chrome/browser/extensions/requirements_checker.h

   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 CHROME_BROWSER_EXTENSIONS_REQUIREMENTS_CHECKER_H_
   6 #define CHROME_BROWSER_EXTENSIONS_REQUIREMENTS_CHECKER_H_
   7
   8 #include <vector>
   9
  10 #include "base/callback.h"
  11 #include "base/memory/ref_counted.h"
  12 #include "base/memory/weak_ptr.h"
  13 #include "chrome/browser/extensions/extension_service.h"
  14
  15 class GPUFeatureChecker;
  16
  17 namespace extensions {
  18 class Extension;
  19
  20 // Validates the 'requirements' extension manifest field. This is an
  21 // asynchronous process that involves several threads, but the public interface
  22 // of this class (including constructor and destructor) must only be used on
  23 // the UI thread.
  24 class RequirementsChecker : public base::SupportsWeakPtr<RequirementsChecker> {
  25  public:
  26   RequirementsChecker();
  27   ~RequirementsChecker();
  28
  29   // The vector passed to the callback are any localized errors describing
  30   // requirement violations. If this vector is non-empty, requirements checking
  31   // failed. This should only be called once. |callback| will always be invoked
  32   // asynchronously on the UI thread. |callback| will only be called once, and
  33   // will be reset after called.
  34   void Check(scoped_refptr<const Extension> extension,
  35       base::Callback<void(std::vector<std::string> requirement)> callback);
  36
  37  private:
  38   // Callbacks for the GPUFeatureChecker.
  39   void SetWebGLAvailability(bool available);
  40   void SetCSS3DAvailability(bool available);
  41
  42   void MaybeRunCallback();
  43
  44   std::vector<std::string> errors_;
  45
  46   // Every requirement that needs to be resolved asynchronously will add to
  47   // this counter. When the counter is depleted, the callback will be run.
  48   int pending_requirement_checks_;
  49
  50   scoped_refptr<GPUFeatureChecker> webgl_checker_;
  51   scoped_refptr<GPUFeatureChecker> css3d_checker_;
  52
  53   base::Callback<void(std::vector<std::string> requirement_errorss)> callback_;
  54 };
  55
  56 }  // namespace extensions
  57
  58 #endif  // CHROME_BROWSER_EXTENSIONS_REQUIREMENTS_CHECKER_H_