LibCore+LibGUI: Add fallible versions of Widget::load_from_gml()

The existing `load_from_gml()` methods look the same as before from the
outside. Inside though, they now forward to `try_load_from_gml()` which
returns Error when things go wrong. It also now calls the `try_create()`
factory method for Objects instead of the `construct()` one.
This commit is contained in:
Sam Atkins 2022-12-28 20:35:16 +00:00 committed by Tim Flynn
parent e58fe1cdd7
commit b32f5dbcff
8 changed files with 73 additions and 69 deletions

View file

@ -263,7 +263,7 @@ static HashMap<StringView, ObjectClassRegistration*>& object_classes()
return s_map;
}
ObjectClassRegistration::ObjectClassRegistration(StringView class_name, Function<RefPtr<Object>()> factory, ObjectClassRegistration* parent_class)
ObjectClassRegistration::ObjectClassRegistration(StringView class_name, Function<ErrorOr<NonnullRefPtr<Object>>()> factory, ObjectClassRegistration* parent_class)
: m_class_name(class_name)
, m_factory(move(factory))
, m_parent_class(parent_class)

View file

@ -22,18 +22,18 @@
namespace Core {
#define REGISTER_ABSTRACT_CORE_OBJECT(namespace_, class_name) \
namespace Core { \
namespace Registration { \
Core::ObjectClassRegistration registration_##class_name(#namespace_ "::" #class_name##sv, []() { return RefPtr<Object>(); }); \
} \
#define REGISTER_ABSTRACT_CORE_OBJECT(namespace_, class_name) \
namespace Core { \
namespace Registration { \
Core::ObjectClassRegistration registration_##class_name(#namespace_ "::" #class_name##sv, []() { return Error::from_string_literal("Attempted to construct an abstract object."); }); \
} \
}
#define REGISTER_CORE_OBJECT(namespace_, class_name) \
namespace Core { \
namespace Registration { \
Core::ObjectClassRegistration registration_##class_name(#namespace_ "::" #class_name##sv, []() { return namespace_::class_name::construct(); }); \
} \
#define REGISTER_CORE_OBJECT(namespace_, class_name) \
namespace Core { \
namespace Registration { \
Core::ObjectClassRegistration registration_##class_name(#namespace_ "::" #class_name##sv, []() { return namespace_::class_name::try_create(); }); \
} \
}
class ObjectClassRegistration {
@ -41,12 +41,12 @@ class ObjectClassRegistration {
AK_MAKE_NONMOVABLE(ObjectClassRegistration);
public:
ObjectClassRegistration(StringView class_name, Function<RefPtr<Object>()> factory, ObjectClassRegistration* parent_class = nullptr);
ObjectClassRegistration(StringView class_name, Function<ErrorOr<NonnullRefPtr<Object>>()> factory, ObjectClassRegistration* parent_class = nullptr);
~ObjectClassRegistration() = default;
StringView class_name() const { return m_class_name; }
ObjectClassRegistration const* parent_class() const { return m_parent_class; }
RefPtr<Object> construct() const { return m_factory(); }
ErrorOr<NonnullRefPtr<Object>> construct() const { return m_factory(); }
bool is_derived_from(ObjectClassRegistration const& base_class) const;
static void for_each(Function<void(ObjectClassRegistration const&)>);
@ -54,7 +54,7 @@ public:
private:
StringView m_class_name;
Function<RefPtr<Object>()> m_factory;
Function<ErrorOr<NonnullRefPtr<Object>>()> m_factory;
ObjectClassRegistration* m_parent_class { nullptr };
};

View file

@ -202,18 +202,18 @@ public:
}
}
// Uses IterationDecision to allow the callback to interrupt the iteration, like a for-loop break.
template<IteratorFunction<NonnullRefPtr<Object>> Callback>
void for_each_child_object_interruptible(Callback callback)
template<FallibleFunction<NonnullRefPtr<Object>> Callback>
ErrorOr<void> try_for_each_child_object(Callback callback)
{
for (NonnullRefPtr<Node> child : m_sub_objects) {
// doesn't capture layout as intended, as that's behind a kv-pair
if (is<Object>(child.ptr())) {
auto object = static_ptr_cast<Object>(child);
if (callback(object) == IterationDecision::Break)
return;
TRY(callback(object));
}
}
return {};
}
RefPtr<Object> layout_object() const

View file

@ -143,8 +143,8 @@ void AutocompleteProvider::provide_completions(Function<void(Vector<CodeComprehe
// FIXME: Don't show properties that are already specified in the scope.
auto registration = Core::ObjectClassRegistration::find(class_name);
if (registration && (registration->is_derived_from(widget_class) || registration->is_derived_from(layout_class))) {
if (auto instance = registration->construct()) {
for (auto& it : instance->properties()) {
if (auto instance = registration->construct(); !instance.is_error()) {
for (auto& it : instance.value()->properties()) {
if (!it.value->is_readonly() && it.key.matches(pattern))
identifier_entries.empend(DeprecatedString::formatted("{}: ", it.key), partial_input_length, CodeComprehension::Language::Unspecified, it.key);
}

View file

@ -102,7 +102,7 @@ void ScrollableContainerWidget::set_widget(GUI::Widget* widget)
update_widget_position();
}
bool ScrollableContainerWidget::load_from_gml_ast(NonnullRefPtr<GUI::GML::Node> ast, RefPtr<Core::Object> (*unregistered_child_handler)(DeprecatedString const&))
ErrorOr<void> ScrollableContainerWidget::load_from_gml_ast(NonnullRefPtr<GUI::GML::Node> ast, RefPtr<Core::Object> (*unregistered_child_handler)(DeprecatedString const&))
{
if (is<GUI::GML::GMLFile>(ast.ptr()))
return load_from_gml_ast(static_ptr_cast<GUI::GML::GMLFile>(ast)->main_class(), unregistered_child_handler);
@ -116,15 +116,13 @@ bool ScrollableContainerWidget::load_from_gml_ast(NonnullRefPtr<GUI::GML::Node>
auto content_widget_value = object->get_property("content_widget"sv);
if (!content_widget_value.is_null() && !is<GUI::GML::Object>(content_widget_value.ptr())) {
dbgln("content widget is not an object");
return false;
return Error::from_string_literal("ScrollableContainerWidget content_widget is not an object");
}
auto has_children = false;
object->for_each_child_object([&](auto) { has_children = true; });
if (has_children) {
dbgln("children specified for ScrollableContainerWidget, but only 1 widget as content_widget is supported");
return false;
return Error::from_string_literal("Children specified for ScrollableContainerWidget, but only 1 widget as content_widget is supported");
}
if (!content_widget_value.is_null() && is<GUI::GML::Object>(content_widget_value.ptr())) {
@ -133,19 +131,18 @@ bool ScrollableContainerWidget::load_from_gml_ast(NonnullRefPtr<GUI::GML::Node>
RefPtr<Core::Object> child;
if (auto* registration = Core::ObjectClassRegistration::find(class_name)) {
child = registration->construct();
child = TRY(registration->construct());
} else {
child = unregistered_child_handler(class_name);
}
if (!child)
return false;
return Error::from_string_literal("Unable to construct a Widget class for ScrollableContainerWidget content_widget property");
auto widget_ptr = verify_cast<GUI::Widget>(child.ptr());
set_widget(widget_ptr);
static_ptr_cast<Widget>(child)->load_from_gml_ast(content_widget.release_nonnull(), unregistered_child_handler);
return true;
TRY(static_ptr_cast<Widget>(child)->load_from_gml_ast(content_widget.release_nonnull(), unregistered_child_handler));
}
return true;
return {};
}
}

View file

@ -30,7 +30,7 @@ private:
void update_widget_size();
void update_widget_position();
void update_widget_min_size();
virtual bool load_from_gml_ast(NonnullRefPtr<GUI::GML::Node> ast, RefPtr<Core::Object> (*unregistered_child_handler)(DeprecatedString const&)) override;
virtual ErrorOr<void> load_from_gml_ast(NonnullRefPtr<GUI::GML::Node> ast, RefPtr<Core::Object> (*unregistered_child_handler)(DeprecatedString const&)) override;
ScrollableContainerWidget();

View file

@ -1145,26 +1145,31 @@ void Widget::set_override_cursor(AK::Variant<Gfx::StandardCursor, NonnullRefPtr<
}
}
bool Widget::load_from_gml(StringView gml_string)
ErrorOr<void> Widget::try_load_from_gml(StringView gml_string)
{
return load_from_gml(gml_string, [](DeprecatedString const& class_name) -> RefPtr<Core::Object> {
return try_load_from_gml(gml_string, [](DeprecatedString const& class_name) -> RefPtr<Core::Object> {
dbgln("Class '{}' not registered", class_name);
return nullptr;
});
}
bool Widget::load_from_gml(StringView gml_string, RefPtr<Core::Object> (*unregistered_child_handler)(DeprecatedString const&))
ErrorOr<void> Widget::try_load_from_gml(StringView gml_string, RefPtr<Core::Object> (*unregistered_child_handler)(DeprecatedString const&))
{
auto value = GML::parse_gml(gml_string);
if (value.is_error()) {
// FIXME: We don't report the error, so at least print it.
dbgln("Error while parsing GML: {}", value.error());
return false;
}
return load_from_gml_ast(value.release_value(), unregistered_child_handler);
auto value = TRY(GML::parse_gml(gml_string));
return load_from_gml_ast(value, unregistered_child_handler);
}
bool Widget::load_from_gml_ast(NonnullRefPtr<GUI::GML::Node> ast, RefPtr<Core::Object> (*unregistered_child_handler)(DeprecatedString const&))
bool Widget::load_from_gml(StringView gml_string)
{
return !try_load_from_gml(gml_string).is_error();
}
bool Widget::load_from_gml(StringView gml_string, RefPtr<Core::Object> (*unregistered_child_handler)(DeprecatedString const&))
{
return !try_load_from_gml(gml_string, unregistered_child_handler).is_error();
}
ErrorOr<void> Widget::load_from_gml_ast(NonnullRefPtr<GUI::GML::Node> ast, RefPtr<Core::Object> (*unregistered_child_handler)(DeprecatedString const&))
{
if (is<GUI::GML::GMLFile>(ast.ptr()))
return load_from_gml_ast(static_ptr_cast<GUI::GML::GMLFile>(ast)->main_class(), unregistered_child_handler);
@ -1180,21 +1185,20 @@ bool Widget::load_from_gml_ast(NonnullRefPtr<GUI::GML::Node> ast, RefPtr<Core::O
if (!layout.is_null()) {
auto class_name = layout->name();
if (class_name.is_null()) {
dbgln("Invalid layout class name");
return false;
return Error::from_string_literal("Invalid layout class name");
}
auto& layout_class = *Core::ObjectClassRegistration::find("GUI::Layout"sv);
if (auto* registration = Core::ObjectClassRegistration::find(class_name)) {
auto layout = registration->construct();
if (!layout || !registration->is_derived_from(layout_class)) {
auto layout = TRY(registration->construct());
if (!registration->is_derived_from(layout_class)) {
dbgln("Invalid layout class: '{}'", class_name.to_deprecated_string());
return false;
return Error::from_string_literal("Invalid layout class");
}
set_layout(static_ptr_cast<Layout>(layout).release_nonnull());
set_layout(static_ptr_cast<Layout>(layout));
} else {
dbgln("Unknown layout class: '{}'", class_name.to_deprecated_string());
return false;
return Error::from_string_literal("Unknown layout class");
}
layout->for_each_property([&](auto key, auto value) {
@ -1204,33 +1208,32 @@ bool Widget::load_from_gml_ast(NonnullRefPtr<GUI::GML::Node> ast, RefPtr<Core::O
auto& widget_class = *Core::ObjectClassRegistration::find("GUI::Widget"sv);
bool is_tab_widget = is<TabWidget>(*this);
object->for_each_child_object_interruptible([&](auto child_data) {
TRY(object->try_for_each_child_object([&](auto child_data) -> ErrorOr<void> {
auto class_name = child_data->name();
// It is very questionable if this pseudo object should exist, but it works fine like this for now.
if (class_name == "GUI::Layout::Spacer") {
if (!this->layout()) {
dbgln("Specified GUI::Layout::Spacer in GML, but the parent has no Layout.");
return IterationDecision::Break;
return Error::from_string_literal("Specified GUI::Layout::Spacer in GML, but the parent has no Layout.");
}
this->layout()->add_spacer();
} else {
RefPtr<Core::Object> child;
if (auto* registration = Core::ObjectClassRegistration::find(class_name)) {
child = registration->construct();
if (!child || !registration->is_derived_from(widget_class)) {
child = TRY(registration->construct());
if (!registration->is_derived_from(widget_class)) {
dbgln("Invalid widget class: '{}'", class_name);
return IterationDecision::Break;
return Error::from_string_literal("Invalid widget class");
}
} else {
child = unregistered_child_handler(class_name);
}
if (!child)
return IterationDecision::Break;
return Error::from_string_literal("Unable to construct a Widget class for child");
add_child(*child);
// This is possible as we ensure that Widget is a base class above.
static_ptr_cast<Widget>(child)->load_from_gml_ast(child_data, unregistered_child_handler);
TRY(static_ptr_cast<Widget>(child)->load_from_gml_ast(child_data, unregistered_child_handler));
if (is_tab_widget) {
// FIXME: We need to have the child added before loading it so that it can access us. But the TabWidget logic requires the child to not be present yet.
@ -1239,10 +1242,10 @@ bool Widget::load_from_gml_ast(NonnullRefPtr<GUI::GML::Node> ast, RefPtr<Core::O
}
}
return IterationDecision::Continue;
});
return {};
}));
return true;
return {};
}
bool Widget::has_focus_within() const

View file

@ -32,12 +32,12 @@ extern Core::ObjectClassRegistration registration_Widget;
}
}
#define REGISTER_WIDGET(namespace_, class_name) \
namespace Core { \
namespace Registration { \
Core::ObjectClassRegistration registration_##class_name( \
#namespace_ "::" #class_name##sv, []() { return static_ptr_cast<Core::Object>(namespace_::class_name::construct()); }, &registration_Widget); \
} \
#define REGISTER_WIDGET(namespace_, class_name) \
namespace Core { \
namespace Registration { \
Core::ObjectClassRegistration registration_##class_name( \
#namespace_ "::" #class_name##sv, []() -> ErrorOr<NonnullRefPtr<Core::Object>> { return static_ptr_cast<Core::Object>(TRY(namespace_::class_name::try_create())); }, &registration_Widget); \
} \
}
namespace GUI {
@ -353,7 +353,11 @@ public:
AK::Variant<Gfx::StandardCursor, NonnullRefPtr<Gfx::Bitmap>> const& override_cursor() const { return m_override_cursor; }
void set_override_cursor(AK::Variant<Gfx::StandardCursor, NonnullRefPtr<Gfx::Bitmap>>);
bool load_from_gml(StringView);
ErrorOr<void> try_load_from_gml(StringView);
ErrorOr<void> try_load_from_gml(StringView, RefPtr<Core::Object> (*unregistered_child_handler)(DeprecatedString const&));
// FIXME: Replace all uses of load_from_gml() with try_load_from_gml()
bool load_from_gml(StringView gml_string);
bool load_from_gml(StringView, RefPtr<Core::Object> (*unregistered_child_handler)(DeprecatedString const&));
// FIXME: remove this when all uses of shrink_to_fit are eliminated
@ -363,7 +367,7 @@ public:
bool has_pending_drop() const;
// In order for others to be able to call this, it needs to be public.
virtual bool load_from_gml_ast(NonnullRefPtr<GUI::GML::Node> ast, RefPtr<Core::Object> (*unregistered_child_handler)(DeprecatedString const&));
virtual ErrorOr<void> load_from_gml_ast(NonnullRefPtr<GUI::GML::Node> ast, RefPtr<Core::Object> (*unregistered_child_handler)(DeprecatedString const&));
protected:
Widget();