public class

Constraints

extends ViewGroup

 java.lang.Object

↳ViewGroup

↳androidx.constraintlayout.widget.Constraints

Gradle dependencies

compile group: 'androidx.constraintlayout', name: 'constraintlayout', version: '2.2.0-beta01'

  • groupId: androidx.constraintlayout
  • artifactId: constraintlayout
  • version: 2.2.0-beta01

Artifact androidx.constraintlayout:constraintlayout:2.2.0-beta01 it located at Google repository (https://maven.google.com/)

Androidx artifact mapping:

androidx.constraintlayout:constraintlayout com.android.support.constraint:constraint-layout

Androidx class mapping:

androidx.constraintlayout.widget.Constraints android.support.constraint.Constraints

Overview

This defines the internally defined Constraint set It allows you to have a group of References which point to other views and provide them with constraint attributes

Summary

Fields
public static final java.lang.StringTAG

Constructors
publicConstraints(Context context)

publicConstraints(Context context, AttributeSet attrs)

publicConstraints(Context context, AttributeSet attrs, int defStyleAttr)

Methods
protected Constraints.LayoutParamsgenerateDefaultLayoutParams()

public Constraints.LayoutParamsgenerateLayoutParams(AttributeSet attrs)

protected ViewGroup.LayoutParamsgenerateLayoutParams(ViewGroup.LayoutParams p)

public ConstraintSetgetConstraintSet()

get the Constraints associated with this constraint

protected voidonLayout(boolean changed, int l, int t, int r, int b)

from java.lang.Objectclone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Fields

public static final java.lang.String TAG

Constructors

public Constraints(Context context)

public Constraints(Context context, AttributeSet attrs)

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

Methods

public Constraints.LayoutParams generateLayoutParams(AttributeSet attrs)

protected Constraints.LayoutParams generateDefaultLayoutParams()

protected ViewGroup.LayoutParams generateLayoutParams(ViewGroup.LayoutParams p)

public ConstraintSet getConstraintSet()

get the Constraints associated with this constraint

Returns:

protected void onLayout(boolean changed, int l, int t, int r, int b)

Source

/*
 * Copyright (C) 2017 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package androidx.constraintlayout.widget;

import android.content.Context;
import android.content.res.TypedArray;
import android.os.Build;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;

/**
 *
 * This defines the internally defined Constraint set
 * It allows you to have a group of References which point to other views and provide them with
 * constraint attributes
 *
 */
public class Constraints extends ViewGroup {

    public static final String TAG = "Constraints";
    ConstraintSet mConstraintSet;

    public Constraints(Context context) {
        super(context);
        super.setVisibility(View.GONE);
    }

    public Constraints(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
        super.setVisibility(View.GONE);
    }

    public Constraints(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init();
        super.setVisibility(View.GONE);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public LayoutParams generateLayoutParams(AttributeSet attrs) {
        return new LayoutParams(getContext(), attrs);
    }

    public static class LayoutParams extends ConstraintLayout.LayoutParams {

        public float alpha = 1;
        public boolean applyElevation = false;
        public float elevation = 0;
        public float rotation = 0;
        public float rotationX = 0;
        public float rotationY = 0;
        public float scaleX = 1;
        public float scaleY = 1;
        public float transformPivotX = 0;
        public float transformPivotY = 0;
        public float translationX = 0;
        public float translationY = 0;
        public float translationZ = 0;

        public LayoutParams(int width, int height) {
            super(width, height);
        }

        public LayoutParams(LayoutParams source) {
            super(source);
        }

        public LayoutParams(Context c, AttributeSet attrs) {
            super(c, attrs);
            TypedArray a = c.obtainStyledAttributes(attrs, R.styleable.ConstraintSet);
            final int count = a.getIndexCount();
            for (int i = 0; i < count; i++) {
                int attr = a.getIndex(i);
                if (attr == R.styleable.ConstraintSet_android_alpha) {
                    alpha = a.getFloat(attr, alpha);
                } else if (attr == R.styleable.ConstraintSet_android_elevation) {
                    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
                        elevation = a.getFloat(attr, elevation);
                        applyElevation = true;
                    }
                } else if (attr == R.styleable.ConstraintSet_android_rotationX) {
                    rotationX = a.getFloat(attr, rotationX);
                } else if (attr == R.styleable.ConstraintSet_android_rotationY) {
                    rotationY = a.getFloat(attr, rotationY);
                } else if (attr == R.styleable.ConstraintSet_android_rotation) {
                    rotation = a.getFloat(attr, rotation);
                } else if (attr == R.styleable.ConstraintSet_android_scaleX) {
                    scaleX = a.getFloat(attr, scaleX);
                } else if (attr == R.styleable.ConstraintSet_android_scaleY) {
                    scaleY = a.getFloat(attr, scaleY);
                } else if (attr == R.styleable.ConstraintSet_android_transformPivotX) {
                    transformPivotX = a.getFloat(attr, transformPivotX);
                } else if (attr == R.styleable.ConstraintSet_android_transformPivotY) {
                    transformPivotY = a.getFloat(attr, transformPivotY);
                } else if (attr == R.styleable.ConstraintSet_android_translationX) {
                    translationX = a.getFloat(attr, translationX);
                } else if (attr == R.styleable.ConstraintSet_android_translationY) {
                    translationY = a.getFloat(attr, translationY);
                } else if (attr == R.styleable.ConstraintSet_android_translationZ) {
                    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
                        translationZ = a.getFloat(attr, translationZ);
                    }
                }
            }
            a.recycle();
        }
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected LayoutParams generateDefaultLayoutParams() {
        return new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
    }

    private void init() {
        Log.v(TAG, " ################# init");
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected ViewGroup.LayoutParams generateLayoutParams(ViewGroup.LayoutParams p) {
        return new ConstraintLayout.LayoutParams(p);
    }

    /**
     * get the Constraints associated with this constraint
     *
     * @return
     */
    public ConstraintSet getConstraintSet() {
        if (mConstraintSet == null) {
            mConstraintSet = new ConstraintSet();
        }
        // TODO -- could be more efficient...
        mConstraintSet.clone(this);
        return mConstraintSet;
    }

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
    }
}