1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #ifndef UI_AURA_WINDOW_PROPERTY_H_
6 #define UI_AURA_WINDOW_PROPERTY_H_
7
8 #include "base/basictypes.h"
9 #include "ui/aura/aura_export.h"
10 #include "ui/aura/window.h"
11
12 // This header should be included by code that defines WindowProperties. It
13 // should not be included by code that only gets and sets WindowProperties.
14 //
15 // To define a new WindowProperty:
16 //
17 // #include "foo/foo_export.h"
18 // #include "ui/aura/window_property.h"
19 //
20 // DECLARE_EXPORTED_WINDOW_PROPERTY_TYPE(FOO_EXPORT, MyType);
21 // namespace foo {
22 // // Use this to define an exported property that is premitive,
23 // // or a pointer you don't want automatically deleted.
24 // DEFINE_WINDOW_PROPERTY_KEY(MyType, kMyKey, MyDefault);
25 //
26 // // Use this to define an exported property whose value is a heap
27 // // allocated object, and has to be owned and freed by the window.
28 // DEFINE_OWNED_WINDOW_PROPERTY_KEY(gfx::Rect, kRestoreBoundsKey, NULL);
29 //
30 // // Use this to define a non exported property that is primitive,
31 // // or a pointer you don't want to automatically deleted, and is used
32 // // only in a specific file. This will define the property in an unnamed
33 // // namespace which cannot be accessed from another file.
34 // DEFINE_LOCAL_WINDOW_PROPERTY_KEY(MyType, kMyKey, MyDefault);
35 //
36 // } // foo namespace
37 //
38 // To define a new type used for WindowProperty.
39 //
40 // // outside all namespaces:
41 // DECLARE_EXPORTED_WINDOW_PROPERTY_TYPE(FOO_EXPORT, MyType)
42 //
43 // If a property type is not exported, use DECLARE_WINDOW_PROPERTY_TYPE(MyType)
44 // which is a shorthand for DECLARE_EXPORTED_WINDOW_PROPERTY_TYPE(, MyType).
45
46 namespace aura {
47 namespace {
48
49 // No single new-style cast works for every conversion to/from int64, so we
50 // need this helper class. A third specialization is needed for bool because
51 // MSVC warning C4800 (forcing value to bool) is not suppressed by an explicit
52 // cast (!).
53 template<typename T>
54 class WindowPropertyCaster {
55 public:
ToInt64(T x)56 static int64 ToInt64(T x) { return static_cast<int64>(x); }
FromInt64(int64 x)57 static T FromInt64(int64 x) { return static_cast<T>(x); }
58 };
59 template<typename T>
60 class WindowPropertyCaster<T*> {
61 public:
ToInt64(T * x)62 static int64 ToInt64(T* x) { return reinterpret_cast<int64>(x); }
FromInt64(int64 x)63 static T* FromInt64(int64 x) { return reinterpret_cast<T*>(x); }
64 };
65 template<>
66 class WindowPropertyCaster<bool> {
67 public:
ToInt64(bool x)68 static int64 ToInt64(bool x) { return static_cast<int64>(x); }
FromInt64(int64 x)69 static bool FromInt64(int64 x) { return x != 0; }
70 };
71
72 } // namespace
73
74 template<typename T>
75 struct WindowProperty {
76 T default_value;
77 const char* name;
78 Window::PropertyDeallocator deallocator;
79 };
80
81 template<typename T>
SetProperty(const WindowProperty<T> * property,T value)82 void Window::SetProperty(const WindowProperty<T>* property, T value) {
83 int64 old = SetPropertyInternal(
84 property,
85 property->name,
86 value == property->default_value ? NULL : property->deallocator,
87 WindowPropertyCaster<T>::ToInt64(value),
88 WindowPropertyCaster<T>::ToInt64(property->default_value));
89 if (property->deallocator &&
90 old != WindowPropertyCaster<T>::ToInt64(property->default_value)) {
91 (*property->deallocator)(old);
92 }
93 }
94
95 template<typename T>
GetProperty(const WindowProperty<T> * property)96 T Window::GetProperty(const WindowProperty<T>* property) const {
97 return WindowPropertyCaster<T>::FromInt64(GetPropertyInternal(
98 property, WindowPropertyCaster<T>::ToInt64(property->default_value)));
99 }
100
101 template<typename T>
ClearProperty(const WindowProperty<T> * property)102 void Window::ClearProperty(const WindowProperty<T>* property) {
103 SetProperty(property, property->default_value);
104 }
105
106 } // namespace aura
107
108 // Macros to instantiate the property getter/setter template functions.
109 #define DECLARE_EXPORTED_WINDOW_PROPERTY_TYPE(EXPORT, T) \
110 template EXPORT void aura::Window::SetProperty( \
111 const aura::WindowProperty<T >*, T); \
112 template EXPORT T aura::Window::GetProperty( \
113 const aura::WindowProperty<T >*) const; \
114 template EXPORT void aura::Window::ClearProperty( \
115 const aura::WindowProperty<T >*);
116 #define DECLARE_WINDOW_PROPERTY_TYPE(T) \
117 DECLARE_EXPORTED_WINDOW_PROPERTY_TYPE(, T)
118
119 #define DEFINE_WINDOW_PROPERTY_KEY(TYPE, NAME, DEFAULT) \
120 COMPILE_ASSERT(sizeof(TYPE) <= sizeof(int64), property_type_too_large); \
121 namespace { \
122 const aura::WindowProperty<TYPE> NAME ## _Value = {DEFAULT, #NAME, NULL}; \
123 } \
124 const aura::WindowProperty<TYPE>* const NAME = & NAME ## _Value;
125
126 #define DEFINE_LOCAL_WINDOW_PROPERTY_KEY(TYPE, NAME, DEFAULT) \
127 COMPILE_ASSERT(sizeof(TYPE) <= sizeof(int64), property_type_too_large); \
128 namespace { \
129 const aura::WindowProperty<TYPE> NAME ## _Value = {DEFAULT, #NAME, NULL}; \
130 const aura::WindowProperty<TYPE>* const NAME = & NAME ## _Value; \
131 }
132
133 #define DEFINE_OWNED_WINDOW_PROPERTY_KEY(TYPE, NAME, DEFAULT) \
134 namespace { \
135 void Deallocator ## NAME (int64 p) { \
136 enum { type_must_be_complete = sizeof(TYPE) }; \
137 delete aura::WindowPropertyCaster<TYPE*>::FromInt64(p); \
138 } \
139 const aura::WindowProperty<TYPE*> NAME ## _Value = \
140 {DEFAULT,#NAME,&Deallocator ## NAME}; \
141 } \
142 const aura::WindowProperty<TYPE*>* const NAME = & NAME ## _Value;
143
144 #endif // UI_AURA_WINDOW_PROPERTY_H_
145