Summary: Ctors | Methods | Inherited Methods

Guideline

This package is part of the Android support library which is no longer maintained. The Constraint Layout support library has been superseded by the AndroidX Constraint Layout library, which is part of Jetpack. The Guideline class has been superseded by androidx.constraintlayout.widget/Guideline. We recommend using the AndroidX libraries in all new projects. You should also consider migrating existing projects to AndroidX.

public class Guideline
extends View

java.lang.Object
↳	View
	↳	android.support.constraint.Guideline

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 ConstraintLayout.LayoutParams to set a Guideline in XML, as well as the corresponding ConstraintSet.setGuidelineBegin(int, int), ConstraintSet.setGuidelineEnd(int, int) and ConstraintSet.setGuidelinePercent(int, float) functions in ConstraintSet.

Example of a Button constrained to a vertical Guideline:

<android.support.constraint.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">

    <android.support.constraint.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" />

</android.support.constraint.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`	`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.

Inherited methods

From class


        
          java.lang.Object

`Object`	`clone()`
`boolean`	`equals(Object arg0)`
`void`	`finalize()`
`final Class<?>`	`getClass()`
`int`	`hashCode()`
`final void`	`notify()`
`final void`	`notifyAll()`
`String`	`toString()`
`final void`	`wait(long arg0, int arg1)`
`final void`	`wait(long arg0)`
`final void`	`wait()`

Public constructors

Guideline

public Guideline (Context context)

Parameters
`context`	`Context`

Guideline

public Guideline (Context context, 
                AttributeSet attrs)

Parameters
`context`	`Context`
`attrs`	`AttributeSet`

Guideline

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

Parameters
`context`	`Context`
`attrs`	`AttributeSet`
`defStyleAttr`	`int`

Guideline

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

Parameters
`context`	`Context`
`attrs`	`AttributeSet`
`defStyleAttr`	`int`
`defStyleRes`	`int`

Public methods

setGuidelineBegin

public void setGuidelineBegin (int margin)

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

Parameters
`margin`	`int`: the distance to the top or left edge

setGuidelineEnd

public void setGuidelineEnd (int margin)

Set a guideline's distance to end.

Parameters
`margin`	`int`: the margin to the right or bottom side of container

setGuidelinePercent

public void setGuidelinePercent (float ratio)

Set a Guideline's percent.

Parameters
`ratio`	`float`: the ratio between the gap on the left and right 0.0 is top/left 0.5 is middle