feat!(widget): rewrite button & icon widget APIs

src/widget/icon/builder.rs

@@ -0,0 +1,114 @@
+// Copyright 2023 System76 <info@system76.com>
+// SPDX-License-Identifier: MPL-2.0
+
+use super::{handle, Handle, Icon};
+use std::path::PathBuf;
+
+#[must_use]
+#[derive(derive_setters::Setters)]
+pub struct Builder<'a> {
+    /// Name of icon to locate in an XDG icon path.
+    name: &'a str,
+
+    /// Checks for a fallback if the icon was not found.
+    fallback: bool,
+
+    /// Restrict the lookup to a given scale.
+    #[setters(strip_option)]
+    scale: Option<u16>,
+
+    /// Restrict the lookup to a given size.
+    #[setters(strip_option)]
+    size: Option<u16>,
+
+    /// Prioritizes SVG over PNG
+    prefer_svg: bool,
+}
+
+impl<'a> Builder<'a> {
+    pub const fn new(name: &'a str) -> Self {
+        Self {
+            name,
+            fallback: true,
+            size: None,
+            scale: None,
+            prefer_svg: false,
+        }
+    }
+
+    #[must_use]
+    pub fn path(mut self) -> Option<PathBuf> {
+        crate::icon_theme::DEFAULT.with(|theme| {
+            let theme = theme.borrow();
+
+            let locate = || {
+                let mut lookup = freedesktop_icons::lookup(self.name)
+                    .with_theme(theme.as_ref())
+                    .with_cache();
+
+                if let Some(scale) = self.scale {
+                    lookup = lookup.with_scale(scale);
+                }
+
+                if let Some(size) = self.size {
+                    lookup = lookup.with_size(size);
+                }
+
+                if self.prefer_svg {
+                    lookup = lookup.force_svg();
+                }
+
+                lookup.find()
+            };
+
+            let mut result = locate();
+
+            // On failure, attempt to locate fallback icon.
+            if result.is_none() && self.fallback {
+                let name = std::mem::take(&mut self.name);
+
+                for name in name.rmatch_indices('-').map(|(pos, _)| &name[..pos]) {
+                    self.name = name;
+                    result = locate();
+                    if result.is_some() {
+                        break;
+                    }
+                }
+            }
+
+            result
+        })
+    }
+
+    pub fn handle(self) -> Handle {
+        if let Some(path) = self.path() {
+            handle::from_path(path)
+        } else {
+            let bytes: &'static [u8] = &[];
+            handle::from_svg_bytes(bytes)
+        }
+    }
+
+    pub fn icon(self) -> Icon {
+        let size = self.size;
+
+        let icon = super::icon(self.handle());
+
+        match size {
+            Some(size) => icon.size(size),
+            None => icon,
+        }
+    }
+}
+
+impl<'a> From<Builder<'a>> for Handle {
+    fn from(builder: Builder<'a>) -> Self {
+        builder.handle()
+    }
+}
+
+impl<'a> From<Builder<'a>> for Icon {
+    fn from(builder: Builder<'a>) -> Self {
+        builder.icon()
+    }
+}