PercentLayoutHelper

public class PercentLayoutHelper
extends Object

This class was deprecated in API level 26.1.0.
consider using ConstraintLayout and associated layouts instead. The following shows how to replicate the functionality of percentage layouts with a ConstraintLayout. The Guidelines are used to define each percentage break point, and then a Button view is stretched to fill the gap:

 <android.support.constraint.ConstraintLayout
         xmlns:android="http://schemas.android.com/apk/res/android"
         xmlns:app="http://schemas.android.com/apk/res-auto"
         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/left_guideline"
         app:layout_constraintGuide_percent=".15"
         android:orientation="vertical"/>

     <android.support.constraint.Guideline
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:id="@+id/right_guideline"
         app:layout_constraintGuide_percent=".85"
         android:orientation="vertical"/>

     <android.support.constraint.Guideline
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:id="@+id/top_guideline"
         app:layout_constraintGuide_percent=".15"
         android:orientation="horizontal"/>

     <android.support.constraint.Guideline
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:id="@+id/bottom_guideline"
         app:layout_constraintGuide_percent=".85"
         android:orientation="horizontal"/>

     <Button
         android:text="Button"
         android:layout_width="0dp"
         android:layout_height="0dp"
         android:id="@+id/button"
         app:layout_constraintLeft_toLeftOf="@+id/left_guideline"
         app:layout_constraintRight_toRightOf="@+id/right_guideline"
         app:layout_constraintTop_toTopOf="@+id/top_guideline"
         app:layout_constraintBottom_toBottomOf="@+id/bottom_guideline" />

 </android.support.constraint.ConstraintLayout>

  



  
Helper for layouts that want to support percentage based dimensions.

 
This class collects utility methods that are involved in extracting percentage based dimension
 attributes and applying them to ViewGroup's children. If you would like to implement a layout
 that supports percentage based dimensions, you need to take several steps:

 

 
 You need a ViewGroup.LayoutParams subclass in your ViewGroup that implements
 PercentLayoutHelper.PercentLayoutParams.
 
 In your LayoutParams(Context c, AttributeSet attrs) constructor create an instance
 of PercentLayoutHelper.PercentLayoutInfo by calling
 getPercentLayoutInfo(Context, AttributeSet). Return this
 object from public PercentLayoutHelper.PercentLayoutInfo getPercentLayoutInfo()
 method that you implemented for PercentLayoutHelper.PercentLayoutParams interface.
 
 Override
 setBaseAttributes(TypedArray, int, int)
 with a single line implementation PercentLayoutHelper.fetchWidthAndHeight(this, a,
 widthAttr, heightAttr);
 
 In your ViewGroup override generateLayoutParams(AttributeSet) to return
 your LayoutParams.
 
 In your onMeasure(int, int) override, you need to implement following
 pattern:
 
 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
     mHelper.adjustChildren(widthMeasureSpec, heightMeasureSpec);
     super.onMeasure(widthMeasureSpec, heightMeasureSpec);
     if (mHelper.handleMeasuredStateTooSmall()) {
         super.onMeasure(widthMeasureSpec, heightMeasureSpec);
     }
 }
 
 
In your onLayout(boolean, int, int, int, int) override, you need to
 implement following pattern:
 
 protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
     super.onLayout(changed, left, top, right, bottom);
     mHelper.restoreOriginalParams();
 }
 
 










Summary





Nested classes


  
    

      

        
        
        
        
        class
      

        PercentLayoutHelper.PercentLayoutInfo
        

      This class was deprecated
      in API level 26.1.0.
    use ConstraintLayout and Guidelines for layout support.
 
        
    

      
    
    
    
    

      

        
        
        
        
        interface
      

        PercentLayoutHelper.PercentLayoutParams
        

      This interface was deprecated
      in API level 26.1.0.
    this class is deprecated along with its parent class.
 
        
    

      
    
    
    

























Public constructors



  
  

  
  
    

      
      PercentLayoutHelper(ViewGroup host)
      
      
    
  
  











Public methods



  
  

  
  
    

        
        
        
        
        
        void
    
  
    

      
      adjustChildren(int widthMeasureSpec, int heightMeasureSpec)
      
      
        
Iterates over children and changes their width and height to one calculated from percentage
 values.
        
    

      
    
  
  

  
  

  
  
    

        
        
        static
        
        
        void
    
  
    

      
      fetchWidthAndHeight(ViewGroup.LayoutParams params, TypedArray array, int widthAttr, int heightAttr)
      
      
        
Helper method to be called from setBaseAttributes(TypedArray, int, int) override
 that reads layout_width and layout_height attribute values without throwing an exception if
 they aren't present.
        
    

      
    
  
  

  
  

  
  
    

        
        
        static
        
        
        PercentLayoutHelper.PercentLayoutInfo
    
  
    

      
      getPercentLayoutInfo(Context context, AttributeSet attrs)
      
      
        
Constructs a PercentLayoutInfo from attributes associated with a View.
        
    

      
    
  
  

  
  

  
  
    

        
        
        
        
        
        boolean
    
  
    

      
      handleMeasuredStateTooSmall()
      
      
        
Iterates over children and checks if any of them would like to get more space than it
 received through the percentage dimension.
        
    

      
    
  
  

  
  

  
  
    

        
        
        
        
        
        void
    
  
    

      
      restoreOriginalParams()
      
      
        
Iterates over children and restores their original dimensions that were changed for
 percentage values.
        
    

      
    
  
  












Inherited methods




  
    
  From
class

  
    java.lang.Object
  


  

  
  

    

      


  
  

  
  
    

        
        
        
        
        
        Object
    
  
    

      
      clone()
      
      
    
  
  

  
  

  
  
    

        
        
        
        
        
        boolean
    
  
    

      
      equals(Object arg0)
      
      
    
  
  

  
  

  
  
    

        
        
        
        
        
        void
    
  
    

      
      finalize()
      
      
    
  
  

  
  

  
  
    

        
        
        
        final
        
        Class<?>