ArcMotion

public class ArcMotion
extends PathMotion

java.lang.Object
   ↳ androidx.transition.PathMotion
     ↳ androidx.transition.ArcMotion


A PathMotion that generates a curved path along an arc on an imaginary circle containing the two points. If the horizontal distance between the points is less than the vertical distance, then the circle's center point will be horizontally aligned with the end point. If the vertical distance is less than the horizontal distance then the circle's center point will be vertically aligned with the end point.

When the two points are near horizontal or vertical, the curve of the motion will be small as the center of the circle will be far from both points. To force curvature of the path, setMinimumHorizontalAngle(float) and setMinimumVerticalAngle(float) may be used to set the minimum angle of the arc between two points.

This may be used in XML as an element inside a transition.

<changeBounds>
   <arcMotion android:minimumHorizontalAngle="15"
              android:minimumVerticalAngle="0"
              android:maximumAngle="90"/>
 </changeBounds>
 

Summary

Public constructors

ArcMotion()
ArcMotion(Context context, AttributeSet attrs)

Public methods

float getMaximumAngle()

Returns the maximum arc along the circle between two points.

float getMinimumHorizontalAngle()

Returns the minimum arc along the circle between two points aligned near horizontally.

float getMinimumVerticalAngle()

Returns the minimum arc along the circle between two points aligned near vertically.

Path getPath(float startX, float startY, float endX, float endY)

Provide a Path to interpolate between two points (startX, startY) and (endX, endY).

void setMaximumAngle(float angleInDegrees)

Sets the maximum arc along the circle between two points.

void setMinimumHorizontalAngle(float angleInDegrees)

Sets the minimum arc along the circle between two points aligned near horizontally.

void setMinimumVerticalAngle(float angleInDegrees)

Sets the minimum arc along the circle between two points aligned near vertically.

Inherited methods

Public constructors

ArcMotion

public ArcMotion ()

ArcMotion

public ArcMotion (Context context, 
                AttributeSet attrs)

Parameters
context Context

attrs AttributeSet

Public methods

getMaximumAngle

public float getMaximumAngle ()

Returns the maximum arc along the circle between two points. When start and end points have close to equal x and y differences, the curve between them is large. This forces the curved path to have an arc of at most the given angle.

The default value is 70 degrees.

Returns
float The maximum angle of the arc on a circle describing the Path between the start and end points.

getMinimumHorizontalAngle

public float getMinimumHorizontalAngle ()

Returns the minimum arc along the circle between two points aligned near horizontally. When start and end points are close to horizontal, the calculated center point of the circle will be far from both points, giving a near straight path between the points. By setting a minimum angle, this forces the center point to be closer and give an exaggerated curve to the path.

The default value is 0.

Returns
float The minimum arc along the circle between two points aligned near horizontally.

getMinimumVerticalAngle

public float getMinimumVerticalAngle ()

Returns the minimum arc along the circle between two points aligned near vertically. When start and end points are close to vertical, the calculated center point of the circle will be far from both points, giving a near straight path between the points. By setting a minimum angle, this forces the center point to be closer and give an exaggerated curve to the path.

The default value is 0.

Returns
float The minimum angle of the arc on a circle describing the Path between two nearly vertically-separated points.

getPath

public Path getPath (float startX, 
                float startY, 
                float endX, 
                float endY)

Provide a Path to interpolate between two points (startX, startY) and (endX, endY). This allows controlled curved motion along two dimensions.

Parameters
startX float: The x coordinate of the starting point.

startY float: The y coordinate of the starting point.

endX float: The x coordinate of the ending point.

endY float: The y coordinate of the ending point.

Returns
Path A Path along which the points should be interpolated. The returned Path must start at point (startX, startY), typically using Path.moveTo(float, float) and end at (endX, endY).

setMaximumAngle

public void setMaximumAngle (float angleInDegrees)

Sets the maximum arc along the circle between two points. When start and end points have close to equal x and y differences, the curve between them is large. This forces the curved path to have an arc of at most the given angle.

The default value is 70 degrees.

Parameters
angleInDegrees float: The maximum angle of the arc on a circle describing the Path between the start and end points.

setMinimumHorizontalAngle

public void setMinimumHorizontalAngle (float angleInDegrees)

Sets the minimum arc along the circle between two points aligned near horizontally. When start and end points are close to horizontal, the calculated center point of the circle will be far from both points, giving a near straight path between the points. By setting a minimum angle, this forces the center point to be closer and give an exaggerated curve to the path.

The default value is 0.

Parameters
angleInDegrees float: The minimum angle of the arc on a circle describing the Path between two nearly horizontally-separated points.

setMinimumVerticalAngle

public void setMinimumVerticalAngle (float angleInDegrees)

Sets the minimum arc along the circle between two points aligned near vertically. When start and end points are close to vertical, the calculated center point of the circle will be far from both points, giving a near straight path between the points. By setting a minimum angle, this forces the center point to be closer and give an exaggerated curve to the path.

The default value is 0.

Parameters
angleInDegrees float: The minimum angle of the arc on a circle describing the Path between two nearly vertically-separated points.