p>
-This example illustrates how to use directors to implement C++
+This example illustrates how to use directors to implement C++ callbacks in Go.
-callbacks in Go.
+See the <a href="../../../Doc/Manual/Go.html#Go_director_classes">Go Director
-</p>
+Classes</a> documentation subsection for an in-depth explanation how to use the
-
+director feature.
-<p>
-Because Go and C++ use inheritance differently, you must call a
-different function to create a class which uses callbacks.  Instead of
-calling the usual constructor function whose name is <tt>New</tt>
-followed by the capitalized name of the class, you call a function
-named <tt>NewDirector</tt> followed by the capitalized name of the
-class.
-</p>
-
-<p>
-The first argument to the <tt>NewDirector</tt> function is an instance
-of a type.  The <tt>NewDirector</tt> function will return an interface
-value as usual.  However, when calling any method on the returned
-value, the program will first check whether the value passed
-to <tt>NewDirector</tt> implements that method.  If it does, the
-method will be called in Go.  This is true whether the method is
-called from Go code or C++ code.
-</p>
-
-<p>
-Note that the Go code will be called with just the Go value, not the
-C++ value.  If the Go code needs to call a C++ method on itself, you
-need to get a copy of the C++ object.  This is typically done as
-follows:
-
-<blockquote>
-<pre>
-type Child struct { abi Parent }
-func (p *Child) ChildMethod() {
-	p.abi.ParentMethod()
-}
-func f() {
-	p := &Child{nil}
-	d := NewDirectorParent(p)
-	p.abi = d
-	...
-}
-</pre>
-</blockquote>
-
-In other words, we first create the Go value.  We pass that to
-the <tt>NewDirector</tt> function to create the C++ value; this C++
-value will be created with an association to the Go value.  We then
-store the C++ value in the Go value, giving us the reverse
-association.  That permits us to call parent methods from the child.
-
-</p>
-
-<p>
-To delete a director object, use the function <tt>DeleteDirector</tt>
-followed by the capitalized name of the class.
 </p>
 
 <p>
 <ul>
-<li><a href="example.h">example.h</a>.  Header file containing some enums.
+<li><a href="example.h">example.h</a>.  Header with the definition of the Caller and Callback classes.
-<li><a href="example.i">example.i</a>.  Interface file.
+<li><a href="example.i">example.i</a>.  SWIG interface file.
+<li><a href="gocallback.go">gocallback.go</a>.  Go source with the definition of the GoCallback class.
 <li><a href="runme.go">runme.go</a>. Sample Go program.
 </ul>
 

Examples/go/callback/runme.go

@@ -16,26 +16,18 @@ func main() {
 	caller.Call()
 	caller.DelCallback()
 
-	callback = NewDirectorCallback(new(GoCallback))
+	go_callback := NewGoCallback()
 
 	fmt.Println()
 	fmt.Println("Adding and calling a Go callback")
-	fmt.Println("------------------------------------")
+	fmt.Println("--------------------------------")
 
-	caller.SetCallback(callback)
+	caller.SetCallback(go_callback)
 	caller.Call()
 	caller.DelCallback()
 
-	// Test that a double delete does not occur as the object has
+	DeleteGoCallback(go_callback)
-	// already been deleted from the C++ layer.
-	DeleteDirectorCallback(callback)
 
 	fmt.Println()
 	fmt.Println("Go exit")
 }
-
-type GoCallback struct{}
-
-func (p *GoCallback) Run() {
-	fmt.Println("GoCallback.Run")
-}

Examples/go/director/Makefile

@@ -1,7 +1,7 @@
 TOP        = ../..
 SWIG       = $(TOP)/../preinst-swig
-CXXSRCS    = 
+CXXSRCS    =
-GOSRCS     = example.go director.go  # example.go gets generated by SWIG
+GOSRCS     = director.go
 TARGET     = example
 INTERFACE  = example.i
 SWIGOPT    =
@@ -11,13 +11,14 @@ check: build
 
 build:
 	if [ -n '$(SRCDIR)' ]; then \
-		cp $(SRCDIR)/director.go .; \
+		cp $(GOSRCS:%=$(SRCDIR)/%) .; \
 	fi
-	$(MAKE) -f $(TOP)/Makefile SRCDIR='$(SRCDIR)' CXXSRCS='$(CXXSRCS)' GOSRCS='$(GOSRCS)' \
+	@# Note: example.go gets generated by SWIG
+	$(MAKE) -f $(TOP)/Makefile SRCDIR='$(SRCDIR)' CXXSRCS='$(CXXSRCS)' GOSRCS='example.go $(GOSRCS)' \
 	SWIG='$(SWIG)' SWIGOPT='$(SWIGOPT)' TARGET='$(TARGET)' INTERFACE='$(INTERFACE)' go_cpp
 
 clean:
 	if [ -n '$(SRCDIR)' ]; then \
-		rm director.go || true; \
+		rm $(GOSRCS) || true; \
 	fi
 	$(MAKE) -f $(TOP)/Makefile SRCDIR='$(SRCDIR)' INTERFACE='$(INTERFACE)' go_clean

Examples/go/extend/Makefile

@@ -1,6 +1,7 @@
 TOP        = ../..
 SWIG       = $(TOP)/../preinst-swig
 CXXSRCS    = extend.cxx
+GOSRCS     = ceo.go
 TARGET     = example
 INTERFACE  = example.i
 SWIGOPT    =
@@ -9,8 +10,15 @@ check: build
 	$(MAKE) -f $(TOP)/Makefile SRCDIR='$(SRCDIR)' CXXSRCS='$(CXXSRCS)' TARGET='$(TARGET)' INTERFACE='$(INTERFACE)' go_run
 
 build:
-	$(MAKE) -f $(TOP)/Makefile SRCDIR='$(SRCDIR)' CXXSRCS='$(CXXSRCS)' SWIG='$(SWIG)' \
+	if [ -n '$(SRCDIR)' ]; then \
-	SWIGOPT='$(SWIGOPT)' TARGET='$(TARGET)' INTERFACE='$(INTERFACE)' go_cpp
+		cp $(GOSRCS:%=$(SRCDIR)/%) .; \
+	fi
+	@# Note: example.go gets generated by SWIG
+	$(MAKE) -f $(TOP)/Makefile SRCDIR='$(SRCDIR)' CXXSRCS='$(CXXSRCS)' GOSRCS='example.go $(GOSRCS)' \
+	SWIG='$(SWIG)' SWIGOPT='$(SWIGOPT)' TARGET='$(TARGET)' INTERFACE='$(INTERFACE)' go_cpp
 
 clean:
+	if [ -n '$(SRCDIR)' ]; then \
+		rm $(GOSRCS) || true; \
+	fi
 	$(MAKE) -f $(TOP)/Makefile SRCDIR='$(SRCDIR)' INTERFACE='$(INTERFACE)' go_clean

Examples/go/extend/ceo.go

@@ -0,0 +1,37 @@
+package example
+
+type CEO interface {
+	Manager
+	deleteManager()
+	IsCEO()
+}
+
+type ceo struct {
+	Manager
+}
+
+func (p *ceo) deleteManager() {
+	DeleteDirectorManager(p.Manager)
+}
+
+func (p *ceo) IsCEO() {}
+
+type overwrittenMethodsOnManager struct {
+	p Manager
+}
+
+func NewCEO(name string) CEO {
+	om := &overwrittenMethodsOnManager{}
+	p := NewDirectorManager(om, name)
+	om.p = p
+
+	return &ceo{Manager: p}
+}
+
+func DeleteCEO(p CEO) {
+	p.deleteManager()
+}
+
+func (p *ceo) GetPosition() string {
+	return "CEO"
+}

Examples/go/extend/example.h

@@ -44,7 +44,7 @@ public:
 	const Employee *get_item(int i) {
 		return list[i];
 	}
-	~EmployeeList() { 
+	~EmployeeList() {
 		std::vector<Employee*>::iterator i;
 		std::cout << "~EmployeeList, deleting " << list.size() << " employees." << std::endl;
 		for (i=list.begin(); i!=list.end(); i++) {

Examples/go/extend/index.html

@@ -12,13 +12,16 @@
 <H2>Extending a simple C++ class in Go</H2>
 
 <p>
-This example illustrates the extending of a C++ class with cross
+This example illustrates how to inherit from a C++ class in Go.
-language polymorphism.
+See the <a href="../../../Doc/Manual/Go.html#Go_director_classes">Go Director
-
+Classes</a> documentation subsection for an in-depth explanation how to use the
+director feature.
 <p>
+
 <ul>
-<li><a href="example.h">example.h</a>.  Header file containing some enums.
+<li><a href="ceo.go">ceo.go</a>.  Go source with the definition of the CEO class.
-<li><a href="example.i">example.i</a>.  Interface file.
+<li><a href="example.h">example.h</a>. Header with the definition of the Employee, Manager and EmployeeList classes.
+<li><a href="example.i">example.i</a>.  SWIG interface file.
 <li><a href="runme.go">runme.go</a>. Sample Go program.
 </ul>
 

Examples/go/extend/runme.go

@@ -7,19 +7,12 @@ import (
 	"fmt"
 )
 
-type CEO struct{}
-
-func (p *CEO) GetPosition() string {
-	return "CEO"
-}
-
 func main() {
 	// Create an instance of CEO, a class derived from the Go
 	// proxy of the underlying C++ class.  The calls to getName()
 	// and getPosition() are standard, the call to getTitle() uses
 	// the director wrappers to call CEO.getPosition().
-
+	e := NewCEO("Alice")
-	e := NewDirectorManager(new(CEO), "Alice")
 	fmt.Println(e.GetName(), " is a ", e.GetPosition())
 	fmt.Println("Just call her \"", e.GetTitle(), "\"")
 	fmt.Println("----------------------")
@@ -27,7 +20,6 @@ func main() {
 	// Create a new EmployeeList instance.  This class does not
 	// have a C++ director wrapper, but can be used freely with
 	// other classes that do.
-
 	list := NewEmployeeList()
 
 	// EmployeeList owns its items, so we must surrender ownership
@@ -49,15 +41,13 @@ func main() {
 	// CEO, but now Go thinks the object is an instance of class
 	// Employee.  So the call passes through the Employee proxy
 	// class and on to the C wrappers and C++ director, eventually
-	// ending up back at the Java CEO implementation of
+	// ending up back at the Go CEO implementation of
 	// getPosition().  The call to GetTitle() for item 3 runs the
 	// C++ Employee::getTitle() method, which in turn calls
 	// GetPosition().  This virtual method call passes down
-	// through the C++ director class to the Java implementation
+	// through the C++ director class to the Go implementation
 	// in CEO.  All this routing takes place transparently.
-
 	fmt.Println("(position, title) for items 0-3:")
-
 	fmt.Println("  ", list.Get_item(0).GetPosition(), ", \"", list.Get_item(0).GetTitle(), "\"")
 	fmt.Println("  ", list.Get_item(1).GetPosition(), ", \"", list.Get_item(1).GetTitle(), "\"")
 	fmt.Println("  ", list.Get_item(2).GetPosition(), ", \"", list.Get_item(2).GetTitle(), "\"")
@@ -66,11 +56,11 @@ func main() {
 
 	// Time to delete the EmployeeList, which will delete all the
 	// Employee* items it contains. The last item is our CEO,
-	// which gets destroyed as well.
+	// which gets destroyed as well and hence there is no need to
+	// call DeleteCEO.
 	DeleteEmployeeList(list)
 	fmt.Println("----------------------")
 
 	// All done.
-
 	fmt.Println("Go exit")
 }

Examples/go/index.html

@@ -23,6 +23,7 @@ certain C declarations are turned into constants.
 <li><a href="template/index.html">template</a>. C++ templates.
 <li><a href="callback/index.html">callback</a>. C++ callbacks using directors.
 <li><a href="extend/index.html">extend</a>. Polymorphism using directors.
+<li><a href="director/index.html">director</a>. Example how to utilize the director feature.
 </ul>
 
 <h2>Compilation Issues</h2>