I am trying to make my app more tablet-friendly, and so I'm trying to learn fragments. I want the typical two-pane layout, where the left side is the "navigation", and you click on one of the elements, and it changes the fragment on the right.
I can duplicate the tutorials that use a ListFragment for the left, and if you click on one of them, it updates the "details" fragment on the right.
I've tried the best I can to duplicate that code, and just use a LinearLayout, with buttons for the left side, so that if a button is clicked, it loads the appropriate fragment on the right, but it's not working.
When I commit the FragmentTransaction, I get java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first. What is the child's parent, and why do I have to call removeView on it?
I'm trying to load the fragment into a FrameLayout, but I've also just tried replacing another Fragment in the layout, and still get the error.
Ideally I want the left fragment to take up the whole screen until a button is pressed that requires a fragment to come in from the left, but one problem at a time I suppose.
Code
Main Activity
public class FragmentExample2Activity extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
}
SelectorFragment (Left side)
public class SelectorFragment extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
View fragment = inflater.inflate(R.layout.selector, container);
Button button1 = (Button) fragment.findViewById(R.id.button1);
button1.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View v) {
getFragmentManager().beginTransaction().replace(R.id.detail_holder, new DetailsFragment(), "stuff").commit();
}
});
return fragment;
}
}
DetailsFragment
public class DetailsFragment extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
return inflater.inflate(R.layout.details, container);
}
}
main.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<fragment class="com.coreno.testfragment.SelectorFragment"
android:id="#+id/select"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
/>
<fragment class="com.coreno.testfragment.DetailsFragment"
android:id="#+id/detail_holder"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="2"
/>
<!--
<FrameLayout
android:id="#+id/detail_holder"
android:layout_width="0px"
android:layout_height="match_parent"
android:layout_weight="2"
/>
-->
</LinearLayout>
When you inflate a layout xml file, don't specify the parent view. It sounds very counter-intuitive to not specify where you're putting this inflated view but it works.
So, for example, in your SelectorFragment change the line:
View fragment = inflater.inflate(R.layout.selector, container);
to
View fragment = inflater.inflate(R.layout.selector, null);
or even better
View fragment = inflater.inflate(R.layout.selector, container, false);
Don't forget to do the same in your DetailsFragment too.
When you inflate a layout inside the getView method of a Fragment, you must use the next inflate method:
inflater.inflate(R.layout.details, container, false);
The key is the third parameter. It must be false not to attach the inflated layout to the container, because the system already done it. If it is true or is not indicated a redundant group view is created.
Related
I created a progress dialog into a fragment by using this effect. Now i must call it in different activities. When I call the effect the buttons at the background must not work. How can I do that?
First i need to learn how to call the fragment in a different activity. Then i must make the buttons at the background unclickable but there are many of them so ‘setclickabla(false)’ would be a tiring choice.
Progress Dialog Fragment XML:
<FrameLayout 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"
xmlns:app="http://schemas.android.com/apk/res-auto"
tools:context=".ProgressDialogFragment">
<com.skyfishjy.library.RippleBackground
android:id="#+id/ProgressDialogs"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#CB000000"
app:rb_color="#80FFFFFF"
app:rb_duration="2500"
app:rb_radius="32dp"
app:rb_rippleAmount="4"
app:rb_scale="6">
<ImageView
android:id="#+id/centerImage"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:src="#drawable/logo" />
</com.skyfishjy.library.RippleBackground>
ProgressDialogFragment.java
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
final View view = inflater.inflate(R.layout.fragment_progress_dialog, container, false);
RippleBackground rippleBackground = (RippleBackground)view.findViewById(R.id.ProgressDialogs);
rippleBackground.startRippleAnimation();
return view;
}
For the buttons at the background to respond to clicks, you have to implement the onClick listener of the various buttons.
<com.skyfishjy.library.RippleBackground
android:id="#+id/ProgressDialogs"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#CB000000"
app:rb_color="#80FFFFFF"
app:rb_duration="2500"
app:rb_radius="32dp"
app:rb_rippleAmount="4"
app:rb_scale="6">
<Button
android:id="#+id/centerButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:src="#drawable/logo" />
In your layout above, you are making use of ImageView which I changed to centerButton and you can make it respond to clicks this way:
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
final View view = inflater.inflate(R.layout.fragment_progress_dialog, container, false);
RippleBackground rippleBackground = (RippleBackground)view.findViewById(R.id.ProgressDialogs);
rippleBackground.startRippleAnimation();
Button button=(Button)view.findViewById(R.id.centerButton);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
// your respond to clicks
}
});
return view;
}
Call your fragment from your activity:
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Fragment fragment = new MainFragment(); // your fragment
getSupportFragmentManager().beginTransaction()
.replace(R.id.fragment_frame, fragment, fragment.getClass().getSimpleName()).addToBackStack(null).commit();
}
}
Solved! Thanks everyone for your help.
I am struggling with Fragments as a concept, and especially seem stuck on this one thing. What I'm trying to do is, using my fragment, manipulate its own layout's data. Every time I try to access an ImageButton from within the Fragment, it crashes the application. It works fine from the activity. Am I just misunderstanding Fragments fundamentally?
Code(cut down for size)-
This is the beginning of the activity my fragment is called from:
Display.java
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_display);
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
MyFragmentClass MyFragment = new MyFragmentClass();
fragmentTransaction.add(R.id.fragment_container, MyFragment);
fragmentTransaction.commit();
The XML for that Activity:
activity_display.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"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
android:paddingBottom="#dimen/activity_vertical_margin"
tools:context="com.mycompanyname.myprojectname.Display"
android:id="#+id/display_layout">
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/fragment_container">
</FrameLayout>
</RelativeLayout>
The Fragment
MyFragmentClass.java
public class MyFragmentClass extends Fragment
{
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_layout_screen, container, false);;
}
public void MethodTest()
{
}
}
The Fragment's XML file:
fragment_layout_screen.xml
<?xml version="1.0" encoding="utf-8"?>
<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"
android:id="#+id/fragment_layout_screen"
tools:context="com.mycompanyname.myprojectname.MyFragmentClass">
<ImageButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/my_button"
android:clickable="true"
android:onClick="buttonPress"
android:src="#drawable/button"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"/>
</RelativeLayout>
Basically I had all of this originally in Display.java, but wanted to add fragments, so I'm trying to move stuff out and into fragments, but I still need the ability to manipulate the xml info, I just can't.
From inside the Display.java activity I can easily call the ImageButton like this:
ImageButton myButton = (ImageButton) findViewById(R.id.my_button)
but if I do the same from MethodTest in the fragment, the app crashes.
I've searched many suggestions on here, trying various solutions from here: findViewById in Fragment but none of those seemed to work.
I've been reading through this for the setup: http://developer.android.com/guide/components/fragments.html and can't seem to find what I'm doing wrong.
Any help would be appreciated, and if you have any questions about my setup, please ask.
declare on fragment private View rootView;
On the onCreateView(...) set rootView = inflater.Inflate(..); and then access the imagebutton as ImageButton mButton =(ImageButton) rootView.findViewById(..);
Do like this in fragment
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.gridview, container, false);
GridView gridview = (GridView) view.findViewById(R.id.grid);
return view ;
I am trying to get a fragment to show that contains an EditText and a button. I am new to using fragments, so I am not sure exactly what the error message I get when trying to create the fragment means.
I have a class that extends Fragment, this is where the EditText and button are created.
public class EditNameFragment extends android.support.v4.app.Fragment {
EditText editText;
ImageButton button;
public EditNameFragment(){
}
#Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.edit_name_dialog, container, false);
editText = (EditText) view.findViewById(R.id.editTextDialog);
button = (ImageButton) view.findViewById(R.id.submitNewItemButtonDialog);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
//stuff
}
});
return view;
}
Here is edit_name_dialog.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal" android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center"
android:id="#+id/edit_name_dialog"
>
<EditText
android:id="#+id/editTextDialog"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
<ImageButton
android:id="#+id/submitNewItemButtonDialog"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
/>
</LinearLayout>
And here in my main activity (which must extend FragmentActivity because of another part) is where I try to set up my Fragment. I think it has something to do with what id I am referencing. I have seen some people using container classes when using fragments, but I do not understand why this is done.
FragmentManager fragmentManager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
EditNameFragment fragment = new EditNameFragment();
fragmentTransaction.add(R.id.edit_name_dialog, fragment, "tag");
fragmentTransaction.commit();
I get the error message when trying to run the code above
No view found for id 0x7f09002a (com.myapp:id/edit_name_dialog) for fragment EditNameFragment
If anyone could explain what I am missing here/ why people use container classes, that would be great. I know some people add fragments using XML, but I would like to do this only using java.
EDIT
I have added a class that extends FragmentActivity, following the model for a container class
public class EditNameFragmentActivity extends FragmentActivity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.edit_name_fragment_container);
}
}
Is the parameter for setContentView supposed to be the layout, or an id?
Here is the xml file that defines where the fragment should be
edit_name_fragment_container.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent"
>
<fragment android:name="com.returnjump.spoilfoil.EditNameFragment"
android:id="#+id/edit_name_fragment_container"
android:layout_weight="1"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:layout="#layout/edit_name_fragment" />
</LinearLayout>
So for the parameter in
fragmentTransaction.add(R.id.edit_name_dialog, fragment, "tag");
this is supposed to reference the id of the fragment, correct?
It still gives me the same error, what am I missing?
There are basically two ways to add a fragment to an activity like the documentation say:
"statically": by declaring the fragment inside the activity's layout file.
"dynamically": adding the fragment programmatically. Like you tried to do.
Here is the documentation: http://developer.android.com/guide/components/fragments.html
If you wish to add it dynamically, here is the documentation part that you want to read:
At any time while your activity is running, you can add fragments to your activity layout. You simply need to specify a ViewGroup in which to place the fragment.
To make fragment transactions in your activity (such as add, remove, or replace a fragment), you must use APIs from FragmentTransaction. You can get an instance of FragmentTransaction from your Activity like this:
FragmentManager fragmentManager = getFragmentManager()
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
You can then add a fragment using the add() method, specifying the fragment to add and the view in which to insert it. For example:
ExampleFragment fragment = new ExampleFragment();
fragmentTransaction.add(R.id.fragment_container, fragment);
fragmentTransaction.commit();
The first argument passed to add() is the ViewGroup in which the fragment should be placed, specified by resource ID, and the second parameter is the fragment to add.
Once you've made your changes with FragmentTransaction, you must call commit() for the changes to take effect.
And about why to use dynamic fragments instead of static fragments, it has been made for interactive UI allowing you to simply handle different fragments into one activity as you please.
I'm writing and android 4.4 project using android studio.
I'm new to the fragments idea and trying to create a simple application with a button that the click handler sends a message to the log.
this is the fragment class
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main_menu, container, false);
return rootView;
}
public void addStringClickHandler(View v) {
Log.d("tag","hello");
}
}
this is the fragment layout 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"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
android:paddingBottom="#dimen/activity_vertical_margin"
tools:context="com.tuxin.myalcoholist.myalcoholist.myalcoholist.MainMenuActivity$PlaceholderFragment">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/add_drink"
android:id="#+id/add_drink"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="36dp"
android:onClick="addStringClickHandler" />
</RelativeLayout>
as you can see i set in the XML android:onclick to addStringClickHandler
and in the fragment class i created that function, but when I execute the application
I get an error that the runtime could not find a method addStringClickHandler(view)
what am I missing?
Your android:onClick handler method has to belong to the Activity hosting your fragment. Just move addStringClickHandler() method to the activity.
If you want to have a listener method in the fragment you have to set listener in the code like this.
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main_menu, container, false);
rootView.findViewById(R.id.add_drink).setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
Log.d("tag","hello");
}
});
return rootView;
}
Try to register the onClick method when inflating the view.
View rootView = inflater.inflate(R.layout.fragment_main_menu, container, false);
rootView.findViewById(R.id.add_drink).setOnClickListener(new OnClickListener() {
public void onClick(View view) {
// do what you need
}
});
return rootView;
Or you can set the fragment to be the on click listener
View rootView = inflater.inflate(R.layout.fragment_main_menu, container, false);
rootView.findViewById(R.id.add_drink).setOnClickListener(this);
return rootView;
and then make the fragment implement OnClickListener.
I have one activity that holds multiple fragments. Each fragment implements my UpdateRequest interface, where each of these fragments do some asynctask and downloads data from web service. My problem is that I don't really understand how to update existing fragments. I read this
Android Refreshing Fragment View after AsyncTask
but I still can't figure out how to locate views of each fragment and then update them. I'll give an example:
There's an UserFragment, which should represents user profile:
public class UserFragment extends SherlockFragment implements
UpdateRequest {
View rootView;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
rootView = inflater.inflate(R.layout.fragment_user_info,
container, false);
return rootView;
}
...
public void update(final OnFragmentUpdatedListener context) {
...
asyntask
...
}
}
And fragment_user_info looks like this:
<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" >
<ImageView
android:id="#+id/fragment_user_picture"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:contentDescription="#string/image_of_user" />
<TextView
android:id="#+id/fragment_user_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/user_info" />
</RelativeLayout>
What I want is to locate instance of UserFragment and then in its AsyncTask.onPostExecute() method change text in fragment_user_name textView to something that asynctask returns.
The easiest way to do this is to create a final variable in the fragment to hold a reference to the TextView. Then the AsyncTask, being an anonymous inner class of the fragment, will have direct access to it. So, something like this:
public class UserFragment extends SherlockFragment implements UpdateRequest {
private View rootView;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
rootView = inflater.inflate(R.layout.fragment_user_info, container, false);
return rootView;
}
...
public void update(final OnFragmentUpdatedListener context) {
final TextView userNameView = (TextView) rootView.findViewById(R.id.fragment_user_name);
...
asyntask
...
onPostExecute() {
userNameView.setText(....);
}
}