How check if my previous activity exist? - android

In my app, there are 3 activities and their calling sequence is like this...
Splash activity--->Dashboard Activity--->List Activity
If it goes like this then If I press back button on List activity then it will follow the reverse sequence of above.
There is one requirement where user can navigate to List Activity directly from Splash (Skipping Dashboard Activity) Now when user will hit back button on List Activity then I wan't to show Dashboard Activity which is not there in the Activity Stack.
So please help me with the best approach.

Pass a boolean through the intent for going to List Activity from either of the others. Using onBackPressed check if the boolean is true or false for skipping Dashboard Activity.
Then if true put new intent for loading dashboard activity and finish(); on list activity.

You have to pass class name as intent extra from both Splash and DashboardActiviy.
In List Activity you have to get the class name using getIntent().
When the user click back button, you need to check the class name based on that you can take decision.
if(name.equalIgnorecase(DashboardActivit.class.getSimpleName()){
//Add your intent
}else{
//
}
This may give you definite solution to you.Give a try

you can directly go to splash from list Activity while going to
ListActivity from Dashboard Activity call finish()
Intent i = new Intent(DashboardActivity.this,ListActivity);
startActivtiy(i);
finish();

Start your inner activities with startAcvitiyForResult
Intent i = new Intent(this, Activity_2.class);
startActivityForResult(i, 1);
and in your inner activity
#Override
public void onBackPressed ()
{
finish();
}
You can also do stuff in your outer activity as you like after your inner activity finishes
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == 1) {
if(resultCode == 1){
Log.i("TEST", "RESULT_OK");
}
else {
return;
}
}
}

Related

How to transition from activity 3rd to 1st?

I have a problem with Shared Element Activity Transition between activities. I have MainActivity, it has a recyclerview with boxes (recyclerview.horizontal). Each box when clicked will go to the corresponding activity. The problem that appears when I click on a box, I switch to the second activity, in the second activity I press a button to switch to the third activity. And here I swipe to right to return to the MainActivity with transition and I want it to transition right to the box corresponding to the 3rd activity in the recyclerview in MainActivity. So, my purpose is:
MainActivity (Shared Element Activity Transition)-> Second Activity ->
Third Activity (Shared Element Activity Transition)-> MainActivity
(exactly scroll to position for Third Activity in RecyclerView).
My MainActivity
I hope everyone offer me the solution. Thank you so much.
You can use startActivityForResult instead of startActivity in SecondActivity when you are going to start ThirdActivity.Like this :
Intent i = new Intent(this, ThirdActivity.class);
startActivityForResult(i, 1);
And when you are finishing your ThirdActivity
Intent returnIntent = new Intent();
returnIntent.putExtra("activity_finish",true);
setResult(Activity.RESULT_OK,returnIntent);
finish();
If you use startActivityForResult() then it gives callback in the Activity who started it,so as soon as ThirdActivity finishes, it will return to the onActvityResult() in SecondActivity.Where you have to check result_code and request code like this :
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == 1) {
if(resultCode == Activity.RESULT_OK){
boolean isActivityFinish=data.getBooleanExtra("activity_finish");
if(isActivityFinish){
// finish your Second Activity here
}
if (resultCode == Activity.RESULT_CANCELED) {
//Write your code if there's no result
}
}
}
For more info : How to manage `startActivityForResult` on Android?

How to choose which fragment to open from specific activity?

My mainActivity contains 5 fragments which you can switch through with tabs. The main tab shown on start is the third one (the one in the middle). I have a button in fragment #1 which opens activityTwo. What should I put in the onBackPressed method in activityTwo in order for it to bring me back to mainActivity with selected tab #1. I currently have this, but it opens mainActivity and shows the main tab (#3)
#Override
public void onBackPressed() {
Intent intent = new Intent(this, MainActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_NO_HISTORY);
startActivity(intent);
ActivityTwo.this.finish();
}
How can I make it show tab #1 instead of tab #3?
Your first activity should still be on the activity stack, so you should not call startActivity again. Instead, you can use setResult to pass a value back to your first activity:
// Inside your second activity
#Override
public void onBackPressed() {
setResult(RESULT_OK);
finish();
}
Then, from your first activity, replace startActivity with startActivityForResult, with a request code (any integer you want, as long as it's unique):
startActivityForResult(intent, YOUR_REQUEST_CODE);
Then override onActivityResult:
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == YOUR_REQUEST_CODE) {
if (resultCode == RESULT_OK) {
// Code to select tab 1 here
// mTabLayout.getTabAt(0).select();
}
}
}
i think you are using view pager , so while you return from activity 2, use viewPager.setCurrentItem(page);
where page will be your tab no, (in this case it will be 2, since it starts with 0). Hope this helps, if not then please clarify a bit more.

How to restart previous activity in android?

In my android app, I have an activity that displays profile information. Then it opens a new activity to make changes to the activity. After you save changes, it closes the edit activity from the edit activity, then goes back to the profile displaying activity, there I need to restart this activity to refresh the data.
Is there a way I can restart the activity that opened the current activity?
There are three ways you can achieve what you want:
Start the profile activity by calling startActivityForResult() and refresh your data in onActivityResult()
Finish() the activity when start the profile activity and then override onBackPress() in the profile activity to start the previous activity and then call finish().
Override onBackPress() in the profile activity to start the previous activity with the flag Intent.FLAG_ACTIVITY_CLEAR_TOP and refresh your data in onNewIntent()
Use Android Activity Result Pattern that communticates parent and child activities:
In your profile activity (parent):
#Override
public void onClick(View v) {
startActivityForResult(
new Intent(this, NameActivity.class),
1); // 1 to identify caller activity.
}
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (resultCode == RESULT_OK) {
updateProfile();
}
}
In your editor activity (child):
#Override
public void onClick(View v) {
setResult(
RESULT_OK);
finish();
}
You won't have to "restart" Activity A.
You can call startActivityForResult(Intent, int) to start your new Activity, and then receive extras via the onActivityResult(int, int, Intent) call.
http://developer.android.com/reference/android/app/Activity.html#StartingActivities
Alternatively, look into the onResume() method, which is called every time your screen becomes visible. Assuming you persisted some state in Activity B (e.g. a SharedPreference or a database record), in onResume() you can refresh Activity A.
Activity Display;
Activity Modification;
When you startActivity M in your Activity D,don't D.finish();
then, when you M.finish(),you don't need "restart" Activity D,because it is already there.
You have two choices to "refresh the data":
1.startActivityForResult as they said.I won't explain any more.
2.make a cache.
save data in some static variables or sqlite or even sharedPreference.Then in onResume() of Activity D,get those data and show them.
Try this: If A is calling B and when B ends you need to update A, then in A launch B with startActivityForResult(). When B returns, the method onActivityResult() of A will be called. In this method (of A) you can test, if necessary, that some stored values are changed. At this point you do something like:
finish();
startActivity(intent); //start the activity A

How to maintain the previous state of an activity

I am having two activities (activity1 and activiy2) and each activity is having one button each. In activity1 i having a spinner with few options. Suppose i am selecting option 2 from this spinner and i am clicking the button in activity1, then activity2 starts. When i click back button activity1 is resumed and the same option 2 is visible (like i need). Now the problem is that if my activity2 is started and i am clicking a button in it, activity1 is started. But instead of resuming the previous state of activity1 it starts in a way that it has just created and the previous selection is changed. How can i get the same facility like back button (not the facility of going back to previous activity, i mean automatically resuming the previous state of any activity) even when i start the activity again. Simply i need to know how to maintain the previous state of an activity if it is again visited.
It is with this code I go from one activity to another when button is clicked:
Intent intent=new Intent();
intent.setClassName(getApplicationContext(),"com.myapp.activityname");
startActivity(intent);
Kindly help me.I am a beginner in android, so if any one is giving the answer please explain it a bit. Thanks in adavnce
Think I found the answer. Let me tell what I have done in simple words,
Suppose i am having two activities activity1 and activity2 and i am navigating from activity1 to activity2(i have done some works in activity2) and again back to activity 1 by clicking on a button in activity1. Now at this stage I wanted to go back to activity2 and i want to see my activity2 in the same condition when I last left activity2.
For the above scenario what i have done is that in the manifest i made some changes like this:
<activity android:name=".activity2"
android:alwaysRetainTaskState="true"
android:launchMode="singleInstance">
</activity>
And in the activity1 on the button click event i have done like this:
Intent intent=new Intent();
intent.setFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
intent.setClassName(this,"com.mainscreen.activity2");
startActivity(intent);
And in activity2 on button click event i have done like this:
Intent intent=new Intent();
intent.setClassName(this,"com.mainscreen.activity1");
startActivity(intent);
Now what will happen is that whatever the changes we have made in the activity2 will not be lost, and we can view activity2 in the same state as we left previously.
I believe this is the answer and this works fine for me.
By overriding an Activity’s onSaveInstanceState event handler, you can use its Bundle parameter to save instance values. Here is an example:
#Override
public void onSaveInstanceState(Bundle outState) {
// Retrieve the View
TextView myTextView = (TextView)findViewById(R.id.myTextView);
// Save its state
outState.putString("My text",
myTextView.getText().toString());
super.onSaveInstanceState(outState);
}
The saved Bundle is passed into the onRestoreInstanceState and onCreate methods if the application is forced to restart during a session. You can then extract values from the Bundle and use them to update the Activity instance state. Here is an example:
#Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.main);
TextView myTextView = (TextView)findViewById(R.id.myTextView);
String text = “”;
if (icicle != null && icicle.containsKey("My text")) {
text = icicle.getString(TEXTVIEW_STATE_KEY);
}
myTextView.setText(text);
}
It’s important to remember that onSaveInstanceState is called only when an Activity becomes inactive, but not when it is being closed by a call to finish or by the user pressing the Back button.
Download source code or see the entire post
For activity one, you need to use the startActivityForResult() function that returns values to the parent activity which is the activity one.
Intent intent = new Intent(MainActivity.this, Activity2.class);
startActivityForResult(intent, 1);
And to receive the values from activity two without alteration of activity one, add the following code
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == 1) {
if(resultCode == RESULT_OK){
String text=data.getStringExtra("text");
vTxt.setText("Name 1: "+eTxt.getText()+ "\n Name 2: "+text);
}
}
}
Activity 2
add the following code to return to activity one and pass some values
Intent intent=new Intent(Activity2.this, MainActivity.class);
Bundle extra=new Bundle();
extra.putString("text", eTxt.getText().toString());
intent.putExtras(extra);
setResult(RESULT_OK, intent);
finish();
Finally you are done

Switching between activity?

In an given Android activity, I would like to start a new activity for the user at some point. Once they leave the first activity and arrive at the second, the first activity is hidden..
Now my question is
I want to bring back the first activity (i dont want to create a new instance of the first activity but to bring back the already existing instance of the first activity) when a button is clicked in the second activity ...
thanks :)
so simple. integrate the below code in your second activity
Button b = (Button)findViewById(yourbuttonid here);
b.setOnClickListener(new View.onClickListener(){
public void onClick(View v){
finish();
}
});
This will work
You would define the first activity with launchMode="singleInstance", then you would start the activity as usual.
Depending on the usage of your second activity, you could also use startActivityForResult() when you start your second activity...
FirstActivity.java{
private static final int SECOND_ACTIVITY = 0;
openSecondActivity(){
Intent forChildIntent= new Intent( this ,FirstActivity. class );
//data for second activity
forChildIntent.putExtra("userName", getUsrName());
this.startActivityForResult(forChildIntent, SECOND_ACTIVITY);
}
protected void onActivityResult(int requestCode, int resultCode, Intent data){
switch (resultCode) {
case RESULT_OK: //do something
default:break;
}
}
SecondActivity.java{
goBackButtonClick(){
Intent retData=new Intent();
//set data to pass back ,if required
//retData.putExtra("userName", getUsrName());
setResult(RESULT_OK, retData);
finish();//will take you to the first activity
}
}

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