Support to upload multiple custom images for NTP background

This PR allows users to upload multiple images for NTP background.

* The maximum number of images is 24
* These images are stored in a dedicated directory.
* Users can select one of these or toggle on "Random" button.
* Users also can remove these images.

browser/ntp_background/custom_background_file_manager.cc

@@ -103,6 +103,14 @@ void CustomBackgroundFileManager::MoveImage(
   MakeSureDirExists(std::move(on_check_dir));
 }
 
+void CustomBackgroundFileManager::RemoveImage(
+    const base::FilePath& file_path,
+    base::OnceCallback<void(bool /*result*/)> callback) {
+  base::ThreadPool::PostTaskAndReplyWithResult(
+      FROM_HERE, {base::MayBlock()},
+      base::BindOnce(base::DeleteFile, file_path), std::move(callback));
+}
+
 base::FilePath CustomBackgroundFileManager::GetCustomBackgroundDirectory()
     const {
   return profile_->GetPath().AppendASCII(
@@ -191,7 +199,7 @@ void CustomBackgroundFileManager::SaveImageAsPNG(
         base::FilePath modified_path = target_path;
         for (int i = 1; base::PathExists(modified_path); ++i) {
           modified_path = target_path.InsertBeforeExtensionASCII(
-              base::StringPrintf("(%d)", i));
+              base::StringPrintf("-%d", i));
         }
 
         if (!base::WriteFile(

browser/ntp_background/custom_background_file_manager.h

@@ -8,10 +8,18 @@
 
 #include <memory>
 #include <string>
+#include <type_traits>
 
 #include "base/callback.h"
+#include "base/files/file_path.h"
 #include "base/memory/ref_counted_memory.h"
 #include "base/memory/weak_ptr.h"
+#include "base/strings/string_util.h"
+#include "base/strings/sys_string_conversions.h"
+#include "base/strings/utf_string_conversions.h"
+#include "brave/components/ntp_background_images/browser/url_constants.h"
+#include "url/gurl.h"
+#include "url/url_util.h"
 
 namespace base {
 class FilePath;
@@ -32,10 +40,124 @@ class Profile;
 // * Manages custom images
 //   * Have a list of custom images in Prefs.
 //   * Make it sure that we have local files mapped to entries.
-// * Deregisters custom image(TODO)
+// * Deregisters custom image
 //   * remove the local file.
 class CustomBackgroundFileManager final {
  public:
+  // |Converter| is a convience class to convert values to and from each layer.
+  //
+  //    [Web UI] - GURL with percent encoded path.
+  //       ||      The path value should be same with the value in PrefService
+  //     (path)
+  //       ||
+  //     (value)
+  //       ||
+  //  [PrefService] - std::string. The value is a file name. Encoding is
+  //       ||         usually UTF8, but on some platform it might not be
+  //     (value)      specified.
+  //       ||
+  //   (file name)
+  //       ||
+  //  [File System] - base::FilePath. On Windows, it uses wide string.
+  //                  and on other platforms, uses string but encoding might
+  //                  not be specified.
+  //
+  // This class is designed to be used for a short time and then destroyed.
+  // Don't pass this class around code base. Use this just right where you
+  // need to convert values.
+  //
+  // example:
+  //  auto file_path = Converter(url, file_manager).To<base::FilePath>();
+  //  auto url = Converter(prefs_value).To<GURL>();
+  //
+  template <class FromT>
+  class Converter final {
+   public:
+    explicit Converter(const FromT& value,
+                       CustomBackgroundFileManager* file_manager = nullptr)
+        : file_manager_(file_manager) {
+      if constexpr (std::is_same_v<FromT, std::string>) {
+        DCHECK(!base::StartsWith(value,
+                                 ntp_background_images::kCustomWallpaperURL))
+            << "Make sure that you don't pass a URL to this method";
+        value_ = value;
+      } else if constexpr (std::is_same_v<FromT, GURL>) {
+        // GURL(webui data url) -> std::string(prefs value)
+        // When GURL is given, its path is percent encoded pref name. So
+        // decode it and create Converter with it.
+        DCHECK(value.SchemeIs("chrome") &&
+               value.host() == ntp_background_images::kCustomWallpaperHost)
+            << "Not a custom wallpaper URL";
+
+        // remove leading slash
+        const auto path = value.path().substr(1);
+        DCHECK(!path.empty()) << "URL path is empty " << value;
+        url::RawCanonOutputT<char16_t> pref_value;
+        url::DecodeURLEscapeSequences(path.data(), path.length(),
+                                      url::DecodeURLMode::kUTF8OrIsomorphic,
+                                      &pref_value);
+        value_ = base::UTF16ToUTF8(
+            std::u16string(pref_value.data(), pref_value.length()));
+      } else {
+        // FilePath(local file path) -> std::string(prefs value)
+        static_assert(std::is_same_v<FromT, base::FilePath>,
+                      "FromT must be one of std::string, GURL, base::FilePath");
+
+        // When base::FilePath is given, its file name is used as pref value.
+        // But the file path's underlying type and encoding is platform
+        // dependent. So, extract file name and convert it to UTF8 if needed.
+#if defined(OS_WIN)
+        auto file_name = base::SysWideToUTF8(value.BaseName().value());
+#else
+        auto file_name = std::string(value.BaseName().value().c_str());
+#endif
+        DCHECK(!file_name.empty())
+            << "Couldn't extract file name from the given path " << value;
+        value_ = file_name;
+      }
+    }
+    Converter(const Converter&) = delete;
+    Converter& operator=(const Converter&) = delete;
+    Converter(Converter&&) noexcept = delete;
+    Converter& operator=(Converter&&) noexcept = delete;
+    ~Converter() = default;
+
+    // Converter functions. Not allowing to convert to what it was created from.
+    template <class ToT>
+    [[nodiscard]] std::enable_if_t<!std::is_same_v<FromT, ToT>, ToT> To()
+        const&& {
+      if constexpr (std::is_same_v<ToT, std::string>) {
+        return value_;
+      } else if constexpr (std::is_same_v<ToT, GURL>) {
+        // std::string(pref_value) -> GURL(webui data url)
+        // Do percent encoding and compose it with base url so that it can
+        // be used as webui data url.
+        url::RawCanonOutputT<char> encoded;
+        url::EncodeURIComponent(value_.c_str(), value_.length(), &encoded);
+        return GURL(ntp_background_images::kCustomWallpaperURL +
+                    std::string(encoded.data(), encoded.length()));
+      } else {
+        static_assert(std::is_same_v<ToT, base::FilePath>,
+                      "ToT must be one of std::string, GURL, base::FilePath");
+        // std::string(pref_value) -> base::FilePath(local file path)
+        DCHECK(file_manager_) << "Converting to local file path requires "
+                                 "CustomBackgroundFileManager";
+        base::FilePath file_path =
+            file_manager_->GetCustomBackgroundDirectory();
+#if defined(OS_WIN)
+        file_path = file_path.Append(base::SysUTF8ToWide(value_));
+#else
+        file_path = file_path.Append(value_);
+#endif
+        return file_path;
+      }
+    }
+
+   private:
+    raw_ptr<CustomBackgroundFileManager> file_manager_ = nullptr;
+    std::string value_;
+  };
+
   using SaveFileCallback = base::OnceCallback<void(const base::FilePath&)>;
 
   explicit CustomBackgroundFileManager(Profile* profile);
@@ -48,6 +170,8 @@ class CustomBackgroundFileManager final {
                  SaveFileCallback callback);
   void MoveImage(const base::FilePath& source_file_path,
                  base::OnceCallback<void(bool /*result*/)> callback);
+  void RemoveImage(const base::FilePath& file_path,
+                   base::OnceCallback<void(bool /*result*/)> callback);
 
   base::FilePath GetCustomBackgroundDirectory() const;
 

browser/ntp_background/ntp_background_prefs.cc

@@ -9,6 +9,7 @@
 #include <utility>
 
 #include "base/notreached.h"
+#include "base/ranges/algorithm.h"
 #include "brave/components/constants/pref_names.h"
 #include "components/pref_registry/pref_registry_syncable.h"
 #include "components/prefs/pref_service.h"
@@ -135,6 +136,13 @@ void NTPBackgroundPrefs::AddCustomImageToList(const std::string& file_name) {
   update->GetList().Append(file_name);
 }
 
+void NTPBackgroundPrefs::RemoveCustomImageFromList(
+    const std::string& file_name) {
+  ListPrefUpdate update(service_, NTPBackgroundPrefs::kCustomImageListPrefName);
+  auto& list = update->GetList();
+  list.erase(base::ranges::remove(update->GetList(), file_name), list.end());
+}
+
 std::vector<std::string> NTPBackgroundPrefs::GetCustomImageList() const {
   const auto* list = service_->GetList(kCustomImageListPrefName);
   std::vector<std::string> result;

browser/ntp_background/ntp_background_prefs.h

@@ -85,6 +85,7 @@ class NTPBackgroundPrefs final {
   absl::variant<GURL, std::string> GetSelectedValue() const;
 
   void AddCustomImageToList(const std::string& file_name);
+  void RemoveCustomImageFromList(const std::string& file_name);
   std::vector<std::string> GetCustomImageList() const;
 
  private:

browser/ntp_background/ntp_custom_background_images_service_delegate.cc

@@ -15,6 +15,7 @@
 #include "brave/components/constants/pref_names.h"
 #include "brave/components/ntp_background_images/browser/ntp_background_images_data.h"
 #include "brave/components/ntp_background_images/browser/ntp_background_images_service.h"
+#include "brave/components/ntp_background_images/browser/url_constants.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/url_constants.h"
@@ -79,28 +80,20 @@ bool NTPCustomBackgroundImagesServiceDelegate::IsCustomImageBackgroundEnabled()
   return NTPBackgroundPrefs(profile_->GetPrefs()).IsCustomImageType();
 }
 
-base::FilePath NTPCustomBackgroundImagesServiceDelegate::
-    GetCustomBackgroundImageLocalFilePath() const {
-  if (!IsCustomImageBackgroundEnabled())
-    return base::FilePath();
+base::FilePath
+NTPCustomBackgroundImagesServiceDelegate::GetCustomBackgroundImageLocalFilePath(
+    const GURL& url) const {
+  return CustomBackgroundFileManager::Converter(url, file_manager_.get())
+      .To<base::FilePath>();
+}
 
-  auto value = NTPBackgroundPrefs(profile_->GetPrefs()).GetSelectedValue();
-  if (!absl::holds_alternative<std::string>(value)) {
-    // This can happen during migration.
-    return base::FilePath();
-  }
+GURL NTPCustomBackgroundImagesServiceDelegate::GetCustomBackgroundImageURL()
+    const {
+  DCHECK(IsCustomImageBackgroundEnabled());
 
-#if defined(OS_WIN)
-  // On Windows path is wchar type and we should convert it to utf8.
-  // So we suppose |value| is utf8.
-  const auto file_name =
-      base::FilePath::FromUTF8Unsafe(absl::get<std::string>(value)).value();
-#else
-  // On other platform, path's encoding is not specified, and we store value
-  // as it was given.
-  const auto file_name = absl::get<std::string>(value);
-#endif
-  return file_manager_->GetCustomBackgroundDirectory().Append(file_name);
+  auto prefs = NTPBackgroundPrefs(profile_->GetPrefs());
+  auto name = absl::get<std::string>(prefs.GetSelectedValue());
+  return CustomBackgroundFileManager::Converter(name).To<GURL>();
 }
 
 bool NTPCustomBackgroundImagesServiceDelegate::IsColorBackgroundEnabled()

browser/ntp_background/ntp_custom_background_images_service_delegate.h

@@ -40,7 +40,9 @@ class NTPCustomBackgroundImagesServiceDelegate
 
   // NTPCustomBackgroundImagesService::Delegate overrides:
   bool IsCustomImageBackgroundEnabled() const override;
-  base::FilePath GetCustomBackgroundImageLocalFilePath() const override;
+  base::FilePath GetCustomBackgroundImageLocalFilePath(
+      const GURL& url) const override;
+  GURL GetCustomBackgroundImageURL() const override;
   bool IsColorBackgroundEnabled() const override;
   std::string GetColor() const override;
   bool ShouldUseRandomValue() const override;