Merge pull request #630 from blefevre/asymmetric-padding

Add support for asymmetrical padding

1 files changed, 107 insertions, 0 deletions

diff --git a/core/src/padding.rs b/core/src/padding.rs
new file mode 100644
index 00000000..22467d6b
--- /dev/null
+++ b/core/src/padding.rs
@@ -0,0 +1,107 @@
+/// An amount of space to pad for each side of a box
+///
+/// You can leverage the `From` trait to build [`Padding`] conveniently:
+///
+/// ```
+/// # use iced_core::Padding;
+/// #
+/// let padding = Padding::from(20);              // 20px on all sides
+/// let padding = Padding::from([10, 20]);        // top/bottom, left/right
+/// let padding = Padding::from([5, 10, 15, 20]); // top, right, bottom, left
+/// ```
+///
+/// Normally, the `padding` method of a widget will ask for an `Into<Padding>`,
+/// so you can easily write:
+///
+/// ```
+/// # use iced_core::Padding;
+/// #
+/// # struct Widget;
+/// #
+/// impl Widget {
+///     # pub fn new() -> Self { Self }
+///     #
+///     pub fn padding(mut self, padding: impl Into<Padding>) -> Self {
+///         // ...
+///         self
+///     }
+/// }
+///
+/// let widget = Widget::new().padding(20);              // 20px on all sides
+/// let widget = Widget::new().padding([10, 20]);        // top/bottom, left/right
+/// let widget = Widget::new().padding([5, 10, 15, 20]); // top, right, bottom, left
+/// ```
+#[derive(Debug, Hash, Copy, Clone)]
+pub struct Padding {
+    /// Top padding
+    pub top: u16,
+    /// Right padding
+    pub right: u16,
+    /// Bottom padding
+    pub bottom: u16,
+    /// Left padding
+    pub left: u16,
+}
+
+impl Padding {
+    /// Padding of zero
+    pub const ZERO: Padding = Padding {
+        top: 0,
+        right: 0,
+        bottom: 0,
+        left: 0,
+    };
+
+    /// Create a Padding that is equal on all sides
+    pub const fn new(padding: u16) -> Padding {
+        Padding {
+            top: padding,
+            right: padding,
+            bottom: padding,
+            left: padding,
+        }
+    }
+
+    /// Returns the total amount of vertical [`Padding`].
+    pub fn vertical(self) -> u16 {
+        self.top + self.bottom
+    }
+
+    /// Returns the total amount of horizontal [`Padding`].
+    pub fn horizontal(self) -> u16 {
+        self.left + self.right
+    }
+}
+
+impl std::convert::From<u16> for Padding {
+    fn from(p: u16) -> Self {
+        Padding {
+            top: p,
+            right: p,
+            bottom: p,
+            left: p,
+        }
+    }
+}
+
+impl std::convert::From<[u16; 2]> for Padding {
+    fn from(p: [u16; 2]) -> Self {
+        Padding {
+            top: p[0],
+            right: p[1],
+            bottom: p[0],
+            left: p[1],
+        }
+    }
+}
+
+impl std::convert::From<[u16; 4]> for Padding {
+    fn from(p: [u16; 4]) -> Self {
+        Padding {
+            top: p[0],
+            right: p[1],
+            bottom: p[2],
+            left: p[3],
+        }
+    }
+}