# MotionKey

Artifact: [androidx.constraintlayout:constraintlayout-core](https://developer.android.com/jetpack/androidx/releases/constraintlayout) [View Source](https://cs.android.com/search?q=file:androidx/constraintlayout/core/motion/key/MotionKey.java+class:androidx.constraintlayout.core.motion.key.MotionKey) Added in [1.1.2](https://developer.android.com/jetpack/androidx/releases/constraintlayout#1.1.2)

*** ** * ** ***


```
public abstract class MotionKey implements TypedValues
```

<br />

Known direct subclasses [MotionKeyAttributes](https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKeyAttributes), [MotionKeyCycle](https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKeyCycle), [MotionKeyPosition](https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKeyPosition), [MotionKeyTimeCycle](https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKeyTimeCycle), [MotionKeyTrigger](https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKeyTrigger)

|---|---|
| `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKeyAttributes` |   |
| `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKeyCycle` |   |
| `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKeyPosition` |   |
| `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKeyTimeCycle` |   |
| `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKeyTrigger` |   |

*** ** * ** ***

Base class in an element in a KeyFrame

## Summary

| ### Constants |
|---|---|
| `static final https://developer.android.com/reference/java/lang/String.html` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey#ALPHA() = "alpha"` |
| `static final https://developer.android.com/reference/java/lang/String.html` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey#CUSTOM() = "CUSTOM"` |
| `static final https://developer.android.com/reference/java/lang/String.html` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey#ELEVATION() = "elevation"` |
| `static final https://developer.android.com/reference/java/lang/String.html` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey#ROTATION() = "rotationZ"` |
| `static final https://developer.android.com/reference/java/lang/String.html` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey#ROTATION_X() = "rotationX"` |
| `static final https://developer.android.com/reference/java/lang/String.html` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey#SCALE_X() = "scaleX"` |
| `static final https://developer.android.com/reference/java/lang/String.html` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey#SCALE_Y() = "scaleY"` |
| `static final https://developer.android.com/reference/java/lang/String.html` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey#TRANSITION_PATH_ROTATE() = "transitionPathRotate"` |
| `static final https://developer.android.com/reference/java/lang/String.html` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey#TRANSLATION_X() = "translationX"` |
| `static final https://developer.android.com/reference/java/lang/String.html` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey#TRANSLATION_Y() = "translationY"` |
| `static final https://developer.android.com/reference/java/lang/String.html` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey#VISIBILITY() = "visibility"` |

| ### Public fields |
|---|---|
| `static int` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey#UNSET()` |
| `https://developer.android.com/reference/java/util/HashMap.html<https://developer.android.com/reference/java/lang/String.html, https://developer.android.com/reference/androidx/constraintlayout/core/motion/CustomVariable>` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey#mCustom()` |
| `int` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey#mFramePosition()` |
| `int` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey#mType()` |

| ### Public constructors |
|---|
| `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey#MotionKey()()` |

| ### Public methods |
|---|---|
| `abstract void` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey#addValues(java.util.HashMap<java.lang.String,androidx.constraintlayout.core.motion.utils.SplineSet>)(https://developer.android.com/reference/java/util/HashMap.html<https://developer.android.com/reference/java/lang/String.html, https://developer.android.com/reference/androidx/constraintlayout/core/motion/utils/SplineSet> splines)` Defines method to add a a view to splines derived form this key frame. |
| `abstract https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey#clone()()` |
| `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey#copy(androidx.constraintlayout.core.motion.key.MotionKey)(https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey src)` |
| `abstract void` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey#getAttributeNames(java.util.HashSet<java.lang.String>)(https://developer.android.com/reference/java/util/HashSet.html<https://developer.android.com/reference/java/lang/String.html> attributes)` |
| `int` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey#getFramePosition()()` Gets the current frame position |
| `void` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey#setCustomAttribute(java.lang.String,int,boolean)(https://developer.android.com/reference/java/lang/String.html name, int type, boolean value)` |
| `void` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey#setCustomAttribute(java.lang.String,int,float)(https://developer.android.com/reference/java/lang/String.html name, int type, float value)` |
| `void` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey#setCustomAttribute(java.lang.String,int,int)(https://developer.android.com/reference/java/lang/String.html name, int type, int value)` |
| `void` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey#setCustomAttribute(java.lang.String,int,java.lang.String)(https://developer.android.com/reference/java/lang/String.html name, int type, https://developer.android.com/reference/java/lang/String.html value)` |
| `void` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey#setFramePosition(int)(int pos)` sets the frame position |
| `void` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey#setInterpolation(java.util.HashMap<java.lang.String,java.lang.Integer>)(https://developer.android.com/reference/java/util/HashMap.html<https://developer.android.com/reference/java/lang/String.html, https://developer.android.com/reference/java/lang/Integer.html> interpolation)` Key frame can specify the type of interpolation it wants on various attributes For each string it set it to -1, CurveFit.LINEAR or CurveFit.SPLINE |
| `boolean` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey#setValue(int,boolean)(int type, boolean value)` Used to set boolean values |
| `boolean` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey#setValue(int,float)(int type, float value)` Used to set float values |
| `boolean` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey#setValue(int,int)(int type, int value)` Used to set integer values |
| `boolean` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey#setValue(int,java.lang.String)(int type, https://developer.android.com/reference/java/lang/String.html value)` Used to set String values |
| `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/key/MotionKey#setViewId(int)(int id)` |

| ### Inherited Constants |
|---|
| From [androidx.constraintlayout.core.motion.utils.TypedValues](https://developer.android.com/reference/androidx/constraintlayout/core/motion/utils/TypedValues) |---|---| | `static final int` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/utils/TypedValues#BOOLEAN_MASK() = 1` | | `static final int` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/utils/TypedValues#FLOAT_MASK() = 4` | | `static final int` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/utils/TypedValues#INT_MASK() = 2` | | `static final int` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/utils/TypedValues#STRING_MASK() = 8` | | `static final https://developer.android.com/reference/java/lang/String.html` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/utils/TypedValues#S_CUSTOM() = "CUSTOM"` | | `static final int` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/utils/TypedValues#TYPE_FRAME_POSITION() = 100` | | `static final int` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/utils/TypedValues#TYPE_TARGET() = 101` | |

| ### Inherited methods |
|---|
| From [androidx.constraintlayout.core.motion.utils.TypedValues](https://developer.android.com/reference/androidx/constraintlayout/core/motion/utils/TypedValues) |---|---| | `abstract int` | `https://developer.android.com/reference/androidx/constraintlayout/core/motion/utils/TypedValues#getId(java.lang.String)(https://developer.android.com/reference/java/lang/String.html name)` | |

## Constants

### ALPHA

Added in [1.1.2](https://developer.android.com/jetpack/androidx/releases/constraintlayout#1.1.2)

```
public static final String ALPHA = "alpha"
```

### CUSTOM

Added in [1.1.2](https://developer.android.com/jetpack/androidx/releases/constraintlayout#1.1.2)

```
public static final String CUSTOM = "CUSTOM"
```

### ELEVATION

Added in [1.1.2](https://developer.android.com/jetpack/androidx/releases/constraintlayout#1.1.2)

```
public static final String ELEVATION = "elevation"
```

### ROTATION

Added in [1.1.2](https://developer.android.com/jetpack/androidx/releases/constraintlayout#1.1.2)

```
public static final String ROTATION = "rotationZ"
```

### ROTATION_X

Added in [1.1.2](https://developer.android.com/jetpack/androidx/releases/constraintlayout#1.1.2)

```
public static final String ROTATION_X = "rotationX"
```

### SCALE_X

Added in [1.1.2](https://developer.android.com/jetpack/androidx/releases/constraintlayout#1.1.2)

```
public static final String SCALE_X = "scaleX"
```

### SCALE_Y

Added in [1.1.2](https://developer.android.com/jetpack/androidx/releases/constraintlayout#1.1.2)

```
public static final String SCALE_Y = "scaleY"
```

### TRANSITION_PATH_ROTATE

Added in [1.1.2](https://developer.android.com/jetpack/androidx/releases/constraintlayout#1.1.2)

```
public static final String TRANSITION_PATH_ROTATE = "transitionPathRotate"
```

### TRANSLATION_X

Added in [1.1.2](https://developer.android.com/jetpack/androidx/releases/constraintlayout#1.1.2)

```
public static final String TRANSLATION_X = "translationX"
```

### TRANSLATION_Y

Added in [1.1.2](https://developer.android.com/jetpack/androidx/releases/constraintlayout#1.1.2)

```
public static final String TRANSLATION_Y = "translationY"
```

### VISIBILITY

Added in [1.1.2](https://developer.android.com/jetpack/androidx/releases/constraintlayout#1.1.2)

```
public static final String VISIBILITY = "visibility"
```

## Public fields

### UNSET

Added in [1.1.2](https://developer.android.com/jetpack/androidx/releases/constraintlayout#1.1.2)

```
public static int UNSET
```

### mCustom

Added in [1.1.2](https://developer.android.com/jetpack/androidx/releases/constraintlayout#1.1.2)

```
public HashMap<String, CustomVariable> mCustom
```

### mFramePosition

Added in [1.1.2](https://developer.android.com/jetpack/androidx/releases/constraintlayout#1.1.2)

```
public int mFramePosition
```

### mType

Added in [1.1.2](https://developer.android.com/jetpack/androidx/releases/constraintlayout#1.1.2)

```
public int mType
```

## Public constructors

### MotionKey

Added in 1.1.2

```
public MotionKey()
```

## Public methods

### addValues

Added in [1.1.2](https://developer.android.com/jetpack/androidx/releases/constraintlayout#1.1.2)

```
public abstract void addValues(HashMap<String, SplineSet> splines)
```

Defines method to add a a view to splines derived form this key frame. The values are written to the spline

| Parameters |
|---|---|
| `https://developer.android.com/reference/java/util/HashMap.html<https://developer.android.com/reference/java/lang/String.html, https://developer.android.com/reference/androidx/constraintlayout/core/motion/utils/SplineSet> splines` | splines to write values to |

### clone

Added in [1.1.2](https://developer.android.com/jetpack/androidx/releases/constraintlayout#1.1.2)

```
public abstract MotionKey clone()
```

### copy

Added in [1.1.2](https://developer.android.com/jetpack/androidx/releases/constraintlayout#1.1.2)

```
public MotionKey copy(MotionKey src)
```

### getAttributeNames

Added in [1.1.2](https://developer.android.com/jetpack/androidx/releases/constraintlayout#1.1.2)

```
public abstract void getAttributeNames(HashSet<String> attributes)
```

### getFramePosition

Added in [1.1.2](https://developer.android.com/jetpack/androidx/releases/constraintlayout#1.1.2)

```
public int getFramePosition()
```

Gets the current frame position

### setCustomAttribute

Added in [1.1.2](https://developer.android.com/jetpack/androidx/releases/constraintlayout#1.1.2)

```
public void setCustomAttribute(String name, int type, boolean value)
```

### setCustomAttribute

Added in [1.1.2](https://developer.android.com/jetpack/androidx/releases/constraintlayout#1.1.2)

```
public void setCustomAttribute(String name, int type, float value)
```

### setCustomAttribute

Added in [1.1.2](https://developer.android.com/jetpack/androidx/releases/constraintlayout#1.1.2)

```
public void setCustomAttribute(String name, int type, int value)
```

### setCustomAttribute

Added in [1.1.2](https://developer.android.com/jetpack/androidx/releases/constraintlayout#1.1.2)

```
public void setCustomAttribute(String name, int type, String value)
```

### setFramePosition

Added in [1.1.2](https://developer.android.com/jetpack/androidx/releases/constraintlayout#1.1.2)

```
public void setFramePosition(int pos)
```

sets the frame position

### setInterpolation

Added in [1.1.2](https://developer.android.com/jetpack/androidx/releases/constraintlayout#1.1.2)

```
public void setInterpolation(HashMap<String, Integer> interpolation)
```

Key frame can specify the type of interpolation it wants on various attributes For each string it set it to -1, CurveFit.LINEAR or CurveFit.SPLINE

### setValue

Added in [1.1.2](https://developer.android.com/jetpack/androidx/releases/constraintlayout#1.1.2)

```
public boolean setValue(int type, boolean value)
```

Used to set boolean values

| Returns |
|---|---|
| `boolean` | true if it accepted the value |

### setValue

Added in [1.1.2](https://developer.android.com/jetpack/androidx/releases/constraintlayout#1.1.2)

```
public boolean setValue(int type, float value)
```

Used to set float values

| Returns |
|---|---|
| `boolean` | true if it accepted the value |

### setValue

Added in [1.1.2](https://developer.android.com/jetpack/androidx/releases/constraintlayout#1.1.2)

```
public boolean setValue(int type, int value)
```

Used to set integer values

| Returns |
|---|---|
| `boolean` | true if it accepted the value |

### setValue

Added in [1.1.2](https://developer.android.com/jetpack/androidx/releases/constraintlayout#1.1.2)

```
public boolean setValue(int type, String value)
```

Used to set String values

| Returns |
|---|---|
| `boolean` | true if it accepted the value |

### setViewId

Added in [1.1.2](https://developer.android.com/jetpack/androidx/releases/constraintlayout#1.1.2)

```
public MotionKey setViewId(int id)
```