ui/base/l10n/l10n_util_win_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 "ui/base/l10n/l10n_util_win.h"

#include <windows.h>

#include "base/command_line.h"
#include "base/win/win_util.h"
#include "testing/gtest/include/gtest/gtest.h"
#include "testing/platform_test.h"
#include "ui/display/display.h"
#include "ui/display/display_switches.h"
#include "ui/display/win/screen_win.h"

typedef PlatformTest L10nUtilWinTest;

TEST_F(L10nUtilWinTest, TestDPIScaling) {
  // Baseline font for comparison.
  NONCLIENTMETRICS_XP metrics;
  base::win::GetNonClientMetrics(&metrics);
  LOGFONT lf = metrics.lfMessageFont;
  l10n_util::AdjustUIFont(&lf);
  int size = lf.lfHeight;
  float rounding = size < 0 ? -0.5f : 0.5f;

  // Test that font size is properly normalized for DIP. In high-DPI mode, the
  // font metrics are scaled based on the DPI scale factor. For Windows 8, 140%
  // and 180% font scaling are supported. Simulate size normalization for a DPI-
  // aware process by manually scaling up the font and checking that it returns
  // to the expected size.
  lf.lfHeight = static_cast<int>(1.4 * size + rounding);
  l10n_util::AdjustUIFontForDIP(1.4f, &lf);
  EXPECT_NEAR(size, lf.lfHeight, 1);

  lf.lfHeight = static_cast<int>(1.8 * size + rounding);
  l10n_util::AdjustUIFontForDIP(1.8f, &lf);
  EXPECT_NEAR(size, lf.lfHeight, 1);
}

// Test for crbug.com/675933. Since font size is a Windows metric we need to
// normalize to DIPs based on the real device scale factor, not the forced one.
TEST_F(L10nUtilWinTest, TestForcedScaling) {
  base::CommandLine::ForCurrentProcess()->AppendSwitchASCII(
      switches::kForceDeviceScaleFactor, "4");
  display::Display::ResetForceDeviceScaleFactorForTesting();

  NONCLIENTMETRICS_XP metrics;
  base::win::GetNonClientMetrics(&metrics);
  LOGFONT lf = metrics.lfMessageFont;

  // Set the font size to an arbitrary value and make sure it comes through
  // correctly on the other end.
  constexpr int test_font_size = 18;
  lf.lfHeight = test_font_size;
  l10n_util::AdjustUIFont(&lf);
  EXPECT_EQ(test_font_size / display::win::ScreenWin::GetSystemScaleFactor(),
            lf.lfHeight);
}