i have a webview that read HTML from SD-card and show it . when user open activity for first time, HTML file load correctly . but in some devices (such as Samsung galaxy series) if close activity and open it again, webview not show anything and is empty.
public class page extends Activity {
private static WebView web;
private int path;
#SuppressLint("SetJavaScriptEnabled")
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Intent intent = getIntent();
Bundle bundle = intent.getExtras();
path = bundle.getInt("path");
web = (WebView) findViewById(R.id.webview);
web.setBackgroundColor(Color.TRANSPARENT);
web.getSettings().setJavaScriptEnabled(true);
web.setWebChromeClient(new WebChromeClient());
}
#Override
protected void onResume() {
super.onResume();
loadPage();
}
#Override
protected void onPause() {
super.onPause();
resetWebView();
}
// becuase my webview play audio and if close activity sound also playing
private void resetWebView(){
if (web != null){
web.loadUrl("about:blank");
web.destroy();
web.destroyDrawingCache();
}
}
private void loadPage(){
String DIR = Environment.getExternalStorageDirectory().getAbsolutePath()+"/myApp";
if(path != null && web != null){
switch (path) {
case 3: {
// something like this
// /storage/emulated/0/myApp/1/page_three.html/
File file = new File(DIR+path+"page_three.html/");
web.loadUrl("file://"+file);
}
break;
case 2: {
File file = new File(G.DIR_APP+path+"page_two.html/");
web.loadUrl("file://"+file);
}
break;
case 1: {
File file = new File(G.DIR_APP+path+"page_one.html/");
web.loadUrl("file://"+file);
}
break;
case 0: {
File file = new File(G.DIR_APP+path+"welcome.html/");
web.loadUrl("file://"+file);
}
break;
default:
// do nothing
}
}
}
I had the same issue. This is for API 11 and greater. Adding webview.onResume() inside the onResume() function of fragment solved it for me.
So in your case:
public void onResume() {
super.onResume();
web.onResume();
}
If the activity is destroyed while paused, the Android system may re-create it when the user returns to it later. To ensure that the same data that was originally used to intialise the activity is restored, you need to override onSaveInstanceState() and onRestoreInstanceState(). I recommend this pattern - this will ensure the correct data is loaded for initial creation, resume after pause, recreation and resume after being destroyed, and when sent a new intent to load new data.
static final String ARG_PATH = "path";
protected Bundle bundle = null;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
bundle = getIntent().getExtras();
// perform other create-time initialisation here
}
#Override
protected void onNewIntent(Intent intent) {
super.onNewIntent(intent);
setIntent(intent);
bundle = intent.getExtras();
}
#Override
protected void onRestoreInstanceState(#NonNull Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
bundle = savedInstanceState;
}
#Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putInt(ARG_PATH, path);
}
#Override
protected void onResume() {
super.onResume();
if(bundle != null) {
path = bundle.getInt(ARG_PATH);
bundle = null;
loadPage();
} else
web.onResume();
// if bundle was already null, we were just resumed after pause, not destroyed so no reload is required.
}
#Override
protected void onPause() {
web.onPause(); // pause any video etc.
super.onPause();
}
when you leave activity, finish the activity, so next time you come, a method onCreate(Bundle savedInstanceState) must be called again.
i add the following code to webview and problem solved
webView.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
Related
I have a MainActivity with some cards which have different names. onClick, the title is passed as an intent via the adapter to the secondActivity and displayed as the header. From there, I can go to other activities. If I come back from one of these other activities (via the back button created by establishing second activity as the parent activity) the header is gone. How do I keep the header that was originally passed on as an intent or should I go about this completely different?
I have tried using onResume() and onStart() in the secondActivity to reassign the intent from a global variable.
The adapter class, where the card onClick method is written:
#Override
public void onBindViewHolder(final TripHolder tripHolder, final int position) {
Trip trip = trips.get(position);
tripHolder.setDetails(trip);
tripHolder.itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(context, SecondActivity.class);
TextView card_title = v.findViewById(R.id.TripNamecl);
intent.putExtra("card_title", card_title.getText().toString());
context.startActivity(intent);
}
});
}
The secondActivity where the header should be displayed:
public class SecondActivity extends AppCompatActivity {
String name;
TextView header;
static final String STATE_HEADER = "header";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_second);
name = getIntent().getStringExtra("card_title");
header = findViewById(R.id.TripsHeader);
header.setText(name);
}
#Override
public void onSaveInstanceState(Bundle savedInstanceState) {
super.onSaveInstanceState(savedInstanceState);
savedInstanceState.putString(STATE_HEADER, name);
}
#Override
public void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
name = savedInstanceState.getString(STATE_HEADER);
header.setText(name);
}
public void launchMapsActivity(View view) {
Uri gmmIntentUri = Uri.parse("geo:48.8566°,2.3522");
Intent mapIntent = new Intent(Intent.ACTION_VIEW, gmmIntentUri);
mapIntent.setPackage("com.google.android.apps.maps");
if (mapIntent.resolveActivity(getPackageManager()) != null) {
startActivity(mapIntent);
}
}
public void launchTravelActivity(View view) {
Intent intent = new Intent(this, TravelActivity.class);
startActivity(intent);
}
public void launchPlansActivity(View view) {
Intent intent = new Intent(this, PlansActivity.class);
startActivity(intent);
}
}
SOLUTION:
The solution was to put android:launchMode="singleTop" into the manifest file for the secondactivity. It's described in more detail here: How can I return to a parent activity correctly?
In order to do it you should override onSavedInstanceState in your SecondActivity.
You can use something like that, obv adapt it to your needs:
#Override
public void onSaveInstanceState(Bundle savedInstanceState) {
super.onSaveInstanceState(savedInstanceState);
//here you can save your variables
savedInstanceState.putString("myHeader", name);
}
#Override
public void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
//here you can retrieve your variables
name = savedInstanceState.getString("myHeader");
}
Let me know if this worked! good luck
remove header.setText(name); from onResume and onStart methods
If you want to save data in first activity between lifecicle method calls you have to save your data in Bundle object.
Override method onSaveInstanceState(Bundle bundle) of your activity:
#Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putInt("AStringKey", variableData);
outState.putString("AStringKey2", variableData2);
}
And also override Activity method onRestoreInstanceState(Bundle savedInstanceState):
#Override
protected void onRestoreInstanceState(Bundle savedInstanceState){
super.onRestoreInstanceState(savedInstanceState);
variableData = savedInstanceState.getInt("AStringKey");
variableData2 = savedInstanceState.getString("AStringKey2");
setYourHeaderMethodExample(variableData2)
}
When coming back from third activity to second activity onStart() and onResume() method call executes. Try not using onStart() and onResume() for setting the header and use onCreate method for setting the header.
onCreate() method executes only once in its lifetime, but onStart() and onResume() will execute whenever the activity comes to screen. So when coming back from third activity we don't have any values in the intent.
In your second activity's onCreate method add:
getSupportActionBar().setHomeButtonEnabled(true);
and override the onOptionsItemSelected() method in the class and add the following code:
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()){
case android.R.id.home:
finish();
return true;
}
return super.onOptionsItemSelected(item);
}
You don't need to override the onStart() and onResume() methods.
Saving the State of Drawable xml Button.
private boolean mJam;
private button mSwitch;
private static final String KEY_ENABLE = "KEY_ENABLE";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if( null == savedInstanceState ) {
mJam = false;
} else {
mJam = savedInstanceState.getBoolean(KEY_ENABLE);
}
button_layout();
}
#Override
protected void onSaveInstanceState(Bundle outState) {
outState.putBoolean(KEY_ENABLE, mJam);
outState.putBoolean(KEY_ENABLE, mSwitch.isSelected()); // Saving the state of the
super.onSaveInstanceState(outState);
}
#Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
mSwitch.setSelected(savedInstanceState.getBoolean(KEY_ENABLE));
mJam = savedInstanceState.getBoolean(KEY_ENABLE);
super.onRestoreInstanceState(savedInstanceState);
}
Note: If you don't want to use ScreenSize in Android manifest, This code can be used,
If you want to do it Manually, then go for this one.
P.S: setting Screen Size in Manifest, never go to onCreate if the Orientation Change, It Just saved all the instance and display as it is, when
Android orientation Change.
I am using XWalkView to show a mobile web site as an application. My problem is when application goes background and comes back it reloads the page it shows. I want to keep it state and continue from that state when it comes from background. Here is my code:
public class MainActivity extends AppCompatActivity {
static final String URL = "https://www.biletdukkani.com.tr";
static final int MY_PERMISSIONS_REQUEST_ACCESS_LOCATION = 55;
static final String SHOULD_ASK_FOR_LOCATION_PERMISSION = "shouldAskForLocationPermission";
static final String TAG = "MainActivity";
static final String COMMAND = "/system/bin/ping -c 1 185.22.184.184";
static XWalkView xWalkWebView;
TextView noInternet;
static Bundle stateBundle;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.d(TAG, "onCreate");
// Check whether we're recreating a previously destroyed instance
if (savedInstanceState != null) {
// Restore value of members from saved state
stateBundle = savedInstanceState.getBundle("xwalk");
}
setContentView(R.layout.activity_main);
initNoInternetTextView();
}
public void onRestoreInstanceState(Bundle savedInstanceState) {
// Always call the superclass so it can restore the view hierarchy
super.onRestoreInstanceState(savedInstanceState);
stateBundle = savedInstanceState.getBundle("xwalk");
Log.d(TAG, "onRestoreInstanceState");
}
/**
* İnternet yok mesajı gösteren TextVidew'i ayarlar.
*/
private void initNoInternetTextView() {
Log.d(TAG, "initNoInternetTextView");
noInternet = (TextView) findViewById(R.id.no_internet);
if (noInternet != null) {
noInternet.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
checkInternetConnection();
}
});
}
}
/**
* WebView'i ayarlar.
*/
private void initWebView() {
Log.d(TAG, "initWebView");
if (xWalkWebView == null) {
ProgressBar progressBar = (ProgressBar) findViewById(R.id.progressBar);
xWalkWebView = (XWalkView) findViewById(R.id.webView);
//xWalkWebView.clearCache(true);
xWalkWebView.load(URL, null);
xWalkWebView.setResourceClient(new BDResourceClient(xWalkWebView, progressBar));
}
}
#Override
protected void onResume() {
super.onResume();
Log.d(TAG, "onResume");
checkLocationPermissions();
checkInternetConnection();
if (xWalkWebView != null && stateBundle != null) {
xWalkWebView.restoreState(stateBundle);
}
}
#Override
protected void onPause() {
super.onPause();
Log.d(TAG, "onPause");
if (xWalkWebView != null) {
stateBundle = new Bundle();
xWalkWebView.saveState(stateBundle);
}
}
public void onSaveInstanceState(Bundle savedInstanceState) {
Log.d(TAG, "onSaveInstanceState");
// Save the user's current game state
savedInstanceState.putBundle("xwalk", stateBundle);
// Always call the superclass so it can save the view hierarchy state
super.onSaveInstanceState(savedInstanceState);
}
#Override
public void onBackPressed() {
Log.d(TAG, "onBackPressed");
if (xWalkWebView != null && xWalkWebView.getNavigationHistory().canGoBack()) {
xWalkWebView.getNavigationHistory().navigate(XWalkNavigationHistory.Direction.BACKWARD, 1);
} else {
super.onBackPressed();
}
}
}
I have also tried to add following lines to manifest but didn't work.
android:launchMode="singleTask"
android:alwaysRetainTaskState="true"
How can i do that?
Thanks in advcance.
One way would be to initialize the view inside a fragment which is set to retain it's instance.
I am trying to save values while leaving from activity and retrieve when coming back to screen.
So I'm using onSaveInstanceState method to save data and using Bundle object from onCreate method while coming back.
Below is my scenario..
Activity A:
protected void onCreate(Bundle savedInstanceState) {
if (savedInstanceState != null) {
Log.d(TAG, "Object received from savedInstanceState");
}
else{
Log.d(TAG, "savedInstanceState value is null");
}
}
public void onSaveInstanceState(Bundle savedInstanceState) {
super.onSaveInstanceState(savedInstanceState);
Log.d(TAG, "In onSaveInstanceState");
savedInstanceState.putString("obj_name", DashBoardDisplay_l.getName());
}
OnClickListener save_click = new OnClickListener() {
#Override
public void onClick(View arg0) {
Intent i = new Intent(getApplicationContext(),PointLogActivity.class);
i.putExtra("ref_name", Name_ref);
startActivity(i);}};
I could see the log for onSaveInstanceState method while leaving to PointLogActivity.
PointLogActivity:
#Override
protected void onCreate(Bundle savedInstanceState){
Intent intent = getIntent();
String YourtransferredData = intent.getExtras().getString("ref_name");
Log.d(TAG, "ref name "+YourtransferredData);
Name=YourtransferredData;
//For getting back button
getActionBar().setDisplayHomeAsUpEnabled(true);
}
I am coming back to Activity A by click back button in top left of the activity.
But while coming back to Activity, I could not find date from Bundle object and getting log from null condition.
savedInstanceState value is null
So can someone tell where I am going wrong.
I resolved it by putting the below at parent activity in manifest file.
android:launchMode="singleTop">
I got a VERY STRANGE situation...(to me)
For example, 2 objects,
1 is an activity member boolean called isInPage,
2 is a static bitmap object called bmpPhoto.
When I get into my own activity called FacebookShareActivity
isInPage will be true until I quit this activity,
bmpPhoto will be given a picture.
After onCreare() and onResume(), there is no any code running, until user click some GUI.
What I did is close screen by press hardware power button, and maybe wait 5 or 10 minutes.
OK, now I press porwe again to wake phone up, unlock screen,
and my FacebookShareActivity goes back to front.
And I click my GUI button to check variable value via Logcat, it says:
isInPage=false;
And I forget bmpPhoto's value, but on my GUI, the photo just gone,
not displayed anymore...
How is this happen ?
And it just not happen every time after I do that......
What if I override onSaveInstanceState(Bundle savedInstanceState) and
onRestoreInstanceState(Bundle savedInstanceState) ?
Will it help ?
And what about the bitmap object ?
Still don't know how is that happen...
Did I miss something ?
I really need your help, please everyone~
Following is part of my code, quite long...
The "isPageRunning" and "bmp" changed sometime when back from desktop, but not everytime.
public class FacebookShareActivity extends Activity
{
private Bundle b=null;
private Bitmap bmp=null;
private boolean isFacebookWorking=false;
private boolean isPageRunning=true; //This value sometime changed when back from desktop, but not every time
protected void onCreate(Bundle savedInstanceState)
{
Log.i(Constants.TAG, "ON Facebook Share create......");
super.onCreate(savedInstanceState);
setContentView(R.layout.facebook_share);
setVolumeControlStream(AudioManager.STREAM_MUSIC);
}
private void initUI()
{
btnBack=(Button)findViewById(R.id.btnBack);
btnBack.setOnClickListener(new ButtonClickHandler());
formImage=(RelativeLayout)findViewById(R.id.form_image);
formImage.setDrawingCacheEnabled(true);
btnShare=(Button)findViewById(R.id.btnShare);
btnShare.setOnClickListener(new ButtonClickHandler());
txtIntroText=(TextView)findViewById(R.id.txtIntroText);
txtIntroText.setOnClickListener(new ButtonClickHandler());
txtIntroText.setText(getUploadInImageText());
photo=(ImageView)findViewById(R.id.photo);
bmp=Constants.PROFILE.getName().getPhoto();
if(bmp!=null)
{photo.setImageBitmap(bmp);} //bmp wouldn't be null, it filled by some other activity before
}
#Override
protected void onResume()
{
super.onResume();
Log.i(Constants.TAG, "Trying to set UI on resume...");
b=getIntent().getExtras();
// ...
// ... Get some String value passed from prev activity
facebook=new Facebook("123456789012345"); //Test
asyncFacebook=new AsyncFacebookRunner(facebook);
initUI();
System.gc();
}
#Override
public void onBackPressed()
{
Log.d(Constants.TAG, "Activity receive back key...");
lockButtons(false);
return;
}
private void lockButtons(boolean b)
{
if(isPageRunning)
{
btnBack.setClickable(!b);
btnShare.setClickable(!b);
}
}
private class DelayReleaseKey implements Runnable
{
public void run()
{
try{Thread.sleep(10000);}
catch(InterruptedException ie){}
handler.sendEmptyMessage(0);
}
}
private class ButtonClickHandler implements OnClickListener
{
public void onClick(View v)
{
if(v==btnBack)
{
if(isFacebookWorking)
{ShowAlertDialog(Constants.MESSAGE_FACEBOOK_WORK);}
else
{
lockButtons(true);
formImage=null;
photo=null;
b=null;
facebook=null;
isPageRunning=false;
Intent intent=new Intent(FacebookShareActivity.this, PracticeListActivity.class);
startActivity(intent);
FacebookShareActivity.this.finish();
overridePendingTransition(android.R.anim.slide_in_left,android.R.anim.slide_out_right);
}
}
if(v==btnShare)
{
lockButtons(true);
facebookLogin();
}
}
}
}
Now I know i must override onSaveInstanceState, onRestoreInstanceState.
They can help me to save variable like String, int, boolean...
What about Bitmap ?
And what if my variable is static ?
Now try again.
public class FacebookShareActivity extends Activity
{
private Bundle b=null;
private static Bitmap bmp=null;
private static boolean isFacebookWorking=false;
private static boolean isPageRunning=true; //This value sometime changed when back from desktop, but not every time
protected void onCreate(Bundle savedInstanceState)
{
Log.i(Constants.TAG, "ON Facebook Share create......");
super.onCreate(savedInstanceState);
setContentView(R.layout.facebook_share);
setVolumeControlStream(AudioManager.STREAM_MUSIC);
}
private void initUI()
{
btnBack=(Button)findViewById(R.id.btnBack);
btnBack.setOnClickListener(new ButtonClickHandler());
formImage=(RelativeLayout)findViewById(R.id.form_image);
formImage.setDrawingCacheEnabled(true);
btnShare=(Button)findViewById(R.id.btnShare);
btnShare.setOnClickListener(new ButtonClickHandler());
txtIntroText=(TextView)findViewById(R.id.txtIntroText);
txtIntroText.setOnClickListener(new ButtonClickHandler());
txtIntroText.setText(getUploadInImageText());
photo=(ImageView)findViewById(R.id.photo);
bmp=Constants.PROFILE.getName().getPhoto();
if(bmp!=null)
{photo.setImageBitmap(bmp);} //bmp wouldn't be null, it filled by some other activity before
}
#Override
protected void onResume()
{
super.onResume();
isPageRunning = true;
Log.i(Constants.TAG, "Trying to set UI on resume...");
b=getIntent().getExtras();
// ...
// ... Get some String value passed from prev activity
facebook=new Facebook("123456789012345"); //Test
asyncFacebook=new AsyncFacebookRunner(facebook);
initUI();
System.gc();
}
#Override
protected void onPause()
{
isPageRunning = false;
}
#Override
public void onBackPressed()
{
Log.d(Constants.TAG, "Activity receive back key...");
lockButtons(false);
return;
}
private void lockButtons(boolean b)
{
if(isPageRunning)
{
btnBack.setClickable(!b);
btnShare.setClickable(!b);
}
}
private class DelayReleaseKey implements Runnable
{
public void run()
{
try{Thread.sleep(10000);}
catch(InterruptedException ie){}
handler.sendEmptyMessage(0);
}
}
private class ButtonClickHandler implements OnClickListener
{
public void onClick(View v)
{
if(v==btnBack)
{
if(isFacebookWorking)
{ShowAlertDialog(Constants.MESSAGE_FACEBOOK_WORK);}
else
{
lockButtons(true);
formImage=null;
photo=null;
b=null;
facebook=null;
isPageRunning=false;
Intent intent=new Intent(FacebookShareActivity.this, PracticeListActivity.class);
startActivity(intent);
FacebookShareActivity.this.finish();
overridePendingTransition(android.R.anim.slide_in_left,android.R.anim.slide_out_right);
}
}
if(v==btnShare)
{
lockButtons(true);
facebookLogin();
}
}
}
}
For primitive values, you should use onSaveInstanceState. For restoring you can use onRestoreInstanceState or you can some code in onCreate like this:
if(savedInstanceState != null) {
// restore old state
} else {
// a fresh start
}
Now for restoring objects like Bitmap if they are not expensive to create and doesn't make your UI sluggish, create them again on restore. If you do not want to that then use onRetainNonConfigurationInstance and code will look like this:
#Override
public Object onRetainNonConfigurationInstance () {
return bmp;
}
#Override
public void onCreate() {
if
bmp = (Bitmap)getLastNonConfigurationInstance();
}
WARNING: This api is deprecate, you might use it on old platforms. I put it here for illustration purpose. The new way to do this is more involving.
Here is detailed ref:
getLastNonConfigurationInstance
onRetainNonConfigurationInstance