android-coordinatorlayout.md

title: Android Design Library: CoordinatorLayout basic setup tags: android,android-coordinatorlayout

Now Android has the 'SnackBar' which popups up at the bottom of the screen, it may overlap some of your other elements. The Design library has introduced the CoordinatorLayout to deal with these situations

It allows you to align the elements via android:layout_gravity and has a app:layout_behavior attribtue that takes in the full path of a class such as com.example.blar.myapplication.FloatingActionButtonBehaviour.

That class extends a Behavior which is typed to your view type. It checks if the layout depends on something like a SnackbarLayout, and if so performs a transformation on your view, like animating it out of the way.

He's an example of a Behavior which is typed to a Custom View and moves that out of the way when a SnackBarLayout appears:

package com.example.blar.myapplication;

import android.content.Context;
import android.support.design.widget.CoordinatorLayout;
import android.support.design.widget.Snackbar;
import android.util.AttributeSet;
import android.view.View;

public class FloatingActionButtonBehaviour extends CoordinatorLayout.Behavior<SavingViewStateViewPager> {

    public FloatingActionButtonBehaviour(Context context, AttributeSet attrs) {}

    @Override
    public boolean layoutDependsOn(CoordinatorLayout parent, SavingViewStateViewPager child, View dependency) {
        return dependency instanceof Snackbar.SnackbarLayout;
    }

    @Override
    public boolean onDependentViewChanged(CoordinatorLayout parent, SavingViewStateViewPager child, View dependency) {
        float translationY = Math.min(0, dependency.getTranslationY() - dependency.getHeight());
        child.setTranslationY(translationY);
        return true;
    }
}