chrome/browser/translate/cld_data_harness_factory.h

   1 // Copyright 2014 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 CHROME_BROWSER_TRANSLATE_CLD_DATA_HARNESS_FACTORY_H_
   6 #define CHROME_BROWSER_TRANSLATE_CLD_DATA_HARNESS_FACTORY_H_
   7
   8 #include "base/macros.h"
   9 #include "base/memory/scoped_ptr.h"
  10 #include "chrome/browser/translate/cld_data_harness.h"
  11
  12 namespace test {
  13
  14 // Testing class that allows embedders to inject an arbitrary CldDataHarness
  15 // implementation into the runtime by defining a subclass of
  16 // CldDataHarnessFactory and setting the global instance of it with
  17 // Set(CldDataHarnessFactory*). Chromium code should use the factory instance
  18 // returned by Get() to obtain CldDataHarness instances.
  19 //
  20 // There is significant nuance to obtaining a CldDataHarness object at runtime.
  21 // For each of the "stock" CldDataSource implementations ("standalone",
  22 // "static" and "component"), a CldDataHarness implementation is available and
  23 // the default implementation of the CldDataHarnessFactory class knows how to
  24 // do the right thing; but embedders can provider entirely custom CldDataSource
  25 // implementations, and browser tests need to be able to use those data sources
  26 // correctly at test time. Embedders implement a subclass of
  27 // CldDataHarnessFactory and set it using Set(), below, to enable browser tests
  28 // to function as realistically as possible with the embedder's data source.
  29 class CldDataHarnessFactory {
  30  public:
  31   CldDataHarnessFactory() {}
  32   virtual ~CldDataHarnessFactory() {}
  33
  34   // Create a new CldDataHarness.
  35   // The default implementation returns a simple CldDataHarness, which is
  36   // likely to be incorrect for most non-static CLD use cases.
  37   virtual scoped_ptr<CldDataHarness> CreateCldDataHarness();
  38
  39   // Unconditionally sets the factory for this process, overwriting any
  40   // previously-configured value. Open-source Chromium test code should almost
  41   // never use this method; it is provided for embedders to inject a factory
  42   // from outside of the Chromium code base. By default, the choice of which
  43   // factory to use is based on the currently-configured CldDataSource when
  44   // calling Get() (see below).
  45   static void Set(CldDataHarnessFactory* instance);
  46
  47   // Returns the CldDataHarnessFactory instance previously set for the process,
  48   // if one has been set; otherwise, if the currently configured CldDataSource
  49   // is one of the available open-source types defined in CldDataSource, returns
  50   // a compatible harness. Otherwise (e.g., no specific instance has been set
  51   // and the CldDataSource is not one of the known open-source implementations),
  52   // debug builds will crash while release builds will return a no-op harness.
  53   static CldDataHarnessFactory* Get();
  54
  55  private:
  56   DISALLOW_COPY_AND_ASSIGN(CldDataHarnessFactory);
  57
  58   // Fetch the global instance of the "static" factory that produces a harness
  59   // suitable for use with the "static" CLD data source.
  60   // Only use to call Set(CldDataHarnessFactory*).
  61   static CldDataHarnessFactory* GetStaticDataHarnessFactory();
  62
  63   // Fetch the global instance of the "standalone" factory that produces a
  64   // harness suitable for use with the "standalone" CLD data source.
  65   // Only use to call Set(CldDataHarnessFactory*).
  66   static CldDataHarnessFactory* GetStandaloneDataHarnessFactory();
  67
  68   // Fetch the global instance of the "component" factory that produces a
  69   // harness suitable for use with the "component" CLD data source.
  70   // Only use to call Set(CldDataHarnessFactory*).
  71   static CldDataHarnessFactory* GetComponentDataHarnessFactory();
  72 };
  73 }  // namespace test
  74
  75 #endif  // CHROME_BROWSER_TRANSLATE_CLD_DATA_HARNESS_FACTORY_H_