refactor: use ObjectFromUintptr/VMFromUintptr in all examples

Replace unsafe.Pointer(activity.clazz) and unsafe.Pointer(activity.vm)
with the new uintptr-based constructors across all 55 examples. Fixes
go vet "possible misuse of unsafe.Pointer" warnings caused by CGo
mapping jobject to uintptr.

Author: xaionaro@dx.center

object_ref.go

@@ -18,10 +18,10 @@ func ObjectFromRef(ref capi.Object) *Object {
 }
 
 // ObjectFromPtr wraps a raw C jobject pointer in an Object, mirroring
-// VMFromPtr. Use this from NativeActivity callbacks to avoid importing
-// the capi package:
+// VMFromPtr. Prefer ObjectFromUintptr for NativeActivity callbacks to
+// avoid go vet "possible misuse of unsafe.Pointer" warnings:
 //
-//	jni.ObjectFromPtr(unsafe.Pointer(activity.clazz))
+//	jni.ObjectFromUintptr(uintptr(activity.clazz))
 func ObjectFromPtr(ptr unsafe.Pointer) *Object {
 	return &Object{ref: capi.Object(uintptr(ptr))}
 }

tools/transform_examples.sh

@@ -287,16 +287,16 @@ static void _onResume(ANativeActivity* a) { goOnResume(a); }\
         print "//export ANativeActivity_onCreate"
         print "func ANativeActivity_onCreate(activity *C.ANativeActivity, savedState unsafe.Pointer, savedStateSize C.size_t) {"
         print "\tui.OnCreate("
-        print "\t\tjni.VMFromPtr(unsafe.Pointer(activity.vm)),"
-        print "\t\tjni.ObjectFromRef(capi.Object(uintptr(unsafe.Pointer(activity.clazz)))),"
+        print "\t\tjni.VMFromUintptr(uintptr(activity.vm)),"
+        print "\t\tjni.ObjectFromUintptr(uintptr(activity.clazz)),"
         print "\t)"
         print "\tactivity.callbacks.onResume = C._onResume"
         print "}"
         print ""
         print "//export goOnResume"
         print "func goOnResume(activity *C.ANativeActivity) {"
         print "\tui.OnResume("
-        print "\t\tjni.ObjectFromRef(capi.Object(uintptr(unsafe.Pointer(activity.clazz)))),"
+        print "\t\tjni.ObjectFromUintptr(uintptr(activity.clazz)),"
         print "\t)"
         print "}"
     }