public abstract class ConstraintHelper extends View

Known direct subclasses
Barrier

Added in 1.1

Group

Control the visibility and elevation of the referenced views Added in 1.1

Layer

Layer adds the ability to move and rotate a group of views as if they were contained in a viewGroup Added in 2.0 Methods such as setRotation(float) rotate all views about a common center.

MotionHelper
VirtualLayout

Added in 2.0

Known indirect subclasses
Carousel

Carousel works within a MotionLayout to provide a simple recycler like pattern.

CircularFlow

CircularFlow virtual layout.

Flow

Flow VirtualLayout.

Grid

A helper class that helps arrange widgets in a grid form

MotionEffect

MotionHelper that automatically inserts keyframes for views moving in a given direction, out of:

MotionPlaceholder

Added in 1.1

This class manages a set of referenced widgets. HelperWidget objects can be created to act upon the set of referenced widgets. The difference between ConstraintHelper and ViewGroup is that multiple ConstraintHelper can reference the same widgets.

Widgets are referenced by being added to a comma separated list of ids, e.g.:

        <androidx.constraintlayout.widget.Barrier
             android:id="@+id/barrier"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             app:barrierDirection="start"
             app:constraint_referenced_ids="button1,button2" />
    

Summary

Constants

static final String
CHILD_TAG = "CONSTRAINT_LAYOUT_HELPER_CHILD"

Public constructors

ConstraintHelper(Context context, AttributeSet attrs, int defStyleAttr)

Public methods

void
addView(View view)

Add a view to the helper.

void

hook for helpers to apply parameters in MotionLayout

boolean
containsId(int id)

does id table contain the id

int[]

Helpers typically reference a collection of ids

int
indexFromId(int id)

find the position of an id

static boolean
void
loadParameters(
    ConstraintSet.Constraint constraint,
    HelperWidget child,
    ConstraintLayout.LayoutParams layoutParams,
    SparseArray<ConstraintWidget> mapIdToWidget
)

Load the parameters

void
int

Remove a given view from the helper.

void
resolveRtl(ConstraintWidget widget, boolean isRtl)

resolve the RTL

void
setReferencedIds(int[] ids)

Helpers typically reference a collection of ids

void
setTag(int key, Object tag)
void

update after constraints are resolved

void

Allows a helper a chance to update its internal object post layout or set up connections for the pointed elements

void
void

called before the draw

void

Allows a helper a chance to update its internal object pre layout or set up connections for the pointed elements

void
updatePreLayout(
    ConstraintWidgetContainer container,
    Helper helper,
    SparseArray<ConstraintWidget> map
)

called before solver resolution

void

Allows a helper to replace the default ConstraintWidget in LayoutParams by its own subclass

Protected methods

void
void
void
View[]
void
void
void
onMeasure(int widthMeasureSpec, int heightMeasureSpec)
void
setIds(String idList)
void

Inherited Constants

From android.view.View
static final int
static final int
static final int
static final int
static final int
static final int
static final Property<ViewFloat>
static final int
static final String
AUTOFILL_HINT_CREDIT_CARD_EXPIRATION_DATE = "creditCardExpirationDate"
static final String
AUTOFILL_HINT_CREDIT_CARD_EXPIRATION_DAY = "creditCardExpirationDay"
static final String
AUTOFILL_HINT_CREDIT_CARD_EXPIRATION_MONTH = "creditCardExpirationMonth"
static final String
AUTOFILL_HINT_CREDIT_CARD_EXPIRATION_YEAR = "creditCardExpirationYear"
static final String
static final String
AUTOFILL_HINT_CREDIT_CARD_SECURITY_CODE = "creditCardSecurityCode"
static final String
static final String
static final String
static final String
static final String
static final String
static final String
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int

This field is deprecated.

static final int

This field is deprecated.

static final int

This field is deprecated.

static final int[]
static final int[]
static final int[]
static final int[]
static final int[]
static final int[]
static final int[]
static final int[]
static final int[]
static final int
static final int
static final int
static final int
static final int
static final int
static final int[]
static final int[]
static final int[]
static final int[]
static final int
static final int
static final int
static final int
static final int
static final int
static final int
GONE = 8
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
KEEP_SCREEN_ON = 67108864
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
NO_ID = -1
static final int
static final int
static final int
static final int[]
static final int[]
static final int[]
static final int[]
static final int[]
static final int[]
static final int[]
static final int[]
static final int[]
static final int[]
static final int[]
static final int[]
static final int[]
static final int[]
static final int[]
static final int[]
static final Property<ViewFloat>
static final Property<ViewFloat>
static final Property<ViewFloat>
static final Property<ViewFloat>
static final Property<ViewFloat>
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int[]
static final int[]
static final int
static final int

This field is deprecated.

static final int

This field is deprecated.

static final int

This field is deprecated.

static final int

This field is deprecated.

static final int

This field is deprecated.

static final int

This field is deprecated.

static final int

This field is deprecated.

static final int

This field is deprecated.

static final int

This field is deprecated.

static final int

This field is deprecated.

static final int

This field is deprecated.

static final int

This field is deprecated.

static final int

This field is deprecated.

static final int

This field is deprecated.

static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final int
static final Property<ViewFloat>
static final Property<ViewFloat>
static final Property<ViewFloat>
static final String
VIEW_LOG_TAG = "View"
static final int
static final int[]
static final Property<ViewFloat>
static final Property<ViewFloat>
static final Property<ViewFloat>

Inherited methods

From android.view.View
void
void
addExtraDataToAccessibilityNodeInfo(
    AccessibilityNodeInfo info,
    String extraDataKey,
    Bundle arguments
)
void
addFocusables(ArrayList<View> views, int direction)
void
void
void
void
void
ViewPropertyAnimator
void
void
boolean
void
void

This method is deprecated.

void
boolean
boolean
boolean
boolean
boolean
canScrollHorizontally(int direction)
boolean
canScrollVertically(int direction)
final void
void
final void
boolean
void
void
void
static int
combineMeasuredStates(int curState, int newState)
int
int
int
void
WindowInsets
int
int
int
AccessibilityNodeInfo
void
void

This method is deprecated.

WindowInsets
boolean
void
void
dispatchCreateViewTranslationRequest(
    Map<AutofillId, long[]> viewIds,
    int[] supportedFormats,
    TranslationCapability capability,
    List<ViewTranslationRequest> requests
)
void
boolean
void
void
dispatchDrawableHotspotChanged(float x, float y)
void
boolean
boolean
boolean
boolean
boolean
boolean
boolean
boolean
dispatchNestedFling(float velocityX, float velocityY, boolean consumed)
boolean
dispatchNestedPreFling(float velocityX, float velocityY)
boolean
dispatchNestedPrePerformAccessibilityAction(
    int action,
    Bundle arguments
)
boolean
dispatchNestedPreScroll(
    int dx,
    int dy,
    int[] consumed,
    int[] offsetInWindow
)
boolean
dispatchNestedScroll(
    int dxConsumed,
    int dyConsumed,
    int dxUnconsumed,
    int dyUnconsumed,
    int[] offsetInWindow
)
void
dispatchPointerCaptureChanged(boolean hasCapture)
boolean
void
void
void
void
void
dispatchScrollCaptureSearch(
    Rect localVisibleRect,
    Point windowOffset,
    Consumer<ScrollCaptureTarget> targets
)
void
dispatchSetActivated(boolean activated)
void
dispatchSetPressed(boolean pressed)
void
dispatchSetSelected(boolean selected)
void
void

This method is deprecated.

boolean
boolean
boolean
dispatchUnhandledMove(View focused, int direction)
void
dispatchVisibilityChanged(View changedView, int visibility)
void
dispatchWindowFocusChanged(boolean hasFocus)
void
void
WindowInsets
WindowInsetsAnimation.Bounds
void

This method is deprecated.

void
void
draw(Canvas canvas)
void
drawableHotspotChanged(float x, float y)
void
View
final OnBackInvokedDispatcher
final T
<T extends View> findViewById(int id)
final T
<T extends View> findViewWithTag(Object tag)
void
findViewsWithText(
    ArrayList<View> outViews,
    CharSequence searched,
    int flags
)
boolean

This method is deprecated.

View
focusSearch(int direction)
void
forceHasOverlappingRendering(boolean hasOverlappingRendering)
void
boolean
void
generateDisplayHash(
    String hashAlgorithm,
    Rect bounds,
    Executor executor,
    DisplayHashResultCallback callback
)
static int
CharSequence
View.AccessibilityDelegate
int
AccessibilityNodeProvider
CharSequence
int
int
String
String
float
Animation
Matrix
IBinder
int[]
Map<IntegerInteger>
String[]
final AutofillId
int
AutofillValue
Drawable
BlendMode
ColorStateList
PorterDuff.Mode
int
final int
float
int
float
Rect
boolean
final boolean
final ContentCaptureSession
CharSequence
final Context
ContextMenu.ContextMenuInfo
final boolean
static int
getDefaultSize(int size, int measureSpec)
Display
final int[]
Bitmap

This method is deprecated.

int

This method is deprecated.

int

This method is deprecated.

void
long
float
int
boolean
boolean
int
ArrayList<View>
getFocusables(int direction)
void
Drawable
int
BlendMode
ColorStateList
PorterDuff.Mode
boolean
getGlobalVisibleRect(Rect r, Point globalOffset)
Handler
float
float
float
float
Runnable
final boolean
final int
void
getHitRect(Rect outRect)
int
int
Drawable
Drawable
int
int
int
int
boolean
KeyEvent.DispatcherState
int
int
int
ViewGroup.LayoutParams
final int
float
int
final boolean
void
getLocationInSurface(int[] location)
void
getLocationInWindow(int[] outLocation)
void
getLocationOnScreen(int[] outLocation)
Matrix
final int
final int
final int
final int
final int
int
int
int
int
int
int
int
int
View.OnFocusChangeListener
int
ViewOutlineProvider
int
int
ViewOverlay
int
int
int
int
int
int
final ViewParent
ViewParent
float
float
PointerIcon
final List<Rect>
String[]
Resources
final boolean
final int
float
int
AttachedSurfaceControl
View
WindowInsets
float
float
float
float
float
int
int
int
int
int
int
final int
final int
int
int
final CharSequence
StateListAnimator
int
int
List<Rect>
int

This method is deprecated.

Object
int
int
CharSequence
final int
float
int
TouchDelegate
ArrayList<View>
float
String
float
float
float
long
int
int
Drawable
Drawable
int
ViewTranslationResponse
ViewTreeObserver
int
final int
int
WindowId
WindowInsetsController
int

This method is deprecated.

IBinder
int
void
float
float
float
boolean
boolean
boolean
boolean
boolean
boolean
boolean
boolean
boolean
boolean
static View
inflate(Context context, int resource, ViewGroup root)
void

This method is deprecated.

void
void
boolean
boolean
boolean
boolean
boolean
boolean
boolean
boolean
boolean
boolean
boolean

This method is deprecated.

boolean
boolean
final boolean
final boolean
boolean
final boolean
boolean
boolean
boolean
boolean
boolean
boolean
boolean
boolean
final boolean
final boolean
boolean
boolean
boolean
final boolean
boolean
boolean
boolean
boolean
boolean
boolean
boolean
boolean
boolean
final boolean
boolean
boolean
boolean
boolean
boolean
boolean
boolean
final boolean
boolean
boolean
final boolean
boolean
boolean
boolean
boolean
boolean
void
View
keyboardNavigationClusterSearch(View currentCluster, int direction)
void
layout(int l, int t, int r, int b)
final void
measure(int widthMeasureSpec, int heightMeasureSpec)
static int[]
mergeDrawableStates(int[] baseState, int[] additionalState)
void
offsetLeftAndRight(int offset)
void
offsetTopAndBottom(int offset)
void
void
WindowInsets
void
boolean
boolean
void
void
int[]
onCreateDrawableState(int extraSpace)
InputConnection
void
onCreateViewTranslationRequest(
    int[] supportedFormats,
    Consumer<ViewTranslationRequest> requestsCollector
)
void
onCreateVirtualViewTranslationRequests(
    long[] virtualIds,
    int[] supportedFormats,
    Consumer<ViewTranslationRequest> requestsCollector
)
void
void
onDisplayHint(int hint)
boolean
void
final void
boolean
void
void
void
onFocusChanged(
    boolean gainFocus,
    int direction,
    Rect previouslyFocusedRect
)
boolean
void
onHoverChanged(boolean hovered)
boolean
void
void
boolean
onKeyDown(int keyCode, KeyEvent event)
boolean
onKeyLongPress(int keyCode, KeyEvent event)
boolean
onKeyMultiple(int keyCode, int repeatCount, KeyEvent event)
boolean
onKeyPreIme(int keyCode, KeyEvent event)
boolean
onKeyShortcut(int keyCode, KeyEvent event)
boolean
onKeyUp(int keyCode, KeyEvent event)
void
onLayout(boolean changed, int left, int top, int right, int bottom)
void
onOverScrolled(
    int scrollX,
    int scrollY,
    boolean clampedX,
    boolean clampedY
)
void
onPointerCaptureChange(boolean hasCapture)
void
void
onProvideAutofillStructure(ViewStructure structure, int flags)
void
void
void
void
ContentInfo
PointerIcon
onResolvePointerIcon(MotionEvent event, int pointerIndex)
void
void
onRtlPropertiesChanged(int layoutDirection)
Parcelable
void
onScreenStateChanged(int screenState)
void
onScrollCaptureSearch(
    Rect localVisibleRect,
    Point windowOffset,
    Consumer<ScrollCaptureTarget> targets
)
void
onScrollChanged(int l, int t, int oldl, int oldt)
boolean
onSetAlpha(int alpha)
void
onSizeChanged(int w, int h, int oldw, int oldh)
void
boolean
boolean
void
void
void
onVisibilityAggregated(boolean isVisible)
void
onVisibilityChanged(View changedView, int visibility)
void
onWindowFocusChanged(boolean hasWindowFocus)
void

This method is deprecated.

void
onWindowVisibilityChanged(int visibility)
boolean
overScrollBy(
    int deltaX,
    int deltaY,
    int scrollX,
    int scrollY,
    int scrollRangeX,
    int scrollRangeY,
    int maxOverScrollX,
    int maxOverScrollY,
    boolean isTouchEvent
)
boolean
performAccessibilityAction(int action, Bundle arguments)
boolean
boolean
performContextClick(float x, float y)
boolean
performHapticFeedback(int feedbackConstant)
boolean
ContentInfo
void
playSoundEffect(int soundConstant)
boolean
post(Runnable action)
boolean
postDelayed(Runnable action, long delayMillis)
void
void
postInvalidateDelayed(long delayMilliseconds)
void
void
void
postOnAnimationDelayed(Runnable action, long delayMillis)
void
void
boolean
void
void
void
void
void

This method is deprecated.

final boolean
final boolean
void
void
boolean
final void
final T
<T extends View> requireViewById(int id)
void
static int
resolveSize(int size, int measureSpec)
static int
resolveSizeAndState(int size, int measureSpec, int childMeasuredState)
boolean
void
final void
saveAttributeDataForStyleable(
    Context context,
    int[] styleable,
    AttributeSet attrs,
    TypedArray t,
    int defStyleAttr,
    int defStyleRes
)
void
void
scheduleDrawable(Drawable who, Runnable what, long when)
void
scrollBy(int x, int y)
void
scrollTo(int x, int y)
void
sendAccessibilityEvent(int eventType)
void
void
setAccessibilityDataSensitive(int accessibilityDataSensitive)
void
void
setAccessibilityHeading(boolean isHeading)
void
void
setAccessibilityPaneTitle(CharSequence accessibilityPaneTitle)
void
void
void
setActivated(boolean activated)
void
setAllowClickWhenDisabled(boolean clickableWhenDisabled)
void
void
void
setAlpha(float alpha)
void
void
void
setAutoHandwritingEnabled(boolean enabled)
void
setAutofillHints(String[] autofillHints)
void
void
setBackground(Drawable background)
void
setBackgroundColor(int color)
void

This method is deprecated.

void
void
void
void
final void
setBottom(int bottom)
void
setCameraDistance(float distance)
void
setClickable(boolean clickable)
void
setClipBounds(Rect clipBounds)
void
setClipToOutline(boolean clipToOutline)
void
void
setContentDescription(CharSequence contentDescription)
void
setContextClickable(boolean contextClickable)
void
setDefaultFocusHighlightEnabled(boolean defaultFocusHighlightEnabled)
void

This method is deprecated.

void
setDrawingCacheEnabled(boolean enabled)

This method is deprecated.

void

This method is deprecated.

void
void
setElevation(float elevation)
void
setEnabled(boolean enabled)
void
setFadingEdgeLength(int length)
void
void
setFitsSystemWindows(boolean fitSystemWindows)
void
setFocusable(boolean focusable)
void
setFocusableInTouchMode(boolean focusableInTouchMode)
void
setFocusedByDefault(boolean isFocusedByDefault)
void
setForceDarkAllowed(boolean allow)
void
setForeground(Drawable foreground)
void
setForegroundGravity(int gravity)
void
void
void
void
setHandwritingBoundsOffsets(
    float offsetLeft,
    float offsetTop,
    float offsetRight,
    float offsetBottom
)
void
void
setHapticFeedbackEnabled(boolean hapticFeedbackEnabled)
void
setHasTransientState(boolean hasTransientState)
void
setHorizontalFadingEdgeEnabled(boolean horizontalFadingEdgeEnabled)
void
setHorizontalScrollBarEnabled(boolean horizontalScrollBarEnabled)
void
void
void
setHovered(boolean hovered)
void
setId(int id)
void
void
void
void
setIsCredential(boolean isCredential)
void
setIsHandwritingDelegate(boolean isHandwritingDelegate)
void
setKeepScreenOn(boolean keepScreenOn)
void
setKeyboardNavigationCluster(boolean isCluster)
void
setLabelFor(int id)
void
void
setLayerType(int layerType, Paint paint)
void
setLayoutDirection(int layoutDirection)
void
final void
setLeft(int left)
final void
setLeftTopRightBottom(int left, int top, int right, int bottom)
void
setLongClickable(boolean longClickable)
final void
setMeasuredDimension(int measuredWidth, int measuredHeight)
void
setMinimumHeight(int minHeight)
void
setMinimumWidth(int minWidth)
void
setNestedScrollingEnabled(boolean enabled)
void
setNextClusterForwardId(int nextClusterForwardId)
void
setNextFocusDownId(int nextFocusDownId)
void
setNextFocusForwardId(int nextFocusForwardId)
void
setNextFocusLeftId(int nextFocusLeftId)
void
setNextFocusRightId(int nextFocusRightId)
void
setNextFocusUpId(int nextFocusUpId)
void
void
void
void
void
void
void
void
void
void
void
void
setOnReceiveContentListener(
    String[] mimeTypes,
    OnReceiveContentListener listener
)
void
void

This method is deprecated.

void
void
void
void
void
setOverScrollMode(int overScrollMode)
void
setPadding(int left, int top, int right, int bottom)
void
setPaddingRelative(int start, int top, int end, int bottom)
void
setPivotX(float pivotX)
void
setPivotY(float pivotY)
void
final void
setPreferKeepClear(boolean preferKeepClear)
final void
void
setPressed(boolean pressed)
void
final void
setRevealOnFocusHint(boolean revealOnFocus)
final void
setRight(int right)
void
setRotation(float rotation)
void
setRotationX(float rotationX)
void
setRotationY(float rotationY)
void
setSaveEnabled(boolean enabled)
void
setSaveFromParentEnabled(boolean enabled)
void
setScaleX(float scaleX)
void
setScaleY(float scaleY)
void
setScreenReaderFocusable(boolean screenReaderFocusable)
void
setScrollBarDefaultDelayBeforeFade(
    int scrollBarDefaultDelayBeforeFade
)
void
setScrollBarFadeDuration(int scrollBarFadeDuration)
void
setScrollBarSize(int scrollBarSize)
void
setScrollBarStyle(int style)
final void
void
void
setScrollContainer(boolean isScrollContainer)
void
setScrollIndicators(int indicators)
void
setScrollX(int value)
void
setScrollY(int value)
void
setScrollbarFadingEnabled(boolean fadeScrollbars)
void
setSelected(boolean selected)
void
setSoundEffectsEnabled(boolean soundEffectsEnabled)
void
void
void
void
setSystemUiVisibility(int visibility)

This method is deprecated.

void
void
setTextAlignment(int textAlignment)
void
setTextDirection(int textDirection)
void
final void
setTop(int top)
void
void
setTransitionAlpha(float alpha)
final void
setTransitionName(String transitionName)
void
setTransitionVisibility(int visibility)
void
setTranslationX(float translationX)
void
setTranslationY(float translationY)
void
setTranslationZ(float translationZ)
void
setVerticalFadingEdgeEnabled(boolean verticalFadingEdgeEnabled)
void
setVerticalScrollBarEnabled(boolean verticalScrollBarEnabled)
void
void
void
void
void
setVisibility(int visibility)
void
setWillNotCacheDrawing(boolean willNotCacheDrawing)

This method is deprecated.

void
setWillNotDraw(boolean willNotDraw)
void
void
setX(float x)
void
setY(float y)
void
setZ(float z)
boolean
ActionMode
void
final boolean
startDrag(
    ClipData data,
    View.DragShadowBuilder shadowBuilder,
    Object myLocalState,
    int flags
)

This method is deprecated.

final boolean
startDragAndDrop(
    ClipData data,
    View.DragShadowBuilder shadowBuilder,
    Object myLocalState,
    int flags
)
boolean
void
String
void
void
void
final void
boolean
boolean

This method is deprecated.

boolean

Constants

CHILD_TAG

Added in 2.2.0-alpha13
protected static final String CHILD_TAG = "CONSTRAINT_LAYOUT_HELPER_CHILD"

Protected fields

mCount

Added in 2.2.0-alpha13
protected int mCount

mHelperWidget

Added in 2.2.0-alpha13
protected Helper mHelperWidget

mIds

Added in 2.2.0-alpha13
protected int[] mIds

mMap

Added in 2.2.0-alpha13
protected HashMap<IntegerStringmMap

mReferenceIds

Added in 2.2.0-alpha13
protected String mReferenceIds

mReferenceTags

Added in 2.2.0-alpha13
protected String mReferenceTags

mUseViewMeasure

Added in 2.2.0-alpha13
protected boolean mUseViewMeasure

myContext

Added in 2.2.0-alpha13
protected Context myContext

Public constructors

ConstraintHelper

Added in 2.2.0-alpha13
public ConstraintHelper(Context context)

ConstraintHelper

Added in 2.2.0-alpha13
public ConstraintHelper(Context context, AttributeSet attrs)

ConstraintHelper

Added in 2.2.0-alpha13
public ConstraintHelper(Context context, AttributeSet attrs, int defStyleAttr)

Public methods

addView

Added in 2.2.0-alpha13
public void addView(View view)

Add a view to the helper. The referenced view need to be a child of the helper's parent. The view also need to have its id set in order to be added.

Parameters
View view

applyHelperParams

Added in 2.2.0-alpha13
public void applyHelperParams()

hook for helpers to apply parameters in MotionLayout

containsId

Added in 2.2.0-alpha13
public boolean containsId(int id)

does id table contain the id

Parameters
int id
Returns
boolean

getReferencedIds

Added in 2.2.0-alpha13
public int[] getReferencedIds()

Helpers typically reference a collection of ids

Returns
int[]

ids referenced

indexFromId

Added in 2.2.0-alpha13
public int indexFromId(int id)

find the position of an id

Parameters
int id
Returns
int

isChildOfHelper

Added in 2.2.0-alpha13
public static boolean isChildOfHelper(View v)

loadParameters

Added in 2.2.0-alpha13
public void loadParameters(
    ConstraintSet.Constraint constraint,
    HelperWidget child,
    ConstraintLayout.LayoutParams layoutParams,
    SparseArray<ConstraintWidget> mapIdToWidget
)

Load the parameters

Parameters
ConstraintSet.Constraint constraint
HelperWidget child
ConstraintLayout.LayoutParams layoutParams
SparseArray<ConstraintWidget> mapIdToWidget

onDraw

Added in 2.2.0-alpha13
public void onDraw(@NonNull Canvas canvas)

removeView

Added in 2.2.0-alpha13
public int removeView(View view)

Remove a given view from the helper.

Parameters
View view
Returns
int

index of view removed

resolveRtl

Added in 2.2.0-alpha13
public void resolveRtl(ConstraintWidget widget, boolean isRtl)

resolve the RTL

Parameters
ConstraintWidget widget
boolean isRtl

setReferencedIds

Added in 2.2.0-alpha13
public void setReferencedIds(int[] ids)

Helpers typically reference a collection of ids

setTag

public void setTag(int key, Object tag)

updatePostConstraints

Added in 2.2.0-alpha13
public void updatePostConstraints(ConstraintLayout container)

update after constraints are resolved

Parameters
ConstraintLayout container

updatePostLayout

Added in 2.2.0-alpha13
public void updatePostLayout(ConstraintLayout container)

Allows a helper a chance to update its internal object post layout or set up connections for the pointed elements

Parameters
ConstraintLayout container

updatePostMeasure

Added in 2.2.0-alpha13
public void updatePostMeasure(ConstraintLayout container)
Parameters
ConstraintLayout container

updatePreDraw

Added in 2.2.0-alpha13
public void updatePreDraw(ConstraintLayout container)

called before the draw

Parameters
ConstraintLayout container

updatePreLayout

Added in 2.2.0-alpha13
public void updatePreLayout(ConstraintLayout container)

Allows a helper a chance to update its internal object pre layout or set up connections for the pointed elements

Parameters
ConstraintLayout container

updatePreLayout

Added in 2.2.0-alpha13
public void updatePreLayout(
    ConstraintWidgetContainer container,
    Helper helper,
    SparseArray<ConstraintWidget> map
)

called before solver resolution

Parameters
ConstraintWidgetContainer container
Helper helper
SparseArray<ConstraintWidget> map

validateParams

Added in 2.2.0-alpha13
public void validateParams()

Allows a helper to replace the default ConstraintWidget in LayoutParams by its own subclass

Protected methods

applyLayoutFeatures

Added in 2.2.0-alpha13
protected void applyLayoutFeatures()

applyLayoutFeatures

Added in 2.2.0-alpha13
protected void applyLayoutFeatures(ConstraintLayout container)
Parameters
ConstraintLayout container

applyLayoutFeaturesInConstraintSet

Added in 2.2.0-alpha13
protected void applyLayoutFeaturesInConstraintSet(ConstraintLayout container)

getViews

Added in 2.2.0-alpha13
protected View[] getViews(ConstraintLayout layout)

init

Added in 2.2.0-alpha13
protected void init(AttributeSet attrs)

onAttachedToWindow

protected void onAttachedToWindow()

onMeasure

protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)

setIds

Added in 2.2.0-alpha13
protected void setIds(String idList)

setReferenceTags

Added in 2.2.0-alpha13
protected void setReferenceTags(String tagList)