Android: Cascade the value of a custom attribute from a parent view to a child view - solution to https://stackoverflow.com/q/15112522/570930

CascadingCustomLayout.java

// See https://stackoverflow.com/q/15112522/570930

class CustomLayout extends WhateverLayout {
  
  private float percent;
  private CustomView customView;
  //View constructors go here
  
  private void init(){
    //Inflation goes here if needed
    percent = //get value passed in to app:percent using TypedArray
  }
  
  @Override public void onFinishInflate(){
    customView = findViewById(R.id.customView1);
    customView.setPercent(percent);
  }
}

class CustomView extends WhateverView {
  private float percent;
  
  //View constructors go here
  public void setPercent(float percent) {
    this.percent = percent;
    //update the UI using this newly set percent
  }
}