FontEditor: Allow specifying which font to edit on the command line.

Also add a quit button. The quit button has a tendency to freeze the kernel.
That doesn't seem entirely right.

FontEditor/FontEditor.cpp

@@ -4,14 +4,14 @@
 #include <LibGUI/GLabel.h>
 #include <LibGUI/GTextBox.h>
 
-FontEditorWidget::FontEditorWidget(GWidget* parent)
+FontEditorWidget::FontEditorWidget(const String& path, RetainPtr<Font>&& edited_font, GWidget* parent)
     : GWidget(parent)
+    , m_edited_font(move(edited_font))
 {
-    m_edited_font = Font::load_from_file("/saved.font");
-    if (m_edited_font)
-        m_edited_font = m_edited_font->clone();
+    if (path.is_empty())
+        m_path = "/saved.font";
     else
-        m_edited_font = Font::default_font().clone();
+        m_path = path;
 
     m_glyph_map_widget = new GlyphMapWidget(*m_edited_font, this);
     m_glyph_map_widget->move_to({ 90, 5 });
@@ -30,7 +30,15 @@ FontEditorWidget::FontEditorWidget(GWidget* parent)
     save_button->set_caption("Save");
     save_button->set_relative_rect({ 5, 170, 100, 20 });
     save_button->on_click = [this] (GButton&) {
-        m_edited_font->write_to_file("/saved.font");
+        dbgprintf("write to file: '%s'\n", m_path.characters());
+        m_edited_font->write_to_file(m_path);
+    };
+
+    auto* quit_button = new GButton(this);
+    quit_button->set_caption("Quit");
+    quit_button->set_relative_rect({ 110, 170, 100, 20 });
+    quit_button->on_click = [] (GButton&) {
+        exit(0);
     };
 
     auto* info_label = new GLabel(this);

FontEditor/FontEditor.h

@@ -9,7 +9,7 @@ class GTextBox;
 
 class FontEditorWidget final : public GWidget {
 public:
-    FontEditorWidget(GWidget* parent = nullptr);
+    FontEditorWidget(const String& path, RetainPtr<Font>&&, GWidget* parent = nullptr);
     virtual ~FontEditorWidget() override;
 
 private:
@@ -18,6 +18,8 @@ private:
     GlyphMapWidget* m_glyph_map_widget { nullptr };
     GlyphEditorWidget* m_glyph_editor_widget { nullptr };
     GTextBox* m_name_textbox { nullptr };
+
+    String m_path;
 };
 
 class GlyphMapWidget final : public GWidget {

FontEditor/main.cpp

@@ -5,14 +5,28 @@
 
 int main(int argc, char** argv)
 {
-    (void) argc;
-    (void) argv;
+    RetainPtr<Font> edited_font;
+    String path;
+
+    if (argc == 2) {
+        path = argv[1];
+        edited_font = Font::load_from_file(path);
+        if (!edited_font) {
+            fprintf(stderr, "Couldn't load font: %s\n", path.characters());
+            return 1;
+        }
+    }
+
+    if (edited_font)
+        edited_font = edited_font->clone();
+    else
+        edited_font = Font::default_font().clone();
 
     GEventLoop loop;
     auto* window = new GWindow;
     window->set_title("FontEditor");
     window->set_rect({ 50, 50, 420, 200 });
-    auto* font_editor = new FontEditorWidget;
+    auto* font_editor = new FontEditorWidget(path, move(edited_font));
     font_editor->set_relative_rect({ 0, 0, 420, 200 });
     window->set_main_widget(font_editor);
     window->show();