# Helper

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/widgets/Helper.java+class:androidx.constraintlayout.core.widgets.Helper) Added in [1.1.2](https://developer.android.com/jetpack/androidx/releases/constraintlayout#1.1.2)

*** ** * ** ***


```
public interface Helper
```

<br />

Known direct subclasses [HelperWidget](https://developer.android.com/reference/androidx/constraintlayout/core/widgets/HelperWidget)

|---|---|
| `https://developer.android.com/reference/androidx/constraintlayout/core/widgets/HelperWidget` | HelperWidget class |

Known indirect subclasses [Barrier](https://developer.android.com/reference/androidx/constraintlayout/core/widgets/Barrier), [Flow](https://developer.android.com/reference/androidx/constraintlayout/core/widgets/Flow), [GridCore](https://developer.android.com/reference/androidx/constraintlayout/core/utils/GridCore), [Placeholder](https://developer.android.com/reference/androidx/constraintlayout/core/widgets/Placeholder), [VirtualLayout](https://developer.android.com/reference/androidx/constraintlayout/core/widgets/VirtualLayout)

|---|---|
| `https://developer.android.com/reference/androidx/constraintlayout/core/widgets/Barrier` | A Barrier takes multiple widgets |
| `https://developer.android.com/reference/androidx/constraintlayout/core/widgets/Flow` | Implements the Flow virtual layout. |
| `https://developer.android.com/reference/androidx/constraintlayout/core/utils/GridCore` | The Grid Helper in the Core library that helps to enable Grid in Compose |
| `https://developer.android.com/reference/androidx/constraintlayout/core/widgets/Placeholder` | Simple VirtualLayout that center the first referenced widget onto itself. |
| `https://developer.android.com/reference/androidx/constraintlayout/core/widgets/VirtualLayout` | Base class for Virtual layouts |

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interface to virtual objects

## Summary

| ### Public methods |
|---|---|
| `abstract void` | `https://developer.android.com/reference/androidx/constraintlayout/core/widgets/Helper#add(androidx.constraintlayout.core.widgets.ConstraintWidget)(https://developer.android.com/reference/androidx/constraintlayout/core/widgets/ConstraintWidget widget)` |
| `abstract void` | `https://developer.android.com/reference/androidx/constraintlayout/core/widgets/Helper#removeAllIds()()` |
| `abstract void` | `https://developer.android.com/reference/androidx/constraintlayout/core/widgets/Helper#updateConstraints(androidx.constraintlayout.core.widgets.ConstraintWidgetContainer)(https://developer.android.com/reference/androidx/constraintlayout/core/widgets/ConstraintWidgetContainer container)` |

## Public methods

### add

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

```
abstract void add(ConstraintWidget widget)
```

### removeAllIds

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

```
abstract void removeAllIds()
```

### updateConstraints

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

```
abstract void updateConstraints(ConstraintWidgetContainer container)
```