Widget

Abstract base class for all UI elements.

Header

#include <neoflux/widget/widget.h>

Public Methods

GetWidgetName()

[[nodiscard]] virtual std::string_view GetWidgetName() const noexcept = 0;

Returns the widget's name for debugging and logging.

AddChild()

void AddChild(std::shared_ptr<Widget> child);

Adds a child widget.

ClearChildren()

void ClearChildren();

Removes all children.

GetChildren()

[[nodiscard]] const std::vector<std::shared_ptr<Widget>>& GetChildren() const noexcept;

Returns the list of children.

GetParent()

[[nodiscard]] Widget* GetParent() const noexcept;

Returns the parent widget, or nullptr if this is the root.

GetBounds()

[[nodiscard]] const Rect& GetBounds() const noexcept;

Returns the widget's computed bounds (position and size) after layout.

GetGlobalPosition()

[[nodiscard]] Point GetGlobalPosition() const;

Returns the widget's position in window coordinates (recursively sums parent offsets).

PerformLayout()

void PerformLayout(float width, float height);

Runs Taitank layout on this widget's subtree. The root widget is sized to width x height.

HitTest()

std::shared_ptr<Widget> HitTest(const Point& parent_pos);

Recursively finds the deepest widget under the given point. Returns nullptr if no widget is hit.

MarkNeedsBuild()

void MarkNeedsBuild() noexcept;

Marks this widget for rebuild on the next frame.

NeedsBuild() / ClearNeedsBuild()

[[nodiscard]] bool NeedsBuild() const noexcept;
void ClearNeedsBuild() noexcept;

Query and clear the build-dirty flag.

GetTaitankNode()

[[nodiscard]] taitank::TaitankNode* GetTaitankNode() const noexcept;

Returns the underlying Taitank layout node.

Virtual Methods (Override in Subclasses)

Build()

virtual std::shared_ptr<Widget> Build(BuildContext& context);

Returns the child widget tree. Called for dirty widgets during the build phase.

OnMeasure()

[[nodiscard]] virtual Size OnMeasure(float width, int width_mode,
                                     float height, int height_mode) = 0;

Returns the widget's intrinsic size. Leaf widgets must override this.

Paint()

virtual void Paint(RenderContext& context) = 0;

Generates render commands for this widget.

OnPointerDown() / OnPointerUp()

virtual bool OnPointerDown(const Point& local_pos);
virtual bool OnPointerUp(const Point& local_pos);

Handle pointer press/release events. Return true to consume the event.

OnPointerScroll()

virtual bool OnPointerScroll(const Point& local_pos, double xoffset,
                             double yoffset);

Handle scroll events. Return true to consume.

ReadLayoutRecursive()

virtual void ReadLayoutRecursive();

Copies Taitank layout results into bounds_. Override for widgets that need custom post-layout processing (e.g., ScrollView computes content size).