LibGUI: Add allowed file types to FilePicker

This patch adds a ComboBox to `FilePicker` where the user can select
which file types to show, all files that doesn't have an
extension that's in the selected file type will be hidden.

When creating a FilePicker with `FilePicker::construct` or
`FilePicker::get_open_filepath`, allowed file types can be
specified as the last argument.

If no file types are provided then there will be no visual change in the
GUI.

'All Files' and 'Image Files' have shorthands with
`GUI::FileTypeFilter::all_files()` and
`GUI::FileTypeFilter::image_files()`, respectively.

Userland/Libraries/LibGUI/FilePicker.cpp

@@ -16,7 +16,9 @@
 #include <LibGUI/FilePicker.h>
 #include <LibGUI/FilePickerDialogGML.h>
 #include <LibGUI/FileSystemModel.h>
+#include <LibGUI/FileTypeFilter.h>
 #include <LibGUI/InputBox.h>
+#include <LibGUI/ItemListModel.h>
 #include <LibGUI/Label.h>
 #include <LibGUI/Menu.h>
 #include <LibGUI/MessageBox.h>
@@ -25,6 +27,7 @@
 #include <LibGUI/TextBox.h>
 #include <LibGUI/Toolbar.h>
 #include <LibGUI/Tray.h>
+#include <LibGUI/Widget.h>
 #include <LibGfx/Font/FontDatabase.h>
 #include <LibGfx/Palette.h>
 #include <string.h>
@@ -32,9 +35,9 @@
 
 namespace GUI {
 
-Optional<DeprecatedString> FilePicker::get_open_filepath(Window* parent_window, DeprecatedString const& window_title, StringView path, bool folder, ScreenPosition screen_position)
+Optional<DeprecatedString> FilePicker::get_open_filepath(Window* parent_window, DeprecatedString const& window_title, StringView path, bool folder, ScreenPosition screen_position, Optional<Vector<FileTypeFilter>> allowed_file_types)
 {
-    auto picker = FilePicker::construct(parent_window, folder ? Mode::OpenFolder : Mode::Open, ""sv, path, screen_position);
+    auto picker = FilePicker::construct(parent_window, folder ? Mode::OpenFolder : Mode::Open, ""sv, path, screen_position, move(allowed_file_types));
 
     if (!window_title.is_null())
         picker->set_title(window_title);
@@ -65,9 +68,10 @@ Optional<DeprecatedString> FilePicker::get_save_filepath(Window* parent_window,
     return {};
 }
 
-FilePicker::FilePicker(Window* parent_window, Mode mode, StringView filename, StringView path, ScreenPosition screen_position)
+FilePicker::FilePicker(Window* parent_window, Mode mode, StringView filename, StringView path, ScreenPosition screen_position, Optional<Vector<FileTypeFilter>> allowed_file_types)
     : Dialog(parent_window, screen_position)
     , m_model(FileSystemModel::create(path))
+    , m_allowed_file_types(move(allowed_file_types))
     , m_mode(mode)
 {
     switch (m_mode) {
@@ -112,6 +116,36 @@ FilePicker::FilePicker(Window* parent_window, Mode mode, StringView filename, St
         set_path(m_location_textbox->text());
     };
 
+    auto* file_types_filters_combo = widget->find_descendant_of_type_named<GUI::ComboBox>("allowed_file_type_filters_combo");
+
+    if (m_allowed_file_types.has_value()) {
+        for (auto& filter : *m_allowed_file_types) {
+            if (!filter.extensions.has_value()) {
+                m_allowed_file_types_names.append(filter.name);
+                continue;
+            }
+
+            StringBuilder extension_list;
+            extension_list.join("; "sv, *filter.extensions);
+            m_allowed_file_types_names.append(DeprecatedString::formatted("{} ({})", filter.name, extension_list.to_deprecated_string()));
+        }
+
+        file_types_filters_combo->set_model(*GUI::ItemListModel<DeprecatedString, Vector<DeprecatedString>>::create(m_allowed_file_types_names));
+        file_types_filters_combo->on_change = [this](DeprecatedString const&, GUI::ModelIndex const& index) {
+            m_model->set_allowed_file_extensions((*m_allowed_file_types)[index.row()].extensions);
+        };
+        file_types_filters_combo->set_selected_index(0);
+    } else {
+        auto* file_types_filter_label = widget->find_descendant_of_type_named<GUI::Label>("allowed_file_types_label");
+        auto& spacer = file_types_filter_label->parent_widget()->add<GUI::Widget>();
+        spacer.set_fixed_height(22);
+        file_types_filter_label->remove_from_parent();
+
+        file_types_filters_combo->parent_widget()->insert_child_before(GUI::Widget::construct(), *file_types_filters_combo);
+
+        file_types_filters_combo->remove_from_parent();
+    }
+
     auto open_parent_directory_action = Action::create(
         "Open parent directory", { Mod_Alt, Key_Up }, Gfx::Bitmap::load_from_file("/res/icons/16x16/open-parent-directory.png"sv).release_value_but_fixme_should_propagate_errors(), [this](Action const&) {
             set_path(DeprecatedString::formatted("{}/..", m_model->root_path()));

Userland/Libraries/LibGUI/FilePicker.h

@@ -8,8 +8,11 @@
 
 #include <AK/LexicalPath.h>
 #include <AK/Optional.h>
+#include <AK/String.h>
 #include <LibCore/StandardPaths.h>
+#include <LibGUI/ComboBox.h>
 #include <LibGUI/Dialog.h>
+#include <LibGUI/FileTypeFilter.h>
 #include <LibGUI/ImageWidget.h>
 #include <LibGUI/Model.h>
 
@@ -28,7 +31,7 @@ public:
         Save
     };
 
-    static Optional<DeprecatedString> get_open_filepath(Window* parent_window, DeprecatedString const& window_title = {}, StringView path = Core::StandardPaths::home_directory(), bool folder = false, ScreenPosition screen_position = Dialog::ScreenPosition::CenterWithinParent);
+    static Optional<DeprecatedString> get_open_filepath(Window* parent_window, DeprecatedString const& window_title = {}, StringView path = Core::StandardPaths::home_directory(), bool folder = false, ScreenPosition screen_position = Dialog::ScreenPosition::CenterWithinParent, Optional<Vector<FileTypeFilter>> allowed_file_types = {});
     static Optional<DeprecatedString> get_save_filepath(Window* parent_window, DeprecatedString const& title, DeprecatedString const& extension, StringView path = Core::StandardPaths::home_directory(), ScreenPosition screen_position = Dialog::ScreenPosition::CenterWithinParent);
 
     virtual ~FilePicker() override;
@@ -43,7 +46,7 @@ private:
     // ^GUI::ModelClient
     virtual void model_did_update(unsigned) override;
 
-    FilePicker(Window* parent_window, Mode type = Mode::Open, StringView filename = "Untitled"sv, StringView path = Core::StandardPaths::home_directory(), ScreenPosition screen_position = Dialog::ScreenPosition::CenterWithinParent);
+    FilePicker(Window* parent_window, Mode type = Mode::Open, StringView filename = "Untitled"sv, StringView path = Core::StandardPaths::home_directory(), ScreenPosition screen_position = Dialog::ScreenPosition::CenterWithinParent, Optional<Vector<FileTypeFilter>> allowed_file_types = {});
 
     static DeprecatedString ok_button_name(Mode mode)
     {
@@ -68,6 +71,9 @@ private:
     NonnullRefPtr<FileSystemModel> m_model;
     DeprecatedString m_selected_file;
 
+    Vector<DeprecatedString> m_allowed_file_types_names;
+    Optional<Vector<FileTypeFilter>> m_allowed_file_types;
+
     RefPtr<GUI::Label> m_error_label;
 
     RefPtr<TextBox> m_filename_textbox;

Userland/Libraries/LibGUI/FilePickerDialog.gml

@@ -25,11 +25,14 @@
         @GUI::Label {
             text: "Filename:"
             text_alignment: "CenterRight"
-            fixed_height: 24
+            fixed_height: 22
         }
 
-        @GUI::Widget {
+        @GUI::Label {
-            fixed_height: 20
+            name: "allowed_file_types_label"
+            text: "Files of Type:"
+            text_alignment: "CenterRight"
+            fixed_height: 22
         }
     }
 
@@ -68,10 +71,6 @@
                     name: "filename_textbox"
                 }
 
-                @GUI::Widget {
-                    fixed_width: 20
-                }
-
                 @GUI::DialogButton {
                     name: "ok_button"
                     text: "OK"
@@ -82,7 +81,10 @@
                 fixed_height: 22
                 layout: @GUI::HorizontalBoxLayout {}
 
-                @GUI::Layout::Spacer {}
+                @GUI::ComboBox {
+                    name: "allowed_file_type_filters_combo"
+                    model_only: true
+                }
 
                 @GUI::DialogButton {
                     name: "cancel_button"

Userland/Libraries/LibGUI/FileTypeFilter.h

@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2023, Marcus Nilsson <marcus.nilsson@genarp.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/DeprecatedString.h>
+#include <AK/Optional.h>
+#include <AK/Vector.h>
+
+namespace GUI {
+
+struct FileTypeFilter {
+    DeprecatedString name;
+    Optional<Vector<DeprecatedString>> extensions;
+
+    static FileTypeFilter all_files()
+    {
+        return FileTypeFilter { "All Files", {} };
+    }
+
+    static FileTypeFilter image_files()
+    {
+        return FileTypeFilter { "Image Files", Vector<DeprecatedString> { "png", "gif", "bmp", "dip", "pbm", "pgm", "ppm", "ico", "jpeg", "jpg", "dds", "qoi" } };
+    }
+};
+
+}