Validate incoming window properties.

ui/aura/mus/property_converter.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_AURA_MUS_PROPERTY_CONVERTER_H_
 #define UI_AURA_MUS_PROPERTY_CONVERTER_H_
 
 #include <stdint.h>
 
 #include <map>
 #include <memory>
 #include <string>
 #include <vector>
 
+#include "base/callback_forward.h"
 #include "base/macros.h"
 #include "ui/aura/aura_export.h"
 #include "ui/aura/window.h"
 
 namespace gfx {
 class Rect;
 class Size;
 }
 
 namespace aura {
 
 // PropertyConverter is used to convert Window properties for transport to the
 // mus window server and back. Any time a property changes from one side it is
 // mapped to the other using this class. Not all Window properties need to map
 // to server properties, and similarly not all transport properties need map to
 // Window properties.
 class AURA_EXPORT PropertyConverter {
  public:
   // All primitive values are stored using this type.
   using PrimitiveType = int64_t;
 
   PropertyConverter();
   ~PropertyConverter();
 
+  // Creates a validation callback for use in RegisterProperty() which will
+  // accept any value.
+  static base::RepeatingCallback<bool(int64_t)> CreateAcceptAnyValueCallback();
+
   // Returns true if RegisterProperty() has been called with the specified
   // transport name.
   bool IsTransportNameRegistered(const std::string& name) const;
 
   // Maps a property on the Window to a property pushed to the server. Return
   // true if the property should be sent to the server, false if the property
   // is only used locally.
   bool ConvertPropertyForTransport(
       Window* window,
       const void* key,
@@ skipping 14 matching lines @@
   // Returns the value for a particular transport value. All primitives are
   // serialized as a PrimitiveType, so this function may be used for any
   // primitive. Returns true on success and sets |value| accordingly. A return
   // value of false indicates the value isn't known or the property type isn't
   // primitive.
   bool GetPropertyValueFromTransportValue(
       const std::string& transport_name,
       const std::vector<uint8_t>& transport_data,
       PrimitiveType* value);
 
-  // Register a property to support conversion between mus and aura.
-  template<typename T>
-  void RegisterProperty(const WindowProperty<T>* property,
-                        const char* transport_name) {
+  // Register a property to support conversion between mus and

[msw, 2017/02/23 22:35:12]

nit: line wrapping

[Elliot Glaysher, 2017/02/23 22:57:35]

Weird that neither emacs nor cl-format correct this. cl-format doesn't undo the
manual reflow, so Done.

+  // aura. |validator| is a callback used to validate incoming values from
+  // transport_data; if it returns false, the value is rejected.
+  template <typename T>
+  void RegisterProperty(
+      const WindowProperty<T>* property,
+      const char* transport_name,
+      const base::RepeatingCallback<bool(int64_t)>& validator) {
     PrimitiveProperty primitive_property;
     primitive_property.property_name = property->name;
     primitive_property.transport_name = transport_name;
     primitive_property.default_value =
         ui::ClassPropertyCaster<T>::ToInt64(property->default_value);
+    primitive_property.validator = validator;
     primitive_properties_[property] = primitive_property;
     transport_names_.insert(transport_name);
   }
 
   // Specializations for properties to pointer types supporting mojo conversion.
   void RegisterProperty(const WindowProperty<gfx::ImageSkia*>* property,
                         const char* transport_name);
   void RegisterProperty(const WindowProperty<gfx::Rect*>* property,
                         const char* transport_name);
   void RegisterProperty(const WindowProperty<gfx::Size*>* property,
                         const char* transport_name);
   void RegisterProperty(const WindowProperty<std::string*>* property,
                         const char* transport_name);
   void RegisterProperty(const WindowProperty<base::string16*>* property,
                         const char* transport_name);
 
  private:
   // Contains data needed to store and convert primitive-type properties.
-  struct PrimitiveProperty {
+  struct AURA_EXPORT PrimitiveProperty {
+    PrimitiveProperty();
+    PrimitiveProperty(const PrimitiveProperty& property);
+    ~PrimitiveProperty();
+
     // The aura::WindowProperty::name used for storage.
     const char* property_name = nullptr;
     // The mus property name used for transport.
     const char* transport_name = nullptr;
     // The aura::WindowProperty::default_value stored using PrimitiveType.
     PrimitiveType default_value = 0;
+    // A callback used to validate incoming values.
+    base::RepeatingCallback<bool(int64_t)> validator;
   };
 
   // A map of aura::WindowProperty<T> to PrimitiveProperty structs.
   // This supports the internal codepaths for primitive types, eg. T=bool.
   std::map<const void*, PrimitiveProperty> primitive_properties_;
 
   // Maps of aura::WindowProperty<T> to their mus property names.
   // This supports types that can be serialized for Mojo, eg. T=std::string*.
   std::map<const WindowProperty<gfx::ImageSkia*>*, const char*>
       image_properties_;
   std::map<const WindowProperty<gfx::Rect*>*, const char*> rect_properties_;
   std::map<const WindowProperty<gfx::Size*>*, const char*> size_properties_;
   std::map<const WindowProperty<std::string*>*, const char*> string_properties_;
   std::map<const WindowProperty<base::string16*>*, const char*>
       string16_properties_;
 
   // Set of transport names supplied to RegisterProperty().
   std::set<std::string> transport_names_;
 
   DISALLOW_COPY_AND_ASSIGN(PropertyConverter);
 };
 
 }  // namespace aura
 
 #endif  // UI_AURA_MUS_PROPERTY_CONVERTER_H_