Added from SpiderMonkey131_BRANCH of ns/js/ref/liveconnect

js/src/liveconnect/jsj_JavaMember.c

@@ -0,0 +1,134 @@
+/* -*- Mode: C; tab-width: 8 -*-
+ * Copyright (C) 1998 Netscape Communications Corporation, All Rights Reserved.
+ */
+
+/*
+ * This file is part of the Java-vendor-neutral implementation of LiveConnect
+ *
+ * It contains the native code implementation of JS's JavaMember class.
+ * JavaMember's are a strange beast required only to handle the special case
+ * of a public field and a public method that appear in the same class and
+ * have the same name.  When such a field/method is used in Java, the compiler
+ * can statically determine from context whether the field or the method is
+ * being referenced, but that is not possible with JavaScript.  For example:
+ *
+ * ambiguousVal = javaObj.fieldOrMethod; // ambiguousVal is a JavaMember object
+ * a = ambiguousVal();                   // ambiguousVal used as a method value
+ * b = ambiguousVal + 4;                 // ambiguousVal used as a field value
+ *
+ * A JavaMember instance carries both the captured value of the Java field and
+ * the method value until the context that the value is to be used in is known,
+ * at which point conversion forces the use of one or the other.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "jsj_private.h"      /* LiveConnect internals */
+
+/* Private, native portion of a JavaMember */
+typedef struct JavaMethodOrFieldValue {
+    jsval method_val;
+    jsval field_val;
+} JavaMethodOrFieldValue;
+
+JSObject *
+jsj_CreateJavaMember(JSContext *cx, jsval method_val, jsval field_val)
+{
+    JavaMethodOrFieldValue *member_val;
+    JSObject *JavaMember_obj;
+    
+    member_val = (JavaMethodOrFieldValue *)JS_malloc(cx, sizeof(*member_val));
+    if (!member_val)
+        return NULL;
+    
+    JavaMember_obj = JS_NewObject(cx, &JavaMember_class, 0, 0);
+    if (!JavaMember_obj) {
+        JS_free(cx, member_val);
+        return NULL;
+    }
+
+    JS_SetPrivate(cx, JavaMember_obj, (void *)member_val);
+    member_val->method_val = method_val;
+    JS_AddRoot(cx, &member_val->method_val);
+    member_val->field_val = field_val;
+    if (JSVAL_IS_GCTHING(field_val))
+        JS_AddRoot(cx, &member_val->field_val);
+
+    return JavaMember_obj;
+}
+
+static void
+JavaMember_finalize(JSContext *cx, JSObject *obj)
+{
+    JavaMethodOrFieldValue *member_val;
+    JNIEnv *jEnv;
+
+    jsj_MapJSContextToJSJThread(cx, &jEnv);
+    if (!jEnv)
+        return;
+
+    member_val = JS_GetPrivate(cx, obj);
+    if (!member_val)
+        return;
+    JS_RemoveRoot(cx, &member_val->method_val);
+    if (JSVAL_IS_GCTHING(member_val->method_val))
+        JS_RemoveRoot(cx, &member_val->method_val);
+    JS_free(cx, member_val);
+}
+
+static JSBool
+JavaMember_convert(JSContext *cx, JSObject *obj, JSType type, jsval *vp)
+{
+    JavaMethodOrFieldValue *member_val;
+        
+    member_val = JS_GetPrivate(cx, obj);
+    if (!member_val) {
+        if (type == JSTYPE_OBJECT) {
+            *vp = OBJECT_TO_JSVAL(obj);
+            return JS_TRUE;
+        }
+        
+        JS_ReportError(cx, "illegal operation on JavaObject prototype object");
+        return JS_FALSE;
+    }
+
+    switch (type) {
+    case JSTYPE_VOID:
+    case JSTYPE_STRING:
+    case JSTYPE_NUMBER:
+    case JSTYPE_BOOLEAN:
+    case JSTYPE_OBJECT:
+        *vp = member_val->field_val;
+        return JS_TRUE;
+
+    case JSTYPE_FUNCTION:
+        *vp = member_val->method_val;
+        return JS_TRUE;
+
+    default:
+        PR_ASSERT(0);
+        return JS_FALSE;
+    }
+}
+
+JSClass JavaMember_class = {
+    "JavaMember", JSCLASS_HAS_PRIVATE,
+    JS_PropertyStub, JS_PropertyStub, JS_PropertyStub, JS_PropertyStub,
+    JS_EnumerateStub, JS_ResolveStub, 
+    JavaMember_convert, JavaMember_finalize
+};
+
+extern PR_IMPORT_DATA(JSObjectOps) js_ObjectOps;
+
+JSBool
+jsj_init_JavaMember(JSContext *cx, JSObject *global_obj)
+{
+    if (!JS_InitClass(cx, global_obj, 
+        0, &JavaMember_class, 0, 0,
+        0, 0,
+        0, 0))
+        return JS_FALSE;
+
+    return JS_TRUE;
+}