I have a custom view CustomSettingEntry this is its xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/layout_custom_setting_entry_container"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="#+id/custom_setting_entry_title"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</RelativeLayout>
</LinearLayout>
Then I use it in a fragment and assign it an id:
<com.mypackage.name.CustomSettingEntry
android:id="#+id/layout_notification_setting"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:setting_title="#string/title"
app:setting_subtitle="#string/subtitle" />
My question is what's the difference between the LinearLayout with id layout_custom_setting_entry_container and the usage with id layout_notification_setting? do they refer to the same thing?
If I set a click listener on the custom view inside the fragment, then later in some condition disabled clicking on the root LinearLayout inside the custom view, will this stop the listener?
I understand your custom view is a subclass of LinearLayout which inflates an xml layout. If so, the resulting view hierarchy is
[LinearLayout (actually a CustomSettingEntry), id : layout_notification_setting]
[LinearLayout, id : layout_custom_setting_entry_container]
...
So there are two levels of viewgroups, each one with it own id.
By the way this is inefficient because, the outer viewgroup (your custom class) has only one child (the root of the xml).
On solution is to use a <merge> as root of the xml layout to skip one level. See Optimize by merging or Inflating layout for your custom view
for more details.
Related
I was planning on having two layout versions for the profile fragment, one for new user and one for logged in user.
How would I dynamically switch/choose the necessary layout in the Fragment's onCreateView() method?
The most straight-forward idea that comes to mind is to use two <include> layouts and hiding one of them in onCreateView() depending on variables. But I was wondering if there is a smarter approach.
Current layout xml:
The main content is inside the second FrameLayout and I'd like to have two versions to choose from.
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".ui.MainActivity">
<ImageView
android:id="#+id/profile_monk_head_imageview"
android:layout_width="match_parent"
android:layout_height="200dp"
android:contentDescription="#string/profile_monk_image_content_desc"
android:src="#drawable/monk_head" />
<androidx.core.widget.NestedScrollView
android:layout_width="match_parent"
android:layout_height="wrap_content">
<!-- This is what I want to switch out -->
<FrameLayout ... >
</androidx.core.widget.NestedScrollView>
</FrameLayout>
Use DataBindingUtil version inflate if layoutId is unknown in advance ( a.k.a dynamic binding). Otherwise, use the generated Binding's inflate method to ensure type-safe inflation.
Crosslink reference
I am writing a simple game and I'm wanting the main screen to have a choice of 3 layouts, for 2 handed, right handed or left handed.
I have an include for the controls. However I'm struggling to get the layout to change programatically. Been searching since last night but cannot find a way to do it, is it even possible?
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".GamePlay">
<include
android:layout_width="match_parent"
android:layout_height="88dp"
layout="#layout/hand_two" <!-- this is what needs to change depending on settings -->
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
android:id="#+id/handLayout"/>
</androidx.constraintlayout.widget.ConstraintLayout>
From the animusmind's answer:
Use a ViewStub instead of include:
<ViewStub
android:id="#+id/layout_stub"
android:inflatedId="#+id/message_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="0.75" />
Then in code, get a reference to the stub, set its layout resource, and inflate it:
ViewStub stub = (ViewStub) findViewById(R.id.layout_stub);
stub.setLayoutResource(R.layout.whatever_layout_you_want);
View inflated = stub.inflate();
Answer collected from kcoppock
If you have multiple views which you would like to load them on demand programatically, ViewStub is one of the solution
please visit like link viewStub for multiple view
I have multiple layouts that are defined in hierarchical order, The issue is when i try to access item that is defined in an inner layout, it gives me NullPointerException.
This is my layout structure.
R.layout.activity_map
-> <include layout="content_map">
-> <include layout="terrace_parent_map">
-> <include layout="terrace_collection_map">
Now terrace_collection_map has constraint layout, that i need to access from the activity.
Following is the layout.
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/constraintTerraceLayout"
>
</android.support.constraint.ConstraintLayout>
But when i try to get id of constraintLayout, it returns null.
constraintTerraceLayout= findViewById(R.id.constraintTerraceLayout);
**Edit - terrace_collection_map **
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/constraintTerraceLayout"
>
<ImageView
android:id="#+id/imageView30"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
android:background="#drawable/terrace" />
</android.support.constraint.ConstraintLayout>
Try by adding the <merge /> tag that helps you to eliminate redundant view groups in your view hierarchy when including one layout within another.
For example, if your main layout is a vertical LinearLayout in which two consecutive views can be re-used in multiple layouts, then the re-usable layout in which you place the two views requires its own root view.
So use <merge> tag, if activity_map.xml has LinearLayout as a parent tag. Then change your terrace_collection_map.xml parent tag as like below code :
<merge xmlns:android="http://schemas.android.com/apk/res/android">
//..........Your Custom Layout Design...........
</merge>
This link helps you briefly, https://developer.android.com/training/improving-layouts/reusing-layouts
As I mentioned in the title, I would like to use ViewStub as a generic layout. What I mean is, currently I have my base activity class and base fragment class to be extended for other activities or fragments. So since I have generic classes, I wonder if I can have a generic layout. Is it possible?
Example layout:
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context=".activities.Activity_Main">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<include layout="#layout/toolbar" />
<ViewStub
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/viewStub"
/>
</LinearLayout>
</android.support.design.widget.CoordinatorLayout>
Where #+id/viewStub content will change according to desired layout.
Yes, you can do that programmatically by using the setLayoutResource() method to which you pass the desired layout id.
ViewStub stub = (ViewStub) findViewById(R.id.viewStub);
stub.setLayoutResource(R.layout.some_layout);
View inflatedLayout = stub.inflate();
When inflate() is invoked, the ViewStub is replaced by the inflated View and the inflated View is returned. This lets applications get a reference to the inflated View without executing an extra findViewById().
Here is the reference.
I place two ListFragment in my MainActivity.
This is the ListFragment xml file: fragment1.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<ListView
android:id="#id/android:list"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:drawSelectorOnTop="false" />
</LinearLayout>
My question is, why must I use android:id="#id/android:list" here? When I use, e.g., #+id/frag_list, the program crashes with Error "inflating class fragment".
ListActivity has a default layout that consists of a single, full-screen list in the center of the screen. However, if you desire, you can customize the screen layout by setting your own view layout with setContentView() in onCreate(). To do this, your own view MUST contain a ListView object with the id "#android:id/list" (or list if it's in code). Its same when your class extends ListFragment.
For more info do check the docs
http://developer.android.com/reference/android/app/ListActivity.html.
You can extend Fragment instead of ListFragment. Have a custom layout with ListView. Then you can provide any id for your listview.