OK, I have a complete layout built; however, I am not really pleased with the long xml file that has resulted. I have a shorted version of the xml outline and designer view below. And I was wondering how I can abstract out each group of similar components into their own custom control.
For example, in the picture below, I have highlighted one such control that I would like to abstract out. Instead of it being a LinearLayout with 2 TextView's inside with their own properties and attributes set. I would like to reference it via <package-name.individual_song_item
android:layout...> ... </>. All I would have to do is set the first TextView's text along with the second one via attributes in the top-level component.
How can this be done? I have the layout done and complete, but I don't like that nothing is abstracted away.
So the expected results that I am looking for are (if you look at the right-side of the image. there would only be one LinearLayout below the image, and the rest would be <package-name.individual_song_item>)
I have tried to just create a new layout xml with just the subsets of components, but I was not able to make it work when combining it back.
OLD WAY
<LinearLayout >
<ImageView />
<LinearLayout >
<LinearLayout >
<TextView />
<TextView />
</LinearLayout>
<LinearLayout >
<TextView />
<TextView />
</LinearLayout>
<LinearLayout >
<TextView />
<TextView />
</LinearLayout>
....
</LinearLayout>
</LinearLayout>
POSSIBLE PROPOSED WAY
<LinearLayout >
<ImageView />
<LinearLayout >
<com.example.individual_song_item />
<com.example.individual_song_item />
<com.example.individual_song_item />
....
<com.example.individual_song_item <!-- example (possible!?!?) -->
....
app:label="Group"
app:value="Group Name" />
</LinearLayout>
</LinearLayout>
Create a custom layout eg.
public class IndividualSongItem extends LinearLayout {
private String mSong;
private String mSongName;
public IndividualSongItem(Context context) {
super(context);
// TODO Auto-generated constructor stub
}
public IndividualSongItem(Context context, AttributeSet attrs) {
super(context, attrs);
TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.IndividualSongItem);
try {
// Read in your custom layout's attributes,
// for example song and songName text attributes
CharSequence s = a.getString(R.styleable.IndividualSongItem_song);
if (s != null) {
setSong(s.toString());
}
s = a.getString(R.styleable.IndividualSongItem_songName);
if (s != null) {
setSongName(s.toString());
}
} finally {
a.recycle();
}
}
....etc
You will also need to create an attributes XML for your new layout class.
For a full example of how to do what you're after look at the LabelView example in the ApiDemos.
It's also very well explained here.
Related
I have a custom Table Row that I am in the process of making. I want to use an XML file to define what a single row looks like. I would like to have a class extend TableRow and define itself to be the file as defined in the XML. The XML file might look like:
<TableRow xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal" >
<TextView
android:id="#+id/label"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingRight="10dp"
android:text="#string/loading"
android:textAppearance="?android:attr/textAppearanceLarge" />
<TextView
android:id="#+id/data"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="right"
android:text="#string/loading"
android:textAppearance="?android:attr/textAppearanceLarge" />
</TableRow>
And the code might look like:
public class SpecialTableRow extends TableRow {
public SpecialTableRow (Context context) {
}
}
Is there something that I can put into the constructor to have the class assume it is the tableRow in it's entirety? Alternatively, is there another structure which would work better? The best that I've figured out is this:
TableRow tr=(TableRow) LayoutInflater.from(context).inflate(R.layout.text_pair,null);
TextView mFieldName=(TextView) tr.findViewById(R.id.label);
TextView mValue=(TextView) tr.findViewById(R.id.data);
tr.removeAllViewsInLayout();
addView(mFieldName);
addView(mValue);
But this removes the layout parameters from the XML. Anything better out there?
Take a look at the tutorial on creating custom views. You will want to subclass TableRow and add the additional views you want to display. Then, you can use your new view directly in your XML layouts and additionally create any custom attributes you might want. I've included an example which creates a custom TableRow named TextPairRow, inflates a layout with two TextViews to show within the TableRow and adds showLabel and showData custom attributes which show/hide the two TextViews. Finally, I've included how you would use your new view directly in your XML layouts.
class TextPairRow extends TableRow {
private TextView label, data;
public TextPairRow (Context context, AttributeSet attrs) {
super(context, attrs);
TypedArray a = context.getTheme().obtainStyledAttributes(
attrs,
R.styleable.TextPairRow, 0, 0);
try {
showLabel = a.getBoolean(R.styleable.TextPairRow_showLabel, false);
showData = a.getBoolean(R.styleable.TextPairRow_showData, false);
} finally {
a.recycle();
}
initViews();
}
private void initViews(){
// Here you can inflate whatever you want to be in your
// view or add views programatically.
// In this example, we'll just assume you have a basic XML
// layout which defines a LinearLayout with two TextViews.
LinearLayout mLayout = (LinearLayout)
LayoutInflater.from(getContext()).inflate(R.layout.textview_layout, this);
label = (TextView) mLayout.findViewById(R.id.label);
data = (TextView) mLayout.findViewById(R.id.data);
if(showLabel)
label.setVisibility(View.VISIBLE);
else
label.setVisibility(View.GONE); // can also use View.INVISIBLE
// depending on your needs
if(showData){
data.setVisibility(View.VISIBLE);
else
data.setVisibility(View.GONE); // can also use View.INVISIBLE
// depending on your needs
}
}
This is where you define your custom XML attributes (locate or create this file: res/values/attrs.xml)
<resources>
<declare-styleable name="TextPairRow">
<attr name="showText" format="boolean" />
<attr name="showLabel" format="boolean" />
</declare-styleable>
</resources>
Finally, to use your new view directly in your XML layouts:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:custom="http://schemas.android.com/apk/res-auto">
<com.thefull.packageforyourview.TextPairRow
android:orientation="horizontal"
custom:showData="true"
custom:showLabel="true" />
</LinearLayout>
Note that you might need to use xmlns:custom="http://schemas.android.com/apk/res/com.thefull.packageforyourview" depending on if your custom view will be in a library project. Regardless, either this or what's in the example will work.
The real trick to doing this is actually quite simple. Use the second parameter of the inflate method. In fact, the best thing to do is this:
LayoutInflater.from(context).inflate(R.layout.text_pair,this);
This will inflate the R.layout.text_pair into this, effectively using the entire row. No need to add the view manually, Android takes care of it for you.
The only thing I can think of is to use a static method instead of constructor. For example:
public static void newInstance (Context context) {
this = context.getLayoutInflater().inflate(R.layout.text_pair, null, null);
}
Then don't use constructor for initializing an object, call this method.
So I'm experimenting with implementing an MVC pattern in Android where my views are subclassed from RelativeLayout, LinearLayout, ScrollView, etc... It's working until I try to get a hold of a view within my view. I get an NPE. I've tried accessing the view in order to set the onClickListener in the constructor and also in onAttachedToWindow(), but I get the NPE in both places.
For example, here's a view class:
public class ViewAchievements extends LinearLayout
{
private RelativeLayout mRelativeLayoutAchievement1;
public ViewAchievements(Context context, AttributeSet attrs)
{
super(context, attrs);
mRelativeLayoutAchievement1 = (RelativeLayout) findViewById(R.id.relativeLayout_achievement1);
mRelativeLayoutAchievement1.setOnClickListener((OnClickListener) context); //NPE on this line
}
#Override
protected void onAttachedToWindow()
{
super.onAttachedToWindow();
mRelativeLayoutAchievement1.setOnClickListener(mOnClickListener); //Also get NPE on this line
}
}
Can someone please tell me the proper way to get a hold of my subviews, in this case mRelativeLayoutAchievement1?
Here's an XML snippet:
<com.beachbody.p90x.achievements.ViewAchievements xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#color/gray_very_dark"
android:orientation="vertical" >
<!-- kv Row 1 -->
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="0dp"
android:orientation="horizontal"
android:layout_weight="1"
android:baselineAligned="false">
<RelativeLayout
android:id="#+id/relativeLayout_achievement1"
style="#style/linearLayout_achievement"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_margin="#dimen/margin_sm"
android:layout_weight="1" >
<TextView
android:id="#+id/textView_achievement1"
style="#style/text_small_bold_gray"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="#dimen/margin_large"
android:text="1/20" />
</RelativeLayout>
...
And here's how I'm creating the view from my Activity:
public class ActivityAchievements extends ActivitySlidingMenu
{
private ViewAchievements mViewAchievements;
#Override
public void onCreate(Bundle savedInstanceState)
{
mViewAchievements = (ViewAchievements) View.inflate(this, R.layout.view_achievements, null);
setContentView(mViewAchievements);
...
You're trying to get the child views during the view's constructor. Since they are child views, they haven't been inflated yet. Can you move this code out of the constructor, possibly into View.onAttachedToWindow()?
http://developer.android.com/reference/android/view/View.html#onAttachedToWindow()
Sorry if this redundant with the ton of questions/answers on inflate, but I could not get a solution to my problem.
I have a compound view (LinearLayout) that has a fixed part defined in XML and additional functionalities in code. I want to dynamically add views to it.
Here is the XML part (compound.xml):
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/compoundView"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<TextView android:id="#+id/myTextView"
android:layout_width="110dp"
android:layout_height="wrap_content"
android:text="000" />
</LinearLayout>
I have defined in code a LinearLayout to refer to the XML:
public class CompoundControlClass extends LinearLayout {
public CompoundControlClass (Context context) {
super(context);
LayoutInflater li;
li = (LayoutInflater)getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
li.inflate(R.layout.compound_xml,*ROOT*, *ATTACH*);
}
public void addAView(){
Button dynBut = new Button();
// buttoin def+layout info stripped for brevity
addView(dynBut);
}
}
I tried to programmatically add a view with addAView.
If ROOT is null and ATTACH is false, I have the following hierarchy (per HierarchyViewer):
CompoundControlClass>dynBut
The original TextView in the XML is gone.
If ROOT is this and ATTACH is true, I have the following hierarchy:
CompoundControlClass>compoundView>myTextView
CompoundControlClass>dynBut
I would like to have
CompoundControlClass>myTextView
CompoundControlClass>dynBut
where basically the code and XML are only one unique View.
What have I grossly missed?
ANSWER BASED on feedback from D Yao ----------------------
The trick is to INCLUDE the compound component in the main layout instead of referencing it directly.
activity_main.xml
<RelativeLayout 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">
<include layout="#layout/comound"
android:id="#+id/compoundView"
android:layout_alignParentBottom="true"
android:layout_width="fill_parent"
android:layout_height="wrap_content"/>
</RelativeLayout>
mainActivity.java
public class MainActivity extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
CompoundControlClass c = (CompoundControlClass) this.findViewById(R.id.compoundView);
c.addAView(this);
}
}
CompoundControlClass.java
public class CompoundControlClass extends LinearLayout {
public CompoundControlClass(Context context) {
super(context);
}
public CompoundControlClass(Context context, AttributeSet attrs) {
super(context, attrs);
}
public CompoundControlClass(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
public void addAView(Context context){
ImageView iv = new ImageView(context);
iv.setImageResource(R.drawable.airhorn);
addView(iv);
}
}
compound.xml
<com.sounddisplaymodule.CompoundControlClass xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/compoundView"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<TextView
android:layout_width="110dp"
android:layout_height="wrap_content"
android:gravity="right"
android:textSize="40sp"
android:textStyle="bold"
android:text="0:00" />
</com.sounddisplaymodule.CompoundControlClass>
Why not just call addView on the linearlayout? I don't see the need for CompoundControlClass based on the needs you have listed.
LinearLayout v = (LinearLayout)findViewById(R.id.compoundView);
v.addView(dynBut);
In this case, v will contain myTextView, then dynBut.
if you wish to have other functions added and thus really feel a need for creating the compound control class, just leave the constructor as super(etc) and remove the rest
Then your xml would look like this:
<com.yourpackage.CompoundControlClass xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/compoundView"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<TextView android:id="#+id/myTextView"
android:layout_width="110dp"
android:layout_height="wrap_content"
android:text="000" />
</com.yourpackage.CompoundControlClass>
you will also have to ensure your CompoundControlClass.java contains the appropriate Constructor which takes both a Context and an attribute set.
Then, in your java, after you've called setContentView, you can do the following:
CompoundControlClass c = (CompoundControlClass)findViewById(R.id.compoundView);
Button b = new Button(context);
//setup b here or inflate your button with inflater
c.addView(b);
this would give you your desired heirarchy.
possible duplicates
Android : autocompletetextview, suggestion list displays above the textview?
I am fully trying to display suggestion list overlapping on keyboard when suggestion list scroll by user but it always open up side.
here I am getting this way
here is my manifest file
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.sl"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk android:minSdkVersion="8" />
<application
android:icon="#drawable/ic_launcher"
android:label="#string/app_name" >
<activity
android:label="#string/app_name"
android:name=".SuggestionListActivity"
android:windowSoftInputMode="adjustResize|adjustPan|stateHidden">
<intent-filter >
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
here is my main.xml file
<?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" android:padding="10dp">
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="#string/hello"
android:layout_margin="10dp"/>
<TextView android:layout_margin="10dp"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="This is testing for the auto complete textview in this application to display suggestion list overlapping on keyboard." />
<AutoCompleteTextView android:id="#+id/autocomplete"
android:layout_width="fill_parent" android:layout_margin="5dp"
android:layout_height="wrap_content" android:hint="Search"
android:layout_marginLeft="5dp" android:dropDownHeight="300dp"
android:inputType="textAutoComplete" android:singleLine="true"
/>
</LinearLayout>
what to do in this code to display the suggestion over keyboard when list was focus.
I've had this problem before. For me, there was more screen space above the AutocompleteTextView than below (testing on a "normal" device), so the list opened upwards. I adjusted my layout slightly so that there was more space below the AutocompleteTextView and it started opening downwards. That's what fixed it for me.
You can either adjust the layout so that there is more space below the AutoCompleteTextView
or
you can change the dropdown height android:dropDownHeight and set some high value,
this would work when its inside a scrollView and the AutoCompleteTextView is near the top.
To display the list of options on focus do something like this
autoCompleteTextView.setOnFocusChangeListener(new OnFocusChangeListener() {
public void onFocusChange(View v, boolean hasFocus) {
if(hasFocus) {
autoCompleteTextView.showDropDown();
}
}
});
This would display a list of options when the user focuses on the AutoCompleteTextView
The trick is to ensure that the desired drop-down height is never larger than the available space below. My approach is to create a subclass that overrides showDropDown:
public class DownOnlyAutoCompleteTextView extends AppCompatAutoCompleteTextView {
private final static int MINIMAL_HEIGHT = 50;
public DownOnlyAutoCompleteTextView(Context context) {
super(context);
}
public DownOnlyAutoCompleteTextView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public DownOnlyAutoCompleteTextView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
#Override
public void showDropDown() {
Rect displayFrame = new Rect();
getWindowVisibleDisplayFrame(displayFrame);
int[] locationOnScreen = new int[2];
getLocationOnScreen(locationOnScreen);
int bottom = locationOnScreen[1] + getHeight();
int availableHeightBelow = displayFrame.bottom - bottom;
if (availableHeightBelow >= MINIMAL_HEIGHT) {
setDropDownHeight(availableHeightBelow);
}
super.showDropDown();
}
}
Then use this in your layout, e.g.:
<your.package.DownOnlyAutoCompleteTextView
android:id="#+id/auto_complete_text_view"
android:layout_margin="12dp"
android:hint="AutoComplete"
android:layout_width="match_parent"
android:layout_height="wrap_content"
tools:ignore="HardcodedText" />
Adjust MINIMAL_HEIGHT to fit your requirements -- if there's no or very little space below, it's probably better not to force the issue.
EDIT
As mentioned in the comments, passing a negative number to setDropDownHeight will trigger an exception in some Android versions. As long as you define a MINIMAL_HEIGHT greater than zero, that should not be a problem.
Here's my solution
private final static int DELAY_MS = 500;
autoCompletionTextView.setOnTouchListener(new View.OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
autoCompletionTextView.requestFocus();
new Handler().postDelayed(() -> autoCompletionTextView.showDropDown(), DELAY_MS);
return false;
}
});
After keyboard shows up suggestion list is listed above yout AutoCompletionTextView.
use: android:dropDownHeight="wrap_content" in AutoCompleteTextView
Just adding the android:dropDownHeight="100dp" to the AutoCompleteTextView tag in your layout file will be the best solution I guess! it will simply control the height of drop down hight and allow us to scroll!
<AutoCompleteTextView
android:id="#+id/acetxt_assignclient"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:dropDownHeight="100dp">
</AutoCompleteTextView>
I have found if you are using a nested scroll view, it is more prone to open the view above or below as it sees fit where as when you are using a regular scroll view it opens below.
Set Full Layout containing Autocompletetextview inside Scrollview
This will solve your problem!
I have several layout files that are mostly the same, except for one section. Is there a way that I can have the common XML all in one place; instead of copy/pasting, and having to update a bunch of files when I want to make 1 change?
I know that I can include XML from other XML files, but the common code isn't an internal control; it is the outer wrapper; so include doesn't work. Basically, I have a bunch of files that all look like this:
<LinearLayout
android:id="#+id/row"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="horizontal">
<ImageView android:layout_height="26dp"
android:id="#+id/checkImage"
android:layout_width="26dp"
android:layout_alignParentTop="true"
android:scaleType="fitCenter"/>
<!-- Different types of views go here depending on which layout file it is -->
<ImageButton android:layout_height="fill_parent"
android:id="#+id/playButton"
android:layout_width="42dp"
android:src="#drawable/play_button"
android:scaleType="center"
android:background="#00000000"/>
</LinearLayout>
Basically, I want to do what ASP.Net does with Master Pages. Is there any option for this?
The solution was pretty easy.
You need to extend "Activity" Class, in onCreate() function SetContentView to your base xml layout and also need to override setContentView in base Activity Class
For Example:
1.Create base_layout.xml with the below code
<?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">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<ImageView
android:id="#+id/image_view_01"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:maxHeight="50dp" />
</LinearLayout>
<LinearLayout
android:id="#+id/base_layout"
android:layout_width="match_parent"
android:layout_height="match_parent" >
</LinearLayout>
</LinearLayout>
Create BaseActivity.java
public class BaseActivity extends Activity {
ImageView image;
LinearLayout baseLayout;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
super.setContentView(R.layout.base_layout);
this.image = (ImageView) this.findViewById(R.id.image_view_01);
this.baseLayout = (LinearLayout) this.findViewById(R.id.base_layout);
this.image.setImageResource(R.drawable.header);
}
#Override
public void setContentView(int id) {
LayoutInflater inflater = (LayoutInflater)getBaseContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
inflater.inflate(id, this.baseLayout);
}
}
and SomeActivity.java
public class SomeActivity extends BaseActivity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
super.setContentView(R.layout.some_layout);
//rest of code
}
}
The only thing I noticed so far was that when requesting a progress bar (requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS)) this needs to be done before calling super.onCreate. I think this is because nothing can be drawn yet before calling this function.
This worked great for me and hopefully you will find this useful in your own coding.
Maybe you could use one main layout XML file and then add/remove other widgets dynamically through code as needed.
I was trying to do exactly this - I wanted a view that had a button on the left and a button on the right, but could have arbitrary content in the middle (depending on who was including it). Basically a custom view group that could have child view in the XML layout, and would wrap those child views with another XML layout. Here is how I did it:
top_bar.xml: This represents the common layout to wrap things with. Note the LinearLayout (could be any layout) with an ID "addChildrenHere" - it is referenced later.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/topBarLayout1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal">
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="left" />
<LinearLayout
android:id="#+id/addChildrenHere"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"/>
<Button
android:id="#+id/button3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="right" />
</LinearLayout>
main.xml: The main layout. This includes a custom viewgroup (WrappedLayout) with a few children. Note how it declares a custom XML namespace, and sets two custom attributes on the WrappedLayout tag (these say which layout to wrap the children with, and where within that layout the children of this node should be placed).
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:karl="http://schemas.android.com/apk/res/karl.test"
android:id="#+id/linearLayout1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<karl.test.WrappedLayout
android:id="#+id/topBarLayout1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
karl:layoutToInflate="#layout/top_bar"
karl:childContainerID="#+id/addChildrenHere">
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="This is a child of the special wrapper."
android:textAppearance="?android:attr/textAppearanceMedium" />
<TextView
android:id="#+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="This is another child; you can put anything here."
android:textAppearance="?android:attr/textAppearanceMedium" />
</karl.test.WrappedLayout>
</LinearLayout>
attrs.xml: This goes in res/values. This defines the custom XML attributes used in the XML above.
<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="WrappedLayout">
<attr name="layoutToInflate" format="integer"/>
<attr name="childContainerID" format="integer"/>
</declare-styleable>
</resources>
Finally, WrappedLayout.java: This handles reading the custom attributes, and doing a bit of hackery to make addView() actually add the views in a different place.
package karl.test;
import android.content.Context;
import android.content.res.TypedArray;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.widget.FrameLayout;
public class WrappedLayout extends FrameLayout
{
///Attempts to add children to this layout will actually get forwarded through to mChildContainer.
///This would be final, but it's actually used indirectly by the constructor before it's initialised.
private ViewGroup mChildContainer;
public WrappedLayout(Context context, AttributeSet attrs)
{
super(context, attrs);
//read the custom attributes
final int layoutToInflate;
final int childContainerID;
{
final TypedArray styledAttributes = context.obtainStyledAttributes(attrs, R.styleable.WrappedLayout);
layoutToInflate = styledAttributes.getResourceId(R.styleable.WrappedLayout_layoutToInflate, 0);
childContainerID = styledAttributes.getResourceId(R.styleable.WrappedLayout_childContainerID, 0);
styledAttributes.recycle();
}
if(layoutToInflate == 0
|| childContainerID == 0)
{
Log.e("Error", "WrappedLayout.WrappedLayout(): Error reading custom attributes from XML. layoutToInflate = " + layoutToInflate + ", childContainerID =" + childContainerID);
}
else
{
//inflate the layout and (implicitly) add it as a child view
final View inflatedLayout = View.inflate(context, layoutToInflate, this);
//grab the reference to the container to pass children through to
mChildContainer = (ViewGroup)inflatedLayout.findViewById(childContainerID);
}
}
///All the addView() overloads eventually call this method.
#Override
public void addView(View child, int index, ViewGroup.LayoutParams params)
{
if(mChildContainer == null)
{
//still inflating - we're adding one of the views that makes up the wrapper structure
super.addView(child, index, params);
}
else
{
//finished inflating - forward the view through to the child container
mChildContainer.addView(child, index, params);
}
}
}
This works, as far as I can tell. It doesn't work very well with the Eclipse layout editor (I'm not quite sure what the problem is), but you can view the layout fine. Changing the children of the WrappedLayout seems to require editing the XML manually.
Have you looked at Applying Styles and Themes?