I have plugged in lock screen logic into my app. It shows ComfirmPatternActivity (above my MainActivity) which controls graphical pin code input to be correct.
When onCreate() method of MainActivity is call everything is OK. But I also want to lock screen when I simply turn app down not destroying MainActivity. So it goes from onRestart() -> onResume(). In onResume() I placed method handleLockScreen(); as in onCreate(). But for now I got into infinite loop hich shows me ComfirmPatternActivity screen for ages. It seamed out that the last command of code in ComfirmPatternActivity after user inputs correct pin - is Activity finish(). After that finish() Im redirected to MainActivity.onResume() - prev Activity on the stack - in which I again start ComfirmPatternActivity() and so on. I want resume logic only in case user pressed on app icon again, not in case top Activity is destroyed. How this can be handled? Thx in advance.
MainActivity
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
handleLockScreen();
setContentView(R.layout.activity_main);
}
protected void onResume() {
super.onResume();
handleLockScreen();
..
public void handleLockScreen(){
SharedPreferences prefs = this.getSharedPreferences("LOCK_SCREEN",
Context.MODE_PRIVATE);
String lock_screen_code = prefs.getString("LOCK_SCREEN_CODE","");
if (lock_screen_code.isEmpty()) {
Intent intent = new Intent(this, SampleSetPatternActivity.class);
this.startActivity(intent);
}
else{
Intent intent = new Intent(this, SampleConfirmPatternActivity.class);
this.startActivity(intent);
}
}
public class SampleConfirmPatternActivity extends ConfirmPatternActivity {
SharedPreferences prefs = this.getSharedPreferences("LOCK_SCREEN",
Context.MODE_PRIVATE);
String patternSha1 = prefs.getString("LOCK_SCREEN_CODE","");
return TextUtils.equals(PatternUtils.patternToSha1String(pattern), patternSha1);
... finish() is called further in this activity
}
This finish() returns to my onResume() which triggers all over again. And I want handle onResume() only in case smth external happend to my app like user returned to my app etc. I dont want get back to onResume() when pin code is checked and everything is OK.
You could possibly declare a boolean (global to application) in LockScreen Activity to fix this issue and tell(to the MainActivity) if it is coming to onResume from outside or from LockScreen (y)
I have a lot of activities in my app, and I want that if the user closes the app in activity 13 for example, when opening the app at another time the activity returns in activitty n° 13. how can I do this? thank in advance
You could use SharedPreferences to keep track of the last used activity.
Then you can redirect the user in the onCreate of your main activity to the correct activity, and call finish on your main activity.
This could look something like this:
#Override
protected void onCreate(Bundle savedInstanceState)
(...)
int last_activity = getLastActivityIdFromSharedPreferences();
if (last_activity == 1)
{
this.startActivity(new Intent(this, ActivityOne.class));
finish();
}
(...)
}
There are three different cases:
1) A user launches an app, navigates in it, pressed home and click on the app icon again to launch our app again.
2) A user launches an app, navigates in it, presses home, chooses recent and click on the app to launch our app again.
3) A user launches an app, navigates in it, click something in the app (TextView with a link), which calls another app (as example Email) and user clicks back button, which bring us back to our app.
I know about flag "clearTaskOnLaunch" flag, it solves case #1.
I know about about flag "excludeFromRecents", it solves case #2 (may be not the most user friendly solution, but it works).
What about case #3? I have a workaround right now. However, I will have to put it on all activities which can be lead to another app. I wonder, whether there is better way to solve it (without handling it in all such activities).
This should be handled on the Application level.
For API level 14, you can register an ActivityLifeCycleCallback in your Application class
public void registerActivityLifecycleCallbacks (Application.ActivityLifecycleCallbacks callback)
You can use it, to know on an Application level, which activities are destroyed, paused, resumed etc etc. Whenever, an activity is paused, without a new activity being created/resumed, you should clear the Activity stack, and re-launch your startActivity
If you target SDK versions < 14, you should implement your own method, to know which activities are created/resumed and paused, and do the same whenever an activity is paused, without a new activity being created/resumed
1) define a public static normalPause = true variable in a Class.
2) in onPause method of all of your activities set it false (I am worry. We might not be in a normal pause)
2) in onCreate method of all of your activities set it true (Do not worry. We are in a normal pause)
3) in onResume of all of your Activities:
if(!Utilities.normalPause)
{
this.finish()
}
Enjoy!
It seems a similar question has already been asked. It sounds like the OP came up with a working solution. How do I collapse "child activities"?
EDIT:
Instead of using a button you can use a boolean to tell whether or not you need to collapse back to the main activity. Have your root activity extend from Activity and the child activities extend from CollapsableActivity. To get this to work in all cases I added startOutsideActivity() and startOutsideActivityForResult().
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
public class CollapsableActivity extends Activity {
private boolean returnToRoot;
public static final int COLLAPSE_BACK = -1; // something other than RESULT_CANEL (0)
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
returnToRoot = true;
}
#Override
protected void onStart() {
super.onStart();
returnToRoot = true;
}
#Override
protected void onRestart() {
super.onRestart();
// start collapsing the stack
if (returnToRoot) {
setResult(COLLAPSE_BACK);
finish();
}
}
#Override
public void startActivityForResult(Intent intent, int requestCode) {
super.startActivityForResult(intent, requestCode);
returnToRoot = false;
}
public void startOutsideActivityForResult(Intent intent, int requestCode) {
super.startActivityForResult(intent, requestCode);
returnToRoot = true;
}
#Override
public void startActivity(Intent intent) {
// call startActivityForResult to make sure and catch the collapse condition
super.startActivityForResult(intent, 0);
returnToRoot = false;
}
public void startOutsideActivity(Intent intent) {
super.startActivity(intent);
returnToRoot = true;
}
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == COLLAPSE_BACK) {
returnToRoot = true;
}
}
}
This worked properly for me in all cases you listed. The only difference is you need to call startOutsideActivity() or startOutsideActivityForResult() when you navigate away from you app. Personally, I think this adds clarity to your intentions. Hope it helps!
I know you don't want to manage it in all activities but you can do this and still handle the code in one place with a super activity
public abstract class BlundellActivity extends Activity {
#Override
public void onPause(){
// Whatever strategy you want
}
}
public class SomeActivity extends BlundellActivity {
// Do whatever you normally want to do
}
public class SomeActivity extends BlundellActivity {
// Do whatever you normally want to do here as well
}
Perhaps, android:noHistory is what you're looking for. If you declare all your activities except StartupActivity with this attribute, then they will be finished as the user navigates away from them and only StartupActivity will appear.
You can try this steps:
use one boolean static flag isFinish in StartupActivity with default false value.
in onCreate() of StartupActivity set isFinish value to false.
write below code in onResume() method of all activities in your project.
if(isFinish)
{
finish();
}
set isFinish value to true when you open any native app like email, browser etc.
or
5 . set isFinish value to true in onBackPress() method whenever you want to close application on back press.
Case 6: if android browser open on clicking on any link then use below code is onPause() method
if(isBrowserRunning("com.android.browser"))
{
isFinish = true;
finish();
}
////////////////
private boolean isBrowserRunning(String processName)
{
ActivityManager manager = (ActivityManager) this.getSystemService(ACTIVITY_SERVICE);
String packageName = manager.getRunningTasks(1).get(0).topActivity.getPackageName();
Log.i("LogTest", "Current process package name: " + packageName);
return processName.equalsIgnoreCase(packageName);
}
You can create a sample project to know other browser package name like opera mini, US browser etc.
add below permission in manifest:
<uses-permission
android:name="android.permission.GET_TASKS" />
You can call this.finish() on the onPause() of your Activity, that way the activity will be closed in the three cases.
You need to use bundle and pass appropriate parameter/or parameters from the calling app (i.e. click something in the app (TextView with a link)).
Retrieve the parameter in the called app (Email app).
You can send the name of the activity in the parameter.
Now being in Email app(the called app) Click of back button navigate back to your calling application.
Optionally you can save the state of activity from the caller program, as required.
You need to use Bundle, and Intent to implement this logic.
Code snippet:
In the calling program, we need to store parameters/data required for back button functionality in the called program.
Bundle bndleData = new Bundle();
Use putString(), putInt() methods of Bundle class.
String prefix = getPackageName().toString();
(this prefix can be stored in application level constants.java file as applicable)
bndleData.putString("ParentActivity", this.getLocalClassName());
Also store additional parameters if required
bndleData.putString("paramName", valueofParamName);
bndleData.putInt("IntChannelImage", chImageInt);
Intent intent = new Intent(v.getContext(), AMRChannelPlayer.class);
intent.putExtra(prefix + "bndleChnlData", bndleData);
startActivity(intent);
Caller Program:
Retrive the data, activity nae from bundle and use it in back button implementation:
prefix = getPackageName().toString();
Bundle extras = getIntent().getBundleExtra(prefix + "bndleData");
String parentActivity = extras.getString("ParentActivity");
extras.getString("paramName");
I hope this helps you.
Instead of using multiple solutions you can use a single one that solves all the problems.
Check this answer:
https://stackoverflow.com/a/8576529/327011
With a Broadcast and BroadcastReceivers in each activities of your application you can kill all activities whenever your application goes to background.
UPDATE:
To detect if your application when to background you can use onStop, check this to understand the theory: Activity side-by-side lifecycle
And this is the implementation: https://stackoverflow.com/a/5862048/327011
I think this is all you need :-)
Quick question: I have an activitygroup. Within that Activitygroup I have an activity. If I press back while inside this activity. the onBackPressed method of the activity is called - Not the Activitygroups onBackPressed - Why is that ?
EDIT: Got my answer but the problem remains. Here follows code and explanation of my original issue:
I am using ActivityGroups within a TabHost and as such have been "forced" into overriding onBackPressed. I can navigate through my application without issue by pressing back on my phone and by pressing the tabs on my tabhost. But I cannot interact with the interface after pressing Back.
Once I press one of the tabs on the tabhost again I can interact with everything like normal. Why is this happening? Do I need to override onResume?
Relevant code
SettingsActivityGroup :
public class SettingsActivityGroup extends ActivityGroup
{
// Keep this in a static variable to make it accessible for all the nested activities, lets them manipulate the view
public static SettingsActivityGroup group;
// Need to keep track of the history if you want the back-button to work properly, don't use this if your activities requires a lot of memory.
private ArrayList<View> history;
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
// Allocate history
this.history = new ArrayList<View>();
// Set group
group = this;
// Start root (first) activity
Intent myIntent = new Intent(this, SettingsActivity.class); // Change to the first activity of your ActivityGroup
myIntent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
ReplaceView("SettingsActivity", myIntent);
}
/*
* Replace the activity with a new activity and add previous one to history
*/
public void ReplaceView(String pId, Intent pIntent)
{
Window window = getLocalActivityManager().startActivity(pId, pIntent);
View view = (window != null) ? window.getDecorView() : null;
// Add the old activity to the history
history.add(view);
// Set content view to new activity
setContentView(view);
}
/*
* Go back from previous activity or close application if there is no previous activity
*/
public void back()
{
if(history.size() > 1)
{
// Remove previous activity from history
history.remove(history.size()-1);
// Go to activity
View view = history.get(history.size() - 1);
Activity activity = (Activity) view.getContext();
// "Hack" used to determine when going back from a previous activity
// This is not necessary, if you don't need to redraw an activity when going back
activity.onWindowFocusChanged(true);
// Set content view to new activity
setContentView(view);
}
else
{
// Close the application
finish();
}
}
/*
* Overwrite the back button
*/
#Override
public void onBackPressed()
{
// Go one back, if the history is not empty
// If history is empty, close the application
SettingsActivityGroup.group.back();
return;
}
}
Arbitrary child of SettingsActivityGroup(CallForwardActivity)
public class CallForwardActivity extends ListActivity
{
....
#Override
public void onBackPressed()
{
// Go one back, if the history is not empty
// If history is empty, close the application
SettingsActivityGroup.group.back();
return;
}
}
Because I believe calling onBackPressed() of the currently selected activity is the desired behavior.
It's also worth noting that ActivityGroup is deprecated, but I assume you are coding for <3.0 and don't fancy working with the support libraries.
Regarding your edited question:
Another question on this site cites this article as a good ActivityGroup example, and I would agree http://ericharlow.blogspot.com/2010/09/experience-multiple-android-activities.html
This example just calls finish() on the current activity when back is pressed, and lets the os restart the previous activity, which is simpler than what you are doing, and will hopefully work! You can just call getParent() in your child activities too to avoid using that static reference (just seems easier to read to me that way!).
This looks very similar to my previous question because it's some sort of follow up. I was not very happy with the only solution given; also, the solution was for a problem slightly different from this one. So let me try to explain the problem again...
A notification is created at boot (with a BroadcastReceiver).
My app main activity is opened and the home button is pressed (the activity will be sent to the back stack).
I pull down the status bar and press on the notification previously created at boot.
That will start some activity, different from the main one.
I press the back button and the main activity is displayed.
This is not very different from my previous question... The thing is, "main activity" was just an example. I could have opened the app main activity and then opened the about activity through a menu option and pressed the home button. The back stack would now be MainActivity » AboutActivity. Which means that when the back button is pressed while in "some activity" (started by pressing the notification), we would be brought to the top of the back stack, that is, the about activity.
What basically want is to prevent any other activity to be opened when I press the back button while in "some activity" (again, started by pressing the notification). I want to be brought exactly where I was, that could be the desktop or some other app's activity, but not my app's MainActivity nor AboutAcitivity cause that's not where I was, those were in the back stack, "sleeping" in the background.
I have come up with a solution, but I don't think it's very elegant and I was looking for something more, well, elegant... If you have any other suggestion, please, let me know.
Anyway, this is my proposed solution:
// I use this class for public static (or public static final) members and
// methods
public final class AppHelper {
public static final String KEY_RESUME_FROM_NOTIFICATION = "resumeFromNotification";
private static boolean sResumeFromNotification = false;
public static boolean getResumeFromNotification() {
return sResumeFromNotification;
}
public static void setResumeFromNotification(boolean resumeFromNotification) {
sResumeFromNotification = resumeFromNotification;
}
}
public class MainActivity extends ListActivity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
(...)
}
#Override
protected void onResume() {
super.onResume();
if(AppHelper.getResumeFromNotification()) {
AppHelper.setResumeFromNotification(false);
moveTaskToBack(true);
}
}
}
public class AboutActivity extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
(...)
}
#Override
protected void onResume() {
super.onResume();
if(AppHelper.getResumeFromNotification()) {
AppHelper.setResumeFromNotification(false);
moveTaskToBack(true);
}
}
}
public class SomeActivity extends Activity {
// This will be called when the notification is pressed and the activity is
// not opened yet
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
(...)
extractIntentExtras(intent);
}
// This will be called if the activity is already opened and the
// notification is pressed
#Override
protected void onNewIntent(Intent intent) {
extractIntentExtras(intent);
super.onNewIntent(intent);
}
private void extractIntentExtras(Intent intent) {
Bundle bundleExtras = intent.getExtras();
if(bundleExtras != null) {
// These intent extras are set on the Intent that starts this activity
// when the notification is pressed
AppHelper.setResumeFromNotification(bundleExtras.getBoolean(
AppHelper.KEY_RESUME_FROM_NOTIFICATION));
mRowId = bundleExtras.getLong(AgendaNotesAdapter.KEY_ROW_ID);
populateNoteUpdateFields();
}
}
}
I don't know, but this solution doesn't look very elegant to me (but it works as I expect it) and I'm looking for alternatives or for strong opinions on my proposed solution as an acceptable and good solution. Thoughts?
After doing some more reading perhaps this is the combination of flags you need:
Intent intent = new Intent(mContext, SomeActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_MULTIPLE_TASK);
startActivity(intent);
I think that should force your SomeActivity class to be launched in a completely new task.
When launching the Activity from the notification, you can control how the Activity you are about to open is put on the back stack, and what task it's associated with with Intent flags. You can try something like:
Intent intent = new Intent(mContext, SomeActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
If that doesn't work, try setting a few of the other flags until you get the desired behavior.
Do you ever want your MainActivity to stay in history? If not then my simple, crude solution is to finish the MainActivity when it is paused.
(Call this in your MainActivity)
#Override
public void onPause() {
finish();
}
This will ensure that your MainActivity is removed from history when you navigate away from it, and will never appear when the back button is pressed.
This could be used for AboutActivity as well.