feat(bar): add widget grouping options

This commit adds various widget grouping and transparency options to
komorebi-bar, and is comprised of the individual commits listed below,
worked on in PR #1108, squashed into one.

e8f5952abb
* adding RenderConfig, and some test frames on widgets

0a5e0a4c0a
* no clone

a5a7d6906c
* comment

6a91dd46cd
* ignore unused

80f0214e47
* Group enum, Copy RenderConfig

fbe5e2c1f7
* Group -> Grouping

ce49b433f9
* GroupingConfig

f446a6a45f
* "fmt --check" fix (thanks VS)

d188222be7
* added widget grouping and group module

1008ec2031
* rounding from settings, and apply_on_side

7fff6d29a9
* dereferencing

655e8ce4c1
* AlphaColour, transparency, bar background, more grouping config options

cba0fcd882
* added RoundingConfig

ec5f7dc82d
* handling grouping edge case for komorebi focus window

12117b832b
* changed default values

645c46beb8
* background color using theme color, AlphaColour.to_color32_or, updating json format for Grouping and RoundingConfig

10d2ab21c7
* hot-reload on grouping

d88774328a
* grouping correction on init

2cd237fd0d
* added shadow to grouping, optional width on grouping stroke

4f4b617f26
* grouping on bar, converting AlphaColour from_rgba_unmultiplied, simplified grouping

3808fcec8f
* widget rounding based on grouping, atomic background color, simplified config, style on grouping

be45d14f6d
* renamed Side to Alignment, group spacing

be45d14f6d
* proper widget spacing based on alignment

b43a5bda69
* added widget_spacing to config

c18e5f4dbe
* test commit

cba2b2f7ac
* refactoring of render and grouping, widget spacing WIP

9311cb00ec
* simplify no_spacing

36c267246b
* correct spacing on komorebi and network widgets (WIP)

85a41bf5b2
* correct widget spacing on all widgets

50b49ccf69
* refactoring widget spacing

9ec67ad988
* account for ui item_spacing when setting the widget_spacing

e88a2fd9c0
* format

komorebi-bar/src/render.rs

@@ -0,0 +1,263 @@
+use crate::bar::Alignment;
+use crate::config::KomobarConfig;
+use eframe::egui::Color32;
+use eframe::egui::Frame;
+use eframe::egui::InnerResponse;
+use eframe::egui::Margin;
+use eframe::egui::Rounding;
+use eframe::egui::Shadow;
+use eframe::egui::Ui;
+use eframe::egui::Vec2;
+use schemars::JsonSchema;
+use serde::Deserialize;
+use serde::Serialize;
+
+#[derive(Copy, Clone, Debug, Serialize, Deserialize, JsonSchema)]
+#[serde(tag = "kind")]
+pub enum Grouping {
+    /// No grouping is applied
+    None,
+    /// Widgets are grouped as a whole
+    Bar(GroupingConfig),
+    /// Widgets are grouped by alignment
+    Alignment(GroupingConfig),
+    /// Widgets are grouped individually
+    Widget(GroupingConfig),
+}
+
+#[derive(Copy, Clone)]
+pub struct RenderConfig {
+    /// Spacing between widgets
+    pub spacing: f32,
+    /// Sets how widgets are grouped
+    pub grouping: Grouping,
+    /// Background color
+    pub background_color: Color32,
+    /// Alignment of the widgets
+    pub alignment: Option<Alignment>,
+    /// Add more inner margin when adding a widget group
+    pub more_inner_margin: bool,
+    /// Set to true after the first time the apply_on_widget was called on an alignment
+    pub applied_on_widget: bool,
+}
+
+pub trait RenderExt {
+    fn new_renderconfig(&self, background_color: Color32) -> RenderConfig;
+}
+
+impl RenderExt for &KomobarConfig {
+    fn new_renderconfig(&self, background_color: Color32) -> RenderConfig {
+        RenderConfig {
+            spacing: self.widget_spacing.unwrap_or(10.0),
+            grouping: self.grouping.unwrap_or(Grouping::None),
+            background_color,
+            alignment: None,
+            more_inner_margin: false,
+            applied_on_widget: false,
+        }
+    }
+}
+
+impl RenderConfig {
+    pub fn new() -> Self {
+        Self {
+            spacing: 0.0,
+            grouping: Grouping::None,
+            background_color: Color32::BLACK,
+            alignment: None,
+            more_inner_margin: false,
+            applied_on_widget: false,
+        }
+    }
+
+    pub fn apply_on_bar<R>(
+        &mut self,
+        ui: &mut Ui,
+        add_contents: impl FnOnce(&mut Ui) -> R,
+    ) -> InnerResponse<R> {
+        self.alignment = None;
+
+        if let Grouping::Bar(config) = self.grouping {
+            return self.define_group(None, config, ui, add_contents);
+        }
+
+        Self::fallback_group(ui, add_contents)
+    }
+
+    pub fn apply_on_alignment<R>(
+        &mut self,
+        ui: &mut Ui,
+        add_contents: impl FnOnce(&mut Ui) -> R,
+    ) -> InnerResponse<R> {
+        self.alignment = None;
+
+        if let Grouping::Alignment(config) = self.grouping {
+            return self.define_group(None, config, ui, add_contents);
+        }
+
+        Self::fallback_group(ui, add_contents)
+    }
+
+    pub fn apply_on_widget<R>(
+        &mut self,
+        more_inner_margin: bool,
+        ui: &mut Ui,
+        add_contents: impl FnOnce(&mut Ui) -> R,
+    ) -> InnerResponse<R> {
+        self.more_inner_margin = more_inner_margin;
+        let outer_margin = self.widget_outer_margin(ui);
+
+        if let Grouping::Widget(config) = self.grouping {
+            return self.define_group(Some(outer_margin), config, ui, add_contents);
+        }
+
+        self.fallback_widget_group(Some(outer_margin), ui, add_contents)
+    }
+
+    fn fallback_group<R>(ui: &mut Ui, add_contents: impl FnOnce(&mut Ui) -> R) -> InnerResponse<R> {
+        InnerResponse {
+            inner: add_contents(ui),
+            response: ui.response().clone(),
+        }
+    }
+
+    fn fallback_widget_group<R>(
+        &mut self,
+        outer_margin: Option<Margin>,
+        ui: &mut Ui,
+        add_contents: impl FnOnce(&mut Ui) -> R,
+    ) -> InnerResponse<R> {
+        Frame::none()
+            .outer_margin(outer_margin.unwrap_or(Margin::ZERO))
+            .inner_margin(match self.more_inner_margin {
+                true => Margin::symmetric(5.0, 0.0),
+                false => Margin::same(0.0),
+            })
+            .show(ui, add_contents)
+    }
+
+    fn define_group<R>(
+        &mut self,
+        outer_margin: Option<Margin>,
+        config: GroupingConfig,
+        ui: &mut Ui,
+        add_contents: impl FnOnce(&mut Ui) -> R,
+    ) -> InnerResponse<R> {
+        Frame::group(ui.style_mut())
+            .outer_margin(outer_margin.unwrap_or(Margin::ZERO))
+            .inner_margin(match self.more_inner_margin {
+                true => Margin::symmetric(8.0, 3.0),
+                false => Margin::symmetric(3.0, 3.0),
+            })
+            .stroke(ui.style().visuals.widgets.noninteractive.bg_stroke)
+            .rounding(match config.rounding {
+                Some(rounding) => rounding.into(),
+                None => ui.style().visuals.widgets.noninteractive.rounding,
+            })
+            .fill(
+                self.background_color
+                    .try_apply_alpha(config.transparency_alpha),
+            )
+            .shadow(match config.style {
+                Some(style) => match style {
+                    // new styles can be added if needed here
+                    GroupingStyle::Default => Shadow::NONE,
+                    GroupingStyle::DefaultWithShadow => Shadow {
+                        blur: 4.0,
+                        offset: Vec2::new(1.0, 1.0),
+                        spread: 3.0,
+                        color: Color32::BLACK.try_apply_alpha(config.transparency_alpha),
+                    },
+                },
+                None => Shadow::NONE,
+            })
+            .show(ui, add_contents)
+    }
+
+    fn widget_outer_margin(&mut self, ui: &mut Ui) -> Margin {
+        let spacing = if self.applied_on_widget {
+            // Remove the default item spacing from the margin
+            self.spacing - ui.spacing().item_spacing.x
+        } else {
+            0.0
+        };
+
+        if !self.applied_on_widget {
+            self.applied_on_widget = true;
+        }
+
+        Margin {
+            left: match self.alignment {
+                Some(align) => match align {
+                    Alignment::Left => spacing,
+                    Alignment::Right => 0.0,
+                },
+                None => 0.0,
+            },
+            right: match self.alignment {
+                Some(align) => match align {
+                    Alignment::Left => 0.0,
+                    Alignment::Right => spacing,
+                },
+                None => 0.0,
+            },
+            top: 0.0,
+            bottom: 0.0,
+        }
+    }
+}
+
+#[derive(Copy, Clone, Debug, Serialize, Deserialize, JsonSchema)]
+pub struct GroupingConfig {
+    /// Styles for the grouping
+    pub style: Option<GroupingStyle>,
+    /// Alpha value for the color transparency [[0-255]] (default: 200)
+    pub transparency_alpha: Option<u8>,
+    /// Rounding values for the 4 corners. Can be a single or 4 values.
+    pub rounding: Option<RoundingConfig>,
+}
+
+#[derive(Copy, Clone, Debug, Serialize, Deserialize, JsonSchema)]
+pub enum GroupingStyle {
+    Default,
+    /// A black shadow is added under the default group
+    DefaultWithShadow,
+}
+
+#[derive(Copy, Clone, Debug, Serialize, Deserialize, JsonSchema)]
+#[serde(untagged)]
+pub enum RoundingConfig {
+    /// All 4 corners are the same    
+    Same(f32),
+    /// All 4 corners are custom. Order: NW, NE, SW, SE
+    Individual([f32; 4]),
+}
+
+impl From<RoundingConfig> for Rounding {
+    fn from(value: RoundingConfig) -> Self {
+        match value {
+            RoundingConfig::Same(value) => Rounding::same(value),
+            RoundingConfig::Individual(values) => Self {
+                nw: values[0],
+                ne: values[1],
+                sw: values[2],
+                se: values[3],
+            },
+        }
+    }
+}
+
+pub trait Color32Ext {
+    fn try_apply_alpha(self, transparency_alpha: Option<u8>) -> Self;
+}
+
+impl Color32Ext for Color32 {
+    /// Tries to apply the alpha value to the Color32
+    fn try_apply_alpha(self, transparency_alpha: Option<u8>) -> Self {
+        if let Some(alpha) = transparency_alpha {
+            return Color32::from_rgba_unmultiplied(self.r(), self.g(), self.b(), alpha);
+        }
+
+        self
+    }
+}