1 /* This file is part of the KDE project
2    Copyright (C) 2010 Maksim Orlovich <maksim@kde.org>
3 
4    This library is free software; you can redistribute it and/or
5    modify it under the terms of the GNU Library General Public
6    License as published by the Free Software Foundation; either
7    version 2 of the License, or (at your option) any later version.
8 
9    This library is distributed in the hope that it will be useful,
10    but WITHOUT ANY WARRANTY; without even the implied warranty of
11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12    Library General Public License for more details.
13 
14    You should have received a copy of the GNU Library General Public License
15    along with this library; see the file COPYING.LIB.  If not, write to
16    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
17    Boston, MA 02110-1301, USA.
18 */
19 
20 #ifndef KJS_SCRIPTABLE_H
21 #define KJS_SCRIPTABLE_H
22 
23 #include <khtml_part.h>
24 #include <kparts/scriptableextension.h>
25 #include <kjs/object.h>
26 #include <kjs/list.h>
27 #include <QHash>
28 
29 using namespace KParts;
30 
31 namespace KJS
32 {
33 
34 // First, a couple of helpers: these let clients perform basic getOwnPropertySlot or
35 // put (with a bool effect return) on the root of given extension.
36 bool pluginRootGet(ExecState *exec, ScriptableExtension *ext, const KJS::Identifier &i, PropertySlot &slot);
37 bool pluginRootPut(ExecState *exec, ScriptableExtension *ext, const KJS::Identifier &i, JSValue *v);
38 
39 class WrapScriptableObject;
40 
41 // We have two ScriptableExtension subclasses.
42 // ScriptableOperations is a singleton used to perform operations on objects.
43 // This is because objects in child  parts (and other windows) can survive their
44 // parent, and we still need to perform operations on them.
45 class ScriptableOperations: public ScriptableExtension
46 {
47     Q_OBJECT
48 public:
49     // ScriptableExtension API
50     QVariant callAsFunction(ScriptableExtension *callerPrincipal, quint64 objId, const ArgList &args) override;
51     virtual QVariant callFunctionReference(ScriptableExtension *callerPrincipal, quint64 objId,
52                                            const QString &f, const ArgList &args) override;
53     QVariant callAsConstructor(ScriptableExtension *callerPrincipal, quint64 objId, const ArgList &args) override;
54     bool hasProperty(ScriptableExtension *callerPrincipal, quint64 objId, const QString &propName) override;
55     QVariant get(ScriptableExtension *callerPrincipal, quint64 objId, const QString &propName) override;
56     bool put(ScriptableExtension *callerPrincipal, quint64 objId, const QString &propName, const QVariant &value) override;
57     bool removeProperty(ScriptableExtension *callerPrincipal, quint64 objId, const QString &propName) override;
58     bool enumerateProperties(ScriptableExtension *callerPrincipal, quint64 objId, QStringList *result) override;
59 
60     void acquire(quint64 objid) override;
61     void release(quint64 objid) override;
62 
63     // May return null.
64     static JSObject *objectForId(quint64 objId);
65 
66     static ScriptableOperations *self();
67 
68     void mark();
69 public:
70     // We keep a weak table of our wrappers for external objects, so that
71     // the same object gets the same wrapper all the time.
72     static QHash<Object,      WrapScriptableObject *> *importedObjects();
73     static QHash<FunctionRef, WrapScriptableObject *> *importedFunctions();
74 
75     // For exported objects, we keep refcounts, and mark them
76     static QHash<JSObject *, int> *exportedObjects();
77 
78     static JSValue *importValue(ExecState *exec, const QVariant &v, bool alreadyRefd);
79     static JSValue *importFunctionRef(ExecState *exec, const QVariant &v, bool alreadyRefd);
80     static JSObject *importObject(ExecState *exec, const QVariant &v, bool alreadyRefd);
81     static List importArgs(ExecState *exec, const ArgList &args);
82 
83     static QVariant exportValue(JSValue *v, bool preRef);
84     static QVariant exportObject(JSObject *o, bool preRef);
85     static QVariant exportFuncRef(JSObject *base, const QString &field, bool preRef);
86 
87     // Both methods may return 0. Used for security checks!
88     static KHTMLPart *partForPrincipal(ScriptableExtension *callerPrincipal);
89     static ExecState *execStateForPrincipal(ScriptableExtension *callerPrincipal);
90 private:
91     // input should not be a WrapScriptableObject.
92     static ScriptableExtension::Object exportNativeObject(JSObject *o, bool preRef);
93 
94     // Checks exception state before handling conversion
95     QVariant handleReturn(ExecState *exec, JSValue *v);
96 
97     // If the given object is owned by a KHTMLScriptable, return the
98     // JS object for it. If not, return 0.
99     static JSObject *tryGetNativeObject(const Object &sObj);
100 
101     static QHash<JSObject *, int> *s_exportedObjects;
102     static QHash<Object,      WrapScriptableObject *> *s_importedObjects;
103     static QHash<FunctionRef, WrapScriptableObject *> *s_importedFunctions;
104 
105     ScriptableOperations();
106     ~ScriptableOperations();
107 
108     // copy ctor, etc., disabled already, being a QObject
109     static ScriptableOperations *s_instance;
110 };
111 
112 // KHTMLPartScriptable, on other hands, is tied to a part, and
113 // is used for part-specific operations such as looking up
114 // root objects and script execution.
115 class KHTMLPartScriptable: public ScriptableExtension
116 {
117     Q_OBJECT
118     friend class ScriptableOperations;
119 public:
120     KHTMLPartScriptable(KHTMLPart *part);
121 
122     QVariant rootObject() override;
123     QVariant encloserForKid(KParts::ScriptableExtension *kid) override;
124 
125     bool setException(ScriptableExtension *callerPrincipal, const QString &message) override;
126 
127     virtual QVariant evaluateScript(ScriptableExtension *callerPrincipal,
128                                     quint64 contextObjectId,
129                                     const QString &code,
130                                     ScriptLanguage language = ECMAScript) override;
131     bool isScriptLanguageSupported(ScriptLanguage lang) const override;
132 
133     // For paranoia: forward to ScriptOperations
134     void acquire(quint64 objid) override;
135     void release(quint64 objid) override;
136 private:
137     KJS::Interpreter *interpreter();
138     KHTMLPart *m_part;
139 };
140 
141 // This represents an object we imported from a foreign ScriptableExtension
142 class WrapScriptableObject: public JSObject
143 {
144 public:
145     friend class ScriptableOperations;
146 
147     enum Type {
148         Object,
149         FunctionRef
150     };
151 
152     WrapScriptableObject(ExecState *exec, Type t,
153                          ScriptableExtension *owner, quint64 objId,
154                          const QString &field = QString());
155 
156     ~WrapScriptableObject();
157 
classInfo()158     const ClassInfo *classInfo() const override
159     {
160         return &info;
161     }
162     static const ClassInfo info;
163 
164     bool getOwnPropertySlot(ExecState *, const Identifier &, PropertySlot &) override;
165     using JSObject::getOwnPropertySlot;
166     void put(ExecState *exec, const Identifier &propertyName, JSValue *value, int) override;
167     using JSObject::put;
168     bool deleteProperty(ExecState *exec, const Identifier &i) override;
169     using JSObject::deleteProperty;
170 
isFunctionType()171     bool isFunctionType() const override
172     {
173         return false;
174     }
implementsCall()175     bool implementsCall() const override
176     {
177         return true;
178     }
179     JSValue *callAsFunction(ExecState *exec, JSObject *thisObj, const List &args) override;
180 
181     // We claim true, since may be calleable
implementsConstruct()182     bool implementsConstruct() const override
183     {
184         return true;
185     }
186     JSObject *construct(ExecState *exec, const List &args) override;
187     using JSObject::construct;
188 
189     void getOwnPropertyNames(ExecState *, PropertyNameArray &, PropertyMap::PropertyMode mode) override;
190 
191     UString toString(ExecState *exec) const override;
192 
193     // This method is used to note that the object has been ref'd on our
194     // behalf by an external producer.
195     void reportRef();
196 private:
197     // If we're a function reference type, before we perform non-call operations we need
198     // to actually lookup the field. This takes care of that.
199     ScriptableExtension::Object resolveAnyReferences(ExecState *exec, bool *ok);
200 
201     // resolves all function references to get an ref, if any.
202     ScriptableExtension::Object resolveReferences(ExecState *exec,
203             const ScriptableExtension::FunctionRef &f,
204             bool *ok);
205 
206     // gets a field of the given object id, base
207     QVariant doGet(ExecState *exec, const ScriptableExtension::Object &o,
208                    const QString &field, bool *ok);
209 
210     ScriptableExtension::ArgList exportArgs(const List &l);
211     void releaseArgs(ScriptableExtension::ArgList &a);
212 
213     // Looks up the principal we're running as
214     ScriptableExtension *principal(ExecState *exec);
215 
216     // what we wrap
217     QWeakPointer<ScriptableExtension> objExtension;
218     quint64 objId;
219     QString field;
220     Type    type;
221     int     refsByUs; // how many references we hold
222 
223     // this is an unguarded copy of objExtension. We need it in order to
224     // clean ourselves up from the imports tables properly even if the peer
225     // was destroyed.
226     ScriptableExtension *tableKey;
227 };
228 
229 }
230 
231 #endif
232