feat(cosmic-theme): produce QPalette ini for more compatibility

cosmic-theme/src/output/mod.rs

@@ -46,8 +46,10 @@ impl Theme {
     pub fn write_exports(&self) -> Result<(), OutputError> {
         let gtk_res = self.write_gtk4();
         let qt_res = self.write_qt();
+        let qt56ct_res = self.write_qt56ct();
         gtk_res?;
         qt_res?;
+        qt56ct_res?;
         Ok(())
     }
 
@@ -56,8 +58,10 @@ impl Theme {
     pub fn reset_exports() -> Result<(), OutputError> {
         let gtk_res = Theme::reset_gtk();
         let qt_res = Theme::reset_qt();
+        let qt56ct_res = Theme::reset_qt56ct();
         gtk_res?;
         qt_res?;
+        qt56ct_res?;
         Ok(())
     }
 }

cosmic-theme/src/output/qt56ct_output.rs

@@ -1,8 +1,11 @@
 use crate::Theme;
 use configparser::ini::Ini;
+use palette::{Mix, Srgba, WithAlpha, blend::Compose, rgb::Rgba};
 use std::{
     fs::{self, File},
+    io::Write,
     path::PathBuf,
+    vec,
 };
 
 use super::{OutputError, qt_settings_ini_style};
@@ -15,7 +18,117 @@ impl Theme {
     /// Increment this value when changes to qt{5,6}ct.conf are needed.
     /// If the config's version is outdated, we update several sections.
     /// Otherwise, only the light/dark mode is updated.
-    const COSMIC_QT_VERSION: u64 = 1;
+    const COSMIC_QT_VERSION: u64 = 2;
+
+    /// Produces a QPalette ini file for qt5ct and qt6ct.
+    ///
+    /// Example file: https://github.com/trialuser02/qt6ct/blob/master/colors/airy.conf
+    #[must_use]
+    #[cold]
+    pub fn as_qpalette(&self) -> String {
+        let lightest = if self.is_dark {
+            self.background.on
+        } else {
+            self.background.base
+        };
+        let darkest = if self.is_dark {
+            self.background.base
+        } else {
+            self.background.on
+        };
+        let active = QPaletteGroup {
+            window_text: self.background.on,
+            button: self.button.base,
+            light: self.button.base.mix(lightest, 0.1),
+            midlight: self.button.base.mix(lightest, 0.05),
+            dark: self.button.base.mix(darkest, 0.1),
+            mid: self.button.base.mix(darkest, 0.05),
+            text: self.background.component.on,
+            bright_text: lightest,
+            button_text: self.button.on,
+            base: self.background.component.base,
+            window: self.background.base,
+            shadow: darkest,
+            // selection colors are swapped to fix menu bar contrast
+            highlight: self.background.component.selected_text,
+            highlighted_text: self.background.component.selected,
+            link: self.link_button.on,
+            link_visited: self.link_button.on.mix(self.secondary.component.base, 0.2),
+            alternate_base: self.background.base.mix(self.accent.base, 0.05),
+            no_role: self.background.component.disabled,
+            tool_tip_base: self.background.component.base,
+            tool_tip_text: self.background.component.on,
+            placeholder_text: self.background.component.on.with_alpha(0.5),
+        };
+        let inactive = QPaletteGroup {
+            window_text: active.window_text.with_alpha(0.8),
+            text: active.text.with_alpha(0.8),
+            highlighted_text: active.highlighted_text.with_alpha(0.8),
+            tool_tip_text: active.tool_tip_text.with_alpha(0.8),
+            ..active
+        };
+        let disabled = QPaletteGroup {
+            button: self.button.disabled,
+            text: self.background.component.on_disabled,
+            button_text: self.button.on_disabled,
+            base: self.background.component.disabled,
+            highlighted_text: active.highlighted_text.with_alpha(0.5),
+            link: self.link_button.on_disabled,
+            link_visited: self
+                .link_button
+                .on_disabled
+                .mix(self.secondary.component.disabled, 0.2),
+            alternate_base: self.background.base.mix(self.accent.disabled, 0.05),
+            tool_tip_base: self.background.component.disabled,
+            tool_tip_text: self.background.component.on_disabled,
+            placeholder_text: self.background.component.on_disabled.with_alpha(0.5),
+            ..inactive
+        };
+
+        format!(
+            r#"# GENERATED BY COSMIC
+
+[ColorScheme]
+active_colors={}
+disabled_colors={}
+inactive_colors={}
+"#,
+            active.as_list(),
+            disabled.as_list(),
+            inactive.as_list(),
+        )
+    }
+
+    /// Writes the QPalette ini files to:
+    /// - `~/.config/qt6ct/colors/`
+    /// - `~/.config/qt5ct/colors/`
+    #[cold]
+    pub fn write_qt56ct(&self) -> Result<(), OutputError> {
+        let qpalette = self.as_qpalette();
+        let qt5ct_res = self.write_ct("qt5ct", &qpalette);
+        let qt6ct_res = self.write_ct("qt6ct", &qpalette);
+        qt5ct_res?;
+        qt6ct_res?;
+        Ok(())
+    }
+    #[must_use]
+    #[cold]
+    fn write_ct(&self, ct: &str, qpalette: &str) -> Result<(), OutputError> {
+        let file_path = Self::get_qpalette_path(ct, self.is_dark)?;
+        let tmp_file_path = file_path.with_extension("conf.new");
+
+        let mut tmp_file = File::create(&tmp_file_path).map_err(OutputError::Io)?;
+        let res = tmp_file
+            .write_all(qpalette.as_bytes())
+            .and_then(|_| tmp_file.flush())
+            .and_then(|_| std::fs::rename(&tmp_file_path, file_path));
+        if let Err(e) = res {
+            _ = std::fs::remove_file(&tmp_file_path);
+            return Err(OutputError::Io(e));
+        }
+
+        Ok(())
+    }
 
     /// Edits qt{5,6}ct.conf to use COSMIC styles if needed.
     #[cold]
@@ -39,7 +152,7 @@ impl Theme {
             .map_err(OutputError::Ini)?
             .unwrap_or_default();
 
-        let color_scheme_path = Self::get_qt_colors_path(is_dark)?;
+        let color_scheme_path = Self::get_qpalette_path(ct, is_dark)?;
         let icon_theme = if is_dark { "breeze-dark" } else { "breeze" };
 
         ini.set(
@@ -91,11 +204,48 @@ impl Theme {
         Ok(())
     }
 
+    /// Reset the applied qt56ct config by removing COSMIC-specific entries from the config file.
+    #[cold]
+    pub fn reset_qt56ct() -> Result<(), OutputError> {
+        let qt5ct_res = Self::reset_ct("qt5ct");
+        let qt6ct_res = Self::reset_ct("qt6ct");
+        qt5ct_res?;
+        qt6ct_res?;
+        Ok(())
+    }
+    #[must_use]
+    #[cold]
+    fn reset_ct(ct: &str) -> Result<(), OutputError> {
+        let path = Self::get_conf_path(ct)?;
+        let file_content = fs::read_to_string(&path).map_err(OutputError::Io)?;
+        let mut ini = Ini::new_cs();
+        ini.read(file_content).map_err(OutputError::Ini)?;
+
+        let old_version = ini
+            .getuint("Appearance", "cosmic_qt_version")
+            .map_err(OutputError::Ini)?
+            .unwrap_or_default();
+        if old_version == 0 {
+            return Ok(());
+        }
+
+        ini.remove_key("Appearance", "cosmic_qt_version");
+        ini.remove_key("Appearance", "color_scheme_path");
+        ini.remove_key("Appearance", "icon_theme");
+
+        ini.pretty_write(path, &qt_settings_ini_style())
+            .map_err(OutputError::Io)?;
+        Ok(())
+    }
+
     /// Returns the file paths of the form `~/.config/ct/ct.conf`:
     /// e.g. `~/.config/qt6ct/qt6ct.conf`.
     ///
     /// The file and its parent directory are created if they don't exist.
+    #[cold]
     fn get_conf_path(ct: &str) -> Result<PathBuf, OutputError> {
+        assert!(ct == "qt5ct" || ct == "qt6ct");
+
         let Some(mut config_dir) = dirs::config_dir() else {
             return Err(OutputError::MissingConfigDir);
         };
@@ -111,4 +261,131 @@ impl Theme {
 
         Ok(file_path)
     }
+
+    /// Gets a path like `~/.config/qt6ct/colors/CosmicDark.conf`
+    ///
+    /// Its parent directory is created if it doesn't exist.
+    #[cold]
+    fn get_qpalette_path(ct: &str, is_dark: bool) -> Result<PathBuf, OutputError> {
+        assert!(ct == "qt5ct" || ct == "qt6ct");
+
+        let Some(mut config_dir) = dirs::config_dir() else {
+            return Err(OutputError::MissingConfigDir);
+        };
+        config_dir.push(&ct);
+        config_dir.push("colors");
+        if !config_dir.exists() {
+            fs::create_dir_all(&config_dir).map_err(OutputError::Io)?;
+        }
+
+        let file_name = if is_dark {
+            "CosmicDark.conf"
+        } else {
+            "CosmicLight.conf"
+        };
+
+        Ok(config_dir.join(file_name))
+    }
+}
+
+/// Defines the different symbolic color roles used in current GUIs.
+///
+/// qt5ct and qt6ct consume this as a list of colors, ordered by ColorRole:
+/// - https://doc.qt.io/qt-6/qpalette.html#ColorRole-enum
+/// - https://doc.qt.io/archives/qt-5.15/qpalette.html#ColorRole-enum
+struct QPaletteGroup {
+    /// A general foreground color.
+    window_text: Srgba,
+    /// The general button background color.
+    button: Srgba,
+    /// Lighter than [button] color, used mostly for 3D bevel and shadow effects.
+    light: Srgba,
+    /// Between [button] and [light], used mostly for 3D bevel and shadow effects.
+    midlight: Srgba,
+    /// Darker than [button], used mostly for 3D bevel and shadow effects.
+    dark: Srgba,
+    /// Between [button] and [dark], used mostly for 3D bevel and shadow effects.
+    mid: Srgba,
+    /// The foreground color used with [base].
+    text: Srgba,
+    /// A text color that is very different from [window_text], and contrasts well with e.g. [dark].
+    /// Typically used for text that needs to be drawn where [text] or [window_text] would give poor contrast, such as on pressed push buttons.
+    bright_text: Srgba,
+    /// A foreground color used with the [button] color.
+    button_text: Srgba,
+    /// Used mostly as the background color for text entry widgets, but can also be used for other painting -
+    /// such as the background of combobox drop down lists and toolbar handles.
+    base: Srgba,
+    /// A general background color.
+    window: Srgba,
+    /// A very dark color, used mostly for 3D bevel and shadow effects.
+    /// Opaque black by default.
+    shadow: Srgba,
+    /// A color to indicate a selected item or the current item.
+    highlight: Srgba,
+    /// A text color that contrasts with [highlight].
+    highlighted_text: Srgba,
+    /// A text color used for unvisited hyperlinks.
+    link: Srgba,
+    /// A text color used for already visited hyperlinks.
+    link_visited: Srgba,
+    /// Used as the alternate background color in views with alternating row colors.
+    alternate_base: Srgba,
+    /// No role; this special role is often used to indicate that a role has not been assigned.
+    no_role: Srgba,
+    /// Used as the background color for QToolTip and QWhatsThis.
+    /// Tool tips use the inactive color group of QPalette, because tool tips are not active windows.
+    tool_tip_base: Srgba,
+    /// Used as the foreground color for QToolTip and QWhatsThis.
+    /// Tool tips use the inactive color group of QPalette, because tool tips are not active windows.
+    tool_tip_text: Srgba,
+    /// Used as the placeholder color for various text input widgets.
+    placeholder_text: Srgba,
+    // /// [accent] only exists since Qt 6.6. Including it here breaks qt5ct.
+    // /// When omitted, it defaults to [highlight].
+    // accent: Srgba,
+}
+
+impl QPaletteGroup {
+    /// Returns a comma-separated list of the colors as hex codes.
+    /// E.g. `#ff000000, #ffdcdcdc, ...`
+    ///
+    /// Any transparent colors are flattened with [base] to avoid issues with
+    /// the Fusion style.
+    fn as_list(&self) -> String {
+        let colors = vec![
+            to_argb_hex(self.window_text.over(self.base)),
+            to_argb_hex(self.button.over(self.base)),
+            to_argb_hex(self.light.over(self.base)),
+            to_argb_hex(self.midlight.over(self.base)),
+            to_argb_hex(self.dark.over(self.base)),
+            to_argb_hex(self.mid.over(self.base)),
+            to_argb_hex(self.text.over(self.base)),
+            to_argb_hex(self.bright_text.over(self.base)),
+            to_argb_hex(self.button_text.over(self.base)),
+            to_argb_hex(self.base.over(self.base)),
+            to_argb_hex(self.window.over(self.base)),
+            to_argb_hex(self.shadow.over(self.base)),
+            to_argb_hex(self.highlight.over(self.base)),
+            to_argb_hex(self.highlighted_text.over(self.base)),
+            to_argb_hex(self.link.over(self.base)),
+            to_argb_hex(self.link_visited.over(self.base)),
+            to_argb_hex(self.alternate_base.over(self.base)),
+            to_argb_hex(self.no_role.over(self.base)),
+            to_argb_hex(self.tool_tip_base.over(self.base)),
+            to_argb_hex(self.tool_tip_text.over(self.base)),
+            to_argb_hex(self.placeholder_text.over(self.base)),
+        ];
+        colors.join(", ")
+    }
+}
+
+/// Converts a color to a hex string in the format `#AARRGGBB`.
+/// Do not use [to_hex] since that uses the format `RRGGBBAA`.
+fn to_argb_hex(c: Srgba) -> String {
+    let c_u8: Rgba<palette::encoding::Srgb, u8> = c.into_format();
+    format!(
+        "#{:02x}{:02x}{:02x}{:02x}",
+        c_u8.alpha, c_u8.red, c_u8.green, c_u8.blue
+    )
 }

cosmic-theme/src/output/qt_output.rs

@@ -14,10 +14,11 @@ impl Theme {
     /// Produces a color scheme ini file for Qt.
     ///
     /// Some high-level documentation for this file can be found at:
-    /// https://web.archive.org/web/20250402234329/https://docs.kde.org/stable5/en/plasma-workspace/kcontrol/colors/
+    /// - https://api.kde.org/kcolorscheme.html
+    /// - https://web.archive.org/web/20250402234329/https://docs.kde.org/stable5/en/plasma-workspace/kcontrol/colors/
     #[must_use]
     #[cold]
-    pub fn as_qt(&self) -> String {
+    pub fn as_kcolorscheme(&self) -> String {
         // Usually, disabled elements will have strongly reduced contrast and are often notably darker or lighter
         let disabled_color_effects = IniColorEffects {
             color: self.button.disabled,
@@ -41,7 +42,7 @@ impl Theme {
 
         let bg = self.background.base;
         // the background container
-        let view_colors = IniColors {
+        let window_colors = IniColors {
             background_alternate: bg.mix(self.accent.base, 0.05),
             background_normal: bg,
             decoration_focus: self.accent_text_color(),
@@ -56,16 +57,17 @@ impl Theme {
             foreground_visited: self.accent_text_color(),
         };
         // components inside the background container
-        let window_colors = IniColors {
+        let view_colors = IniColors {
             background_alternate: self.background.component.base.mix(self.accent.base, 0.05),
             background_normal: self.background.component.base,
-            ..view_colors
+            ..window_colors
         };
 
         // selected text and items
         let selection_colors = {
-            let selected = self.background.component.selected;
+            // selection colors are swapped to fix menu bar contrast
-            let selected_text = self.background.component.selected_text;
+            let selected = self.background.component.selected_text;
+            let selected_text = self.background.component.selected;
             IniColors {
                 background_alternate: selected.mix(bg, 0.5),
                 background_normal: selected,
@@ -116,10 +118,10 @@ impl Theme {
         };
 
         // headers in cosmic don't have a background
-        let header_colors = &view_colors;
+        let header_colors = &window_colors;
-        let header_colors_inactive = &view_colors;
+        let header_colors_inactive = &window_colors;
         // tool tips, "What's This" tips, and similar elements
-        let tooltip_colors = &window_colors;
+        let tooltip_colors = &view_colors;
 
         let general_color_scheme = if self.is_dark {
             "CosmicDark"
@@ -198,7 +200,7 @@ widgetStyle=qt6ct-style
             format_ini_colors(&tooltip_colors, bg),
             format_ini_colors(&view_colors, bg),
             format_ini_colors(&window_colors, bg),
-            format_ini_wm_colors(&view_colors, self.is_dark),
+            format_ini_wm_colors(&window_colors, self.is_dark),
         )
     }
 
@@ -212,14 +214,14 @@ widgetStyle=qt6ct-style
     /// Returns an `OutputError` if there is an error writing the colors file.
     #[cold]
     pub fn write_qt(&self) -> Result<(), OutputError> {
-        let colors = self.as_qt();
+        let kcolorscheme = self.as_kcolorscheme();
-        let file_path = Self::get_qt_colors_path(self.is_dark)?;
+        let file_path = Self::get_kcolorscheme_path(self.is_dark)?;
         let tmp_file_path = file_path.with_extension("colors.new");
 
         // Write to tmp_file_path first, then move it to file_path
         let mut tmp_file = File::create(&tmp_file_path).map_err(OutputError::Io)?;
         let res = tmp_file
-            .write_all(colors.as_bytes())
+            .write_all(kcolorscheme.as_bytes())
             .and_then(|_| tmp_file.flush())
             .and_then(|_| std::fs::rename(&tmp_file_path, file_path));
         if let Err(e) = res {
@@ -245,7 +247,7 @@ widgetStyle=qt6ct-style
         let kdeglobals_file = config_dir.join("kdeglobals");
         let mut kdeglobals_ini = Self::read_ini(&kdeglobals_file)?;
 
-        let src_file = Self::get_qt_colors_path(is_dark)?;
+        let src_file = Self::get_kcolorscheme_path(is_dark)?;
         let src_ini = Self::read_ini(&src_file)?;
 
         Self::backup_non_cosmic_kdeglobals(&kdeglobals_ini, &kdeglobals_file)
@@ -288,7 +290,7 @@ widgetStyle=qt6ct-style
         }
 
         let is_dark = false; // doesn't matter since we're only reading keys
-        let src_file = Self::get_qt_colors_path(is_dark)?;
+        let src_file = Self::get_kcolorscheme_path(is_dark)?;
         let src_ini = Self::read_ini(&src_file)?;
 
         for (section, key_value) in src_ini.get_map_ref() {
@@ -303,8 +305,8 @@ widgetStyle=qt6ct-style
         Ok(())
     }
 
-    /// Gets a path like `~/.config/color-schemes/CosmicDark.colors`
+    /// Gets a path like `~/.local/share/color-schemes/CosmicDark.colors`
-    pub fn get_qt_colors_path(is_dark: bool) -> Result<PathBuf, OutputError> {
+    fn get_kcolorscheme_path(is_dark: bool) -> Result<PathBuf, OutputError> {
         let Some(mut data_dir) = dirs::data_dir() else {
             return Err(OutputError::MissingDataDir);
         };