Userland: Improve support for vector desktop wallpapers

When loading or setting a wallpaper pass the desktop size as the "ideal
size". This allows the loader to appropriately scale vector wallpapers
to match the desktop size.

Userland/Applications/DisplaySettings/BackgroundSettingsWidget.cpp

@@ -248,7 +248,7 @@ void BackgroundSettingsWidget::apply_settings()
 {
     // We need to provide an empty path (not OptionalNone) to set_wallpaper to save a solid color wallpaper.
     auto wallpaper_path = m_monitor_widget->wallpaper().value_or(""sv);
-    if (!GUI::Desktop::the().set_wallpaper(m_monitor_widget->wallpaper_bitmap(), wallpaper_path)) {
+    if (!GUI::Desktop::the().set_wallpaper(wallpaper_path)) {
         if (!wallpaper_path.is_empty())
             GUI::MessageBox::show_error(window(), MUST(String::formatted("Unable to load file {} as wallpaper", wallpaper_path)));
         else

Userland/Applications/DisplaySettings/MonitorSettingsWidget.cpp

@@ -11,6 +11,7 @@
 #include <LibGUI/Button.h>
 #include <LibGUI/ComboBox.h>
 #include <LibGUI/ConnectionToWindowServer.h>
+#include <LibGUI/Desktop.h>
 #include <LibGUI/ItemListModel.h>
 #include <LibGUI/Label.h>
 #include <LibGUI/MessageBox.h>

Userland/Applications/DisplaySettings/MonitorWidget.cpp

@@ -30,8 +30,9 @@ ErrorOr<NonnullRefPtr<MonitorWidget>> MonitorWidget::try_create()
 void MonitorWidget::load_wallpaper(String path)
 {
     (void)Threading::BackgroundAction<NonnullRefPtr<Gfx::Bitmap>>::construct(
-        [path](auto&) -> ErrorOr<NonnullRefPtr<Gfx::Bitmap>> {
-            return Gfx::Bitmap::load_from_file(path);
+        [path, this](auto&) -> ErrorOr<NonnullRefPtr<Gfx::Bitmap>> {
+            constexpr auto scale_factor = 1;
+            return Gfx::Bitmap::load_from_file(path, scale_factor, m_monitor_rect.size());
         },
 
         [this, path](NonnullRefPtr<Gfx::Bitmap> bitmap) -> ErrorOr<void> {

Userland/Applications/FileManager/main.cpp

@@ -279,7 +279,8 @@ void do_set_wallpaper(ByteString const& file_path, GUI::Window* window)
         GUI::MessageBox::show(window, ByteString::formatted("Failed to set {} as wallpaper.", file_path), "Failed to set wallpaper"sv, GUI::MessageBox::Type::Error);
     };
 
-    auto bitmap_or_error = Gfx::Bitmap::load_from_file(file_path);
+    constexpr auto scale_factor = 1;
+    auto bitmap_or_error = Gfx::Bitmap::load_from_file(file_path, scale_factor, GUI::Desktop::the().rect().size());
     if (bitmap_or_error.is_error()) {
         show_error();
         return;
@@ -572,33 +573,18 @@ ErrorOr<int> run_in_desktop_mode()
             desktop_view_context_menu->popup(event.screen_position());
         }
     };
-
     struct BackgroundWallpaperListener : Config::Listener {
         virtual void config_string_did_change(StringView domain, StringView group, StringView key, StringView value) override
         {
-            if (domain == "WindowManager" && group == "Background" && key == "Wallpaper") {
-                if (value.is_empty()) {
-                    GUI::Desktop::the().set_wallpaper(nullptr, {});
-                    return;
-                }
-                auto wallpaper_bitmap_or_error = Gfx::Bitmap::load_from_file(value);
-                if (wallpaper_bitmap_or_error.is_error())
-                    dbgln("Failed to load wallpaper bitmap from path: {}", wallpaper_bitmap_or_error.error());
-                else
-                    GUI::Desktop::the().set_wallpaper(wallpaper_bitmap_or_error.release_value(), {});
-            }
+            if (domain == "WindowManager" && group == "Background" && key == "Wallpaper")
+                GUI::Desktop::the().apply_wallpaper(nullptr, value);
         }
     } wallpaper_listener;
 
-    auto selected_wallpaper = Config::read_string("WindowManager"sv, "Background"sv, "Wallpaper"sv, ""sv);
-    RefPtr<Gfx::Bitmap> wallpaper_bitmap {};
-    if (!selected_wallpaper.is_empty()) {
-        wallpaper_bitmap = TRY(Gfx::Bitmap::load_from_file(selected_wallpaper));
-    }
     // This sets the wallpaper at startup, even if there is no wallpaper, the
     // desktop should still show the background color. It's fine to pass a
     // nullptr to Desktop::set_wallpaper.
-    GUI::Desktop::the().set_wallpaper(wallpaper_bitmap, {});
+    GUI::Desktop::the().load_current_wallpaper();
 
     window->show();
     return GUI::Application::the()->exec();

Userland/Libraries/LibGUI/Desktop.cpp

@@ -59,13 +59,28 @@ RefPtr<Gfx::Bitmap> Desktop::wallpaper_bitmap() const
     return ConnectionToWindowServer::the().get_wallpaper().bitmap();
 }
 
-bool Desktop::set_wallpaper(RefPtr<Gfx::Bitmap const> wallpaper_bitmap, Optional<StringView> path)
+bool Desktop::apply_wallpaper(RefPtr<Gfx::Bitmap const> wallpaper_bitmap, Optional<StringView> path)
 {
     if (m_is_setting_desktop_wallpaper)
         return false;
 
+    if (!wallpaper_bitmap && path.has_value() && !path->is_empty()) {
+        constexpr auto scale_factor = 1;
+        auto maybe_wallpaper_bitmap = Gfx::Bitmap::load_from_file(*path, scale_factor, rect().size());
+        if (maybe_wallpaper_bitmap.is_error()) {
+            dbgln("Failed to load wallpaper bitmap from path: {}", maybe_wallpaper_bitmap.error());
+            return false;
+        }
+        wallpaper_bitmap = maybe_wallpaper_bitmap.release_value();
+    }
+
     TemporaryChange is_setting_desktop_wallpaper_change(m_is_setting_desktop_wallpaper, true);
-    auto result = ConnectionToWindowServer::the().set_wallpaper(wallpaper_bitmap ? wallpaper_bitmap->to_shareable_bitmap() : Gfx::ShareableBitmap {});
+    return ConnectionToWindowServer::the().set_wallpaper(wallpaper_bitmap ? wallpaper_bitmap->to_shareable_bitmap() : Gfx::ShareableBitmap {});
+}
+
+bool Desktop::set_wallpaper(RefPtr<Gfx::Bitmap const> wallpaper_bitmap, Optional<StringView> path)
+{
+    bool result = apply_wallpaper(wallpaper_bitmap, path);
 
     if (result && path.has_value()) {
         dbgln("Saving wallpaper path '{}' to ConfigServer", *path);
@@ -75,4 +90,10 @@ bool Desktop::set_wallpaper(RefPtr<Gfx::Bitmap const> wallpaper_bitmap, Optional
     return result;
 }
 
+bool Desktop::load_current_wallpaper()
+{
+    auto current_wallpaper = Config::read_string("WindowManager"sv, "Background"sv, "Wallpaper"sv, ""sv);
+    return apply_wallpaper({}, current_wallpaper);
+}
+
 }

Userland/Libraries/LibGUI/Desktop.h

@@ -34,6 +34,9 @@ public:
     ByteString wallpaper_path() const;
     RefPtr<Gfx::Bitmap> wallpaper_bitmap() const;
     bool set_wallpaper(RefPtr<Gfx::Bitmap const> wallpaper_bitmap, Optional<StringView> path);
+    bool apply_wallpaper(RefPtr<Gfx::Bitmap const> wallpaper_bitmap, Optional<StringView> path);
+    bool set_wallpaper(StringView path) { return set_wallpaper({}, path); }
+    bool load_current_wallpaper();
 
     void set_system_effects(Vector<bool> effects) { m_system_effects = { effects }; }
     SystemEffects const& system_effects() const { return m_system_effects; }

Userland/Utilities/wallpaper.cpp

@@ -65,8 +65,7 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
             return Error::from_string_literal("No wallpapers found");
 
         auto& chosen_wallpaper_path = wallpaper_paths.at(get_random_uniform(wallpaper_paths.size()));
-        auto chosen_wallpaper_bitmap = TRY(Gfx::Bitmap::load_from_file(chosen_wallpaper_path));
-        if (!GUI::Desktop::the().set_wallpaper(chosen_wallpaper_bitmap, chosen_wallpaper_path))
+        if (!GUI::Desktop::the().set_wallpaper(chosen_wallpaper_path))
             return Error::from_string_literal("Failed to set wallpaper");
 
         outln("Set wallpaper to {}", chosen_wallpaper_path);
@@ -74,8 +73,7 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
         if (path.is_null())
             return Error::from_string_literal("Must provide a path to a wallpaper");
 
-        auto wallpaper_bitmap = TRY(Gfx::Bitmap::load_from_file(path));
-        if (!GUI::Desktop::the().set_wallpaper(wallpaper_bitmap, path))
+        if (!GUI::Desktop::the().set_wallpaper(path))
             return Error::from_string_literal("Failed to set wallpaper");
     }
     return 0;