Oxygen Icons

Oxygen Icons is a freedesktop.org compatible icon theme originally developed for the KDE Plasma desktop environment in combination with the Oxygen Style. It features smooth gradients, soft shadows, and a slightly glossy look.

Declarative icon configuration (prototype)

The experimental Plasma settings implementation and build instructions are maintained in pinheiro/oxygen2, plasma-icon-configuration. That directory contains a patch against Plasma Workspace v6.7.4, including the generic renderer and regression tests, plus an opt-in CMake build/installer. Enable INSTALL_PATCHED_ICON_SETTINGS=ON there to build the patched settings; installation backs up replaced files and provides a rollback command. See its README for dependencies, distribution-specific paths and installation commands. This feature requires that patched Plasma implementation; Oxygen itself needs no compiled configuration component. Unpatched desktops continue to use Oxygen normally and ignore the extra configuration metadata.

Oxygen supplies only data: index.theme declares X-KDE-IconConfiguration=DeclarativeV1, and icon-settings.json describes the configuration title, description, tabs, checkboxes, defaults and actions. No theme-side executable, C++, Python, script or compiled UI is needed.

The corresponding Plasma System Settings implementation provides a generic Qt Widgets renderer. For example, a checkbox is declared as:

{
  "id": "symbolic22",
  "type": "checkbox",
  "label": "Include 22 px symbolic artwork",
  "default": true
}

Checkboxes belong to pages, each with a title and a controls array. All UI text is plain text. Controls describe only UI and defaults. A separate top-level installation object requests changes to the user's theme installation:

{
  "type": "userThemeCopy",
  "rules": [
    {
      "when": {"control": "symbolic22", "equals": false},
      "operation": {
        "type": "omitDirectories",
        "directories": ["applets/22x22"]
      }
    }
  ]
}

Plasma validates the requested installation type, condition, operation and paths. This rule says: when symbolic22 is false, omit applets/22x22 and its index entries from the user copy. External themes can use their own control IDs, directories and conditions, including omission when a checkbox is true. A control can trigger multiple rules, and each rule may list several registered directories. Rules must not overlap. The only supported control is checkbox; the permitted installation is userThemeCopy, with conditional omitDirectories operations. Unknown fields, action types, unsupported versions, escaping paths and invalid data are rejected.

Save applies settings to Oxygen, preserving its name, translations and theme ID. System-wide themes get a same-ID user override, normally ~/.local/share/icons/oxygen/; there is no separate configured-theme tile. Source artwork is copied, not linked; aliases are dereferenced only within the original theme. Output contains no symlinks or executable files. System-wide root-owned themes work identically as long as their artwork and metadata are readable; no write permission on the source is needed. System-installed artwork is read-only to this operation. The system fixes the output path; theme data cannot choose destinations, run commands, load plugins or request administrator access.

User choices are INI booleans in the generated index.theme under [X-KDE-IconConfigurationValues]. The managed source is recorded under [X-KDE-GeneratedIconConfiguration]; reopening that copy uses the original declaration, so disabled artwork can be restored. Restore Defaults uses the declared checkbox defaults. Cancel writes nothing; Save applies the settings and activates the same theme immediately, without requiring the enclosing Apply. If the theme was originally user-installed, its original artwork is retained under ~/.local/share/icons/.icon-config-sources/<theme-id>/ before replacing the visible installation. This hidden source is not a second theme tile. The pencil is also available for declarative system-wide installations; it requests a per-user override, not permission to edit the packaged installation. The dialog identifies its original source directory.

The pencil appears only for a supported declaration and an installed generic System Settings renderer. Editing this JSON needs no compilation. The common renderer is part of Plasma, not Oxygen. This is a proposed KDE extension, not a feature of unmodified released Plasma. Older desktops ignore the metadata.

Normal KDE fallback remains unchanged. Another enabled size or an inherited theme may still provide symbolic artwork. These are artwork-directory controls, not strict logical requested-size rules. The applet controls cover 16, 22, 24 and 32 px. The 64 px display-layout artwork is always included. GTK/private loaders retain their own fallback rules.

A future Actions tab is planned to select symbolic rather than colorful action artwork at 16, 22, 32 and 48 px. It is not enabled yet: the current schema supports directory omission only, requires a real installation rule for every checkbox and does not support inactive placeholder tabs. Adding that tab requires renderer/schema support and a defined action-artwork switching operation; omitting colorful action directories is not an equivalent replacement.

The following tab is reserved for future usage, not part of the active icon-settings.json. Defaults retain colorful action artwork. Do not activate these controls until their installation operation is implemented:

// For future usage: symbolic action selection is not implemented yet.
// Proposed entry in the "pages" array:
// {
//   "title": "Actions",
//   "controls": [
//     {
//       "id": "symbolicActions16",
//       "type": "checkbox",
//       "label": "Use symbolic action icons at 16 px",
//       "default": false
//     },
//     {
//       "id": "symbolicActions22",
//       "type": "checkbox",
//       "label": "Use symbolic action icons at 22 px",
//       "default": false
//     },
//     {
//       "id": "symbolicActions32",
//       "type": "checkbox",
//       "label": "Use symbolic action icons at 32 px",
//       "default": false
//     },
//     {
//       "id": "symbolicActions48",
//       "type": "checkbox",
//       "label": "Use symbolic action icons at 48 px",
//       "default": false
//     }
//   ]
// }

The copy operation is bounded, serialized with a user-icon lock, staged before activation and refuses to overwrite an unrelated same-ID user theme. It rejects external symlinks and special files. The original installation must remain available for future reconfiguration; source changes become visible after another Save.