LineageOS/android_development
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Update fragment API demos for new fragment APIs:

Browse Source 
- Correctly work with state saving and restoring.
- Add new sample showing a fragment that is retained across activities.

Change-Id: I7b1e02135177e69e9fff23fcc55e86d93a75c7e0
This commit is contained in:
Dianne Hackborn
2010-05-12 18:58:18 -07:00
parent 5b4766d4a2
commit edb8628b41
7 changed files with 373 additions and 18 deletions
Download Patch File Download Diff File Expand all files Collapse all files

39
samples/ApiDemos/src/com/example/android/apis/app/FragmentLayout.java
View File

@@ -44,12 +44,32 @@ public class FragmentLayout extends Activity {
}
static class FirstFragment extends Fragment {
TextView mTextView;
// Explicit constructor needed for inflation.
public FirstFragment() {
}
public View onCreateView(LayoutInflater inflater, ViewGroup container) {
return inflater.inflate(R.layout.hello_world, container, false);
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.labeled_text_edit, container, false);
View tv = v.findViewById(R.id.msg);
((TextView)tv).setText("The fragment saves and restores this text.");
// Retrieve the text editor, and restore the last saved state if needed.
mTextView = (TextView)v.findViewById(R.id.saved);
if (savedInstanceState != null) {
mTextView.setText(savedInstanceState.getCharSequence("text"));
}
return v;
}
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
// Remember the current text, to restore if we later restart.
outState.putCharSequence("text", mTextView.getText());
}
}
@@ -58,10 +78,17 @@ public class FragmentLayout extends Activity {
public SecondFragment() {
}
public View onCreateView(LayoutInflater inflater, ViewGroup container) {
View v = inflater.inflate(R.layout.hello_world, container, false);
View tv = v.findViewById(R.id.text);
((TextView)tv).setText("Second Hello World!");
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.labeled_text_edit, container, false);
View tv = v.findViewById(R.id.msg);
((TextView)tv).setText("The TextView saves and restores this text.");
// Retrieve the text editor and tell it to save and restore its state.
// Note that you will often set this in the layout XML, but since
// we are sharing our layout with the other fragment we will customize
// it here.
((TextView)v.findViewById(R.id.saved)).setSaveEnabled(true);
return v;
}
}

204
samples/ApiDemos/src/com/example/android/apis/app/FragmentRetainInstance.java Normal file
View File

@@ -0,0 +1,204 @@
/*
* Copyright (C) 2010 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.example.android.apis.app;
import com.example.android.apis.R;
import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ProgressBar;
import android.widget.TextView;
/**
* This example shows how you can use a Fragment to easily propagate state
* (such as threads) across activity instances when an activity needs to be
* restarted due to, for example, a configuration change. This is a lot
* easier than using the raw Activity.onRetainNonConfiguratinInstance() API.
*/
public class FragmentRetainInstance extends Activity {
RetainedFragment mRetainedFragment;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment_retain_instance);
// Watch for button clicks.
Button button = (Button)findViewById(R.id.restart);
button.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
mRetainedFragment.restart();
}
});
// Check to see if we retained the fragment.
mRetainedFragment = (RetainedFragment)findFragmentByTag("retained");
// If not retained (or first time running), we need to re-create it.
if (mRetainedFragment == null) {
mRetainedFragment = new RetainedFragment();
openFragmentTransaction().add(mRetainedFragment, "retained").commit();
}
}
/**
* This is the Fragment implementation that will be retained across
* activity instances. It represents some ongoing work, here a thread
* we have that sits around incrementing a progress indicator.
*/
static class RetainedFragment extends Fragment {
ProgressBar mProgressBar;
int mPosition;
boolean mReady = false;
boolean mQuiting = false;
/**
* This is the thread that will do our work. It sits in a loop running
* the progress up until it has reached the top, then stops and waits.
*/
final Thread mThread = new Thread() {
@Override
public void run() {
// We'll figure the real value out later.
int max = 10000;
// This thread runs almost forever.
while (true) {
// Update our shared state with the UI.
synchronized (this) {
// Our thread is stopped if the UI is not ready
// or it has completed its work.
while (!mReady || mPosition >= max) {
if (mQuiting) {
return;
}
try {
wait();
} catch (InterruptedException e) {
}
}
// Now update the progress. Note it is important that
// we touch the progress bar with the lock held, so it
// doesn't disappear on us.
mPosition++;
max = mProgressBar.getMax();
mProgressBar.setProgress(mPosition);
}
// Normally we would be doing some work, but put a kludge
// here to pretend like we are.
synchronized (this) {
try {
wait(50);
} catch (InterruptedException e) {
}
}
}
}
};
/**
* Fragment initialization. We way we want to be retained and
* start our thread.
*/
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Tell the framework to try to keep this fragment around
// during a configuration change.
setRetainInstance(true);
// Start up the worker thread.
mThread.start();
}
/**
* This is called when the Fragment's Activity is ready to go, after
* its content view has been installed; it is called both after
* the initial fragment creation and after the fragment is re-attached
* to a new activity.
*/
@Override
public void onReady(Bundle savedInstanceState) {
super.onReady(savedInstanceState);
// Retrieve the progress bar from the current activity.
mProgressBar = (ProgressBar)getActivity().findViewById(
R.id.progress_horizontal);
// We are ready for our thread to go.
synchronized (mThread) {
mReady = true;
mThread.notify();
}
}
/**
* This is called when the fragment is going away. It is NOT called
* when the fragment is being propagated between activity instances.
*/
@Override
public void onDestroy() {
// Make the thread go away.
synchronized (mThread) {
mReady = false;
mQuiting = true;
mThread.notify();
}
super.onDestroy();
}
/**
* This is called right before the fragment is detached from its
* current activity instance.
*/
@Override
public void onDetach() {
// This fragment is being detached from its activity. We need
// to make sure its thread is not going to touch any activity
// state after returning from this function.
synchronized (mThread) {
mProgressBar = null;
mReady = false;
mThread.notify();
}
super.onDetach();
}
/**
* API for our UI to restart the progress thread.
*/
public void restart() {
synchronized (mThread) {
mPosition = 0;
mThread.notify();
}
}
}
}

45
samples/ApiDemos/src/com/example/android/apis/app/FragmentStack.java
View File

@@ -37,11 +37,6 @@ public class FragmentStack extends Activity {
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment_stack);
// Add initial fragment.
Fragment newFragment = new CountingFragment(mStackLevel);
FragmentTransaction ft = openFragmentTransaction();
ft.add(newFragment, R.id.simple_fragment).commit();
// Watch for button clicks.
Button button = (Button)findViewById(R.id.next);
button.setOnClickListener(new OnClickListener() {
@@ -49,8 +44,23 @@ public class FragmentStack extends Activity {
addFragmentToStack();
}
});
if (savedInstanceState == null) {
// Do first time initialization -- add initial fragment.
Fragment newFragment = new CountingFragment(mStackLevel);
FragmentTransaction ft = openFragmentTransaction();
ft.add(newFragment, R.id.simple_fragment).commit();
} else {
mStackLevel = savedInstanceState.getInt("level");
}
}
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putInt("level", mStackLevel);
}
void addFragmentToStack() {
mStackLevel++;
Fragment newFragment = new CountingFragment(mStackLevel);
@@ -61,14 +71,33 @@ public class FragmentStack extends Activity {
ft.commit();
}
class CountingFragment extends Fragment {
final int mNum;
static class CountingFragment extends Fragment {
int mNum;
public CountingFragment() {
mNum = 0;
}
public CountingFragment(int num) {
mNum = num;
}
public View onCreateView(LayoutInflater inflater, ViewGroup container) {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (savedInstanceState != null) {
mNum = savedInstanceState.getInt("num");
}
}
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putInt("num", mNum);
}
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.hello_world, container, false);
View tv = v.findViewById(R.id.text);
((TextView)tv).setText("Fragment #" + mNum);