I would like to create a custom linear layout (to work as some basic list) which accepts a custom parameter from xml, like this:
<MyLinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
myns:layout_to_inflate="#layout/list_item"/>
Then, use it in the constructor:
String layoutToInflate = attrs.getAttributeValue(NAMESPACE, "layout_to_inflate");
I get "#layout/list_item". It is not resolved by the system into the int value which is accessible in R.layout.list_item.
Sure I can parse it and use Resources.getIdentifier to look up the ID, then inflate it, but I think that is not the way.
Then... what is the way? Can I get the system to resolve it directly into the int?
UPDATE:
list_item.xml:
<TextView 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:text="Text here!" />
activity_main.xml:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:myns="http://com.example.layoutinflate"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity" >
<com.example.layoutinflate.MyLinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
myns:layout_to_inflate="#layout/list_item" />
</RelativeLayout>
Contents MyLinearLayout.java:
public class MyLinearLayout extends LinearLayout {
private static final String TAG = MyLinearLayout.class.getSimpleName();
public MyLinearLayout(Context context, AttributeSet attrs) {
super(context, attrs);
TypedArray styledAttributes = context.obtainStyledAttributes(attrs, R.styleable.MyLinearLayout);
int layoutId = styledAttributes.getResourceId(R.styleable.MyLinearLayout_layout_to_inflate, -1);
int layoutIdInt = styledAttributes.getInt(R.styleable.MyLinearLayout_layout_to_inflate, -1);
String str = styledAttributes.getString(R.styleable.MyLinearLayout_layout_to_inflate);
Log.d(TAG, Integer.toString(layoutId) + ";" + str + ";" + layoutIdInt); //-1; null; -1
styledAttributes.recycle();
}
}
Thanks!
Make sure you correctly define this custom attribute inside your attrs.xml. It has to be like this:
<attr name="layout_to_inflate" format="reference" />
<declare-styleable name="MyLinearLayout">
<attr name="layout_to_inflate" />
</declare-styleable>
Then you can get this value inside your MyLinearLayout object with this:
int layoutToInflateId = attributes.getResourceId(R.styleable.MyLinearLayout_layout_to_inflate, R.layout.<default_layout_to_inflate>);
Related
I want to create a custom view with 2 TextViews, with possibility change text and text appearances from xml. This view should have two state - normal and selected (TextViews style should be different for each state).
I need some example for it.
Custom views are pretty basic and there are examples all over the internet. For something simple like two text views, it's usually easiest to extend LinearLayout.
Here is the LinearLayout with two text views, arranged side by side.
res/double_text.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="#+id/left_text"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:maxLines="1"/>
<TextView
android:id="#+id/right_text"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:maxLines="1"/>
</LinearLayout>
Next we define a styleable resource block so we can add custom attributes to our custom layout.
res/values/attrs.xml
<resources>
<declare-styleable name="DoubleText">
<attr name="leftText" format="string" />
<attr name="rightText" format="string" />
<attr name="android:ems" />
</declare-styleable>
</resources>
Next the class file for DoubleText custom view. In here we pull out the custom attributes and set each of the TextViews.
DoubleTextView.java
public class DoubleTextView extends LinearLayout {
LinearLayout layout = null;
TextView leftTextView = null;
TextView rightTextView = null;
Context mContext = null;
public DoubleTextView(Context context) {
super(context);
mContext = context;
}
public DoubleTextView(Context context, AttributeSet attrs) {
super(context, attrs);
mContext = context;
TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.DoubleText);
String leftText = a.getString(R.styleable.DoubleText_leftText);
String rightText = a.getString(R.styleable.DoubleText_rightText);
leftText = leftText == null ? "" : leftText;
rightText = rightText == null ? "" : rightText;
String service = Context.LAYOUT_INFLATER_SERVICE;
LayoutInflater li = (LayoutInflater) getContext().getSystemService(service);
layout = (LinearLayout) li.inflate(R.layout.double_text, this, true);
leftTextView = (TextView) layout.findViewById(R.id.left_text);
rightTextView = (TextView) layout.findViewById(R.id.right_text);
leftTextView.setText(leftText);
rightTextView.setText(rightText);
a.recycle();
}
public DoubleTextView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
mContext = context;
}
#SuppressWarnings("unused")
public void setLeftText(String text) {
leftTextView.setText(text);
}
#SuppressWarnings("unused")
public void setRightText(String text) {
rightTextView.setText(text);
}
#SuppressWarnings("unused")
public String getLeftText() {
return leftTextView.getText().toString();
}
#SuppressWarnings("unused")
public String getRightText() {
return rightTextView.getText().toString();
}
}
Finally, using the custom class is as simple as declaring it in a layout file.
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
tools:showIn="#layout/activity_main"
tools:context=".MainActivity">
<TextView
android:id="#+id/main_text"
android:text="Hello World!"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#color/custom"/>
<example.com.test.DoubleTextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:leftText="Text Left"
app:rightText="Text Right"
android:layout_below="#+id/main_text"/>
</RelativeLayout>
Easy peasy.
Recently I was working on a project that use Resources.getIdentifier() a lot. All works fun but problems come out when I try to use this method to retrieve on custom attributes.
So I declare some attributes int the xml
<declare-styleable name="WemeFloatExpandMenuItem">
<attr name="label" format="string|reference"/>
<attr name="icon" format="reference"/>
<attr name="showDot" format="boolean"/>
</declare-styleable>
Then I apply this attribute in xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:minHeight="36dp"
android:orientation="horizontal"
android:showDividers="middle"
android:divider="#drawable/weme_float_menu_divider"
android:background="#drawable/weme_float_menu_bg">
<com.weme.chat.FloatExpandMenuItem
android:id="#id/wemepay_float_menu_account"
android:layout_width="wrap_content"
android:layout_height="match_parent"
app:label="#string/wemepay_float_menu_title_account"
app:icon="#drawable/weme_float_menu_account"/>
In FloatExpandMenuItem
TypedArray a = context.obtainStyledAttributes(attrs, ResourceUtils.getResIds(getContext().getPackageName(), "styleable", "WemeFloatExpandMenuItem"));
labelRes = a.getString(ResourceUtils.getResId(getContext(),"styleable","WemeFloatExpandMenuItem_label"));
iconRes = a.getDrawable(ResourceUtils.getResId(getContext(), "styleable", "WemeFloatExpandMenuItem_icon"));
showDot = a.getBoolean(ResourceUtils.getResId(getContext(), "styleable", "WemeFloatExpandMenuItem_showDot"), false);
a.recycle();
ResourceUtils.getResId was wrapper for Resources.getIdentifier like this
public static int getResId(Context context, String resTypeName, String resName) {
if (context == null) {
return 0;
}
Resources res = context.getResources();
String packageName = context.getPackageName();
return res.getIdentifier(resName, resTypeName, packageName);
}
And weird things happened, I tried to debug in FloatExpandMenuItem , the ResourceUtils.getResId always return 0 when retrieve the label,icon,showDot attributes.
So I was wondering how I should change the code when I try to deal with custom attributes when using Resources.getIdentifier() ?
I want to implement a SeekBar that automatically updates a TextView, for the actual value, the maximum value and a minimum value. I derive from SeekBar and define 3 named attributes with the format being reference.
In the constructor, I get a TypedArray by calling obtainStyledAttributes(). TypedArray contains a lot of getters for every kind of attribute types. What I am missing is some kind of Object getReference() or int getReferenceId().
How do I obtain the value for a reference attribute?
Edit:
I have an attribute definition for a class MinMaxSlider, that looks like this:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="MinMaxSlider">
<attr name="min" format="integer" />
<attr name="valueView" format="reference" />
</declare-styleable>
</resources>
a snipped out of the layout definition looks like this:
<LinearLayout
style="#style/ParameterLabelLayout"
android:orientation="horizontal">
<TextView
style="#style/ParameterSliderLabel"
android:text="min. Interval" />
<TextView
android:id="#+id/min_connection_interval_slider_value"
style="#style/ParameterSliderValue"/>
</LinearLayout>
<com.roche.rcpclient.MinMaxSlider
style="#style/ParameterSlider"
android:id="#+id/min_connection_interval_slider"
android:max="3200"
custom:valueView="#id/min_connection_interval_slider_value"
custom:min="1"/>
Here, the MinMaxSlider should reference one of the TextViews above to display its current value there.
From within the constructor of MinMaxSlider, I can lookup the min attributes value.
If I try to lookup the valueView attribute as an integer, I always get the default value (0), not R.id.min_connection_interval_slider as I would expect.
Edit: the right function to lookup a reference seems to be getResourceId. The obtained integer id can be used to use findViewById later, when the overall object hierarchy is constructed.
In my case, I register an OnSeekBarChangeListener() and lookup the View in the callback, when the callback is fired.
You can't receive reference via findViewById in constructor. Because it is not attached to layout yet.
Reference: https://developer.android.com/training/custom-views/create-view.html#applyattr
When a view is created from an XML layout, all of the attributes in
the XML tag are read from the resource bundle and passed into the
view's constructor as an AttributeSet. Although it's possible to read
values from the AttributeSet directly, doing so has some
disadvantages:
Resource references within attribute values are not resolved Styles
are not applied Instead, pass the AttributeSet to
obtainStyledAttributes(). This method passes back a TypedArray array
of values that have already been dereferenced and styled.
You can receive in another methods.
For example:
attrs.xml
<declare-styleable name="CustomTextView">
<attr name="viewPart" format="reference"></attr>
</declare-styleable>
yourLayout.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:baselineAligned="false"
android:gravity="center_vertical"
android:orientation="horizontal">
<tr.com.ui.utils.CustomTextView
android:id="#+id/chat_msg"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="right|bottom"
android:focusableInTouchMode="false"
android:gravity="left"
android:text="test"
app:viewPart="#id/date_view" />
<TextView
android:id="#+id/date_view"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:gravity="right" />
</LinearLayout>
CustomTextView.java
public class CustomTextView extends TextView {
private View viewPart;
private int viewPartRef;
public CustomTextView(Context context) {
super(context);
}
public CustomTextView(Context context, AttributeSet attrs) {
super(context, attrs);
TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.CustomTextView, 0, 0);
try {
viewPartRef = a.getResourceId(R.styleable.CustomTextView_viewPart, -1);
} catch (Exception e) {
e.printStackTrace();
}
}
#Override
protected void onAttachedToWindow() {
super.onAttachedToWindow();
viewPart = ((View) this.getParent()).findViewById(viewPartRef);
}
public View getViewPart() {
return viewPart;
}
public void setViewPart(View viewPart) {
this.viewPart = viewPart;
}}
You can decide your scenario and modify this code.
I'd like to define custom attributes in Android fragment using XML (without using bundle additional parameters) like declare-styleable in custom controls. But there are no constructors with AttrSet parameters, so is it possible? Can i just override public void onInflate(android.app.Activity activity, android.util.AttributeSet attrs, android.os.Bundle savedInstanceState) in order to get attributes support?
The Link for Support4Demos is changed or can be changed so posting the complete solution. Here it goes.
Create attrs.xml file in res/values folder. Or add the below content if file already exists.
<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="MyFragment">
<attr name="my_string" format="string"/>
<attr name="my_integer" format="integer"/>
</declare-styleable>
Override the onInflate delegate of fragment and read attributes in it
/**
* Parse attributes during inflation from a view hierarchy into the
* arguments we handle.
*/
#Override
public void onInflate(Activity activity, AttributeSet attrs, Bundle savedInstanceState) {
super.onInflate(activity, attrs, savedInstanceState);
Log.v(TAG,"onInflate called");
TypedArray a = activity.obtainStyledAttributes(attrs,R.styleable.MyFragment);
CharSequence myString = a.getText(R.styleable.MyFragment_my_string);
if(myString != null) {
Log.v(TAG, "My String Received : " + myString.toString());
}
int myInteger = a.getInt(R.styleable.AdFragment_my_integer, -1);
if(myInteger != -1) {
Log.v(TAG,"My Integer Received :" + myInteger);
}
a.recycle();
}
Pass these attributes in your layout file as following. Just an example
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="This is android activity" />
<fragment
android:id="#+id/ad_fragment"
android:name="com.yourapp.packagename.MyFragment"
android:layout_width="fill_parent"
android:layout_height="50dp"
android:layout_alignParentBottom="true"
app:my_string="Hello This is HardCoded String. Don't use me"
app:my_integer="30" />
</RelativeLayout>
Thats all. Its a working solution.
While doing this if you see any namespace error in xml.
try project cleaning again and again.
This is pathetic but Eclipse and adt misbehaves sometimes.
#Override
public void onInflate(Activity activity, AttributeSet attrs, Bundle savedInstanceState) {
super.onInflate(activity, attrs, savedInstanceState);
// Your code here to process the attributes
}
I am trying to create a custom View that would replace a certain layout that I use at multiple places, but I am struggling to do so.
Basically, I want to replace this:
<RelativeLayout
android:id="#+id/dolphinLine"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:background="#drawable/background_box_light_blue"
android:padding="10dip"
android:layout_margin="10dip">
<TextView
android:id="#+id/dolphinTitle"
android:layout_width="200dip"
android:layout_height="100dip"
android:layout_alignParentLeft="true"
android:layout_marginLeft="10dip"
android:text="#string/my_title"
android:textSize="30dip"
android:textStyle="bold"
android:textColor="#2E4C71"
android:gravity="center"/>
<Button
android:id="#+id/dolphinMinusButton"
android:layout_width="100dip"
android:layout_height="100dip"
android:layout_toRightOf="#+id/dolphinTitle"
android:layout_marginLeft="30dip"
android:text="#string/minus_button"
android:textSize="70dip"
android:textStyle="bold"
android:gravity="center"
android:layout_marginTop="1dip"
android:background="#drawable/button_blue_square_selector"
android:textColor="#FFFFFF"
android:onClick="onClick"/>
<TextView
android:id="#+id/dolphinValue"
android:layout_width="100dip"
android:layout_height="100dip"
android:layout_marginLeft="15dip"
android:background="#android:drawable/editbox_background"
android:layout_toRightOf="#+id/dolphinMinusButton"
android:text="0"
android:textColor="#2E4C71"
android:textSize="50dip"
android:gravity="center"
android:textStyle="bold"
android:inputType="none"/>
<Button
android:id="#+id/dolphinPlusButton"
android:layout_width="100dip"
android:layout_height="100dip"
android:layout_toRightOf="#+id/dolphinValue"
android:layout_marginLeft="15dip"
android:text="#string/plus_button"
android:textSize="70dip"
android:textStyle="bold"
android:gravity="center"
android:layout_marginTop="1dip"
android:background="#drawable/button_blue_square_selector"
android:textColor="#FFFFFF"
android:onClick="onClick"/>
</RelativeLayout>
By this:
<view class="com.example.MyQuantityBox"
android:id="#+id/dolphinBox"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:myCustomAttribute="#string/my_title"/>
So, I do not want a custom layout, I want a custom View (it should not be possible for this view to have child).
The only thing that could change from one instance of a MyQuantityBox to another is the title. I would very much like to be able to specify this in the XML (as I do on the last XML line)
How can I do this? Should I put the RelativeLayout in a XML file in /res/layout and inflate it in my MyBoxQuantity class? If yes how do I do so?
Thanks!
A bit old, but I thought sharing how I'd do it, based on chubbsondubs' answer:
I use FrameLayout (see Documentation), since it is used to contain a single view, and inflate into it the view from the xml.
Code following:
public class MyView extends FrameLayout {
public MyView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
initView();
}
public MyView(Context context, AttributeSet attrs) {
super(context, attrs);
initView();
}
public MyView(Context context) {
super(context);
initView();
}
private void initView() {
inflate(getContext(), R.layout.my_view_layout, this);
}
}
Here is a simple demo to create customview (compoundview) by inflating from xml
attrs.xml
<resources>
<declare-styleable name="CustomView">
<attr format="string" name="text"/>
<attr format="reference" name="image"/>
</declare-styleable>
</resources>
CustomView.kt
class CustomView #JvmOverloads constructor(context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = 0) :
ConstraintLayout(context, attrs, defStyleAttr) {
init {
init(attrs)
}
private fun init(attrs: AttributeSet?) {
View.inflate(context, R.layout.custom_layout, this)
val image_thumb = findViewById<ImageView>(R.id.image_thumb)
val text_title = findViewById<TextView>(R.id.text_title)
val ta = context.obtainStyledAttributes(attrs, R.styleable.CustomView)
try {
val text = ta.getString(R.styleable.CustomView_text)
val drawableId = ta.getResourceId(R.styleable.CustomView_image, 0)
if (drawableId != 0) {
val drawable = AppCompatResources.getDrawable(context, drawableId)
image_thumb.setImageDrawable(drawable)
}
text_title.text = text
} finally {
ta.recycle()
}
}
}
custom_layout.xml
We should use merge here instead of ConstraintLayout because
If we use ConstraintLayout here, layout hierarchy will be ConstraintLayout->ConstraintLayout -> ImageView + TextView => we have 1 redundant ConstraintLayout => not very good for performance
<?xml version="1.0" encoding="utf-8"?>
<merge 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"
tools:parentTag="android.support.constraint.ConstraintLayout">
<ImageView
android:id="#+id/image_thumb"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
tools:ignore="ContentDescription"
tools:src="#mipmap/ic_launcher" />
<TextView
android:id="#+id/text_title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_constraintEnd_toEndOf="#id/image_thumb"
app:layout_constraintStart_toStartOf="#id/image_thumb"
app:layout_constraintTop_toBottomOf="#id/image_thumb"
tools:text="Text" />
</merge>
Using
activity_main.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"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<your_package.CustomView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#f00"
app:image="#drawable/ic_android"
app:text="Android" />
<your_package.CustomView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#0f0"
app:image="#drawable/ic_adb"
app:text="ADB" />
</LinearLayout>
Result
See full code on:
Github
Yes you can do this. RelativeLayout, LinearLayout, etc are Views so a custom layout is a custom view. Just something to consider because if you wanted to create a custom layout you could.
What you want to do is create a Compound Control. You'll create a subclass of RelativeLayout, add all our your components in code (TextView, etc), and in your constructor you can read the attributes passed in from the XML. You can then pass that attribute to your title TextView.
http://developer.android.com/guide/topics/ui/custom-components.html
Use the LayoutInflater as I shown below.
public View myView() {
View v; // Creating an instance for View Object
LayoutInflater inflater = (LayoutInflater) getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
v = inflater.inflate(R.layout.myview, null);
TextView text1 = v.findViewById(R.id.dolphinTitle);
Button btn1 = v.findViewById(R.id.dolphinMinusButton);
TextView text2 = v.findViewById(R.id.dolphinValue);
Button btn2 = v.findViewById(R.id.dolphinPlusButton);
return v;
}
In practice, I have found that you need to be a bit careful, especially if you are using a bit of xml repeatedly. Suppose, for example, that you have a table that you wish to create a table row for each entry in a list. You've set up some xml:
In my_table_row.xml:
<?xml version="1.0" encoding="utf-8"?>
<TableRow xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent" android:id="#+id/myTableRow">
<ImageButton android:src="#android:drawable/ic_menu_delete" android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="#+id/rowButton"/>
<TextView android:layout_height="wrap_content" android:layout_width="wrap_content" android:textAppearance="?android:attr/textAppearanceMedium" android:text="TextView" android:id="#+id/rowText"></TextView>
</TableRow>
Then you want to create it once per row with some code. It assume that you have defined a parent TableLayout myTable to attach the Rows to.
for (int i=0; i<numRows; i++) {
/*
* 1. Make the row and attach it to myTable. For some reason this doesn't seem
* to return the TableRow as you might expect from the xml, so you need to
* receive the View it returns and then find the TableRow and other items, as
* per step 2.
*/
LayoutInflater inflater = (LayoutInflater)getBaseContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View v = inflater.inflate(R.layout.my_table_row, myTable, true);
// 2. Get all the things that we need to refer to to alter in any way.
TableRow tr = (TableRow) v.findViewById(R.id.profileTableRow);
ImageButton rowButton = (ImageButton) v.findViewById(R.id.rowButton);
TextView rowText = (TextView) v.findViewById(R.id.rowText);
// 3. Configure them out as you need to
rowText.setText("Text for this row");
rowButton.setId(i); // So that when it is clicked we know which one has been clicked!
rowButton.setOnClickListener(this); // See note below ...
/*
* To ensure that when finding views by id on the next time round this
* loop (or later) gie lots of spurious, unique, ids.
*/
rowText.setId(1000+i);
tr.setId(3000+i);
}
For a clear simple example on handling rowButton.setOnClickListener(this), see Onclicklistener for a programmatically created button.
There are multiple answers which point the same way in different approaches, I believe the below is the simplest approach without using any third-party libraries, even you can use it using Java.
In Kotlin;
Create values/attr.xml
<resources>
<declare-styleable name="DetailsView">
<attr format="string" name="text"/>
<attr format="string" name="value"/>
</declare-styleable>
</resources>
Create layout/details_view.xml file for your view
<?xml version="1.0" encoding="utf-8"?>
<merge xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="#+id/text_label"
android:layout_width="0dip"
android:layout_height="wrap_content"
android:layout_weight="0.5"
tools:text="Label" />
<TextView
android:id="#+id/text_value"
android:layout_width="0dip"
android:layout_height="wrap_content"
android:layout_weight="0.5"
tools:text="Value" />
</LinearLayout>
</merge>
Create the custom view widget DetailsView.kt
import android.content.Context
import android.content.res.TypedArray
import android.util.AttributeSet
import android.view.View
import android.widget.LinearLayout
import android.widget.TextView
import com.payable.taponphone.R
class DetailsView #JvmOverloads constructor(
context: Context,
attrs: AttributeSet? = null,
defStyleAttr: Int = 0
) : LinearLayout(context, attrs, defStyleAttr) {
private val attributes: TypedArray = context.obtainStyledAttributes(attrs, R.styleable.DetailsView)
private val view: View = View.inflate(context, R.layout.details_view, this)
init {
view.findViewById<TextView>(R.id.text_label).text = attributes.getString(R.styleable.DetailsView_text)
view.findViewById<TextView>(R.id.text_value).text = attributes.getString(R.styleable.DetailsView_value)
}
}
That's it now you can call the widget anywhere in your app as below
<com.yourapp.widget.DetailsView
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:text="Welcome"
app:value="Feb" />
A simple Custom View using Kotlin
Replace FrameLayout with whatever view you Like to extend
/**
* Simple Custom view
*/
class CustomView#JvmOverloads
constructor(context: Context,
attrs: AttributeSet? = null,
defStyleAttr: Int = 0)
: FrameLayout(context, attrs, defStyleAttr) {
init {
// Init View
val rootView = (getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE) as LayoutInflater)
.inflate(R.layout.custom_layout, this, true)
val titleView= rootView.findViewById(id.txtTitle)
// Load Values from XML
val attrsArray = getContext().obtainStyledAttributes(attrs, R.styleable.CutsomView, defStyleAttr, 0)
val titleString = attrsArray.getString(R.styleable.cutomAttrsText)
attrsArray.recycle()
}
}