Android
ConstraintSet

소개

프로그래밍 방식으로 ContraintLayout을 사용하는 ConstraintSet

import android.content.Context;
import android.os.Bundle;
import android.support.constraint.ConstraintLayout;
import android.support.constraint.ConstraintSet;
import android.support.transition.TransitionManager;
import android.support.v7.app.AppCompatActivity;
import android.view.View;

public class MainActivity extends AppCompatActivity {
    ConstraintSet mConstraintSet1 = new ConstraintSet(); // create a Constraint Set
    ConstraintSet mConstraintSet2 = new ConstraintSet(); // create a Constraint Set
    ConstraintLayout mConstraintLayout; // cache the ConstraintLayout
    boolean mOld = true;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Context context = this;
        mConstraintSet2.clone(context, R.layout.state2); // get constraints from layout
        setContentView(R.layout.state1);
        mConstraintLayout = (ConstraintLayout) findViewById(R.id.activity_main);
        mConstraintSet1.clone(mConstraintLayout); // get constraints from ConstraintSet
    }

    public void foo(View view) {
        TransitionManager.beginDelayedTransition(mConstraintLayout);
        if (mOld = !mOld) {
            mConstraintSet1.applyTo(mConstraintLayout); // set new constraints
        }  else {
            mConstraintSet2.applyTo(mConstraintLayout); // set new constraints
        }
    }
}