Trouble referring to a custom View in a layout XML - android

I am trying to refer to a custom View in the helloWorld XML layout but I get the following exception:
Error inflating class acme.my.MyTextView.
However, I am able to instantiate the view and add it to the main content view manually. The custom View is built from it's own XML layout. How do I get this to work?
public class MyTextView extends LinearLayout {
MyTextView(Context context){
super(context);
LayoutInflater layoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
layoutInflater.inflate(R.layout.my_text_view,this);
}
MyTextView(Context context, AttributeSet attrs){
super(context, attrs);
LayoutInflater layoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
layoutInflater.inflate(R.layout.my_text_view,this);
}
}
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="#string/hello"
/>
<view class = "acme.my.MyTextView"
android:id="#+id/myView"
android:orientation="vertical"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>

The constructors aren't public.
:(

you have to call it like this
<com.example.MyLayout
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="wrap_content" />
Also make your constructors public

Related

CustomView with xml doesn't show up on screen

I am trying to add my custom view to the main activity's xml.
I have created the following xml for the view:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Testing custom view"
android:textSize="20dp" />
</LinearLayout>
And created the following class in which the above xml is inflated:
public class TestView extends LinearLayout {
public TestView(Context context, #Nullable AttributeSet attrs) {
super(context, attrs);
View.inflate(context, R.layout.test_name, null);
}
And in the xml of the main activity I have added the custom view like below:
<LinearLayout 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"
tools:context="com.example.myapplication.MainActivity">
<com.example.myapplication.TestView
android:id="#+id/submit_area"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
When I am running the app, I am getting an empty screen. It's not showing the textview which displays "Testing custom view".
Any help would much appreciated.
Thanks
Your view inflation code in your custom view looks wrong.Try it the way given below.
LayoutInflater inflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
inflater.inflate(R.layout.view_color_options, this, true);

Android. How to adjust height and width of a custom component using XML attributes?

Is there any way to adjust height and width of a custom component using XML attributes?
For example, I created a component and its layout.
Here is XML layout of the component:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="horizontal" >
<TextView
android:id="#+id/textView1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="TextView" />
<TextView
android:id="#+id/textView2"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="TextView" />
<TextView
android:id="#+id/textView3"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="TextView" />
</LinearLayout>
And here is a simple class that inflates this layout:
public class CustomComponent extends LinearLayout
{
public CustomComponent(Context context, AttributeSet attrs)
{
super(context, attrs);
LayoutInflater inflater = (LayoutInflater)context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
ViewGroup view = (ViewGroup)inflater.inflate(
R.layout.custom_component, null);
addView(view);
}
}
The custom component is used in layout of some activity that looks something like this:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<view
class = "com.tests.CustomComponent"
android:layout_width="fill_parent"
android:layout_height="fill_parent" />
</LinearLayout>
The component is meant to be stretched to full size of a screen (that's why its layout parameters set to "fill_parent") but that is never happen.
Can anyone help me with this?
Seeing as your CustomComponent extends LinearLayout, you just need to inflate the layout directly into it (parsing this as the ViewGroup, as your CustomComponent will be the holding view):
public class CustomComponent extends LinearLayout
{
public CustomComponent(Context context, AttributeSet attrs)
{
super(context, attrs);
inflate( context, R.layout.custom_component, this );
}
}
If that doens't work, try supplying only the constructor that takes a context:
public class CustomComponent extends LinearLayout
{
public CustomComponent(Context context)
{
super(context);
inflate( context, R.layout.custom_component, this );
}
}

Error in creation of custom view

i have customview, i want to add that in the xml file i tried like this but i am getting this error
Custom view TouchImageView is not using the 2- or 3-argument View constructors;
XML attributes will not work
this is the xml i am using..
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<view
class="com.zoom.TouchImageView"
android:id="#+id/webView1"
android:layout_width="fill_parent"
android:layout_height="fill_parent" />
</LinearLayout>
Add the constructor:
public TouchImageView(Context context, AttributeSet attributeSet)
{
super(context, attributeSet);
//TODO:
}
to your custom View class.

How to populate a compound viewgroup extending from LinearLayout?

I am trying to create a compound viewgroup after inflating the group from an XML file.
The viewgroup is composed as: A LinearLayout Root, 2 child LinearLayouts. I am able to see the layout correctly in the layout editor; however, when I attempt to add a view (say a button) from the editor, the view does not show up and the application immediately force closes. I was told i may need to Override the onLayout method to correctly draw the view components but I'm am fairly confused.
My Class:
public class FocusBox extends LinearLayout {
private LinearLayout rootLayout,
contentLayout,
topLayout;
public FocusBox(Context context)
{
super(context, null);
}
public FocusBox(Context context, AttributeSet attrs) {
super(context, attrs);
LayoutInflater inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
inflater.inflate(R.layout.focus_box, this);
rootLayout = (LinearLayout)findViewById(R.id.focusBoxParent);
contentLayout = (LinearLayout)findViewById(R.id.focusBottom);
topLayout = (LinearLayout)findViewById(R.id.focusTop);
}
}
And the 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:padding="4dp"
android:id="#+id/focusBoxParent"
android:orientation="vertical">
<LinearLayout
android:background="#drawable/gradients"
android:layout_weight=".1"
android:gravity="center"
android:id="#+id/focusTop"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<TextView
android:text="TextView"
android:id="#+id/focusTitle"
android:layout_height="wrap_content"
android:gravity="center"
android:layout_width="wrap_content"/>
</LinearLayout>
<LinearLayout
android:layout_height="wrap_content"
android:layout_width="match_parent"
android:layout_weight=".9"
android:id="#+id/focusBottom"
android:background="#drawable/gradient2"
android:orientation="horizontal">
</LinearLayout>
</LinearLayout>
Generally, if you inflate a layout from a valid XML you shouldn't get an error. You should do a clean build and re-deploy the app again.
Also check if you're using the correct class in the import statement in other classes (you could be using a FocusBox from some 3rd-party library instead of the one you made)

Custom layout based on existed layout

I'm trying to create custom layout for android. It normally draws on screen, but without inner views. Draws only my group_box.xml. How i can get access from my custom layout to inner views (TextView with id test) or how to draw they?
main.xml
<my.example.GroupBox
android:layout_width="match_parent"
android:layout_height="40sp">
<TextView android:text="TEST"
android:id="#+id/test"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
</my.example.GroupBox>
group_box.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
style="#style/groupbox">
<LinearLayout style="#style/groupboxContent"
android:id="#+id/content"
android:layout_height="match_parent"
android:layout_width="match_parent"/>
<TextView style="#style/groupboxLabel"
android:id="#+id/caption"
android:text="#string/visit"/>
</RelativeLayout>
GroupBox.java
public class GroupBox extends LinearLayout {
public GroupBox(Context context) {
super(context);
LayoutInflater layoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View view = layoutInflater.inflate(R.layout.group_box, this);
}
public GroupBox(Context context, AttributeSet attrs) {
super(context, attrs);
LayoutInflater layoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View view = layoutInflater.inflate(R.layout.group_box, this);
}
}
you can access to the elements via setters and getters.
put this in your GroupBox.java
caption = (TextView) findViewById(R.id.caption);
public void setLabel(CharSequence text) {
caption.setText(text);
}
add an id to your control in xml:
<my.example.GroupBox
android:layout_width="match_parent"
android:layout_height="40sp"
android:id="mycontrol">
<TextView android:text="TEST"
android:id="#+id/test"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
</my.example.GroupBox>
then find your control in the main activity and do this:
yourcontrol = (GroupBox) findViewById(R.id.mycontrol)
yourcontrol.setLabel("test");

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