Add inset types

dpi/CHANGELOG.md

@@ -11,6 +11,8 @@ Unreleased` header.
 
 ## Unreleased
 
+- Added `Insets`, `LogicalInsets` and `PhysicalInsets` types.
+
 ## 0.1.1
 
 - Derive `Debug`, `Copy`, `Clone`, `PartialEq`, `Serialize`, `Deserialize` traits for `PixelUnit`.

dpi/src/lib.rs

@@ -759,6 +759,145 @@ impl<P: Pixel> From<LogicalPosition<P>> for Position {
     }
 }
 
+/// The logical distance between the edges of two rectangles.
+#[derive(Debug, Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Default, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+pub struct LogicalInsets<P> {
+    /// The distance to the top edge.
+    pub top: P,
+    /// The distance to the left edge.
+    pub left: P,
+    /// The distance to the bottom edge.
+    pub bottom: P,
+    /// The distance to the right edge.
+    pub right: P,
+}
+
+impl<P> LogicalInsets<P> {
+    #[inline]
+    pub const fn new(top: P,
+        left: P,
+     bottom: P,
+         right: P,) -> Self {
+        Self { top, left, bottom, right }
+    }
+}
+
+impl<P: Pixel> LogicalInsets<P> {
+    #[inline]
+    pub fn from_physical<T: Into<LogicalInsets<X>>, X: Pixel>(
+        physical: T,
+        scale_factor: f64,
+    ) -> Self {
+        physical.into().to_logical(scale_factor)
+    }
+
+    #[inline]
+    pub fn to_physical<X: Pixel>(&self, scale_factor: f64) -> PhysicalInsets<X> {
+        assert!(validate_scale_factor(scale_factor));
+        let top = self.top.into() * scale_factor;
+        let left = self.left.into() * scale_factor;
+        let bottom = self.bottom.into() * scale_factor;
+        let right = self.right.into() * scale_factor;
+        PhysicalInsets::new(top, left, bottom, right).cast()
+    }
+
+    #[inline]
+    pub fn cast<X: Pixel>(&self) -> LogicalInsets<X> {
+        LogicalInsets { top: self.top.cast(), left: self.left.cast(), bottom: self.bottom.cast(), right: self.right.cast() }
+    }
+}
+
+/// The physical distance between the edges of two rectangles.
+#[derive(Debug, Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Default, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+pub struct PhysicalInsets<P> {
+    /// The distance to the top edge.
+    pub top: P,
+    /// The distance to the left edge.
+    pub left: P,
+    /// The distance to the bottom edge.
+    pub bottom: P,
+    /// The distance to the right edge.
+    pub right: P,
+}
+
+impl<P> PhysicalInsets<P> {
+    #[inline]
+    pub const fn new(top: P,
+        left: P,
+     bottom: P,
+         right: P,) -> Self {
+        Self { top, left, bottom, right }
+    }
+}
+
+impl<P: Pixel> PhysicalInsets<P> {
+    #[inline]
+    pub fn from_logical<T: Into<LogicalInsets<X>>, X: Pixel>(logical: T, scale_factor: f64) -> Self {
+        logical.into().to_physical(scale_factor)
+    }
+
+    #[inline]
+    pub fn to_logical<X: Pixel>(&self, scale_factor: f64) -> LogicalInsets<X> {
+        assert!(validate_scale_factor(scale_factor));
+        let width = self.width.into() / scale_factor;
+        let height = self.height.into() / scale_factor;
+        let top = self.top.into() / scale_factor;
+        let left = self.left.into() / scale_factor;
+        let bottom = self.bottom.into() / scale_factor;
+        let right = self.right.into() / scale_factor;
+        LogicalInsets::new(top, left, bottom, right).cast()
+    }
+
+    #[inline]
+    pub fn cast<X: Pixel>(&self) -> PhysicalInsets<X> {
+        PhysicalInsets { top: self.top.cast(), left: self.left.cast(), bottom: self.bottom.cast(), right: self.right.cast() }
+    }
+}
+
+/// Insets that are either physical or logical.
+#[derive(Debug, Copy, Clone, PartialEq)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+pub enum Insets {
+    Physical(PhysicalInsets<u32>),
+    Logical(LogicalInsets<f64>),
+}
+
+impl Insets {
+    pub fn new<S: Into<Self>>(insets: S) -> Self {
+        insets.into()
+    }
+
+    pub fn to_logical<P: Pixel>(&self, scale_factor: f64) -> LogicalInsets<P> {
+        match *self {
+            Self::Physical(insets) => insets.to_logical(scale_factor),
+            Self::Logical(insets) => insets.cast(),
+        }
+    }
+
+    pub fn to_physical<P: Pixel>(&self, scale_factor: f64) -> PhysicalInsets<P> {
+        match *self {
+            Self::Physical(insets) => insets.cast(),
+            Self::Logical(insets) => insets.to_physical(scale_factor),
+        }
+    }
+}
+
+impl<P: Pixel> From<PhysicalInsets<P>> for Insets {
+    #[inline]
+    fn from(insets: PhysicalInsets<P>) -> Self {
+        Self::Physical(insets.cast())
+    }
+}
+
+impl<P: Pixel> From<LogicalInsets<P>> for Insets {
+    #[inline]
+    fn from(insets: LogicalInsets<P>) -> Self {
+        Self::Logical(insets.cast())
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use std::collections::HashSet;