src/tools/telemetry/telemetry/page/actions/scroll_bounce.py

   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 import os
   5
   6 from telemetry.page.actions.gesture_action import GestureAction
   7 from telemetry.page.actions import page_action
   8
   9 class ScrollBounceAction(GestureAction):
  10   def __init__(self, attributes=None):
  11     super(ScrollBounceAction, self).__init__(attributes)
  12
  13   def WillRunAction(self, page, tab):
  14     for js_file in ['gesture_common.js', 'scroll_bounce.js']:
  15       with open(os.path.join(os.path.dirname(__file__), js_file)) as f:
  16         js = f.read()
  17         tab.ExecuteJavaScript(js)
  18
  19     # Fail if browser doesn't support synthetic scroll bounce gestures.
  20     if not tab.EvaluateJavaScript(
  21         'window.__ScrollBounceAction_SupportedByBrowser()'):
  22       raise page_action.PageActionNotSupported(
  23           'Synthetic scroll bounce not supported for this browser')
  24
  25     # Fail if we can't send touch events (bouncing is really only
  26     # interesting for touch)
  27     if not GestureAction.IsGestureSourceTypeSupported(tab, 'touch'):
  28       raise page_action.PageActionNotSupported(
  29           'Touch scroll not supported for this browser')
  30
  31     if (GestureAction.GetGestureSourceTypeFromOptions(tab) ==
  32         'chrome.gpuBenchmarking.MOUSE_INPUT'):
  33       raise page_action.PageActionNotSupported(
  34           'ScrollBounce page action does not support mouse input')
  35
  36     done_callback = 'function() { window.__scrollBounceActionDone = true; }'
  37     tab.ExecuteJavaScript("""
  38         window.__scrollBounceActionDone = false;
  39         window.__scrollBounceAction = new __ScrollBounceAction(%s);"""
  40         % (done_callback))
  41
  42   def RunGesture(self, page, tab):
  43     left_start_percentage = 0.5
  44     top_start_percentage = 0.5
  45     direction = 'down'
  46     # Should be big enough to do more than just hide the URL bar.
  47     distance = 100
  48     # This needs to be < height / repeat_count so we don't walk off the screen.
  49     # We also probably don't want to spend more than a couple frames in
  50     # overscroll since it may mask any synthetic delays.
  51     overscroll = 10
  52     # It's the transitions we really want to stress, make this big.
  53     repeat_count = 10
  54     # 7 pixels per frame should be plenty of frames.
  55     speed = 400
  56     if hasattr(self, 'left_start_percentage'):
  57       left_start_percentage = self.left_start_percentage
  58     if hasattr(self, 'top_start_percentage'):
  59       top_start_percentage = self.top_start_percentage
  60     if hasattr(self, 'direction'):
  61       direction = self.direction
  62       if direction not in ['down', 'up', 'left', 'right']:
  63         raise page_action.PageActionNotSupported(
  64             'Invalid scroll bounce direction: %s' % direction)
  65     if hasattr(self, 'distance'):
  66       distance = self.distance
  67     if hasattr(self, 'overscroll'):
  68       overscroll = self.overscroll
  69     if hasattr(self, 'repeat_count'):
  70       repeat_count = self.repeat_count
  71     if hasattr(self, 'speed'):
  72       speed = self.speed
  73     if hasattr(self, 'element_function'):
  74       tab.ExecuteJavaScript("""
  75           (%s)(function(element) { window.__scrollBounceAction.start(
  76              { element: element,
  77                left_start_percentage: %s,
  78                top_start_percentage: %s,
  79                direction: '%s',
  80                distance: %s,
  81                overscroll: %s,
  82                repeat_count: %s,
  83                speed: %s })
  84              });""" % (self.element_function,
  85                        left_start_percentage,
  86                        top_start_percentage,
  87                        direction,
  88                        distance,
  89                        overscroll,
  90                        repeat_count,
  91                        speed))
  92     else:
  93       tab.ExecuteJavaScript("""
  94           window.__scrollBounceAction.start(
  95           { element: document.body,
  96             left_start_percentage: %s,
  97             top_start_percentage: %s,
  98             direction: '%s',
  99             distance: %s,
 100             overscroll: %s,
 101             repeat_count: %s,
 102             speed: %s });"""
 103         % (left_start_percentage,
 104            top_start_percentage,
 105            direction,
 106            distance,
 107            overscroll,
 108            repeat_count,
 109            speed))
 110
 111     tab.WaitForJavaScriptExpression('window.__scrollBounceActionDone', 60)
 112
 113   def CanBeBound(self):
 114     return True
 115
 116   def BindMeasurementJavaScript(self, tab, start_js, stop_js):
 117     # Make the scroll bounce action start and stop measurement automatically.
 118     tab.ExecuteJavaScript("""
 119         window.__scrollBounceAction.beginMeasuringHook = function() { %s };
 120         window.__scrollBounceAction.endMeasuringHook = function() { %s };
 121     """ % (start_js, stop_js))