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1 /*
2  * Copyright 2009, 2010, The Android Open Source Project
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *  * Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  *  * Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24  */
25 
26 #ifndef PlatformBridge_h
27 #define PlatformBridge_h
28 
29 #include "FloatRect.h"
30 #include "KURL.h"
31 #include "PlatformString.h"
32 #include "npapi.h"
33 
34 #include <wtf/Vector.h>
35 
36 // V8 bindings use the ARRAYSIZE_UNSAFE macro. This macro was copied
37 // from http://src.chromium.org/viewvc/chrome/trunk/src/base/basictypes.h
38 //
39 // ARRAYSIZE_UNSAFE performs essentially the same calculation as arraysize,
40 // but can be used on anonymous types or types defined inside
41 // functions. It's less safe than arraysize as it accepts some
42 // (although not all) pointers. Therefore, you should use arraysize
43 // whenever possible.
44 //
45 // The expression ARRAYSIZE_UNSAFE(a) is a compile-time constant of type
46 // size_t.
47 //
48 // ARRAYSIZE_UNSAFE catches a few type errors. If you see a compiler error
49 //
50 //   "warning: division by zero in ..."
51 //
52 // when using ARRAYSIZE_UNSAFE, you are (wrongfully) giving it a pointer.
53 // You should only use ARRAYSIZE_UNSAFE on statically allocated arrays.
54 //
55 // The following comments are on the implementation details, and can
56 // be ignored by the users.
57 //
58 // ARRAYSIZE_UNSAFE(arr) works by inspecting sizeof(arr) (the # of bytes in
59 // the array) and sizeof(*(arr)) (the # of bytes in one array
60 // element). If the former is divisible by the latter, perhaps arr is
61 // indeed an array, in which case the division result is the # of
62 // elements in the array. Otherwise, arr cannot possibly be an array,
63 // and we generate a compiler error to prevent the code from
64 // compiling.
65 //
66 // Since the size of bool is implementation-defined, we need to cast
67 // !(sizeof(a) & sizeof(*(a))) to size_t in order to ensure the final
68 // result has type size_t.
69 //
70 // This macro is not perfect as it wrongfully accepts certain
71 // pointers, namely where the pointer size is divisible by the pointee
72 // size. Since all our code has to go through a 32-bit compiler,
73 // where a pointer is 4 bytes, this means all pointers to a type whose
74 // size is 3 or greater than 4 will be (righteously) rejected.
75 
76 #define ARRAYSIZE_UNSAFE(a) \
77   ((sizeof(a) / sizeof(*(a))) / \
78    static_cast<size_t>(!(sizeof(a) % sizeof(*(a)))))
79 
80 
81 class NPObject;
82 
83 namespace WebCore {
84 
85 class Document;
86 class FrameView;
87 class Node;
88 class ScrollView;
89 class Widget;
90 
91 // An interface to the embedding layer, which has the ability to answer
92 // questions about the system and so on...
93 // This is very similar to chromium/PlatformBridge and the two are likely to converge
94 // in the future.
95 //
96 // The methods in this class all need to reach across a JNI layer to the Java VM
97 // where the embedder runs. The JNI machinery is currently all in WebKit/android
98 // but the long term plan is to move to the WebKit API and share the bridge and its
99 // implementation with Chromium. The JNI machinery will then move outside of WebKit,
100 // similarly to how Chromium's IPC layer lives outside of WebKit.
101 class PlatformBridge {
102 public:
103     // KeyGenerator
104     static WTF::Vector<String> getSupportedKeyStrengthList();
105     static String getSignedPublicKeyAndChallengeString(unsigned index, const String& challenge, const KURL&);
106     // Cookies
107     static void setCookies(const Document*, const KURL&, const String& value);
108     static String cookies(const Document*, const KURL&);
109     static bool cookiesEnabled(const Document*);
110     // Plugin
111     static NPObject* pluginScriptableObject(Widget*);
112     // Popups
113     static bool popupsAllowed(NPP);
114 
115     // These ids need to be in sync with the constants in BrowserFrame.java
116     enum rawResId {
117         NoDomain = 1,
118         LoadError,
119         DrawableDir,
120         FileUploadLabel,
121         ResetLabel,
122         SubmitLabel,
123         FileUploadNoFileChosenLabel
124     };
125     static String* globalLocalizedName(rawResId resId);
126 
127     static String resolveFilePathForContentUri(const String&);
128 
129     static int screenDepth();
130     static FloatRect screenRect();
131 
132     // Update the viewport meta data.
133     static void updateViewport(FrameView*);
134 
135     static void updateTextfield(FrameView*, Node*, const WTF::String& text);
136 
137     static void setScrollPosition(ScrollView*, int x, int y);
138 
139     // Language
140     static String computeDefaultLanguage();
141     // Memory details for V8 GC
142     static int lowMemoryUsageMB();
143     static int highMemoryUsageMB();
144     static int highUsageDeltaMB();
145     static int memoryUsageMB();
146     static int actualMemoryUsageMB();
147     static bool canSatisfyMemoryAllocation(long bytes);
148 
149     static int screenWidthInDocCoord(const FrameView*);
150     static int screenHeightInDocCoord(const FrameView*);
151 };
152 
153 }
154 #endif // PlatformBridge_h
155