feat(custom_layout): implement navigation

This commit introduces a number of refactors to layouts in general in
order to enable navigation across custom layouts and integrate both
default and custom layouts cleanly into komorebi and komorebic.

Layout has been renamed to DefaultLayout, and Layout is now an enum with
the variants Default and Custom, both of which implement the new traits
Arrangement (for layout calculation) and Direction (for operation
destination calculation).

CustomLayout has been simplified to wrap Vec<Column> and no longer
requires the primary column index to be explicitly defined as this can
be looked up at runtime for any valid CustomLayout.

Given the focus on ultrawide layouts for this feature, I have disabled
(and have not yet written the logic for) vertical column splits in
custom layouts.

Since CustomLayouts will be loaded from a file path, a bunch of
clap-related code generation stuff has been removed from the related
enums and structs.

Layout flipping has not yet been worked on for custom layouts.

When switching between Default and Custom layout variants, the primary
column index and the 0 element are swapped to ensure that the same
window container is always at the focal point of every layout.

Resizing/dragging to resize is in a bit of weird spot at the moment
because the logic is only implemented for DefaultLayout::BSP right now
and nothing else. I think eventually this will need to be extracted to a
Resize trait and implemented on everything.

komorebi-core/src/default_layout.rs

@@ -0,0 +1,125 @@
+use clap::ArgEnum;
+use serde::Deserialize;
+use serde::Serialize;
+use strum::Display;
+use strum::EnumString;
+
+use crate::OperationDirection;
+use crate::Rect;
+use crate::Sizing;
+
+#[derive(Clone, Copy, Debug, Serialize, Deserialize, Display, EnumString, ArgEnum)]
+#[strum(serialize_all = "snake_case")]
+pub enum DefaultLayout {
+    BSP,
+    Columns,
+    Rows,
+    VerticalStack,
+    HorizontalStack,
+    UltrawideVerticalStack,
+}
+
+impl DefaultLayout {
+    #[must_use]
+    #[allow(clippy::cast_precision_loss)]
+    pub fn resize(
+        &self,
+        unaltered: &Rect,
+        resize: &Option<Rect>,
+        edge: OperationDirection,
+        sizing: Sizing,
+        step: Option<i32>,
+    ) -> Option<Rect> {
+        if !matches!(self, Self::BSP) {
+            return None;
+        };
+
+        let max_divisor = 1.005;
+        let mut r = resize.unwrap_or_default();
+
+        let resize_step = step.unwrap_or(50);
+
+        match edge {
+            OperationDirection::Left => match sizing {
+                Sizing::Increase => {
+                    // Some final checks to make sure the user can't infinitely resize to
+                    // the point of pushing other windows out of bounds
+
+                    // Note: These checks cannot take into account the changes made to the
+                    // edges of adjacent windows at operation time, so it is still possible
+                    // to push windows out of bounds by maxing out an Increase Left on a
+                    // Window with index 1, and then maxing out a Decrease Right on a Window
+                    // with index 0. I don't think it's worth trying to defensively program
+                    // against this; if people end up in this situation they are better off
+                    // just hitting the retile command
+                    let diff = ((r.left + -resize_step) as f32).abs();
+                    let max = unaltered.right as f32 / max_divisor;
+                    if diff < max {
+                        r.left += -resize_step;
+                    }
+                }
+                Sizing::Decrease => {
+                    let diff = ((r.left - -resize_step) as f32).abs();
+                    let max = unaltered.right as f32 / max_divisor;
+                    if diff < max {
+                        r.left -= -resize_step;
+                    }
+                }
+            },
+            OperationDirection::Up => match sizing {
+                Sizing::Increase => {
+                    let diff = ((r.top + resize_step) as f32).abs();
+                    let max = unaltered.bottom as f32 / max_divisor;
+                    if diff < max {
+                        r.top += -resize_step;
+                    }
+                }
+                Sizing::Decrease => {
+                    let diff = ((r.top - resize_step) as f32).abs();
+                    let max = unaltered.bottom as f32 / max_divisor;
+                    if diff < max {
+                        r.top -= -resize_step;
+                    }
+                }
+            },
+            OperationDirection::Right => match sizing {
+                Sizing::Increase => {
+                    let diff = ((r.right + resize_step) as f32).abs();
+                    let max = unaltered.right as f32 / max_divisor;
+                    if diff < max {
+                        r.right += resize_step;
+                    }
+                }
+                Sizing::Decrease => {
+                    let diff = ((r.right - resize_step) as f32).abs();
+                    let max = unaltered.right as f32 / max_divisor;
+                    if diff < max {
+                        r.right -= resize_step;
+                    }
+                }
+            },
+            OperationDirection::Down => match sizing {
+                Sizing::Increase => {
+                    let diff = ((r.bottom + resize_step) as f32).abs();
+                    let max = unaltered.bottom as f32 / max_divisor;
+                    if diff < max {
+                        r.bottom += resize_step;
+                    }
+                }
+                Sizing::Decrease => {
+                    let diff = ((r.bottom - resize_step) as f32).abs();
+                    let max = unaltered.bottom as f32 / max_divisor;
+                    if diff < max {
+                        r.bottom -= resize_step;
+                    }
+                }
+            },
+        };
+
+        if r.eq(&Rect::default()) {
+            None
+        } else {
+            Option::from(r)
+        }
+    }
+}