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
|
// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "ui/display/win/dpi.h"
#include <windows.h>
#include "base/win/scoped_hdc.h"
#include "ui/display/display.h"
#include "ui/display/win/uwp_text_scale_factor.h"
namespace display {
namespace win {
namespace {
const float kDefaultDPI = 96.f;
float g_device_scale_factor = 0.f;
} // namespace
void SetDefaultDeviceScaleFactor(float scale) {
DCHECK_NE(0.f, scale);
g_device_scale_factor = scale;
}
float GetDPIScale() {
if (Display::HasForceDeviceScaleFactor())
return Display::GetForcedDeviceScaleFactor();
return display::win::internal::GetUnforcedDeviceScaleFactor();
}
int GetDPIFromScalingFactor(float device_scaling_factor) {
return kDefaultDPI * device_scaling_factor;
}
double GetAccessibilityFontScale() {
return 1.0 / UwpTextScaleFactor::Instance()->GetTextScaleFactor();
}
namespace internal {
int GetDefaultSystemDPI() {
static int dpi_x = 0;
static int dpi_y = 0;
static bool should_initialize = true;
if (should_initialize) {
should_initialize = false;
base::win::ScopedGetDC screen_dc(NULL);
// This value is safe to cache for the life time of the app since the
// user must logout to change the DPI setting. This value also applies
// to all screens.
dpi_x = GetDeviceCaps(screen_dc, LOGPIXELSX);
dpi_y = GetDeviceCaps(screen_dc, LOGPIXELSY);
DCHECK_EQ(dpi_x, dpi_y);
}
return dpi_x;
}
float GetUnforcedDeviceScaleFactor() {
return g_device_scale_factor ? g_device_scale_factor
: GetScalingFactorFromDPI(GetDefaultSystemDPI());
}
float GetScalingFactorFromDPI(int dpi) {
return static_cast<float>(dpi) / kDefaultDPI;
}
} // namespace internal
} // namespace win
} // namespace display
|
