Plumbs touch calibration API to the display manager

extensions/browser/api/system_display/system_display_api.cc

 // 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.
 
 #include "extensions/browser/api/system_display/system_display_api.h"
 
 #include <map>
 #include <memory>
 #include <set>
 #include <string>
@@ skipping 252 matching lines @@
         Error("Calibration not started for display ID: " + params->id));
   }
   OverscanTracker::RemoveDisplay(GetSenderWebContents(), params->id);
   return RespondNow(NoArguments());
 }
 
 ExtensionFunction::ResponseAction
 SystemDisplayTouchCalibrationStartFunction::Run() {
   std::unique_ptr<display::TouchCalibrationStart::Params> params(
       display::TouchCalibrationStart::Params::Create(*args_));
-  if (!DisplayInfoProvider::Get()->IsTouchCalibrationActive(params->id)) {
-    return RespondNow(Error(
-        "Another touch calibration is already active."));
-  }

[stevenjb, 2016/12/27 19:37:27]

This seems like a useful error? (Although the logic appears to be backwards).

[malaykeshav, 2016/12/27 20:07:01]

This check has been moved to ValidateParamsForTouchCalibration() in
https://codereview.chromium.org/2603563002/diff/20001/chrome/browser/extensio...

Will add it to TouchCalibrationStart() when this API is plumbed through after
the UX is complete.

[stevenjb, 2016/12/27 21:58:12]

Looking at that code, that seems like a strange place to do this test. The error
really should be detected here. I am fine with moving the test to
DisplayInfoProvider::TouchCalibrationStart and passing &error to that like in
the other methods, but just moving that test, even temporarily, seems odd.

[malaykeshav, 2016/12/28 12:34:28]

Done

   if (!DisplayInfoProvider::Get()->TouchCalibrationStart(params->id))
     return RespondNow(Error("Invalid display ID: " + params->id));
   return RespondNow(NoArguments());
 }
 
 ExtensionFunction::ResponseAction
 SystemDisplayTouchCalibrationSetFunction::Run() {
   std::unique_ptr<display::TouchCalibrationSet::Params> params(
       display::TouchCalibrationSet::Params::Create(*args_));
-  if (!DisplayInfoProvider::Get()->IsTouchCalibrationActive(params->id)) {
-    return RespondNow(Error(
-        "Another touch calibration is already active."));
-  }
-  if (!DisplayInfoProvider::Get()->TouchCalibrationSet(params->id,
-                                                       params->pairs,
-                                                       params->bounds)) {
-    return RespondNow(Error("Invalid display ID: " + params->id));
+  std::string error;
+  if (!DisplayInfoProvider::Get()->TouchCalibrationSet(
+          params->id, params->pairs, params->bounds, &error)) {
+    return RespondNow(Error(error));
   }
   return RespondNow(NoArguments());
 }
 
 ExtensionFunction::ResponseAction
 SystemDisplayTouchCalibrationResetFunction::Run() {
   std::unique_ptr<display::TouchCalibrationReset::Params> params(
       display::TouchCalibrationReset::Params::Create(*args_));
-  if (!DisplayInfoProvider::Get()->IsTouchCalibrationActive(params->id)) {
-    return RespondNow(Error(
-        "Another touch calibration is already active."));
-  }
-  if (!DisplayInfoProvider::Get()->TouchCalibrationReset(params->id))
-    return RespondNow(Error("Invalid display ID: " + params->id));
+  std::string error;
+  if (!DisplayInfoProvider::Get()->TouchCalibrationReset(params->id, &error))
+    return RespondNow(Error(error));
   return RespondNow(NoArguments());
 }
 
 }  // namespace extensions