CUGL 2.1
Cornell University Game Library
Classes | Public Member Functions | Static Public Member Functions | Protected Attributes | List of all members
cugl::scene2::AnchoredLayout Class Reference

#include <CUAnchoredLayout.h>

Inheritance diagram for cugl::scene2::AnchoredLayout:
cugl::scene2::Layout

Classes

class  Entry
 

Public Member Functions

 AnchoredLayout ()
 
 ~AnchoredLayout ()
 
virtual bool initWithData (const std::shared_ptr< JsonValue > &data) override
 
virtual void dispose () override
 
virtual bool add (const std::string key, const std::shared_ptr< JsonValue > &data) override
 
bool addAbsolute (const std::string key, Anchor anchor, const Vec2 offset)
 
bool addRelative (const std::string key, Anchor anchor, const Vec2 offset)
 
virtual bool remove (const std::string key) override
 
virtual void layout (scene2::SceneNode *node) override
 
- Public Member Functions inherited from cugl::scene2::Layout
 Layout ()
 
 ~Layout ()
 
virtual bool init ()
 

Static Public Member Functions

static std::shared_ptr< AnchoredLayoutalloc ()
 
static std::shared_ptr< AnchoredLayoutallocWithData (const std::shared_ptr< JsonValue > &data)
 
- Static Public Member Functions inherited from cugl::scene2::Layout
static Anchor getAnchor (const std::string &x_anchor, const std::string &y_anchor)
 
static void placeNode (SceneNode *node, Anchor anchor, const Rect bounds, const Vec2 offset)
 
static void reanchor (SceneNode *node, Anchor anchor)
 

Protected Attributes

std::unordered_map< std::string, Entry_entries
 

Additional Inherited Members

- Public Types inherited from cugl::scene2::Layout
enum  Anchor : int {
  Anchor::BOTTOM_LEFT = 0, Anchor::MIDDLE_LEFT = 1, Anchor::TOP_LEFT = 2, Anchor::BOTTOM_CENTER = 3,
  Anchor::CENTER = 4, Anchor::TOP_CENTER = 5, Anchor::BOTTOM_RIGHT = 6, Anchor::MIDDLE_RIGHT = 7,
  Anchor::TOP_RIGHT = 8, Anchor::BOTTOM_FILL = 9, Anchor::MIDDLE_FILL = 10, Anchor::TOP_FILL = 11,
  Anchor::LEFT_FILL = 12, Anchor::CENTER_FILL = 13, Anchor::RIGHT_FILL = 14, Anchor::TOTAL_FILL = 15,
  Anchor::NONE = 16
}
 

Detailed Description

This class provides an anchored layout manager.

An anchored layout attaches a child node to one of nine "anchors" in the parent (corners, sides or middle), together with a percentage (or absolute) offset. As the parent grows or shinks, the child will move according to its anchor. For example, nodes in the center will stay centered, while nodes on the left side will move to keep the appropriate distance from the left side. In fact, the stretching behavior is very similar to that of a NinePatch.

Layout information is indexed by key. To look up the layout information of a scene graph node, we use the name of the node. This requires all nodes to have unique names. The Scene2Loader prefixes all child names by the parent name, so this is the case in any well-defined JSON file.

Constructor & Destructor Documentation

◆ AnchoredLayout()

cugl::scene2::AnchoredLayout::AnchoredLayout ( )
inline

Creates a degenerate layout manager with no data.

NEVER USE A CONSTRUCTOR WITH NEW. If you want to allocate an object on the heap, use one of the static constructors instead.

◆ ~AnchoredLayout()

cugl::scene2::AnchoredLayout::~AnchoredLayout ( )
inline

Deletes this layout manager, disposing of all resources.

Member Function Documentation

◆ add()

virtual bool cugl::scene2::AnchoredLayout::add ( const std::string  key,
const std::shared_ptr< JsonValue > &  data 
)
overridevirtual

Assigns layout information for a given key.

The JSON object may contain any of the following attribute values:

 "x_anchor": One of 'left', 'center', 'right', or 'fill'
 "y_anchor": One of 'bottom', 'middle', 'top', or 'fill'
 "absolute": Whether to use absolute instead of relative (percentage) offsets
 "x_offset": A number indicating the horizontal offset from the anchor.
             If "absolute" is true, this is the distance in coordinate space.
             Otherwise it is a percentage of the width.
 "y_offset": A number indicating the vertical offset from the anchor.
             If "absolute" is true, this is the distance in coordinate space.
             Otherwise it is a percentage of the height.

All attributes are optional. There are no required attributes.

To look up the layout information of a scene graph node, we use the name of the node. This requires all nodes to have unique names. The Scene2Loader prefixes all child names by the parent name, so this is the case in any well-defined JSON file. If the key is already in use, this method will fail.

Parameters
keyThe key identifying the layout information
dataA JSON object with the layout information
Returns
true if the layout information was assigned to that key

Reimplemented from cugl::scene2::Layout.

◆ addAbsolute()

bool cugl::scene2::AnchoredLayout::addAbsolute ( const std::string  key,
Anchor  anchor,
const Vec2  offset 
)

Assigns layout information for a given key.

This method specifies the anchor offset in absolute terms. That is, offset is the distance from the anchor in Node coordinate space.

To look up the layout information of a scene graph node, we use the name of the node. This requires all nodes to have unique names. The Scene2Loader prefixes all child names by the parent name, so this is the case in any well-defined JSON file. If the key is already in use, this method will fail.

Parameters
keyThe key identifying the layout information
anchorThe anchor point to use
offsetThe offset from the anchor point
Returns
true if the layout information was assigned to that key

◆ addRelative()

bool cugl::scene2::AnchoredLayout::addRelative ( const std::string  key,
Anchor  anchor,
const Vec2  offset 
)

Assigns layout information for a given key.

This method specifies the anchor offset in relative terms. That is, offset is the percentage of the width and height of the Node.

To look up the layout information of a scene graph node, we use the name of the node. This requires all nodes to have unique names. The Scene2Loader prefixes all child names by the parent name, so this is the case in any well-defined JSON file. If the key is already in use, this method will fail.

Parameters
keyThe key identifying the layout information
anchorThe anchor point to use
offsetThe offset from the anchor point
Returns
true if the layout information was assigned to that key

◆ alloc()

static std::shared_ptr<AnchoredLayout> cugl::scene2::AnchoredLayout::alloc ( )
inlinestatic

Returns a newly allocated layout manager.

The layout manager is initially empty. Before using it to perform a layout, layout information must be registered throught the add method interface.

Returns
a newly allocated layout manager.

◆ allocWithData()

static std::shared_ptr<AnchoredLayout> cugl::scene2::AnchoredLayout::allocWithData ( const std::shared_ptr< JsonValue > &  data)
inlinestatic

Returns a newly allocated layout manager with the given JSON specificaton.

The JSON specification format is simple. It only supports one (required) attribute: 'type'. The type should specify "anchored".

Parameters
dataThe JSON object specifying the node
Returns
a newly allocated layout manager with the given JSON specificaton.

◆ dispose()

virtual void cugl::scene2::AnchoredLayout::dispose ( )
inlineoverridevirtual

Deletes the layout resources and resets all attributes.

A disposed layout manager can be safely reinitialized.

Reimplemented from cugl::scene2::Layout.

◆ initWithData()

virtual bool cugl::scene2::AnchoredLayout::initWithData ( const std::shared_ptr< JsonValue > &  data)
inlineoverridevirtual

Initializes a new layout manager with the given JSON specificaton.

The JSON specification format is simple. It only supports one (required) attribute: 'type'. The type should specify "anchored".

Parameters
dataThe JSON object specifying the node
Returns
true if initialization was successful.

Reimplemented from cugl::scene2::Layout.

◆ layout()

virtual void cugl::scene2::AnchoredLayout::layout ( scene2::SceneNode node)
overridevirtual

Performs a layout on the given node.

This layout manager will searches for those children that are registered with it. For those children, it repositions and/or resizes them according to the layout information.

This manager attaches a child node to one of nine "anchors" in the parent (corners, sides or middle), together with a percentage (or absolute) offset. As the parent grows or shinks, the child will move according to its anchor. For example, nodes in the center will stay centered, while nodes on the left side will move to keep the appropriate distance from the left side. In fact, the stretching behavior is very similar to that of a NinePatch.

To look up the layout information of a scene graph node, this method uses the name of the node. This requires all nodes to have unique names. The Scene2Loader prefixes all child names by the parent name, so this is the case in any well-defined JSON file.

Children not registered with this layout manager are not affected.

Parameters
nodeThe scene graph node to rearrange

Reimplemented from cugl::scene2::Layout.

◆ remove()

virtual bool cugl::scene2::AnchoredLayout::remove ( const std::string  key)
overridevirtual

Removes the layout information for a given key.

To look up the layout information of a scene graph node, we use the name of the node. This requires all nodes to have unique names. The Scene2Loader prefixes all child names by the parent name, so this is the case in any well-defined JSON file.

If the key is not in use, this method will fail.

Parameters
keyThe key identifying the layout information
Returns
true if the layout information was removed for that key

Reimplemented from cugl::scene2::Layout.

Member Data Documentation

◆ _entries

std::unordered_map<std::string,Entry> cugl::scene2::AnchoredLayout::_entries
protected

The map of keys to layout information


The documentation for this class was generated from the following file: