blob: 51dacd7e6e9b88134f17b66fdd4c786be2a21376 [file] [log] [blame]
// Copyright 2018 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 "ash/magnifier/magnifier_scale_utils.h"
#include "testing/gtest/include/gtest/gtest.h"
namespace ash {
namespace magnifier_scale_utils {
namespace {
TEST(MagnifierScaleUtilsTest, AdjustScaleFromScroll) {
// Scaling by offset 0.2f followed by another 0.2f should result in the same
// scale if scaling by offset 0.4f (given that we start from the same scale).
const float min_scale = 1.0f;
const float max_scale = 20.f;
const float starting_scale = 1.0f;
// Calculate scale if we're stepping by 0.2f twice.
float linear_offset = 0.2f;
const float step_1_scale =
GetScaleFromScroll(linear_offset, starting_scale, min_scale, max_scale);
const float step_2_scale =
GetScaleFromScroll(linear_offset, step_1_scale, min_scale, max_scale);
// Calculate scale if we're stepping by 0.4f from the same starting scale.
linear_offset = 0.4f;
const float final_scale =
GetScaleFromScroll(linear_offset, starting_scale, min_scale, max_scale);
EXPECT_FLOAT_EQ(final_scale, step_2_scale);
// However, each step doesn't change the scale linearly.
EXPECT_NE(step_1_scale - starting_scale, step_2_scale - step_1_scale);
TEST(MagnifierScaleUtilsTest, GetNextMagnifierScaleValue) {
const float min = 3.0f;
const float max = 40.0f;
float current_scale = min;
// A positive |delta_index| always result in an increasing scale values that
// are less than |max|.
int delta_index = 1;
while (current_scale < max) {
float new_scale =
GetNextMagnifierScaleValue(delta_index, current_scale, min, max);
EXPECT_GT(new_scale, current_scale);
current_scale = new_scale;
EXPECT_FLOAT_EQ(current_scale, max);
// And vice versa for a negative |delta_index|.
delta_index = -1;
while (current_scale > min) {
float new_scale =
GetNextMagnifierScaleValue(delta_index, current_scale, min, max);
EXPECT_LT(new_scale, current_scale);
current_scale = new_scale;
EXPECT_FLOAT_EQ(min, current_scale);
} // namespace
} // namespace magnifier_scale_utils
} // namespace ash