public class Guideline extends View


Utility class representing a Guideline helper object for ConstraintLayout. Helper objects are not displayed on device (they are marked as View.GONE) and are only used for layout purposes. They only work within a ConstraintLayout.

A Guideline can be either horizontal or vertical:

  • Vertical Guidelines have a width of zero and the height of their ConstraintLayout parent
  • Horizontal Guidelines have a height of zero and the width of their ConstraintLayout parent

Positioning a Guideline is possible in three different ways:

  • specifying a fixed distance from the left or the top of a layout (layout_constraintGuide_begin)
  • specifying a fixed distance from the right or the bottom of a layout (layout_constraintGuide_end)
  • specifying a percentage of the width or the height of a layout (layout_constraintGuide_percent)

Widgets can then be constrained to a Guideline, allowing multiple widgets to be positioned easily from one Guideline, or allowing reactive layout behavior by using percent positioning.

See the list of attributes in androidx.constraintlayout.widget.ConstraintLayout.LayoutParams to set a Guideline in XML, as well as the corresponding setGuidelineBegin, setGuidelineEnd and setGuidelinePercent functions in ConstraintSet.

Example of a Button constrained to a vertical Guideline:

         <androidx.constraintlayout.widget.ConstraintLayout
             xmlns:android="http://schemas.android.com/apk/res/android"
             xmlns:app="http://schemas.android.com/apk/res-auto"
             xmlns:tools="http://schemas.android.com/tools"
             android:layout_width="match_parent"
             android:layout_height="match_parent">

             <androidx.constraintlayout.widget.Guideline
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
                 android:id="@+id/guideline"
                 app:layout_constraintGuide_begin="100dp"
                 android:orientation="vertical"/>
             <Button
                 android:text="Button"
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
                 android:id="@+id/button"
                 app:layout_constraintLeft_toLeftOf="@+id/guideline"
                 android:layout_marginTop="16dp"
                 app:layout_constraintTop_toTopOf="parent" />
         </androidx.constraintlayout.widget.ConstraintLayout>
       

Summary

Public constructors

Guideline(Context context)
Guideline(Context context, AttributeSet attrs)
Guideline(Context context, AttributeSet attrs, int defStyleAttr)
Guideline(
    Context context,
    AttributeSet attrs,
    int defStyleAttr,
    int defStyleRes
)

Public methods

void
draw(@NonNull Canvas canvas)

We are overriding draw and not calling super.draw() here because Helper objects are not displayed on device.

void
setFilterRedundantCalls(boolean filter)

filter redundant calls to setGuidelineBegin, setGuidelineEnd &setGuidelinePercent.

void
setGuidelineBegin(int margin)

Set the guideline's distance from the top or left edge.

void
setGuidelineEnd(int margin)

Set a guideline's distance to end.

void
setGuidelinePercent(float ratio)

Set a Guideline's percent.

void
setVisibility(int visibility)

Protected methods

void
onMeasure(int widthMeasureSpec, int heightMeasureSpec)

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
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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

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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
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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
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
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
onDraw(Canvas canvas)
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
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

Public constructors

Guideline

Added in 2.2.0-rc01
public Guideline(Context context)

Guideline

Added in 2.2.0-rc01
public Guideline(Context context, AttributeSet attrs)

Guideline

Added in 2.2.0-rc01
public Guideline(Context context, AttributeSet attrs, int defStyleAttr)

Guideline

Added in 2.2.0-rc01
public Guideline(
    Context context,
    AttributeSet attrs,
    int defStyleAttr,
    int defStyleRes
)

Public methods

draw

public void draw(@NonNull Canvas canvas)

We are overriding draw and not calling super.draw() here because Helper objects are not displayed on device.

setFilterRedundantCalls

Added in 2.2.0-rc01
public void setFilterRedundantCalls(boolean filter)

filter redundant calls to setGuidelineBegin, setGuidelineEnd &setGuidelinePercent. By default calling setGuidelineStart,setGuideLineEnd and setGuidelinePercent will do nothing if the value is the same as the current value. This can disable that behaviour and call setLayoutParams(..) while will call requestLayout

Parameters
boolean filter

default true set false to always generate a setLayoutParams

setGuidelineBegin

Added in 2.2.0-rc01
public void setGuidelineBegin(int margin)

Set the guideline's distance from the top or left edge.

Parameters
int margin

the distance to the top or left edge

setGuidelineEnd

Added in 2.2.0-rc01
public void setGuidelineEnd(int margin)

Set a guideline's distance to end.

Parameters
int margin

the margin to the right or bottom side of container

setGuidelinePercent

Added in 2.2.0-rc01
public void setGuidelinePercent(float ratio)

Set a Guideline's percent.

Parameters
float ratio

the ratio between the gap on the left and right 0.0 is top/left 0.5 is middle

setVisibility

public void setVisibility(int visibility)

Protected methods

onMeasure

protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)