CPLayoutSprite

org.cosplay.CPLayoutSprite

class CPLayoutSprite(id: String, spec: String, shaders: Seq[CPShader], tags: Set[String]) extends CPOffScreenSprite

This is an off-screen sprite that provides layout capabilities for other dynamic sprites. This sprite relies on provided layout specification that dictates how every sprite should be positioned in relation to the entire screen or other sprite.

Here are several important notes about how this sprite works:

This sprite only deals with the XY-position of sprites and does NOT deal with Z-index or the size of the sprite. In other words, it never resizes the sprite it is laying out and expects that all constituent sprites have their size correctly set in CPSceneObject.update method.
Only sprites that extend CPDynamicSprite can be using with this layout sprite.
This sprite perform the layout on each frame.
Laid out sprites can overlap.

Layout Specification

Layout specification is a string that consists of semi-colon separated commands. Each command starts with the sprite ID, followed by '=' character and a set of instructions for this sprite position.

Here's basic BNF form for the layout specification:

  layout: decls* EOF;
  decls
      : decl
      | decls decl
      ;
  decl: ID '='' items ';';
  items
      : item
      | items ','' item
      ;
  item
      : offItem
      | xItem
      | yItem
      ;
  offItem: 'off' ':'' '[' NUM '.' NUM ']';
  xItem: 'x' ':' ('same' | 'before' | 'left' | 'center' | 'right' | 'after') '(' ID? ')'';
  yItem: 'y' ':' ('same' | 'above' | 'top' | 'center' | 'bottom' | 'below') '(' ID? ')';

  NUM: '-'? [0-9] [0-9]*;
  ID: [a-zA-Z0-9-_$]+;

Here's an example of the layout specification (from CPLayoutExample):

// This is the main panel centered on the screen.
Panel-1 = x: center(), y: center();

// These panels are placed in the 4 corners of the panel 1.
Panel-2 = off: [1, 0], x: left(Panel-1), y: top(Panel-1);
Panel-3 = off: [-1, 0], x: right(Panel-1), y: top(Panel-1);
Panel-4 = off: [1, 0], x: left(Panel-1), y: bottom(Panel-1);
Panel-5 = off: [-1, 0], x: right(Panel-1), y: bottom(Panel-1);

// Panels 6 and 7 go after each other.
Panel-6 = x: after(Panel-2), y: below(Panel-2);
Panel-7 = x: after(Panel-6), y: same(Panel-6);

// Centered image with 2-row offset.
img = off: [0, 2], x: center(Panel-1), y: center(Panel-1);

Notes:

Each sprite is positioned by its top-left XY-coordinates.
Offsets can be negative and are applied to the top-left XY-coordinates of the sprite.
Default specification is 'off: [0,0], x: left(), y: top();'
C-style comments are allowed in any place in the specification.
'left', 'right', 'top' and 'bottom' are referring to a relative position inside of the referral.
'before', 'after', 'above', and 'below' are referring to a relative position outside of the referral.
'()' (empty brackets) refer to a entire scene screen as a referral "sprite".
Only sprites extending CPDynamicSprite can be used in layout specification. However, any scene object can act as a referral.
'center' provides centering for either X or Y-coordinates.
'same' allows to use the same X or Y-coordinates as a referral.
Use CPSpacerSprite to help fill up space in your layout.

UI Framework

Although CosPlay does not define an opinionated UI framework, several sprites and supporting classes are often used for constructing UI element on the screen. These include:

You can can also look at the following UI-related examples:

org.cosplay.examples.listbox.CPListBoxExample
org.cosplay.examples.dialog.CPDialogExample
org.cosplay.examples.layout.CPLayoutExample
org.cosplay.examples.textinput.CPTextInputExample

Value parameters

id: ID of this scene object.
shaders: Optional sequence of shaders for this sprite. Default value is an empty sequence.
spec: Layout specification as described above. Note that specification can be updated later using CPLayoutSprite.updateSpec method.
tags: Optional set of organizational or grouping tags. By default, the empty set is used.

Attributes

See also: CPDynamicSprite

CPSpacerSprite

CPLayoutExample
Example: See CPLayoutExample class for the example of using this sprite.
Source: CPLayoutSprite.scala
Graph
Supertypes: class CPOffScreenSprite

class CPSceneObject

trait CPLifecycle

class CPGameObject

class Object

trait Matchable

class Any
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Members list

Value members

Concrete methods

Called after all scene objects have been updated but before any of them were rendered. It allows, for example, to rearrange UI sprites on the screen after all of them had a chance to update their dimensions but before they are actually rendered on the screen. Essentially, it provides for "post-update, pre-render" notification. The order in which scene objects are called is undefined.

Note that in most cases one should not override this callback. It is only meant for the use cases when one needs to be notified when all scene objects to be updated but before any of them are rendered. Default implementation is no-op. No rendering should be done in this callback.

Default implementation is no-op.

Value parameters

ctx: Frame context. This context provides bulk of functionality that a scene object can do in a game, e.g. interact with other scene objects, check collisions, read input events and manage input focus, add or remove scene objects, add new and switch between scenes, etc.

Attributes

See also: render

update
Definition Classes: CPSceneObject
Source: CPLayoutSprite.scala

Updates the layout spec to given value. It will take an effect on the next frame.

Value parameters

spec: Layout specification.

Attributes

Source: CPLayoutSprite.scala

Inherited methods

Compares the receiver object (this) with the argument object (that) for equivalence.

Any implementation of this method should be an equivalence relation:

It is reflexive: for any instance x of type Any, x.equals(x) should return true.
It is symmetric: for any instances x and y of type Any, x.equals(y) should return true if and only if y.equals(x) returns true.
It is transitive: for any instances x, y, and z of type Any if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.

If you override this method, you should verify that your implementation remains an equivalence relation. Additionally, when overriding this method it is usually necessary to override hashCode to ensure that objects which are "equal" (o1.equals(o2) returns true) hash to the same scala.Int. (o1.hashCode.equals(o2.hashCode)).

Value parameters

that: the object to compare against this object for equality.

Attributes

Returns: true if the receiver object is equivalent to the argument; false otherwise.
Definition Classes: CPGameObject -> Any
Inherited from:: CPGameObject
Source: CPGameObject.scala

Gets optional collision shape or hit box for this sprite.

Attributes

Returns: Optional collision shape, None if this sprite does not support collisions.
See also: CPSceneObjectContext.collisions
Inherited from:: CPSceneObject
Source: CPSceneObject.scala

Gets current dimension (width and height) of this object.

Attributes

Definition Classes: CPOffScreenSprite -> CPSceneObject
Inherited from:: CPOffScreenSprite
Source: CPOffScreenSprite.scala

Gets current height of this object.

Attributes

See also: getWidth

getDim
Inherited from:: CPSceneObject
Source: CPSceneObject.scala

Gets unique ID of this game object.

Attributes

Inherited from:: CPGameObject
Source: CPGameObject.scala

Gets rectangular shape of this sprite. It is basically a combination of its top-left corner XY-coordinate and sprite's dimension.

Attributes

Definition Classes: CPOffScreenSprite -> CPSceneObject
Inherited from:: CPOffScreenSprite
Source: CPOffScreenSprite.scala

Gets the optional list of shaders attached to this scene object. By default, returns an empty list. Note that shaders are called regardless of whether the object visible, in camera frame or invisible.

Attributes

Definition Classes: CPOffScreenSprite -> CPSceneObject
Inherited from:: CPOffScreenSprite
Source: CPOffScreenSprite.scala

Gets current lifecycle state.

Attributes

Inherited from:: CPLifecycle
Source: CPLifecycle.scala

Gets optional set of organizational tags. Note that by default the set of tags is empty.

Attributes

See also: CPSceneObjectContext.getObjectsForTags
Inherited from:: CPGameObject
Source: CPGameObject.scala

Gets current width of this object.

Attributes

See also: getHeight

getDim
Inherited from:: CPSceneObject
Source: CPSceneObject.scala

Gets current X-coordinate of this object within dimensions of its scene. Note that returned value is allowed to be outside scene's dimension (e.g. negative value). In such cases, the clipping of the scene rendering will result in showing only portion or none of the object.

Attributes

Definition Classes: CPOffScreenSprite -> CPSceneObject
Inherited from:: CPOffScreenSprite
Source: CPOffScreenSprite.scala

Gets last X-coordinate which is

getX + getWidth - 1

. Note the value when the width is zero.

Attributes

Returns: Last X-coordinate for this sprite.
Inherited from:: CPSceneObject
Source: CPSceneObject.scala

Gets current Y-coordinate of this object within dimensions of its scene. Note that returned value is allowed to be outside scene's dimension (e.g. negative value). In such cases, the clipping of the scene rendering will result in showing only portion or none of the object.

Attributes

Definition Classes: CPOffScreenSprite -> CPSceneObject
Inherited from:: CPOffScreenSprite
Source: CPOffScreenSprite.scala

Gets last Y-coordinate which is

getY + getHeight - 1

. Note the value when the height is zero.

Attributes

Returns: Last Y-coordinate for this sprite.
Inherited from:: CPSceneObject
Source: CPSceneObject.scala

Gets Z-index or order to use in rendering of this object. A pixel with higher Z-index visually overrides the overlapping pixel in the same XY-coordinate with equal or smaller Z-index.

Attributes

Definition Classes: CPOffScreenSprite -> CPSceneObject
Inherited from:: CPOffScreenSprite
Source: CPOffScreenSprite.scala

Shortcut method for hiding this object. Note that by default all scene objects are visible. Note also that this change happens immediately in the same frame. If you want this to happen in the next frame only you need to use CPSceneObjectContext.runNextFrame.

Attributes

See also: setVisible

CPSceneObjectContext.runNextFrame

CPSceneObjectContext.runLater
Inherited from:: CPSceneObject
Source: CPSceneObject.scala

Checks the visibility flag.

If object is invisible than only update method will be called on each frame. If object is visible and in camera frame - method render will be called as well to render itself. Note that shaders are called regardless of whether the object visible, in camera frame or invisible.

Attributes

See also: show

hide

setVisible
Inherited from:: CPSceneObject
Source: CPSceneObject.scala

Callback on lifecycle object activation. Default implementation is no-op.

Attributes

See also: CPLifecycle.State.LF_ACTIVE
Inherited from:: CPLifecycle
Source: CPLifecycle.scala

Callback on lifecycle object deactivation. Default implementation is no-op.

Attributes

See also: CPLifecycle.State.LF_INACTIVE
Inherited from:: CPLifecycle
Source: CPLifecycle.scala

Callback on lifecycle object start. Default implementation is no-op.

Attributes

See also: CPLifecycle.State.LF_STARTED
Inherited from:: CPLifecycle
Source: CPLifecycle.scala

Callback on lifecycle object stop. Default implementation is no-op.

Attributes

See also: CPLifecycle.State.LF_STOPPED
Inherited from:: CPLifecycle
Source: CPLifecycle.scala

Called to render this scene object. Only visible and in camera frame objects will receive this callback. This callback is called on scene object after all scene objects received update and monitor callbacks. Note that unlike update and monitor callbacks and shaders that are called for all scene objects on each frame, this callback is only called for scene objects that are visible and, at least partially, in camera frame. The order in which scene objects are called is undefined.

Note that generally this callback should not modify scene object state (which should be done in either update or monitor callbacks.

Default implementation is no-op.

Value parameters

ctx: Frame context. This context provides bulk of functionality that a scene object can do in a game, e.g. interact with other scene objects, check collisions, read input events and manage input focus, add or remove scene objects, add new and switch between scenes, etc.

Attributes

See also: update

monitor

isVisible
Inherited from:: CPSceneObject
Source: CPSceneObject.scala

Sets visibility flag. Note that by default all scene objects are visible. Note also that this change happens immediately in the same frame. If you want this to happen in the next frame only you need to use CPSceneObjectContext.runNextFrame.

Value parameters

vis: true to make this object visible, false otherwise.

Attributes

See also: show

hide

CPSceneObjectContext.runNextFrame

CPSceneObjectContext.runLater
Inherited from:: CPSceneObject
Source: CPSceneObject.scala

Shortcut method for showing this object. Note that by default all scene objects are visible. Note also that this change happens immediately in the same frame. If you want this to happen in the next frame only you need to use CPSceneObjectContext.runNextFrame.

Attributes

See also: setVisible

CPSceneObjectContext.runNextFrame

CPSceneObjectContext.runLater
Inherited from:: CPSceneObject
Source: CPSceneObject.scala

Called to update the internal state of this scene object. This callback is called each frame on every object in the scene and it is called before any render callback. Note that all scene object will receive this callback before first render callback. The order in which scene objects are called is undefined.

Default implementation is no-op. No rendering should be done in this callback.

Value parameters

ctx: Frame context. This context provides bulk of functionality that a scene object can do in a game, e.g. interact with other scene objects, check collisions, read input events and manage input focus, add or remove scene objects, add new and switch between scenes, etc.

Attributes

See also: render

monitor

isVisible
Inherited from:: CPSceneObject
Source: CPSceneObject.scala

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