Shape


public abstract class Shape
extends Object implements Cloneable

java.lang.Object
   ↳ android.graphics.drawable.shapes.Shape


Defines a generic graphical "shape."

Any Shape can be drawn to a Canvas with its own draw() method, but more graphical control is available if you instead pass it to a ShapeDrawable.

Custom Shape classes must implement clone() and return an instance of the custom Shape class.

Summary

Public constructors

Shape()

Public methods

Shape clone()

Creates and returns a copy of this object.

abstract void draw(Canvas canvas, Paint paint)

Draws this shape into the provided Canvas, with the provided Paint.

boolean equals(Object o)

Indicates whether some other object is "equal to" this one.

final float getHeight()

Returns the height of the Shape.

void getOutline(Outline outline)

Computes the Outline of the shape and return it in the supplied Outline parameter.

final float getWidth()

Returns the width of the Shape.

boolean hasAlpha()

Checks whether the Shape is opaque.

int hashCode()

Returns a hash code value for the object.

final void resize(float width, float height)

Resizes the dimensions of this shape.

Protected methods

void onResize(float width, float height)

Callback method called when resize(float, float) is executed.

Inherited methods

Public constructors

Shape

public Shape ()

Public methods

clone

Added in API level 1
public Shape clone ()

Creates and returns a copy of this object. The precise meaning of "copy" may depend on the class of the object. The general intent is that, for any object x, the expression:

 x.clone() != x
will be true, and that the expression:
 x.clone().getClass() == x.getClass()
will be true, but these are not absolute requirements. While it is typically the case that:
 x.clone().equals(x)
will be true, this is not an absolute requirement.

By convention, the returned object should be obtained by calling super.clone. If a class and all of its superclasses (except Object) obey this convention, it will be the case that x.clone().getClass() == x.getClass().

By convention, the object returned by this method should be independent of this object (which is being cloned). To achieve this independence, it may be necessary to modify one or more fields of the object returned by super.clone before returning it. Typically, this means copying any mutable objects that comprise the internal "deep structure" of the object being cloned and replacing the references to these objects with references to the copies. If a class contains only primitive fields or references to immutable objects, then it is usually the case that no fields in the object returned by super.clone need to be modified.

Returns
Shape a clone of this instance.

Throws
CloneNotSupportedException

draw

Added in API level 1
public abstract void draw (Canvas canvas, 
                Paint paint)

Draws this shape into the provided Canvas, with the provided Paint.

Before calling this, you must call resize(float, float).

Parameters
canvas Canvas: the Canvas within which this shape should be drawn

paint Paint: the Paint object that defines this shape's characteristics

equals

Added in API level 1
public boolean equals (Object o)

Indicates whether some other object is "equal to" this one.

The equals method implements an equivalence relation on non-null object references:

  • It is reflexive: for any non-null reference value x, x.equals(x) should return true.
  • It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
  • It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
  • It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.
  • For any non-null reference value x, x.equals(null) should return false.

An equivalence relation partitions the elements it operates on into equivalence classes; all the members of an equivalence class are equal to each other. Members of an equivalence class are substitutable for each other, at least for some purposes.

Parameters
o Object: the reference object with which to compare.

Returns
boolean true if this object is the same as the obj argument; false otherwise.

getHeight

Added in API level 1
public final float getHeight ()

Returns the height of the Shape.

Returns
float

getOutline

Added in API level 21
public void getOutline (Outline outline)

Computes the Outline of the shape and return it in the supplied Outline parameter. The default implementation does nothing and outline is not changed.

Parameters
outline Outline: the Outline to be populated with the result. Must be non-null.

getWidth

Added in API level 1
public final float getWidth ()

Returns the width of the Shape.

Returns
float

hasAlpha

Added in API level 1
public boolean hasAlpha ()

Checks whether the Shape is opaque.

Default impl returns true. Override if your subclass can be opaque.

Returns
boolean true if any part of the drawable is not opaque.

hashCode

Added in API level 1
public int hashCode ()

Returns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided by HashMap.

The general contract of hashCode is:

  • Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
  • If two objects are equal according to the equals method, then calling the hashCode method on each of the two objects must produce the same integer result.
  • It is not required that if two objects are unequal according to the equals method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.

Returns
int a hash code value for this object.

resize

Added in API level 1
public final void resize (float width, 
                float height)

Resizes the dimensions of this shape.

Must be called before draw(android.graphics.Canvas, android.graphics.Paint).

Parameters
width float: the width of the shape (in pixels)

height float: the height of the shape (in pixels)

Protected methods

onResize

Added in API level 1
protected void onResize (float width, 
                float height)

Callback method called when resize(float, float) is executed.

Parameters
width float: the new width of the Shape

height float: the new height of the Shape