Add basic TUI support (#1)

src/gui/filesystem.rs

@@ -0,0 +1,137 @@
+#[cxx_qt::bridge]
+pub mod qobject {
+    unsafe extern "C++" {
+        // Import Qt Types from C++
+        include!("cxx-qt-lib/qstring.h");
+        type QString = cxx_qt_lib::QString;
+        include!("cxx-qt-lib/qmodelindex.h");
+        type QModelIndex = cxx_qt_lib::QModelIndex;
+        include!(<QtGui/QFileSystemModel>);
+        type QFileSystemModel;
+    }
+
+    unsafe extern "RustQt" {
+        // Export QML Types from Rust
+        #[qobject]
+        #[base = QFileSystemModel]
+        #[qml_element]
+        #[qml_singleton]
+        #[qproperty(QString, file_path, cxx_name = "filePath")]
+        #[qproperty(QModelIndex, root_index, cxx_name = "rootIndex")]
+        type FileSystem = super::FileSystemImpl;
+
+        #[inherit]
+        #[cxx_name = "setRootPath"]
+        fn set_root_path(self: Pin<&mut FileSystem>, path: &QString) -> QModelIndex;
+
+        #[qinvokable]
+        #[cxx_override]
+        #[cxx_name = "columnCount"]
+        fn column_count(self: &FileSystem, _index: &QModelIndex) -> i32;
+
+        #[qinvokable]
+        #[cxx_name = "readFile"]
+        fn read_file(self: &FileSystem, path: &QString) -> QString;
+
+        #[qinvokable]
+        #[cxx_name = "setDirectory"]
+        fn set_directory(self: Pin<&mut FileSystem>, path: &QString) -> QModelIndex;
+    }
+}
+
+use cxx_qt_lib::{QModelIndex, QString};
+use dirs;
+use log::warn;
+use std::fs;
+use std::io::BufRead;
+use syntect::easy::HighlightFile;
+use syntect::highlighting::ThemeSet;
+use syntect::html::{
+    IncludeBackground, append_highlighted_html_for_styled_line, start_highlighted_html_snippet,
+};
+use syntect::parsing::SyntaxSet;
+
+// TODO: Impleent a provider for QFileSystemModel::setIconProvider for icons.
+pub struct FileSystemImpl {
+    file_path: QString,
+    root_index: QModelIndex,
+}
+
+// Default is explicit to make the editor open this source file initially.
+impl Default for FileSystemImpl {
+    fn default() -> Self {
+        Self {
+            file_path: QString::from(file!()),
+            root_index: Default::default(),
+        }
+    }
+}
+
+impl qobject::FileSystem {
+    fn read_file(&self, path: &QString) -> QString {
+        if path.is_empty() {
+            return QString::default();
+        }
+        if !fs::metadata(path.to_string())
+            .expect(format!("Failed to get file metadata {path:?}").as_str())
+            .is_file()
+        {
+            warn!(target:"FileSystem", "Attempted to open file {path:?} that is not a valid file");
+            return QString::default();
+        }
+        let ss = SyntaxSet::load_defaults_nonewlines();
+        let ts = ThemeSet::load_defaults();
+        let theme = &ts.themes["base16-ocean.dark"];
+
+        let mut highlighter =
+            HighlightFile::new(path.to_string(), &ss, theme).expect("Failed to create highlighter");
+        let (mut output, _bg) = start_highlighted_html_snippet(theme);
+        let mut line = String::new();
+        while highlighter
+            .reader
+            .read_line(&mut line)
+            .expect("Failed to read file.")
+            > 0
+        {
+            let regions = highlighter
+                .highlight_lines
+                .highlight_line(&line, &ss)
+                .expect("Failed to highlight");
+
+            append_highlighted_html_for_styled_line(
+                &regions[..],
+                IncludeBackground::Yes,
+                &mut output,
+            )
+            .expect("Failed to insert highlighted html");
+            line.clear();
+        }
+        output.push_str("</pre>\n");
+        QString::from(output)
+    }
+
+    // There will never be more than one column.
+    fn column_count(&self, _index: &QModelIndex) -> i32 {
+        1
+    }
+
+    fn set_directory(self: std::pin::Pin<&mut Self>, path: &QString) -> QModelIndex {
+        if !path.is_empty()
+            && fs::metadata(path.to_string())
+                .expect(format!("Failed to get metadata for path {path:?}").as_str())
+                .is_dir()
+        {
+            self.set_root_path(path)
+        } else {
+            // If the initial directory can't be opened, attempt to find the home directory.
+            self.set_root_path(&QString::from(
+                dirs::home_dir()
+                    .expect("Failed to get home directory")
+                    .as_path()
+                    .to_str()
+                    .unwrap()
+                    .to_string(),
+            ))
+        }
+    }
+}