Android APIs
public class

PathInterpolator

extends Object
implements Interpolator
java.lang.Object
   ↳ android.view.animation.PathInterpolator

Class Overview

An interpolator that can traverse a Path that extends from Point (0, 0) to (1, 1). The x coordinate along the Path is the input value and the output is the y coordinate of the line at that point. This means that the Path must conform to a function y = f(x).

The Path must not have gaps in the x direction and must not loop back on itself such that there can be two points sharing the same x coordinate. It is alright to have a disjoint line in the vertical direction:

     Path path = new Path();
     path.lineTo(0.25f, 0.25f);
     path.moveTo(0.25f, 0.5f);
     path.lineTo(1f, 1f);

Summary

Public Constructors
PathInterpolator(Path path)
Create an interpolator for an arbitrary Path.
PathInterpolator(float controlX, float controlY)
Create an interpolator for a quadratic Bezier curve.
PathInterpolator(float controlX1, float controlY1, float controlX2, float controlY2)
Create an interpolator for a cubic Bezier curve.
PathInterpolator(Context context, AttributeSet attrs)
Public Methods
float getInterpolation(float t)
Using the line in the Path in this interpolator that can be described as y = f(x), finds the y coordinate of the line given t as the x coordinate.
[Expand]
Inherited Methods
From class java.lang.Object
From interface android.animation.TimeInterpolator

Public Constructors

public PathInterpolator (Path path)

Create an interpolator for an arbitrary Path. The Path must begin at (0, 0) and end at (1, 1).

Parameters
path The Path to use to make the line representing the interpolator.

public PathInterpolator (float controlX, float controlY)

Create an interpolator for a quadratic Bezier curve. The end points (0, 0) and (1, 1) are assumed.

Parameters
controlX The x coordinate of the quadratic Bezier control point.
controlY The y coordinate of the quadratic Bezier control point.

public PathInterpolator (float controlX1, float controlY1, float controlX2, float controlY2)

Create an interpolator for a cubic Bezier curve. The end points (0, 0) and (1, 1) are assumed.

Parameters
controlX1 The x coordinate of the first control point of the cubic Bezier.
controlY1 The y coordinate of the first control point of the cubic Bezier.
controlX2 The x coordinate of the second control point of the cubic Bezier.
controlY2 The y coordinate of the second control point of the cubic Bezier.

public PathInterpolator (Context context, AttributeSet attrs)

Public Methods

public float getInterpolation (float t)

Using the line in the Path in this interpolator that can be described as y = f(x), finds the y coordinate of the line given t as the x coordinate. Values less than 0 will always return 0 and values greater than 1 will always return 1.

Parameters
t Treated as the x coordinate along the line.
Returns
  • The y coordinate of the Path along the line where x = t.
See Also