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Diffstat (limited to 'chromium/base/prefs/pref_filter.h')
-rw-r--r-- | chromium/base/prefs/pref_filter.h | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/chromium/base/prefs/pref_filter.h b/chromium/base/prefs/pref_filter.h new file mode 100644 index 00000000000..82a44c6ef9b --- /dev/null +++ b/chromium/base/prefs/pref_filter.h @@ -0,0 +1,55 @@ +// Copyright 2013 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 BASE_PREFS_PREF_FILTER_H_ +#define BASE_PREFS_PREF_FILTER_H_ + +#include <string> + +#include "base/callback_forward.h" +#include "base/memory/scoped_ptr.h" +#include "base/prefs/base_prefs_export.h" + +namespace base { +class DictionaryValue; +class Value; +} // namespace base + +// Filters preferences as they are loaded from disk or updated at runtime. +// Currently supported only by JsonPrefStore. +class BASE_PREFS_EXPORT PrefFilter { + public: + // A callback to be invoked when |prefs| have been read (and possibly + // pre-modified) and are now ready to be handed back to this callback's + // builder. |schedule_write| indicates whether a write should be immediately + // scheduled (typically because the |prefs| were pre-modified). + typedef base::Callback<void(scoped_ptr<base::DictionaryValue> prefs, + bool schedule_write)> PostFilterOnLoadCallback; + + virtual ~PrefFilter() {} + + // This method is given ownership of the |pref_store_contents| read from disk + // before the underlying PersistentPrefStore gets to use them. It must hand + // them back via |post_filter_on_load_callback|, but may modify them first. + // Note: This method is asynchronous, which may make calls like + // PersistentPrefStore::ReadPrefs() asynchronous. The owner of filtered + // PersistentPrefStores should handle this to make the reads look synchronous + // to external users (see SegregatedPrefStore::ReadPrefs() for an example). + virtual void FilterOnLoad( + const PostFilterOnLoadCallback& post_filter_on_load_callback, + scoped_ptr<base::DictionaryValue> pref_store_contents) = 0; + + // Receives notification when a pref store value is changed, before Observers + // are notified. + virtual void FilterUpdate(const std::string& path) = 0; + + // Receives notification when the pref store is about to serialize data + // contained in |pref_store_contents| to a string. Modifications to + // |pref_store_contents| will be persisted to disk and also affect the + // in-memory state. + virtual void FilterSerializeData( + base::DictionaryValue* pref_store_contents) = 0; +}; + +#endif // BASE_PREFS_PREF_FILTER_H_ |