HexEditor: Use FileSystemAccessClient, add unveils

Most of the code here is based off the implementation of how
TextEditor uses FileSystemAccessClient.

Userland/Applications/HexEditor/CMakeLists.txt

@@ -20,4 +20,4 @@ set(SOURCES
 )
 
 serenity_app(HexEditor ICON app-hex-editor)
-target_link_libraries(HexEditor LibGUI LibConfig)
+target_link_libraries(HexEditor LibGUI LibConfig LibFileSystemAccessClient)

Userland/Applications/HexEditor/HexEditor.cpp

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
+ * Copyright (c) 2021, Mustafa Quraish <mustafa@cs.toronto.edu>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -7,10 +8,12 @@
 #include "HexEditor.h"
 #include "SearchResultsModel.h"
 #include <AK/Debug.h>
+#include <AK/ScopeGuard.h>
 #include <AK/StringBuilder.h>
 #include <LibGUI/Action.h>
 #include <LibGUI/Clipboard.h>
 #include <LibGUI/Menu.h>
+#include <LibGUI/MessageBox.h>
 #include <LibGUI/Painter.h>
 #include <LibGUI/Scrollbar.h>
 #include <LibGUI/TextEditor.h>
@@ -91,6 +94,13 @@ bool HexEditor::write_to_file(const String& path)
         return false;
     }
 
+    return write_to_file(fd);
+}
+
+bool HexEditor::write_to_file(int fd)
+{
+    ScopeGuard fd_guard = [fd] { close(fd); };
+
     int rc = ftruncate(fd, m_buffer.size());
     if (rc < 0) {
         perror("ftruncate");
@@ -109,7 +119,6 @@ bool HexEditor::write_to_file(const String& path)
         update();
     }
 
-    close(fd);
     return true;
 }
 

Userland/Applications/HexEditor/HexEditor.h

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
+ * Copyright (c) 2021, Mustafa Quraish <mustafa@cs.toronto.edu>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -34,6 +35,7 @@ public:
     void set_buffer(const ByteBuffer&);
     void fill_selection(u8 fill_byte);
     bool write_to_file(const String& path);
+    bool write_to_file(int fd);
 
     void select_all();
     bool has_selection() const { return !(m_selection_start == -1 || m_selection_end == -1 || (m_selection_end - m_selection_start) < 0 || m_buffer.is_empty()); }

Userland/Applications/HexEditor/HexEditorWidget.cpp

@@ -14,6 +14,7 @@
 #include <Applications/HexEditor/HexEditorWindowGML.h>
 #include <LibConfig/Client.h>
 #include <LibCore/File.h>
+#include <LibFileSystemAccessClient/Client.h>
 #include <LibGUI/Action.h>
 #include <LibGUI/BoxLayout.h>
 #include <LibGUI/Button.h>
@@ -84,10 +85,13 @@ HexEditorWidget::HexEditorWidget()
     });
 
     m_open_action = GUI::CommonActions::make_open_action([this](auto&) {
-        Optional<String> open_path = GUI::FilePicker::get_open_filepath(window());
+        auto response = FileSystemAccessClient::Client::the().open_file(window()->window_id());
 
-        if (!open_path.has_value())
+        if (response.error != 0) {
+            if (response.error != -1)
+                GUI::MessageBox::show_error(window(), String::formatted("Opening \"{}\" failed: {}", *response.chosen_file, strerror(response.error)));
             return;
+        }
 
         if (m_document_dirty) {
             auto save_document_first_result = GUI::MessageBox::show(window(), "Save changes to current document first?", "Warning", GUI::MessageBox::Type::Warning, GUI::MessageBox::InputType::YesNoCancel);
@@ -97,38 +101,47 @@ HexEditorWidget::HexEditorWidget()
                 return;
         }
 
-        open_file(open_path.value());
+        open_file(*response.fd, *response.chosen_file);
     });
 
     m_save_action = GUI::CommonActions::make_save_action([&](auto&) {
-        if (!m_path.is_empty()) {
-            if (!m_editor->write_to_file(m_path)) {
-                GUI::MessageBox::show(window(), "Unable to save file.\n", "Error", GUI::MessageBox::Type::Error);
-            } else {
-                m_document_dirty = false;
-                update_title();
-            }
+        if (m_path.is_empty())
+            return m_save_as_action->activate();
+
+        auto response = FileSystemAccessClient::Client::the().request_file(window()->window_id(), m_path, Core::OpenMode::Truncate | Core::OpenMode::WriteOnly);
+
+        if (response.error != 0) {
+            if (response.error != -1)
+                GUI::MessageBox::show_error(window(), String::formatted("Unable to save file: {}", strerror(response.error)));
             return;
         }
 
-        m_save_as_action->activate();
+        if (!m_editor->write_to_file(*response.fd)) {
+            GUI::MessageBox::show(window(), "Unable to save file.\n", "Error", GUI::MessageBox::Type::Error);
+        } else {
+            m_document_dirty = false;
+            update_title();
+        }
+        return;
     });
 
     m_save_as_action = GUI::CommonActions::make_save_as_action([&](auto&) {
-        Optional<String> save_path = GUI::FilePicker::get_save_filepath(window(), m_name.is_null() ? "Untitled" : m_name, m_extension.is_null() ? "bin" : m_extension);
-        if (!save_path.has_value()) {
-            dbgln("GUI::FilePicker: Cancel button clicked");
+        auto response = FileSystemAccessClient::Client::the().save_file(window()->window_id(), m_name, m_extension);
+
+        if (response.error != 0) {
+            if (response.error != -1)
+                GUI::MessageBox::show_error(window(), String::formatted("Saving \"{}\" failed: {}", *response.chosen_file, strerror(response.error)));
             return;
         }
 
-        if (!m_editor->write_to_file(save_path.value())) {
+        if (!m_editor->write_to_file(*response.fd)) {
             GUI::MessageBox::show(window(), "Unable to save file.\n", "Error", GUI::MessageBox::Type::Error);
             return;
         }
 
         m_document_dirty = false;
-        set_path(save_path.value());
-        dbgln("Wrote document to {}", save_path.value());
+        set_path(*response.chosen_file);
+        dbgln("Wrote document to {}", *response.chosen_file);
     });
 
     m_find_action = GUI::Action::create("&Find", { Mod_Ctrl, Key_F }, Gfx::Bitmap::try_load_from_file("/res/icons/16x16/find.png"), [&](const GUI::Action&) {
@@ -334,14 +347,26 @@ void HexEditorWidget::update_title()
     window()->set_title(builder.to_string());
 }
 
-void HexEditorWidget::open_file(const String& path)
+void HexEditorWidget::open_file(int fd, String const& path)
 {
-    auto file = Core::File::construct(path);
-    if (!file->open(Core::OpenMode::ReadOnly)) {
+    VERIFY(path.starts_with("/"sv));
+    auto file = Core::File::construct();
+
+    if (!file->open(fd, Core::OpenMode::ReadOnly, Core::File::ShouldCloseFileDescriptor::Yes) && file->error() != ENOENT) {
         GUI::MessageBox::show(window(), String::formatted("Opening \"{}\" failed: {}", path, strerror(errno)), "Error", GUI::MessageBox::Type::Error);
         return;
     }
 
+    if (file->is_device()) {
+        GUI::MessageBox::show(window(), String::formatted("Opening \"{}\" failed: Can't open device files", path), "Error", GUI::MessageBox::Type::Error);
+        return;
+    }
+
+    if (file->is_directory()) {
+        GUI::MessageBox::show(window(), String::formatted("Opening \"{}\" failed: Can't open directories", path), "Error", GUI::MessageBox::Type::Error);
+        return;
+    }
+
     m_document_dirty = false;
     m_editor->set_buffer(file->read_all()); // FIXME: On really huge files, this is never going to work. Should really create a framework to fetch data from the file on-demand.
     set_path(path);
@@ -377,6 +402,13 @@ void HexEditorWidget::drop_event(GUI::DropEvent& event)
         if (urls.is_empty())
             return;
         window()->move_to_front();
-        open_file(urls.first().path());
+
+        // TODO: A drop event should be considered user consent for opening a file
+        auto file_response = FileSystemAccessClient::Client::the().request_file(window()->window_id(), urls.first().path(), Core::OpenMode::ReadOnly);
+
+        if (file_response.error != 0)
+            return;
+
+        open_file(*file_response.fd, urls.first().path());
     }
 }

Userland/Applications/HexEditor/HexEditorWidget.h

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
+ * Copyright (c) 2021, Mustafa Quraish <mustafa@cs.toronto.edu>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -21,7 +22,7 @@ class HexEditorWidget final : public GUI::Widget {
     C_OBJECT(HexEditorWidget)
 public:
     virtual ~HexEditorWidget() override;
-    void open_file(const String& path);
+    void open_file(int fd, String const& path);
     void initialize_menubar(GUI::Window&);
     bool request_close();
 

Userland/Applications/HexEditor/main.cpp

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
+ * Copyright (c) 2021, Mustafa Quraish <mustafa@cs.toronto.edu>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -8,6 +9,7 @@
 #include <LibConfig/Client.h>
 #include <LibGUI/Icon.h>
 #include <LibGUI/Menubar.h>
+#include <LibGUI/MessageBox.h>
 #include <stdio.h>
 #include <unistd.h>
 
@@ -22,11 +24,6 @@ int main(int argc, char** argv)
 
     Config::pledge_domains("HexEditor");
 
-    if (pledge("stdio recvfd sendfd rpath cpath wpath thread", nullptr) < 0) {
-        perror("pledge");
-        return 1;
-    }
-
     auto app_icon = GUI::Icon::default_icon("app-hex-editor");
 
     auto window = GUI::Window::construct();
@@ -41,12 +38,49 @@ int main(int argc, char** argv)
         return GUI::Window::CloseRequestDecision::StayOpen;
     };
 
+    String file_to_edit = (argc > 1) ? Core::File::absolute_path(argv[1]) : "";
+
+    if (!file_to_edit.is_empty()) {
+        if (Core::File::exists(file_to_edit)) {
+            dbgln("unveil for: {}", file_to_edit);
+            if (unveil(file_to_edit.characters(), "r") < 0) {
+                perror("unveil");
+                return 1;
+            }
+        } else {
+            file_to_edit = {};
+        }
+    }
+
+    if (unveil("/res", "r") < 0) {
+        perror("unveil");
+        return 1;
+    }
+
+    if (unveil("/tmp/portal/filesystemaccess", "rw") < 0) {
+        perror("unveil");
+        return 1;
+    }
+
+    if (unveil(nullptr, nullptr) < 0) {
+        perror("unveil");
+        return 1;
+    }
+
     hex_editor_widget.initialize_menubar(*window);
     window->show();
     window->set_icon(app_icon.bitmap_for_size(16));
 
-    if (argc >= 2)
-        hex_editor_widget.open_file(argv[1]);
+    if (!file_to_edit.is_empty()) {
+        auto file = Core::File::open(file_to_edit, Core::OpenMode::ReadOnly);
+
+        if (file.is_error()) {
+            GUI::MessageBox::show_error(window, String::formatted("Opening \"{}\" failed: {}", file_to_edit, file.error()));
+            return 1;
+        }
+
+        hex_editor_widget.open_file(file.value()->leak_fd(), file_to_edit);
+    }
 
     return app->exec();
 }