I am developing an Android Project from scratch that has min 23 API level and uses AndroidX. When I complete the XML layouts (for ex. simple activity_layout) there is options to pick like between TextView & androidx.appcompat.widget.AppCompatTextView.
Is TextView targeting AndroidX?
If yes, can I ignore using androidx.appcompat.widget.AppCompatTextView or other AppCompat component if I target min 23 API level?
Is TextView targeting AndroidX?
The question in not clear but the class androidx.appcompat.widget.AppCompatTextView extends android.widget.TextView.
You can check the official doc.
A TextView which supports compatible features on older versions of the platform.
Also:
This will automatically be used when you use TextView in your layouts and the top-level activity / dialog is provided by appcompat. You should only need to manually use this class when writing custom views.
Then.
If yes, can I ignore using androidx.appcompat.widget.AppCompatTextView or other AppCompat component if I target min 23 API level?
You can ignore this view if you are using the androidx.appcompat:appcompat:x.y.z library.
from the standard android documentation for AppCompatTextView:
This will automatically be used when you use TextView in your layouts
and the top-level activity / dialog is provided by appcompat. You
should only need to manually use this class when writing custom views.
taken from here : https://developer.android.com/reference/android/support/v7/widget/AppCompatTextView , so yes, you can just use TextView as long as your activity extends AppCompatActivity
As pointed out by #Gabriele Mariotti (thank you to him) you should check out the documentation here https://developer.android.com/reference/kotlin/androidx/appcompat/widget/AppCompatTextView for more information regarding androidx AppCompatTextView documentation specifically.
The androidX documentation states the following regarding an AppCompatTextView:
This will automatically be used when you use TextView in your layouts
and the top-level activity / dialog is provided by appcompat. You
should only need to manually use this class when writing custom views
an exact duplicate of the standard android documentation.
My initial answer only made use of this : https://developer.android.com/jetpack/androidx/releases/appcompat to check for any known limitations or history regarding androidx AppCompatTextView
I assumed that:
Like the Support Library, AndroidX ships separately from the Android
OS and provides backwards-compatibility across Android releases.
AndroidX fully replaces the Support Library by providing feature
parity and new libraries.
taken from https://developer.android.com/jetpack/androidx would be sufficient to make that assumption, +1 to him for the help :)
Related
Android Studio marks as error this line:
public class ParallaxView extends ImageView
Here the error:
This custom view should extend android.support.v7.widget.AppCompatImageView instead less... (Ctrl+F1)
In order to support features such as tinting, the appcompat library will automatically load special appcompat replacements for the builtin widgets.
However, this does not work for your own custom views. Instead of extending the android.widget classes directly, you should instead extend one of the delegate classes in android.support.v7.widget.AppCompat.
It recommends me to extend AppCompatImageView but then my JUnit test don't pass because AppCompatImageView needs a mock Context with resources and Imageview doesn't need this.
Here the question to solve the other problem:
NullPointerException creating an AppCompatImageView with mock Context
Can I ignore this error and use ImageView? Any other solution?
Using AppCompat widgets allows you to have some material design (and other new) features on devices with pre-Lollipop versions of Android.
At this point AppCompatImageView only provides the support for background tint and vector drawables. If you don't use them, then extending the regular ImageView will be fine.
It's not really an error. The app builds successfully right? It's only Android Studio which marks it as error.
You can change this to warning by editing the 'Appcompat Custom Widgets' inspection settings.
Given the following:
Android documentation says :
AppCompatActivity - Adds an application activity class that can be used as a base class for activities that use the Support Library action bar implementation.
I'm not considering adding action bar to my activity
I need some material design widgets, which I can control only through AppCompat or material theme, but the latest need API >= 21, which is not my case.
I tested Theme.AppCompat.Light.NoActionBar with Activity class and it works well.
--
Is there an issue with using Activity class with AppCompat theme in my case?
The AppCompat library is intended to make compatibility with olders API, so the Theme and all components may work well in older systems.
I think the only concern is to always use the AppCompat elements and not the regular ones.
Example, use AppCompatEditText, AppCompatTextView, etc... And always refers to they with the AppCompat (AppCompatEditText editText;)
I have used a lot the support library and not have others issues, considering the visual elements may be a little different when using an API minor than 21
No.There is not issues with AppcompactActivity & support libaray. You can refere this link
To gain more rich & amazing look go with support library,Try to do material design
I am building app with the sdk levels (min 19- max 22), And i want to use material design in my app. Should i extend Activity or AppcompatActivity? What is the difference? I know AppcompatActivity is support library for backward compatability, Other than that is there any main difference between both?
Extending Activity is deprecated so you should use AppCompatActivity.
Ya we can.Just add the library in the Gradle file and use it in the activity.
I would like to Tint my ToggleButton, which doesn't available in Tintable View support library. Currently I am using appcompat support library v23.1.0
To make ViewCompat.setBackgroundTintList() works, the View needs to implement TintableBackgroundView.
However, there is almost 0 example of how to do this. I looked into the source code of AppCompatButton (which implements TintableBackgroundView), it used of a private class AppCompatBackgroundHelper, which is not accessible outside of the support library.
Any idea?
In Android what is the main difference between extending Lifecycler Activity, Activity,ActionBarActivity & AppCompactActivity? How do these classes differ from each other in terms of usage?
extending ActionBarActivity gives you the ActionBars functionality on every API level >= 7
by extending Activity you can avoid adding additional projects/libraries to your project but you'll lack the ActionBar on api levels below 11
edit: More details:
ActionBarActivity is part of the Support Library. Support libraries are used to deliver newer features on older platforms. For example the ActionBar was introduced in API 11 and is part of the Activity by default (depending on the theme actually). In contrast there is no ActionBar on the older platforms. So the support library adds a child class of Activity (ActionBarActivity) that provides the ActionBar's functionality and ui
edit2: Update April 2015 - it looks like the ActionBarActivityis deprecated in revision 22.1.0 of the Support Library. AppCompatActivity should be used instead.
edit3: Update Aug 2017 - LifecycleActivity is a LifecycleOwner but:
"Since the Architecture Components are in alpha stage, Fragment and
AppCompatActivity classes cannot implement it (because we cannot add a
dependency from a stable component to an unstable API). Until
Lifecycle is stable, LifecycleActivity and LifecycleFragment classes
are provided for convenience. After the Lifecycles project is
released, support library fragments and activities will implement the
LifecycleOwner interface; LifecycleActivity and LifecycleFragment will
be deprecated at that time."
(copied from the Architecture Components guideline)
If you look carefully, you will see this
public class ActionBarActivity extends FragmentActivity
implements ActionBarDrawerToggle.DelegateProvider TaskStackBuilder.SupportParentable
Here you can read about FragmentActivity:
http://developer.android.com/reference/android/support/v4/app/FragmentActivity.html
And differences between Activity and FragmentActivity:
Difference between Activity and FragmentActivity
Also, there are some new themes for styling actionBar...
https://developer.android.com/training/basics/actionbar/styling.html
Actionbar is introduced in API level 11. com.android.support:appcompat-v7:+ is a support library which allows you to have an ActionBar in your app for devices running on Android 3.0 or below. So, if you need actionbar below api level 11 your Activity needs to extend ActionBarActivity.
If you are targetting api level 11 and above then you don't need to extend ActionBarActivity and reference AppCompat. You can simply extend Activity and you will have actionabr by default.
Android Studio default project includes it automatically in dependencies and extends ActionbarActivity instead of Activity in order to use it.
The ActionBarActivity or the SupportActionBarActivity have additional methods and properties that are not in a generic Activity. for example methods for adding tabs are present in the ActionBarActivity and not in a generic Activity.
The major difference being you don't get an ActionBar on a generic Activity.
ActionBarActivity just has more support libraries and better usage of the newer themes available from api 11.
"In its most basic form, the action bar displays the title for the activity and the app icon on the left. Even in this simple form, the action bar is useful for all activities to inform users about where they are and to maintain a consistent identity for your app."
You are using Android support library When you come to to the Actionbaractivity . so the uses of Support library is your application can be suport for maximum number of devices. Support library gives to your application the power of Backward compatibilty. Actionbaractivity gives you the mulitiple feature like Actionbardrawer toggle etc.. there are more support libraries available. see this link .. and share to your friends...https://developer.android.com/tools/support-library/index.html