Indicate whether a touch event will cause scrolling

ui/events/gesture_detection/filtered_gesture_provider_unittest.cc

Index: ui/events/gesture_detection/filtered_gesture_provider_unittest.cc
diff --git a/ui/events/gesture_detection/filtered_gesture_provider_unittest.cc b/ui/events/gesture_detection/filtered_gesture_provider_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..d60490ce71b0c119674e84455efbf6439396ef16
--- /dev/null
+++ b/ui/events/gesture_detection/filtered_gesture_provider_unittest.cc
@@ -0,0 +1,84 @@
+// Copyright 2014 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 "base/basictypes.h"
+#include "base/message_loop/message_loop.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "ui/events/gesture_detection/filtered_gesture_provider.h"
+#include "ui/events/test/motion_event_test_utils.h"
+
+namespace ui {
+
+class FilteredGestureProviderTest : public GestureProviderClient,
+                                    public testing::Test {
+ public:
+  FilteredGestureProviderTest() {}
+  ~FilteredGestureProviderTest() override {}
+
+  // GestureProviderClient implementation.
+  void OnGestureEvent(const GestureEventData&) override {}
+
+ private:
+  base::MessageLoopForUI message_loop_;
+};
+
+TEST_F(FilteredGestureProviderTest, TouchDidGenerateScroll) {
+  GestureProvider::Config config;
+  FilteredGestureProvider provider(config, this);
+
+  const float kSlopRegion = config.gesture_detector_config.touch_slop;
+
+  test::MockMotionEvent event;
+  event.set_event_time(base::TimeTicks::Now());
+  event.PressPoint(0, 0);
+  auto result = provider.OnTouchEvent(event);
+  EXPECT_TRUE(result.succeeded);
+  EXPECT_FALSE(result.did_generate_scroll);
+
+  event.MovePoint(0, kSlopRegion / 2.f, 0);
+  result = provider.OnTouchEvent(event);
+  EXPECT_TRUE(result.succeeded);
+  EXPECT_FALSE(result.did_generate_scroll);
+
+  // Exceeding the slop should triggering scrolling and be reflected in the API.
+  event.MovePoint(0, kSlopRegion * 2.f, 0);
+  result = provider.OnTouchEvent(event);
+  EXPECT_TRUE(result.succeeded);
+  EXPECT_TRUE(result.did_generate_scroll);
+
+  // No movement should indicate no scrolling.
+  result = provider.OnTouchEvent(event);
+  EXPECT_TRUE(result.succeeded);
+  EXPECT_FALSE(result.did_generate_scroll);
+
+  // Nonzero movement should reflect scrolling after exceeding the slop region.
+  event.MovePoint(0, 0, 0);
+  result = provider.OnTouchEvent(event);
+  EXPECT_TRUE(result.succeeded);
+  EXPECT_TRUE(result.did_generate_scroll);
+
+  // Ending a touch with no fling should not indicate scrolling.
+  event.ReleasePoint();
+  result = provider.OnTouchEvent(event);
+  EXPECT_TRUE(result.succeeded);
+  EXPECT_FALSE(result.did_generate_scroll);
+
+  // Ending a touch with a fling *should* indicate scrolling.
+  base::TimeTicks time = base::TimeTicks::Now();
+  event.PressPoint(0, 0);
+  event.set_event_time(time);
+  ASSERT_TRUE(provider.OnTouchEvent(event).succeeded);
+
+  time += base::TimeDelta::FromMilliseconds(10);
+  event.MovePoint(0, kSlopRegion * 50, 0);
+  event.set_event_time(time);
+  ASSERT_TRUE(provider.OnTouchEvent(event).succeeded);
+
+  event.ReleasePoint();
+  result = provider.OnTouchEvent(event);
+  EXPECT_TRUE(result.succeeded);
+  EXPECT_TRUE(result.did_generate_scroll);
+}
+
+}  // namespace ui