summaryrefslogtreecommitdiff
path: root/chromium/ui/base/layout.cc
blob: 40a0a9ccc32dd83c5e2bdf4ee6a661140e43a272 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
// Copyright (c) 2012 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/layout.h"

#include <algorithm>
#include <cmath>
#include <limits>

#include "base/basictypes.h"
#include "base/command_line.h"
#include "base/logging.h"
#include "build/build_config.h"
#include "ui/base/touch/touch_device.h"
#include "ui/base/ui_base_switches.h"
#include "ui/gfx/display.h"
#include "ui/gfx/screen.h"

#if defined(OS_MACOSX) && !defined(OS_IOS)
#include "base/mac/mac_util.h"
#endif

#if defined(OS_WIN)
#include "base/win/metro.h"
#include "ui/gfx/win/dpi.h"
#include <Windows.h>
#endif  // defined(OS_WIN)

#if defined(OS_CHROMEOS)
#include "ui/base/resource/resource_bundle.h"
#endif

namespace ui {

namespace {

bool ScaleFactorComparator(const ScaleFactor& lhs, const ScaleFactor& rhs){
  return GetScaleFactorScale(lhs) < GetScaleFactorScale(rhs);
}

#if defined(OS_WIN)
// Helper function that determines whether we want to optimize the UI for touch.
bool UseTouchOptimizedUI() {
  // If --touch-optimized-ui is specified and not set to "auto", then override
  // the hardware-determined setting (eg. for testing purposes).
  static bool has_touch_optimized_ui = CommandLine::ForCurrentProcess()->
      HasSwitch(switches::kTouchOptimizedUI);
  if (has_touch_optimized_ui) {
    const std::string switch_value = CommandLine::ForCurrentProcess()->
        GetSwitchValueASCII(switches::kTouchOptimizedUI);

    // Note that simply specifying the switch is the same as enabled.
    if (switch_value.empty() ||
        switch_value == switches::kTouchOptimizedUIEnabled) {
      return true;
    } else if (switch_value == switches::kTouchOptimizedUIDisabled) {
      return false;
    } else if (switch_value != switches::kTouchOptimizedUIAuto) {
      LOG(ERROR) << "Invalid --touch-optimized-ui option: " << switch_value;
    }
  }

  // We use the touch layout only when we are running in Metro mode.
  return base::win::IsMetroProcess() && ui::IsTouchDevicePresent();
}
#endif  // defined(OS_WIN)

const float kScaleFactorScales[] = {1.0f, 1.0f, 1.25f, 1.33f, 1.4f, 1.5f, 1.8f,
                                    2.0f};
COMPILE_ASSERT(NUM_SCALE_FACTORS == arraysize(kScaleFactorScales),
               kScaleFactorScales_incorrect_size);
const size_t kScaleFactorScalesLength = arraysize(kScaleFactorScales);

namespace {

// Returns the scale factor closest to |scale| from the full list of factors.
// Note that it does NOT rely on the list of supported scale factors.
// Finding the closest match is inefficient and shouldn't be done frequently.
ScaleFactor FindClosestScaleFactorUnsafe(float scale) {
  float smallest_diff =  std::numeric_limits<float>::max();
  ScaleFactor closest_match = SCALE_FACTOR_100P;
  for (int i = SCALE_FACTOR_100P; i < NUM_SCALE_FACTORS; ++i) {
    const ScaleFactor scale_factor = static_cast<ScaleFactor>(i);
    float diff = std::abs(kScaleFactorScales[scale_factor] - scale);
    if (diff < smallest_diff) {
      closest_match = scale_factor;
      smallest_diff = diff;
    }
  }
  return closest_match;
}

}  // namespace

std::vector<ScaleFactor>& GetSupportedScaleFactorsInternal() {
  static std::vector<ScaleFactor>* supported_scale_factors =
      new std::vector<ScaleFactor>();
  if (supported_scale_factors->empty()) {
#if !defined(OS_IOS)
    // On platforms other than iOS, 100P is always a supported scale factor.
    supported_scale_factors->push_back(SCALE_FACTOR_100P);
#endif

#if defined(OS_ANDROID)
    const gfx::Display display =
        gfx::Screen::GetNativeScreen()->GetPrimaryDisplay();
    const float display_density = display.device_scale_factor();
    const ScaleFactor closest = FindClosestScaleFactorUnsafe(display_density);
    if (closest != SCALE_FACTOR_100P)
      supported_scale_factors->push_back(closest);
#elif defined(OS_IOS)
    gfx::Display display = gfx::Screen::GetNativeScreen()->GetPrimaryDisplay();
    if (display.device_scale_factor() > 1.0) {
      DCHECK_EQ(2.0, display.device_scale_factor());
      supported_scale_factors->push_back(SCALE_FACTOR_200P);
    } else {
      supported_scale_factors->push_back(SCALE_FACTOR_100P);
    }
#elif defined(OS_MACOSX)
    if (base::mac::IsOSLionOrLater())
      supported_scale_factors->push_back(SCALE_FACTOR_200P);
#elif defined(OS_WIN)
    // Have high-DPI resources for 140% and 180% scaling on Windows based on
    // default scaling for Metro mode.  Round to nearest supported scale in
    // all cases.
    if (gfx::IsInHighDPIMode()) {
      supported_scale_factors->push_back(SCALE_FACTOR_140P);
      supported_scale_factors->push_back(SCALE_FACTOR_180P);
    }
#elif defined(OS_CHROMEOS)
    // TODO(oshima): Include 200P only if the device support 200P
    supported_scale_factors->push_back(SCALE_FACTOR_200P);
#endif
    std::sort(supported_scale_factors->begin(),
              supported_scale_factors->end(),
              ScaleFactorComparator);
  }
  return *supported_scale_factors;
}

}  // namespace

DisplayLayout GetDisplayLayout() {
#if defined(OS_WIN)
  if (UseTouchOptimizedUI())
    return LAYOUT_TOUCH;
#endif
  return LAYOUT_DESKTOP;
}

ScaleFactor GetScaleFactorFromScale(float scale) {
  ScaleFactor closest_match = SCALE_FACTOR_100P;
  float smallest_diff =  std::numeric_limits<float>::max();
  const std::vector<ScaleFactor>& supported =
      GetSupportedScaleFactorsInternal();
  for (size_t i = 0; i < supported.size(); ++i) {
    ScaleFactor scale_factor = supported[i];
    float diff = std::abs(kScaleFactorScales[scale_factor] - scale);
    if (diff < smallest_diff) {
      closest_match = scale_factor;
      smallest_diff = diff;
    }
  }
  DCHECK_NE(closest_match, SCALE_FACTOR_NONE);
  return closest_match;
}

float GetScaleFactorScale(ScaleFactor scale_factor) {
  return kScaleFactorScales[scale_factor];
}

ScaleFactor GetMaxScaleFactor() {
#if defined(OS_CHROMEOS)
  return ResourceBundle::GetSharedInstance().max_scale_factor();
#else
  return GetSupportedScaleFactorsInternal().back();
#endif
}

std::vector<ScaleFactor> GetSupportedScaleFactors() {
  return GetSupportedScaleFactorsInternal();
}

bool IsScaleFactorSupported(ScaleFactor scale_factor) {
  const std::vector<ScaleFactor>& supported =
      GetSupportedScaleFactorsInternal();
  return std::find(supported.begin(), supported.end(), scale_factor) !=
      supported.end();
}

namespace test {

void SetSupportedScaleFactors(
    const std::vector<ui::ScaleFactor>& scale_factors) {
  std::vector<ui::ScaleFactor>& supported_scale_factors =
      GetSupportedScaleFactorsInternal();
  supported_scale_factors = scale_factors;
  std::sort(supported_scale_factors.begin(),
            supported_scale_factors.end(),
            ScaleFactorComparator);
}

ScopedSetSupportedScaleFactors::ScopedSetSupportedScaleFactors(
    const std::vector<ui::ScaleFactor>& new_scale_factors)
    : original_scale_factors_(GetSupportedScaleFactors()) {
  SetSupportedScaleFactors(new_scale_factors);
}

ScopedSetSupportedScaleFactors::~ScopedSetSupportedScaleFactors() {
  SetSupportedScaleFactors(original_scale_factors_);
}

}  // namespace test

#if !defined(OS_MACOSX)
ScaleFactor GetScaleFactorForNativeView(gfx::NativeView view) {
  gfx::Screen* screen = gfx::Screen::GetScreenFor(view);
  if (screen->IsDIPEnabled()) {
    gfx::Display display = screen->GetDisplayNearestWindow(view);
    return GetScaleFactorFromScale(display.device_scale_factor());
  }
  return ui::SCALE_FACTOR_100P;
}
#endif  // !defined(OS_MACOSX)

}  // namespace ui