1// Copyright (c) 2012 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
5#include "ui/base/layout.h"
6
7#include <algorithm>
8#include <cmath>
9#include <limits>
10
11#include "base/basictypes.h"
12#include "base/command_line.h"
13#include "base/logging.h"
14#include "build/build_config.h"
15#include "ui/base/touch/touch_device.h"
16#include "ui/base/ui_base_switches.h"
17#include "ui/gfx/display.h"
18#include "ui/gfx/image/image_skia.h"
19#include "ui/gfx/screen.h"
20
21#if defined(OS_WIN)
22#include "base/win/metro.h"
23#include "ui/gfx/win/dpi.h"
24#include <Windows.h>
25#endif  // defined(OS_WIN)
26
27namespace ui {
28
29namespace {
30
31bool ScaleFactorComparator(const ScaleFactor& lhs, const ScaleFactor& rhs){
32  return GetScaleForScaleFactor(lhs) < GetScaleForScaleFactor(rhs);
33}
34
35std::vector<ScaleFactor>* g_supported_scale_factors = NULL;
36
37const float kScaleFactorScales[] = {1.0f, 1.0f, 1.25f, 1.33f, 1.4f, 1.5f, 1.8f,
38                                    2.0f, 2.5f, 3.0f};
39COMPILE_ASSERT(NUM_SCALE_FACTORS == arraysize(kScaleFactorScales),
40               kScaleFactorScales_incorrect_size);
41
42}  // namespace
43
44void SetSupportedScaleFactors(
45    const std::vector<ui::ScaleFactor>& scale_factors) {
46  if (g_supported_scale_factors != NULL)
47    delete g_supported_scale_factors;
48
49  g_supported_scale_factors = new std::vector<ScaleFactor>(scale_factors);
50  std::sort(g_supported_scale_factors->begin(),
51            g_supported_scale_factors->end(),
52            ScaleFactorComparator);
53
54  // Set ImageSkia's supported scales.
55  std::vector<float> scales;
56  for (std::vector<ScaleFactor>::const_iterator it =
57          g_supported_scale_factors->begin();
58       it != g_supported_scale_factors->end(); ++it) {
59    scales.push_back(kScaleFactorScales[*it]);
60  }
61  gfx::ImageSkia::SetSupportedScales(scales);
62}
63
64const std::vector<ScaleFactor>& GetSupportedScaleFactors() {
65  DCHECK(g_supported_scale_factors != NULL);
66  return *g_supported_scale_factors;
67}
68
69ScaleFactor GetSupportedScaleFactor(float scale) {
70  DCHECK(g_supported_scale_factors != NULL);
71  ScaleFactor closest_match = SCALE_FACTOR_100P;
72  float smallest_diff =  std::numeric_limits<float>::max();
73  for (size_t i = 0; i < g_supported_scale_factors->size(); ++i) {
74    ScaleFactor scale_factor = (*g_supported_scale_factors)[i];
75    float diff = std::abs(kScaleFactorScales[scale_factor] - scale);
76    if (diff < smallest_diff) {
77      closest_match = scale_factor;
78      smallest_diff = diff;
79    }
80  }
81  DCHECK_NE(closest_match, SCALE_FACTOR_NONE);
82  return closest_match;
83}
84
85float GetImageScale(ScaleFactor scale_factor) {
86#if defined(OS_WIN)
87  if (gfx::IsHighDPIEnabled())
88    return gfx::win::GetDeviceScaleFactor();
89#endif
90  return GetScaleForScaleFactor(scale_factor);
91}
92
93float GetScaleForScaleFactor(ScaleFactor scale_factor) {
94  return kScaleFactorScales[scale_factor];
95}
96
97namespace test {
98
99ScopedSetSupportedScaleFactors::ScopedSetSupportedScaleFactors(
100    const std::vector<ui::ScaleFactor>& new_scale_factors) {
101  if (g_supported_scale_factors) {
102    original_scale_factors_ =
103        new std::vector<ScaleFactor>(*g_supported_scale_factors);
104  } else {
105    original_scale_factors_ = NULL;
106  }
107  SetSupportedScaleFactors(new_scale_factors);
108}
109
110ScopedSetSupportedScaleFactors::~ScopedSetSupportedScaleFactors() {
111  if (original_scale_factors_) {
112    SetSupportedScaleFactors(*original_scale_factors_);
113    delete original_scale_factors_;
114  } else {
115    delete g_supported_scale_factors;
116    g_supported_scale_factors = NULL;
117  }
118}
119
120}  // namespace test
121
122#if !defined(OS_MACOSX)
123float GetScaleFactorForNativeView(gfx::NativeView view) {
124  gfx::Screen* screen = gfx::Screen::GetScreenFor(view);
125  if (screen->IsDIPEnabled()) {
126    gfx::Display display = screen->GetDisplayNearestWindow(view);
127    return display.device_scale_factor();
128  }
129  return 1.0f;
130}
131#endif  // !defined(OS_MACOSX)
132
133}  // namespace ui
134