Enable hidpi on Linux, refactor a bit on Windows to share

ui/gfx/dpi.cc

Index: ui/gfx/dpi.cc
diff --git a/ui/gfx/win/dpi.cc b/ui/gfx/dpi.cc
similarity index 88%
rename from ui/gfx/win/dpi.cc
rename to ui/gfx/dpi.cc
index 2777f7cb01235bb838de9c8e7b42343a1f5f2499..38a740b4604c7cf18467560c592d11c0ddc414fc 100644
--- a/ui/gfx/win/dpi.cc
+++ b/ui/gfx/dpi.cc
@@ -2,33 +2,28 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "ui/gfx/win/dpi.h"
+#include "ui/gfx/dpi.h"
 
-#include <windows.h>
-#include "base/win/scoped_hdc.h"
-#include "base/win/windows_version.h"
-#include "base/win/registry.h"
+#include "base/logging.h"
 #include "ui/gfx/display.h"
 #include "ui/gfx/point_conversions.h"
 #include "ui/gfx/rect_conversions.h"
 #include "ui/gfx/size_conversions.h"
 
-namespace {
+#if defined(OS_WIN)
+#include <windows.h>
+#include "base/win/registry.h"
+#include "base/win/scoped_hdc.h"
+#include "base/win/windows_version.h"
+#endif
 
-int kDefaultDPIX = 96;
-int kDefaultDPIY = 96;
+#if defined(OS_LINUX)
+#include "ui/gfx/linux_font_delegate.h"
+#endif
 
-bool force_highdpi_for_testing = false;
+namespace {
 
-BOOL IsProcessDPIAwareWrapper() {
-  typedef BOOL(WINAPI *IsProcessDPIAwarePtr)(VOID);
-  IsProcessDPIAwarePtr is_process_dpi_aware_func =
-      reinterpret_cast<IsProcessDPIAwarePtr>(
-          GetProcAddress(GetModuleHandleA("user32.dll"), "IsProcessDPIAware"));
-  if (is_process_dpi_aware_func)
-    return is_process_dpi_aware_func();
-  return FALSE;
-}
+int kDefaultDPI = 96;
 
 float g_device_scale_factor = 0.0f;
 
@@ -40,55 +35,10 @@ float GetUnforcedDeviceScaleFactor() {
   if (g_device_scale_factor)
     return g_device_scale_factor;
   return static_cast<float>(gfx::GetDPI().width()) /
-      static_cast<float>(kDefaultDPIX);
-}
-
-// Duplicated from Win8.1 SDK ShellScalingApi.h
-typedef enum PROCESS_DPI_AWARENESS {
-    PROCESS_DPI_UNAWARE = 0,
-    PROCESS_SYSTEM_DPI_AWARE = 1,
-    PROCESS_PER_MONITOR_DPI_AWARE = 2
-} PROCESS_DPI_AWARENESS;
-
-typedef enum MONITOR_DPI_TYPE {
-    MDT_EFFECTIVE_DPI = 0,
-    MDT_ANGULAR_DPI = 1,
-    MDT_RAW_DPI = 2,
-    MDT_DEFAULT = MDT_EFFECTIVE_DPI
-} MONITOR_DPI_TYPE;
-
-// Win8.1 supports monitor-specific DPI scaling.
-bool SetProcessDpiAwarenessWrapper(PROCESS_DPI_AWARENESS value) {
-  typedef BOOL(WINAPI *SetProcessDpiAwarenessPtr)(PROCESS_DPI_AWARENESS);
-  SetProcessDpiAwarenessPtr set_process_dpi_awareness_func =
-      reinterpret_cast<SetProcessDpiAwarenessPtr>(
-          GetProcAddress(GetModuleHandleA("user32.dll"),
-                          "SetProcessDpiAwarenessInternal"));
-  if (set_process_dpi_awareness_func) {
-    HRESULT hr = set_process_dpi_awareness_func(value);
-    if (SUCCEEDED(hr)) {
-      VLOG(1) << "SetProcessDpiAwareness succeeded.";
-      return true;
-    } else if (hr == E_ACCESSDENIED) {
-      LOG(ERROR) << "Access denied error from SetProcessDpiAwareness. "
-          "Function called twice, or manifest was used.";
-    }
-  }
-  return false;
-}
-
-// This function works for Windows Vista through Win8. Win8.1 must use
-// SetProcessDpiAwareness[Wrapper]
-BOOL SetProcessDPIAwareWrapper() {
-  typedef BOOL(WINAPI *SetProcessDPIAwarePtr)(VOID);
-  SetProcessDPIAwarePtr set_process_dpi_aware_func =
-      reinterpret_cast<SetProcessDPIAwarePtr>(
-      GetProcAddress(GetModuleHandleA("user32.dll"),
-                      "SetProcessDPIAware"));
-  return set_process_dpi_aware_func &&
-    set_process_dpi_aware_func();
+         static_cast<float>(kDefaultDPI);
 }
 
+#if defined(OS_WIN)
 DWORD ReadRegistryValue(HKEY root,
                         const wchar_t* base_key,
                         const wchar_t* value_name,
@@ -103,9 +53,11 @@ DWORD ReadRegistryValue(HKEY root,
   }
   return default_value;
 }
+#endif
 
 }  // namespace
 
+
 namespace gfx {
 
 void InitDeviceScaleFactor(float scale) {
@@ -113,6 +65,23 @@ void InitDeviceScaleFactor(float scale) {
   g_device_scale_factor = scale;
 }
 
+float GetDeviceScaleFactor() {
+  DCHECK_NE(0.0f, g_device_scale_factor);
+  return g_device_scale_factor;
+}
+
+bool IsDeviceScaleFactorSet() {
+  return g_device_scale_factor != 0.0f;
+}
+
+void ForceHighDPISupportForTesting(float scale) {
+  g_device_scale_factor = scale;
+}
+
+bool IsInHighDPIMode() {
+  return GetDPIScale() > 1.0;
+}
+
 Size GetDPI() {
   static int dpi_x = 0;
   static int dpi_y = 0;
@@ -120,12 +89,21 @@ Size GetDPI() {
 
   if (should_initialize) {
     should_initialize = false;
+#if defined(OS_WIN)
     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);
+#else
+    const gfx::LinuxFontDelegate* delegate = gfx::LinuxFontDelegate::instance();
+    if (delegate)
+      dpi_x = delegate->GetFontDPI();
+    if (dpi_x <= 0)
+      dpi_x = 96;
+    dpi_y = dpi_x;
+#endif
   }
   return Size(dpi_x, dpi_y);
 }
@@ -145,42 +123,6 @@ float GetDPIScale() {
   return 1.0;
 }
 
-void ForceHighDPISupportForTesting(float scale) {
-  g_device_scale_factor = scale;
-}
-
-bool IsHighDPIEnabled() {
-  // Flag stored in HKEY_CURRENT_USER\SOFTWARE\\Google\\Chrome\\Profile,
-  // under the DWORD value high-dpi-support.
-  // Default is disabled.
-  static DWORD value = ReadRegistryValue(
-      HKEY_CURRENT_USER, gfx::win::kRegistryProfilePath,
-      gfx::win::kHighDPISupportW, TRUE);
-  return value != 0;
-}
-
-bool IsInHighDPIMode() {
-  return GetDPIScale() > 1.0;
-}
-
-void EnableHighDPISupport() {
-  if (IsHighDPIEnabled() &&
-      !SetProcessDpiAwarenessWrapper(PROCESS_SYSTEM_DPI_AWARE)) {
-    SetProcessDPIAwareWrapper();
-  }
-}
-
-namespace win {
-
-GFX_EXPORT const wchar_t kRegistryProfilePath[] =
-    L"Software\\Google\\Chrome\\Profile";
-GFX_EXPORT const wchar_t kHighDPISupportW[] = L"high-dpi-support";
-
-float GetDeviceScaleFactor() {
-  DCHECK_NE(0.0f, g_device_scale_factor);
-  return g_device_scale_factor;
-}
-
 Point ScreenToDIPPoint(const Point& pixel_point) {
   return ToFlooredPoint(ScalePoint(pixel_point,
                                    1.0f / GetDeviceScaleFactor()));
@@ -217,14 +159,92 @@ Size DIPToScreenSize(const Size& dip_size) {
   return ToCeiledSize(ScaleSize(dip_size, GetDeviceScaleFactor()));
 }
 
+bool IsHighDPIEnabled() {
+#if defined(OS_WIN)
+  static const wchar_t kRegistryProfilePath[] =
+      L"Software\\Google\\Chrome\\Profile";
+  static const wchar_t kHighDPISupportW[] = L"high-dpi-support";
+
+  // Flag stored in HKEY_CURRENT_USER\SOFTWARE\\Google\\Chrome\\Profile,
+  // under the DWORD value high-dpi-support.
+  // Default is disabled.
+  static DWORD value = ReadRegistryValue(
+      HKEY_CURRENT_USER, kRegistryProfilePath, kHighDPISupportW, TRUE);
+  return value != 0;
+#elif defined(OS_LINUX)
+  return true;
+#endif
+}
+
+
+#if defined(OS_WIN)
+
+namespace win {
+
+namespace {
+
+// Duplicated from Win8.1 SDK ShellScalingApi.h
+typedef enum PROCESS_DPI_AWARENESS {
+    PROCESS_DPI_UNAWARE = 0,
+    PROCESS_SYSTEM_DPI_AWARE = 1,
+    PROCESS_PER_MONITOR_DPI_AWARE = 2
+} PROCESS_DPI_AWARENESS;
+
+typedef enum MONITOR_DPI_TYPE {
+    MDT_EFFECTIVE_DPI = 0,
+    MDT_ANGULAR_DPI = 1,
+    MDT_RAW_DPI = 2,
+    MDT_DEFAULT = MDT_EFFECTIVE_DPI
+} MONITOR_DPI_TYPE;
+
+// Win8.1 supports monitor-specific DPI scaling.
+bool SetProcessDpiAwarenessWrapper(PROCESS_DPI_AWARENESS value) {
+  typedef BOOL(WINAPI *SetProcessDpiAwarenessPtr)(PROCESS_DPI_AWARENESS);
+  SetProcessDpiAwarenessPtr set_process_dpi_awareness_func =
+      reinterpret_cast<SetProcessDpiAwarenessPtr>(
+          GetProcAddress(GetModuleHandleA("user32.dll"),
+                          "SetProcessDpiAwarenessInternal"));
+  if (set_process_dpi_awareness_func) {
+    HRESULT hr = set_process_dpi_awareness_func(value);
+    if (SUCCEEDED(hr)) {
+      VLOG(1) << "SetProcessDpiAwareness succeeded.";
+      return true;
+    } else if (hr == E_ACCESSDENIED) {
+      LOG(ERROR) << "Access denied error from SetProcessDpiAwareness. "
+          "Function called twice, or manifest was used.";
+    }
+  }
+  return false;
+}
+
+// This function works for Windows Vista through Win8. Win8.1 must use
+// SetProcessDpiAwareness[Wrapper]
+BOOL SetProcessDPIAwareWrapper() {
+  typedef BOOL(WINAPI *SetProcessDPIAwarePtr)(VOID);
+  SetProcessDPIAwarePtr set_process_dpi_aware_func =
+      reinterpret_cast<SetProcessDPIAwarePtr>(
+      GetProcAddress(GetModuleHandleA("user32.dll"),
+                      "SetProcessDPIAware"));
+  return set_process_dpi_aware_func &&
+    set_process_dpi_aware_func();
+}
+
+}  // namespace
+
+void EnableHighDPISupport() {
+  if (IsHighDPIEnabled() &&
+      !SetProcessDpiAwarenessWrapper(PROCESS_SYSTEM_DPI_AWARE)) {
+    SetProcessDPIAwareWrapper();
+  }
+}
+
 int GetSystemMetricsInDIP(int metric) {
   return static_cast<int>(GetSystemMetrics(metric) /
       GetDeviceScaleFactor() + 0.5);
 }
 
-bool IsDeviceScaleFactorSet() {
-  return g_device_scale_factor != 0.0f;
-}
-
 }  // namespace win
+
+#endif  // OS_WIN
+
 }  // namespace gfx