LibGUI: Remove Button& parameter from Button::on_click hook

There was but a single user of this parameter and it's a bit tedious
to write it out every time, so let's get rid of it.

Libraries/LibGUI/AboutDialog.cpp

@@ -83,7 +83,7 @@ AboutDialog::AboutDialog(const StringView& name, const Gfx::Bitmap* icon, Core::
     auto ok_button = button_container->add<Button>("OK");
     ok_button->set_size_policy(SizePolicy::Fixed, SizePolicy::Fixed);
     ok_button->set_preferred_size(80, 20);
-    ok_button->on_click = [this](auto&) {
+    ok_button->on_click = [this] {
         done(Dialog::ExecOK);
     };
 }

Libraries/LibGUI/Button.cpp

@@ -92,7 +92,7 @@ void Button::click()
         set_checked(!is_checked());
     }
     if (on_click)
-        on_click(*this);
+        on_click();
     if (m_action)
         m_action->activate(this);
 }

Libraries/LibGUI/Button.h

@@ -47,7 +47,7 @@ public:
     void set_text_alignment(Gfx::TextAlignment text_alignment) { m_text_alignment = text_alignment; }
     Gfx::TextAlignment text_alignment() const { return m_text_alignment; }
 
-    Function<void(Button&)> on_click;
+    Function<void()> on_click;
 
     void set_button_style(Gfx::ButtonStyle style) { m_button_style = style; }
     Gfx::ButtonStyle button_style() const { return m_button_style; }

Libraries/LibGUI/ColorPicker.cpp

@@ -75,13 +75,13 @@ void ColorPicker::build()
     auto cancel_button = right_vertical_container->add<Button>("Cancel");
     cancel_button->set_size_policy(SizePolicy::Fill, SizePolicy::Fixed);
     cancel_button->set_preferred_size(0, 20);
-    cancel_button->on_click = [&](auto&) {
+    cancel_button->on_click = [&] {
         done(Dialog::ExecCancel);
     };
     auto ok_button = right_vertical_container->add<Button>("Okay");
     ok_button->set_size_policy(SizePolicy::Fill, SizePolicy::Fixed);
     ok_button->set_preferred_size(0, 20);
-    ok_button->on_click = [&](auto&) {
+    ok_button->on_click = [&] {
         done(Dialog::ExecOK);
     };
 

Libraries/LibGUI/ComboBox.cpp

@@ -49,7 +49,7 @@ ComboBox::ComboBox()
     m_open_button = add<Button>();
     m_open_button->set_focusable(false);
     m_open_button->set_text("\xc3\xb7");
-    m_open_button->on_click = [this](auto&) {
+    m_open_button->on_click = [this] {
         if (m_list_window->is_visible())
             close();
         else

Libraries/LibGUI/FilePicker.cpp

@@ -210,7 +210,7 @@ FilePicker::FilePicker(Mode mode, const StringView& file_name, const StringView&
     cancel_button->set_size_policy(SizePolicy::Fixed, SizePolicy::Fill);
     cancel_button->set_preferred_size(80, 0);
     cancel_button->set_text("Cancel");
-    cancel_button->on_click = [this](auto&) {
+    cancel_button->on_click = [this] {
         done(ExecCancel);
     };
 
@@ -218,7 +218,7 @@ FilePicker::FilePicker(Mode mode, const StringView& file_name, const StringView&
     ok_button->set_size_policy(SizePolicy::Fixed, SizePolicy::Fill);
     ok_button->set_preferred_size(80, 0);
     ok_button->set_text(ok_button_name(m_mode));
-    ok_button->on_click = [this](auto&) {
+    ok_button->on_click = [this] {
         on_file_return();
     };
 

Libraries/LibGUI/InputBox.cpp

@@ -84,7 +84,7 @@ void InputBox::build()
     m_cancel_button->set_size_policy(SizePolicy::Fill, SizePolicy::Fixed);
     m_cancel_button->set_preferred_size(0, 20);
     m_cancel_button->set_text("Cancel");
-    m_cancel_button->on_click = [this](auto&) {
+    m_cancel_button->on_click = [this] {
         dbgprintf("GInputBox: Cancel button clicked\n");
         done(ExecCancel);
     };
@@ -93,7 +93,7 @@ void InputBox::build()
     m_ok_button->set_size_policy(SizePolicy::Fill, SizePolicy::Fixed);
     m_ok_button->set_preferred_size(0, 20);
     m_ok_button->set_text("OK");
-    m_ok_button->on_click = [this](auto&) {
+    m_ok_button->on_click = [this] {
         dbgprintf("GInputBox: OK button clicked\n");
         m_text_value = m_text_editor->text();
         done(ExecOK);

Libraries/LibGUI/MessageBox.cpp

@@ -131,7 +131,7 @@ void MessageBox::build()
         button->set_size_policy(SizePolicy::Fill, SizePolicy::Fixed);
         button->set_preferred_size(0, 20);
         button->set_text(label);
-        button->on_click = [this, label, result](auto&) {
+        button->on_click = [this, label, result] {
             dbg() << "GUI::MessageBox: '" << label << "' button clicked";
             done(result);
         };

Libraries/LibGUI/SpinBox.cpp

@@ -45,12 +45,12 @@ SpinBox::SpinBox()
     m_increment_button = add<Button>();
     m_increment_button->set_focusable(false);
     m_increment_button->set_text("\xc3\xb6");
-    m_increment_button->on_click = [this](auto&) { set_value(m_value + 1); };
+    m_increment_button->on_click = [this] { set_value(m_value + 1); };
     m_increment_button->set_auto_repeat_interval(150);
     m_decrement_button = add<Button>();
     m_decrement_button->set_focusable(false);
     m_decrement_button->set_text("\xc3\xb7");
-    m_decrement_button->on_click = [this](auto&) { set_value(m_value - 1); };
+    m_decrement_button->on_click = [this] { set_value(m_value - 1); };
     m_decrement_button->set_auto_repeat_interval(150);
 }