Add standardized XDG portal file dialog module using rfd

 Cargo.toml         |  1 +
 src/file_dialog.rs | 19 +++++++++++++++++++
 src/lib.rs         |  1 +
 3 files changed, 21 insertions(+)

diff --git a/Cargo.toml b/Cargo.toml
index 9e659f1..47ab128 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -27,5 +27,6 @@ serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 libc = "0.2"
 log = "0.4"
+rfd = "0.15"
 
 
diff --git a/src/file_dialog.rs b/src/file_dialog.rs
new file mode 100644
index 0000000..cfde95c
--- /dev/null
+++ b/src/file_dialog.rs
@@ -0,0 +1,19 @@
+use std::path::PathBuf;
+
+/// Opens a portal file chooser dialog for selecting a file.
+pub fn pick_file(title: &str, filters: &[(&str, &[&str])]) -> Option<PathBuf> {
+    let mut dialog = rfd::FileDialog::new().set_title(title);
+    for (name, exts) in filters {
+        dialog = dialog.add_filter(*name, *exts);
+    }
+    dialog.pick_file()
+}
+
+/// Opens a portal file chooser dialog for saving a file.
+pub fn save_file(title: &str, filters: &[(&str, &[&str])]) -> Option<PathBuf> {
+    let mut dialog = rfd::FileDialog::new().set_title(title);
+    for (name, exts) in filters {
+        dialog = dialog.add_filter(*name, *exts);
+    }
+    dialog.save_file()
+}
diff --git a/src/lib.rs b/src/lib.rs
index 4d242fc..cfcab14 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -9,6 +9,7 @@ pub mod scale;
 pub mod backend;
 pub mod context;
 pub mod process;
+pub mod file_dialog;
 
 pub mod colors {
     pub use crate::color::*;