toggle visibility of chain group in constraint lay

问题:

In previous xml layout, I have multiple view groups with few elements inside. Hide each view group will also hide all of its child elements. Since I wanted to have flat structure and tried ConstraintLayout. Cool I know how to chain element with spread to align properly. Since flat structure does not have wrapped LinearLayout, now i have 3 views to hide instead. I would like to know if there is alternative to achieve this.

Without constraint layout

<RelativeLayout....
..........
..........
<LinearLayout
        android:visibility="gone"
        tools:visibility="visible"
        android:id="@+id/filter_area"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <android.support.v7.widget.AppCompatTextView
            android:id="@+id/lblTerminal"
            android:background="@color/lightGray"
            style="@style/PurpleSubtitle"
            android:drawableRight="@drawable/i_down_yellow"
            android:drawableEnd="@drawable/i_down_yellow"
            android:padding="10dp"
            android:text="@string/lblTerminal"
            android:layout_weight="5"
            android:layout_width="0dp"
            android:layout_height="wrap_content" />

        <View
            android:background="@android:color/black"
            android:layout_width="1dp"
            android:layout_height="match_parent"/>

        <android.support.v7.widget.AppCompatTextView
            android:id="@+id/lblCategory"
            android:background="@color/lightGray"
            android:padding="10dp"
            android:drawableRight="@drawable/i_down_yellow"
            android:drawableEnd="@drawable/i_down_yellow"
            style="@style/PurpleSubtitle"
            android:text="@string/lblCategory"
            android:layout_weight="5"
            android:layout_width="0dp"
            android:layout_height="wrap_content" />


    </LinearLayout>
  .......
  .......
  </RelativeLayout>

With constraint layout

    <android.support.constraint.ConstraintLayout
    .....
    .....
    .....
       #happy that i no longer need LinearLayout for align properly
       <android.support.v7.widget.AppCompatTextView
            android:id="@+id/lblTerminal"
            android:background="@color/lightGray"
            style="@style/PurpleSubtitle"
            android:drawableRight="@drawable/i_down_yellow"
            android:drawableEnd="@drawable/i_down_yellow"
            android:padding="10dp"
            android:text="@string/lblTerminal"
            android:layout_weight="5"
            android:layout_width="0dp"
            android:layout_height="50dp"
            app:layout_constraintTop_toBottomOf="@+id/txt_search"
            app:layout_constraintRight_toLeftOf="@+id/view3"
            app:layout_constraintLeft_toLeftOf="@+id/guideline2"
            app:layout_constraintHorizontal_chainStyle="spread"/>

        <View
            android:background="@android:color/black"
            android:layout_width="1dp"
            android:layout_height="50dp"
            android:id="@+id/view3"
            app:layout_constraintTop_toBottomOf="@+id/txt_search"
            app:layout_constraintRight_toLeftOf="@+id/lblCategory"
            app:layout_constraintLeft_toRightOf="@+id/lblTerminal" />

        <android.support.v7.widget.AppCompatTextView
            android:id="@+id/lblCategory"
            android:background="@color/lightGray"
            android:padding="10dp"
            android:drawableRight="@drawable/i_down_yellow"
            android:drawableEnd="@drawable/i_down_yellow"
            style="@style/PurpleSubtitle"
            android:text="@string/lblCategory"
            android:layout_width="0dp"
            android:layout_height="50dp"
            app:layout_constraintTop_toTopOf="@+id/view3"
            app:layout_constraintRight_toRightOf="parent"
            app:layout_constraintLeft_toRightOf="@+id/view3" />



  ......
  ......
  ......

  </android.support.constraint.ConstraintLayout>

回答1:

Yes, so now in ConstraintLayout also we can handle visibility of particular groups of Views using the Group

This is a new feature introduced in ConstraintLayout which is currently in Beta version.

How to add beta ConstraintLayout to your project? Follow the steps below:

Add maven support in project gradle file as below

allprojects {
    repositories {
        maven { url 'https://maven.google.com' }
        jcenter()
    }
}

Then in app gradle dependencies add ConstraintLayout library dependency

compile 'com.android.support.constraint:constraint-layout:1.1.0-beta3'

Now you have to add a Group in your ConstraintLayout as follows

<android.support.constraint.Group
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:constraint_referenced_ids="button7,button3,button2"
        android:id="@+id/group" />  

Where in Group, the reference id...

app:constraint_referenced_ids="button7,button3,button2"

... contains the comma separated view id's you want to handle run time, so, in an Activity, you just bind the Group as below and handle the visibility

import android.support.constraint.Group; //import statement in activity

Group group=(Group)findViewById(R.id.group); //bind view from xml
group.setVisibility(View.VISIBLE); //this will visible all views
group.setVisibility(View.GONE); //this will set Gone to all views
group.setVisibility(View.INVISIBLE); //this will set INVISIBLE to all view

EDIT: ConstraintLayout 1.1.0 stable version was released on 12 April 2018 https://androidstudio.googleblog.com/2018/04/constraintlayout-110.html

implementation 'com.android.support.constraint:constraint-layout:1.1.0'

Edit for Android X: If anyone is using the Android X package, you can find package info here

https://developer.android.com/jetpack/androidx/migrate

回答2:

If you are using beta version of constraintlayout, please follow @pavan's answer

If you are using AndroidX, Please follow below steps to integrate constraintlayout and Group:

1) Add AndroidX constraint layout dependancy in your project:

implementation 'androidx.constraintlayout:constraintlayout:1.1.3'

2) Use ConstraintLayout Group as below in your project:

<androidx.constraintlayout.widget.Group
                    android:id="@+id/groupDetails"
                    android:layout_width="wrap_content"
                    android:visibility="gone" // Default visibility for group views
                    app:constraint_referenced_ids="textViewUserName, ..." // id's which you want to include in group
                    android:layout_height="wrap_content"/>

3) Here is the coding part for toggle visibility:

private lateinit var groupDetails:Group

...
groupDetails = findViewById(R.id.groupDetails)
groupDetails.visibility = View.GONE // Change visibility

Hope it's helps while using AndroidX.

回答3:

You can use that same Linear Layout as child of Constraint Layout too, OR you can also make all those 3 widgets as child of another Constraint Layout and make that layout as child of main Constraint Layout.

Then you can maintain the visibility and other stuff same as before.