Add file filtering to gtk dialogs. (#903)

CHANGELOG.md

@@ -74,6 +74,7 @@ While some features like the clipboard, menus or file dialogs are not yet availa
 - GTK: Support disabled menu items. ([#897] by [@jneem])
 - X11: Support individual window closing. ([#900] by [@xStrom])
 - X11: Support `Application::quit`. ([#900] by [@xStrom])
+- GTK: Support file filters in open/save dialogs. ([#903] by [@jneem])
 
 ### Visual
 
@@ -154,6 +155,7 @@ While some features like the clipboard, menus or file dialogs are not yet availa
 [#897]: https://github.com/xi-editor/druid/pull/897
 [#898]: https://github.com/xi-editor/druid/pull/898
 [#900]: https://github.com/xi-editor/druid/pull/900
+[#903]: https://github.com/xi-editor/druid/pull/903
 [#909]: https://github.com/xi-editor/druid/pull/909
 
 ## [0.5.0] - 2020-04-01

druid-shell/src/platform/gtk/dialog.rs

@@ -16,11 +16,20 @@
 
 use std::ffi::OsString;
 
-use gtk::{FileChooserAction, FileChooserExt, NativeDialogExt, ResponseType, Window};
+use gtk::{FileChooserAction, FileChooserExt, FileFilter, NativeDialogExt, ResponseType, Window};
 
-use crate::dialog::{FileDialogOptions, FileDialogType};
+use crate::dialog::{FileDialogOptions, FileDialogType, FileSpec};
 use crate::Error;
 
+fn file_filter(fs: &FileSpec) -> FileFilter {
+    let ret = FileFilter::new();
+    ret.set_name(Some(fs.name));
+    for ext in fs.extensions {
+        ret.add_pattern(&format!("*.{}", ext));
+    }
+    ret
+}
+
 pub(crate) fn get_file_dialog_path(
     window: &Window,
     ty: FileDialogType,
@@ -45,6 +54,36 @@ pub(crate) fn get_file_dialog_path(
 
     dialog.set_select_multiple(options.multi_selection);
 
+    let mut found_default_filter = false;
+    if let Some(file_types) = &options.allowed_types {
+        for f in file_types {
+            let filter = file_filter(f);
+            dialog.add_filter(&filter);
+
+            if let Some(default) = &options.default_type {
+                if default == f {
+                    // Note that we're providing the same FileFilter object to
+                    // add_filter and set_filter, because gtk checks them for
+                    // identity, not structural equality.
+                    dialog.set_filter(&filter);
+                    found_default_filter = true;
+                }
+            }
+        }
+    }
+
+    if let Some(default_file_type) = &options.default_type {
+        if options.allowed_types.is_some() && !found_default_filter {
+            // It's ok to set a default file filter without providing a list of
+            // allowed filters, but it's not ok (or at least, doesn't work in gtk)
+            // to provide a default filter that isn't in the (present) list
+            // of allowed filters.
+            log::warn!("default file type not found in allowed types");
+        } else if !found_default_filter {
+            dialog.set_filter(&file_filter(default_file_type));
+        }
+    }
+
     let result = dialog.run();
 
     let result = match result {

druid/examples/open_save.rs

@@ -0,0 +1,106 @@
+// Copyright 2020 The xi-editor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use druid::widget::{Align, Button, Flex, TextBox};
+use druid::{
+    AppDelegate, AppLauncher, Command, DelegateCtx, Env, FileDialogOptions, FileInfo, FileSpec,
+    LocalizedString, Target, Widget, WindowDesc,
+};
+
+struct Delegate;
+
+pub fn main() {
+    let main_window = WindowDesc::new(ui_builder)
+        .title(LocalizedString::new("open-save-demo").with_placeholder("Opening/Saving Demo"));
+    let data = "Type here.".to_owned();
+    AppLauncher::with_window(main_window)
+        .delegate(Delegate)
+        .use_simple_logger()
+        .launch(data)
+        .expect("launch failed");
+}
+
+fn ui_builder() -> impl Widget<String> {
+    let rs = FileSpec::new("Rust source", &["rs"]);
+    let txt = FileSpec::new("Text file", &["txt"]);
+    let other = FileSpec::new("Bogus file", &["foo", "bar", "baz"]);
+    let save_dialog_options = FileDialogOptions::new()
+        .allowed_types(vec![rs, txt, other])
+        .default_type(txt);
+    let open_dialog_options = save_dialog_options.clone();
+
+    let input = TextBox::new();
+    let save = Button::new("Save").on_click(move |ctx, _, _| {
+        ctx.submit_command(
+            Command::new(
+                druid::commands::SHOW_SAVE_PANEL,
+                save_dialog_options.clone(),
+            ),
+            None,
+        )
+    });
+    let open = Button::new("Open").on_click(move |ctx, _, _| {
+        ctx.submit_command(
+            Command::new(
+                druid::commands::SHOW_OPEN_PANEL,
+                open_dialog_options.clone(),
+            ),
+            None,
+        )
+    });
+
+    let mut col = Flex::column();
+    col.add_child(input);
+    col.add_spacer(8.0);
+    col.add_child(save);
+    col.add_child(open);
+    Align::centered(col)
+}
+
+impl AppDelegate<String> for Delegate {
+    fn command(
+        &mut self,
+        _ctx: &mut DelegateCtx,
+        _target: Target,
+        cmd: &Command,
+        data: &mut String,
+        _env: &Env,
+    ) -> bool {
+        match cmd.selector {
+            druid::commands::SAVE_FILE => {
+                if let Ok(file_info) = cmd.get_object::<FileInfo>() {
+                    if let Err(e) = std::fs::write(file_info.path(), &data[..]) {
+                        println!("Error writing file: {}", e);
+                    }
+                }
+                true
+            }
+            druid::commands::OPEN_FILE => {
+                if let Ok(file_info) = cmd.get_object::<FileInfo>() {
+                    match std::fs::read_to_string(file_info.path()) {
+                        Ok(s) => {
+                            let first_line = s.lines().next().unwrap_or("");
+                            *data = first_line.to_owned();
+                        }
+                        Err(e) => {
+                            println!("Error opening file: {}", e);
+                        }
+                    }
+                }
+                true
+            }
+            _ => false,
+        }
+    }
+}

druid/examples/wasm/src/lib.rs

@@ -69,6 +69,7 @@ impl_example!(layout);
 impl_example!(lens);
 impl_example!(list);
 impl_example!(multiwin);
+impl_example!(open_save);
 impl_example!(panels.unwrap());
 impl_example!(parse);
 impl_example!(scroll_colors);