LibGUI: Add GUI::Process::spawn_or_show_error()

This is a wrapper around Core::Process::spawn() for GUI applications,
that shows an error if the call to spawn() failed.

Userland/Libraries/LibGUI/CMakeLists.txt

@@ -79,6 +79,7 @@ set(SOURCES
     PasswordInputDialog.cpp
     PasswordInputDialogGML.h
     PersistentModelIndex.cpp
+    Process.cpp
     ProcessChooser.cpp
     Progressbar.cpp
     RadioButton.cpp

Userland/Libraries/LibGUI/Process.cpp

@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2022, MacDue <macdue@dueutil.tech>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <AK/Format.h>
+#include <AK/StringView.h>
+#include <LibGUI/MessageBox.h>
+#include <LibGUI/Process.h>
+
+template<typename StringType>
+void spawn_or_show_error(GUI::Window* parent_window, StringView path, Span<StringType const> arguments)
+{
+    auto spawn_result = Core::Process::spawn(path, arguments);
+    if (spawn_result.is_error())
+        GUI::MessageBox::show_error(parent_window, String::formatted("Failed to spawn {}: {}", path, spawn_result.error()));
+}
+
+namespace GUI {
+
+void Process::spawn_or_show_error(Window* parent_window, StringView path, Span<String const> arguments)
+{
+    ::spawn_or_show_error<String>(parent_window, path, arguments);
+}
+
+void Process::spawn_or_show_error(Window* parent_window, StringView path, Span<StringView const> arguments)
+{
+    ::spawn_or_show_error<StringView>(parent_window, path, arguments);
+}
+
+void Process::spawn_or_show_error(Window* parent_window, StringView path, Span<char const* const> arguments)
+{
+    ::spawn_or_show_error<char const*>(parent_window, path, arguments);
+}
+
+}

Userland/Libraries/LibGUI/Process.h

@@ -0,0 +1,20 @@
+/*
+ * Copyright (c) 2022, MacDue <macdue@dueutil.tech>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibCore/Process.h>
+#include <LibGUI/Forward.h>
+
+namespace GUI {
+
+struct Process {
+    static void spawn_or_show_error(Window* parent_window, StringView path, Span<String const> arguments);
+    static void spawn_or_show_error(Window* parent_window, StringView path, Span<StringView const> arguments);
+    static void spawn_or_show_error(Window* parent_window, StringView path, Span<char const* const> arguments = {});
+};
+
+}