Refactor GestureNavigation to eliminate code redundancy

content/browser/web_contents/aura/overscroll_window_delegate_unittest.cc

+// Copyright (c) 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 "content/browser/web_contents/aura/overscroll_window_delegate.h"
+
+#include "content/browser/renderer_host/overscroll_controller_delegate.h"
+#include "content/public/browser/overscroll_configuration.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "ui/aura/test/aura_test_base.h"
+#include "ui/aura/window.h"
+#include "ui/events/test/event_generator.h"
+
+namespace content {
+
+namespace {
+  const int kTestWindowWidth = 600;
+}
+
+class OverscrollWindowDelegateTest : public aura::test::AuraTestBase,
+                                     public OverscrollControllerDelegate {
+ public:
+  OverscrollWindowDelegateTest()
+      : window_(nullptr),
+        overscroll_complete_(false),
+        overscroll_started_(false),
+        current_mode_(OVERSCROLL_NONE),
+        touch_start_threshold_(content::GetOverscrollConfig(
+            content::OVERSCROLL_CONFIG_HORIZ_THRESHOLD_START_TOUCHSCREEN)),
+        touch_complete_threshold_(content::GetOverscrollConfig(
+            content::OVERSCROLL_CONFIG_HORIZ_THRESHOLD_COMPLETE)) {}
+
+  ~OverscrollWindowDelegateTest() override {}
+
+  void Reset() {
+    overscroll_complete_ = false;
+    overscroll_started_ = false;
+    current_mode_ = OVERSCROLL_NONE;
+    window_.reset(CreateNormalWindow(
+        0, root_window(), new OverscrollWindowDelegate(this, gfx::Image())));
+    window_->SetBounds(gfx::Rect(0, 0, kTestWindowWidth, kTestWindowWidth));
+  }
+
+  // Accessors.
+  aura::Window* window() { return window_.get(); }
+
+  bool overscroll_complete() { return overscroll_complete_; }
+  bool overscroll_started() { return overscroll_started_; }
+
+  OverscrollMode current_mode() { return current_mode_; }
+
+  const float touch_start_threshold() {
+    return touch_start_threshold_;
+  }
+
+  const float touch_complete_threshold() {
+    return kTestWindowWidth * touch_complete_threshold_;
+  }
+
+ protected:
+  // aura::test::AuraTestBase:
+  void SetUp() override {
+    aura::test::AuraTestBase::SetUp();
+    Reset();
+  }
+
+  void TearDown() override {
+    window_.reset();
+    aura::test::AuraTestBase::TearDown();
+  }
+
+ private:
+  // OverscrollControllerDelegate:
+  gfx::Rect GetVisibleBounds() const override {
+    return gfx::Rect(600, 0);
+  }
+
+  bool OnOverscrollUpdate(float delta_x, float delta_y) override {
+    return true;
+  }
+
+  void OnOverscrollComplete(OverscrollMode overscroll_mode) override {
+    overscroll_complete_ = true;
+  }
+
+  void OnOverscrollModeChange(OverscrollMode old_mode,
+                              OverscrollMode new_mode) override {
+    current_mode_ = new_mode;
+    if (current_mode_ != OVERSCROLL_NONE)
+      overscroll_started_ = true;
+  }
+
+  // Window in which the overscroll window delegate is installed.
+  scoped_ptr<aura::Window> window_;
+
+  // State flags.
+  bool overscroll_complete_;
+  bool overscroll_started_;
+
+  OverscrollMode current_mode_;
+
+  // Config defined constants.
+  const float touch_start_threshold_;
+  const float touch_complete_threshold_;
+
+  DISALLOW_COPY_AND_ASSIGN(OverscrollWindowDelegateTest);
+};
+
+// Tests that the basic overscroll gesture works and sends updates to the
+// delegate.
+TEST_F(OverscrollWindowDelegateTest, BasicOverscroll) {
+  ui::test::EventGenerator generator(root_window());
+
+  // Start an OVERSCROLL_EAST gesture.
+  generator.GestureScrollSequence(
+      gfx::Point(10, 10),
+      gfx::Point(20 + touch_complete_threshold(), 10),

[mfomitchev, 2015/03/27 00:14:05]

10 + touch_complete_threshold() + 1?

[Nina, 2015/03/27 17:52:37]

By using 10, we add 1 per motion, which I thought was clearer. I also replaced
"10 + 10" with "20", it didn't add much to readability and made the line longer.

[mfomitchev, 2015/03/31 22:16:31]

We want to ensure that if we are over the threshold - the overscroll is started.
The number of steps in the gesture is completely irrelevant. It could be 1 or
1000, I don 't think that should impact the behavior in any way.

[Nina, 2015/04/01 18:10:00]

OK, modified test accordingly.

+      base::TimeDelta::FromMilliseconds(10),
+      10);
+  EXPECT_TRUE(overscroll_started());
+  EXPECT_EQ(current_mode(), OVERSCROLL_EAST);

[mfomitchev, 2015/03/27 00:14:05]

SO by the end of the gesture I'd think the mode would be changed back to NONE,
no?
Perhaps we need to check the mode mid-gesture?

[Nina, 2015/03/27 17:52:37]

Yes, the mode in OWD is changed to none. However, it is the delegate
responsibility to change its mode to NONE when the overscroll completes (and
OnOverscrollComplete is fired). This is why we check for OVERSCROLL_EAST and
overscroll_completed here. I'll add another test to verify the internal
OverscrollMode status.

[mfomitchev, 2015/03/31 22:16:31]

Acknowledged.

+  EXPECT_TRUE(overscroll_complete());
+
+  Reset();
+  // Start an OVERSCROLL_WEST gesture.
+  generator.GestureScrollSequence(
+      gfx::Point(20 + touch_complete_threshold(), 10),
+      gfx::Point(10, 10),
+      base::TimeDelta::FromMilliseconds(10),
+      10);
+  EXPECT_TRUE(overscroll_started());
+  EXPECT_EQ(current_mode(), OVERSCROLL_WEST);
+  EXPECT_TRUE(overscroll_complete());
+}
+
+// Tests that the overscroll does not start until the gesture gets past a
+// particular threshold.
+TEST_F(OverscrollWindowDelegateTest, OverscrollThreshold) {
+  ui::test::EventGenerator generator(root_window());
+
+  // Start an OVERSCROLL_EAST gesture.
+  generator.GestureScrollSequence(
+      gfx::Point(10, 10),
+      gfx::Point(10 + touch_start_threshold(), 10),
+      base::TimeDelta::FromMilliseconds(10),
+      10);
+  EXPECT_FALSE(overscroll_started());
+  EXPECT_EQ(current_mode(), OVERSCROLL_NONE);
+  EXPECT_FALSE(overscroll_complete());
+
+  Reset();
+  // Start an OVERSCROLL_WEST gesture.
+  generator.GestureScrollSequence(
+      gfx::Point(10 + touch_start_threshold(), 10),
+      gfx::Point(10, 10),
+      base::TimeDelta::FromMilliseconds(10),
+      10);
+  EXPECT_FALSE(overscroll_started());
+  EXPECT_EQ(current_mode(), OVERSCROLL_NONE);
+  EXPECT_FALSE(overscroll_complete());
+}
+
+// Tests that the overscroll is aborted if the gesture does not get past the
+// completion threshold.
+TEST_F(OverscrollWindowDelegateTest, AbortOverscrollThreshold) {
+  ui::test::EventGenerator generator(root_window());
+
+  // Start an OVERSCROLL_EAST gesture.
+  generator.GestureScrollSequence(
+      gfx::Point(10, 10),
+      gfx::Point(10 + touch_start_threshold() + 10, 10),

[mfomitchev, 2015/03/27 00:14:05]

10 + touch_start_threshold() + 1?

[Nina, 2015/03/27 17:52:37]

Same comment as above, I think it's cleaner (especially for debugging purposes)
to have a +1 per step.

[mfomitchev, 2015/03/31 22:16:31]

ditto

[Nina, 2015/04/01 18:10:00]

Done.

+      base::TimeDelta::FromMilliseconds(10),
+      10);
+  EXPECT_TRUE(overscroll_started());
+  EXPECT_EQ(current_mode(), OVERSCROLL_NONE);
+  EXPECT_FALSE(overscroll_complete());
+
+  Reset();
+  // Start an OVERSCROLL_WEST gesture.
+  generator.GestureScrollSequence(
+      gfx::Point(10 + touch_start_threshold() + 10, 10),
+      gfx::Point(10, 10),
+      base::TimeDelta::FromMilliseconds(10),
+      10);
+  EXPECT_TRUE(overscroll_started());
+  EXPECT_EQ(current_mode(), OVERSCROLL_NONE);
+  EXPECT_FALSE(overscroll_complete());
+}
+
+}  // namespace content