ReventWorkload: State detection fixes

- Corrected code highlighting and phase names in documentation
- Fixed check_states paremeter not being honoured
- Moved state dependencies check to happen earlier in execution
  and to be a user facing error

doc/source/revent.rst

@@ -246,7 +246,7 @@ definition.yaml file
 This defines each state of the workload and lists which templates are expected
 to be found and how many are required to be detected for a conclusive match. It
 also defines the expected state in each workload phase where a state detection
-is run (currently those are setupComplete and runComplete).
+is run (currently those are setup_complete and run_complete).
 
 Templates are picture elements to be matched in a screenshot. Each template
 mentioned in the definition file should be placed as a file with the same name
@@ -260,7 +260,7 @@ understand the format. Note that more than just two states (for the afterSetup
 and afterRun phase) can be defined and this helps track the cause of errors in
 case an unexpected state is encountered.
 
-.. code-block:: python
+.. code-block:: yaml
 
     workload_name: angrybirds
 

wlauto/common/android/workload.py

@@ -240,7 +240,7 @@ class ApkWorkload(Workload):
         context.add_classifiers(apk_version=self.apk_version)
 
         if self.launch_main:
-            self.launch_package() # launch default activity without intent data
+            self.launch_package()  # launch default activity without intent data
         self.device.execute('am kill-all')  # kill all *background* activities
         self.device.clear_logcat()
 
@@ -439,6 +439,7 @@ AndroidBenchmark = ApkWorkload  # backward compatibility
 
 
 class ReventWorkload(Workload):
+    # pylint: disable=attribute-defined-outside-init
 
     def __init__(self, device, _call_super=True, **kwargs):
         if _call_super:
@@ -452,7 +453,9 @@ class ReventWorkload(Workload):
         self.on_device_setup_revent = None
         self.on_device_run_revent = None
         self.statedefs_dir = None
-        self.check_states = None
+
+        if self.check_states:
+            state_detector.check_match_state_dependencies()
 
     def setup(self, context):
         self.revent_setup_file = context.resolver.get(ReventFile(self, 'setup'))

wlauto/utils/statedetect.py

@@ -40,6 +40,8 @@ try:
 except ImportError:
     imutils = None
 
+from wlauto.exceptions import HostError
+
 
 class StateDefinitionError(RuntimeError):
     pass
@@ -58,10 +60,14 @@ def auto_canny(image, sigma=0.33):
     return edged
 
 
+def check_match_state_dependencies():
+    if np is None or cv2 is None or imutils is None:
+        raise HostError("State detection requires numpy, opencv (cv2) and imutils.")
+
+
 def match_state(screenshot_file, defpath, state_definitions):  # pylint: disable=too-many-locals
     # check dependencies
-    if np is None or cv2 is None or imutils is None:
-        raise RuntimeError("State detection requires numpy, opencv (cv2) and imutils.")
+    check_match_state_dependencies()
 
     # check if file exists, then load screenshot into opencv and create edge map
     if not os.path.isfile(screenshot_file):