1 files changed, 159 insertions, 0 deletions

diff --git a/crates/ra_ide_api/src/navigation_target.rs b/crates/ra_ide_api/src/navigation_target.rs
new file mode 100644
index 000000000..b955bbe42
--- /dev/null
+++ b/crates/ra_ide_api/src/navigation_target.rs
@@ -0,0 +1,159 @@
+use ra_db::{FileId, Cancelable};
+use ra_syntax::{
+    SyntaxNode, AstNode, SmolStr, TextRange, ast,
+    SyntaxKind::{self, NAME},
+};
+use hir::{Def, ModuleSource};
+
+use crate::{FileSymbol, db::RootDatabase};
+
+/// `NavigationTarget` represents and element in the editor's UI which you can
+/// click on to navigate to a particular piece of code.
+///
+/// Typically, a `NavigationTarget` corresponds to some element in the source
+/// code, like a function or a struct, but this is not strictly required.
+#[derive(Debug, Clone)]
+pub struct NavigationTarget {
+    file_id: FileId,
+    name: SmolStr,
+    kind: SyntaxKind,
+    full_range: TextRange,
+    focus_range: Option<TextRange>,
+}
+
+impl NavigationTarget {
+    pub fn name(&self) -> &SmolStr {
+        &self.name
+    }
+
+    pub fn kind(&self) -> SyntaxKind {
+        self.kind
+    }
+
+    pub fn file_id(&self) -> FileId {
+        self.file_id
+    }
+
+    pub fn full_range(&self) -> TextRange {
+        self.full_range
+    }
+
+    /// A "most interesting" range withing the `range_full`.
+    ///
+    /// Typically, `range` is the whole syntax node, including doc comments, and
+    /// `focus_range` is the range of the identifier.
+    pub fn focus_range(&self) -> Option<TextRange> {
+        self.focus_range
+    }
+
+    pub(crate) fn from_symbol(symbol: FileSymbol) -> NavigationTarget {
+        NavigationTarget {
+            file_id: symbol.file_id,
+            name: symbol.name.clone(),
+            kind: symbol.ptr.kind(),
+            full_range: symbol.ptr.range(),
+            focus_range: None,
+        }
+    }
+
+    pub(crate) fn from_scope_entry(
+        file_id: FileId,
+        entry: &hir::ScopeEntryWithSyntax,
+    ) -> NavigationTarget {
+        NavigationTarget {
+            file_id,
+            name: entry.name().to_string().into(),
+            full_range: entry.ptr().range(),
+            focus_range: None,
+            kind: NAME,
+        }
+    }
+
+    pub(crate) fn from_module(
+        db: &RootDatabase,
+        module: hir::Module,
+    ) -> Cancelable<NavigationTarget> {
+        let (file_id, source) = module.definition_source(db)?;
+        let name = module
+            .name(db)?
+            .map(|it| it.to_string().into())
+            .unwrap_or_default();
+        let res = match source {
+            ModuleSource::SourceFile(node) => {
+                NavigationTarget::from_syntax(file_id, name, None, node.syntax())
+            }
+            ModuleSource::Module(node) => {
+                NavigationTarget::from_syntax(file_id, name, None, node.syntax())
+            }
+        };
+        Ok(res)
+    }
+
+    // TODO once Def::Item is gone, this should be able to always return a NavigationTarget
+    pub(crate) fn from_def(db: &RootDatabase, def: Def) -> Cancelable<Option<NavigationTarget>> {
+        let res = match def {
+            Def::Struct(s) => {
+                let (file_id, node) = s.source(db)?;
+                NavigationTarget::from_named(file_id.original_file(db), &*node)
+            }
+            Def::Enum(e) => {
+                let (file_id, node) = e.source(db)?;
+                NavigationTarget::from_named(file_id.original_file(db), &*node)
+            }
+            Def::EnumVariant(ev) => {
+                let (file_id, node) = ev.source(db)?;
+                NavigationTarget::from_named(file_id.original_file(db), &*node)
+            }
+            Def::Function(f) => {
+                let (file_id, node) = f.source(db)?;
+                NavigationTarget::from_named(file_id.original_file(db), &*node)
+            }
+            Def::Module(m) => NavigationTarget::from_module(db, m)?,
+            Def::Item => return Ok(None),
+        };
+        Ok(Some(res))
+    }
+
+    #[cfg(test)]
+    pub(crate) fn assert_match(&self, expected: &str) {
+        let actual = self.debug_render();
+        test_utils::assert_eq_text!(expected.trim(), actual.trim(),);
+    }
+
+    #[cfg(test)]
+    pub(crate) fn debug_render(&self) -> String {
+        let mut buf = format!(
+            "{} {:?} {:?} {:?}",
+            self.name(),
+            self.kind(),
+            self.file_id(),
+            self.full_range()
+        );
+        if let Some(focus_range) = self.focus_range() {
+            buf.push_str(&format!(" {:?}", focus_range))
+        }
+        buf
+    }
+
+    fn from_named(file_id: FileId, node: &impl ast::NameOwner) -> NavigationTarget {
+        let name = node.name().map(|it| it.text().clone()).unwrap_or_default();
+        let focus_range = node.name().map(|it| it.syntax().range());
+        NavigationTarget::from_syntax(file_id, name, focus_range, node.syntax())
+    }
+
+    fn from_syntax(
+        file_id: FileId,
+        name: SmolStr,
+        focus_range: Option<TextRange>,
+        node: &SyntaxNode,
+    ) -> NavigationTarget {
+        NavigationTarget {
+            file_id,
+            name,
+            kind: node.kind(),
+            full_range: node.range(),
+            focus_range,
+            // ptr: Some(LocalSyntaxPtr::new(node)),
+        }
+    }
+}