Add quantization option to converting dip / px

Change-Id: I0b0b5d4680ebd4c78d362fa62ecec72629835ffc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1752492
Commit-Queue: Nigel Tao <nigeltao@chromium.org>
Reviewed-by: Dominick Ng <dominickn@chromium.org>
Cr-Commit-Position: refs/heads/master@{#686711}

chrome/browser/apps/app_service/app_icon_factory.cc

@@ -141,11 +141,9 @@ void RunCallbackWithCompressedDataFromExtension(
   // compressed icons (i.e. PNG-formatted data), not uncompressed
   // (i.e. a gfx::ImageSkia).
 
-  const gfx::Size dip_size = gfx::Size(size_hint_in_dip, size_hint_in_dip);
-  float scale =
-      ui::GetScaleForScaleFactor(apps_util::GetPrimaryDisplayUIScaleFactor());
-  int size_hint_in_px = gfx::ScaleToFlooredSize(dip_size, scale).width();
-
+  constexpr bool quantize_to_supported_scale_factor = true;
+  int size_hint_in_px = apps_util::ConvertDipToPx(
+      size_hint_in_dip, quantize_to_supported_scale_factor);
   extensions::ExtensionResource ext_resource =
       extensions::IconsInfo::GetIconResource(extension, size_hint_in_px,
                                              ExtensionIconSet::MATCH_BIGGER);

chrome/browser/apps/app_service/app_icon_source.cc

@@ -78,7 +78,9 @@ void AppIconSource::StartDataRequest(
     LoadDefaultImage(callback);
     return;
   }
-  int size_in_dip = apps_util::ConvertPxToDip(size);
+  constexpr bool quantize_to_supported_scale_factor = false;
+  int size_in_dip =
+      apps_util::ConvertPxToDip(size, quantize_to_supported_scale_factor);
 
   apps::AppServiceProxy* app_service_proxy =
       apps::AppServiceProxyFactory::GetForProfile(profile_);

chrome/browser/apps/app_service/arc_apps.cc

@@ -516,11 +516,14 @@ void ArcApps::LoadIconFromVM(const std::string app_id,
   if (prefs) {
     std::unique_ptr<ArcAppListPrefs::AppInfo> app_info = prefs->GetApp(app_id);
     if (app_info) {
+      constexpr bool quantize_to_supported_scale_factor = false;
       base::OnceCallback<void(apps::ArcApps::AppConnectionHolder*)> pending =
-          base::BindOnce(&LoadIcon0, icon_compression,
-                         apps_util::ConvertDipToPx(size_hint_in_dip),
-                         app_info->package_name, app_info->activity,
-                         app_info->icon_resource_id, std::move(callback));
+          base::BindOnce(
+              &LoadIcon0, icon_compression,
+              apps_util::ConvertDipToPx(size_hint_in_dip,
+                                        quantize_to_supported_scale_factor),
+              app_info->package_name, app_info->activity,
+              app_info->icon_resource_id, std::move(callback));
 
       AppConnectionHolder* app_connection_holder =
           prefs->app_connection_holder();
@@ -544,7 +547,9 @@ void ArcApps::LoadPlayStoreIcon(apps::mojom::IconCompression icon_compression,
                                 IconEffects icon_effects,
                                 LoadIconCallback callback) {
   // Use overloaded Chrome icon for Play Store that is adapted to Chrome style.
-  int size_hint_in_px = apps_util::ConvertDipToPx(size_hint_in_dip);
+  constexpr bool quantize_to_supported_scale_factor = false;
+  int size_hint_in_px = apps_util::ConvertDipToPx(
+      size_hint_in_dip, quantize_to_supported_scale_factor);
   int resource_id = (size_hint_in_px <= 32) ? IDR_ARC_SUPPORT_ICON_32
                                             : IDR_ARC_SUPPORT_ICON_192;
   constexpr bool is_placeholder_icon = false;

chrome/browser/apps/app_service/dip_px_util.cc

@@ -4,12 +4,10 @@
 
 #include "chrome/browser/apps/app_service/dip_px_util.h"
 
-#include <cmath>
-
-#include "base/numerics/safe_conversions.h"
 #include "ui/base/layout.h"
 #include "ui/display/display.h"
 #include "ui/display/screen.h"
+#include "ui/gfx/geometry/size.h"
 
 // TODO(crbug.com/826982): plumb through enough information to use one of
 // Screen::GetDisplayNearest{Window/View/Point}. That way in multi-monitor
@@ -26,18 +24,30 @@ float GetPrimaryDisplayScaleFactor() {
   return screen->GetPrimaryDisplay().device_scale_factor();
 }
 
+int ConvertBetweenDipAndPx(int value,
+                           bool quantize_to_supported_scale_factor,
+                           bool invert) {
+  float scale = GetPrimaryDisplayScaleFactor();
+  if (quantize_to_supported_scale_factor) {
+    scale = ui::GetScaleForScaleFactor(ui::GetSupportedScaleFactor(scale));
+  }
+  DCHECK_NE(0.0f, scale);
+  if (invert) {
+    scale = 1 / scale;
+  }
+  return gfx::ScaleToFlooredSize(gfx::Size(value, value), scale).width();
+}
+
 }  // namespace
 
 namespace apps_util {
 
-int ConvertDipToPx(int dip) {
-  return base::saturated_cast<int>(
-      std::floor(static_cast<float>(dip) * GetPrimaryDisplayScaleFactor()));
+int ConvertDipToPx(int dip, bool quantize_to_supported_scale_factor) {
+  return ConvertBetweenDipAndPx(dip, quantize_to_supported_scale_factor, false);
 }
 
-int ConvertPxToDip(int px) {
-  return base::saturated_cast<int>(
-      std::floor(static_cast<float>(px) / GetPrimaryDisplayScaleFactor()));
+int ConvertPxToDip(int px, bool quantize_to_supported_scale_factor) {
+  return ConvertBetweenDipAndPx(px, quantize_to_supported_scale_factor, true);
 }
 
 ui::ScaleFactor GetPrimaryDisplayUIScaleFactor() {

chrome/browser/apps/app_service/dip_px_util.h

@@ -7,13 +7,17 @@
 
 // Utility functions for converting between DIP (device independent pixels) and
 // PX (physical pixels).
+//
+// "Supported scale factor" means a ui::ScaleFactor enum value (representing
+// one of a finite number of floating point values) returned by
+// ui::GetSupportedScaleFactor, defined in ui/base/layout.h.
 
 #include "ui/base/resource/scale_factor.h"
 
 namespace apps_util {
 
-int ConvertDipToPx(int dip);
-int ConvertPxToDip(int px);
+int ConvertDipToPx(int dip, bool quantize_to_supported_scale_factor);
+int ConvertPxToDip(int px, bool quantize_to_supported_scale_factor);
 ui::ScaleFactor GetPrimaryDisplayUIScaleFactor();
 
 }  // namespace apps_util