Develop Reference

Calling mainActivity method through Fragment

I have implemented fragment in viewpager and Fragment has some buttons. Also viewpager is in activity_main layout.
I want that when button is clicked then it implement a method which is mentioned in mainActivity.java.
How can I do this?
I am a beginner.

You can get MainActivity method from fragment like below.
Make sure your methid is public if MainActivity and ViewPager are not in same package.
((MainActivity) getActivity()).getMethodOfMain();

You can call getActivity Method from your fragment and cast it to the your respective Activity.
lets take an example : You Have MainActivity class
MainActivity {
public void check() {}
}
And you have fragment : MainFragment
MainFragment{
Activity mainActivity = (MainActivity) getActivity();
mainActivity.check();
}
Thats how you can call the Respective Activity Method.

Replace fragment of one viewpager with fragment of another viewpager in the same activity back key pressed

I have 2 viewpagers: swipeViewPager and nonSwipeViewPager in MainActivity
In swipeableViewPager, I have fragments: homeFragmentFirst and homeFragmentSecond
In nonSwipeableViewPager, I have fragments: AppleFragment , MangoFragment, GrapesFragment and CherryFragment
First I want swipeableViewPager to be viewed in MainActivity. So I have set setVisibility of nonSwipeableViewPager as GONE.
After selecting an item from the drawer, I setVisibility of swipeableViewPager as GONE and of nonSwipeableViewPager as Visible.
By this, I open AppleFragment
Situation:
Suppose, I selected Grapes from drawer, GrapesFragment opens.
I do my some stuff there. And then when I press back button, the app closes i.e. the MainActivity closes.
What I want is when back button is pressed, I want to again bring back homeFragmentFirst from swipeableViewPager.
I have tried below code in GrapesFragment
#Override
public void onBackPressed() {
super.onBackPressed();
// Do some operations here
MainActivity mainActivity = new MainActivity();
mainActivity.swipeHomeViewPager.setVisibility(View.VISIBLE);
mainActivity.nonSwipeHomeViewPager.setVisibility(View.GONE);
}

I solved it myself. I added following in MainActivity:
#Override
public void onBackPressed() {
if (nonSwipeHomeViewPager.getVisibility() == View.VISIBLE) {
nonSwipeHomeViewPager.setVisibility(View.GONE);
swipeHomeViewPager.setVisibility(View.VISIBLE);
swipeHomeViewPager.setCurrentItem(0,true);
} else if (swipeHomeViewPager.getVisibility() == View.VISIBLE){
android.os.Process.killProcess(android.os.Process.myPid());
System.exit(0);
}
}

You can implement backstack for the fragments (while adding / replacing fragment) add it to backstack. the back press will automatically take you to previous fragment.
otherwise you need to override OnBackPressed method to handle with your own logic.

How to add Navigation Drawer to all the activities in the application?

Whats the efficient way to add Navigation Drawer on all the activities? I don't want to repeat the code for Navigation Drawer in all the activities and their layouts. Is it possible somehow to add Nav. Drawer in BaseActivity(custom class) and then every other activity will extend BaseActivity inorder to have the Navigation Drawer ?

Is it possible somehow to add Nav. Drawer in BaseActivity(custom class) and then every other activity will extend BaseActivity inorder to have the Navigation Drawer ?
Yes this is definitly the cleanest way to go.
public BaseActivity extends Activity {
#Override
protected void onCreate()
super.onCreate(); // calls Activity.onCreate()
// setup your Navigation Drawer
}
public FirstActivity extends BaseActivity {
#Override
protected void onCreate()
super.onCreate(); // will call the BaseActivitiy.onCreate()
// do something in the FirstActivity
}
public SecondActivity extends BaseActivity {
#Override
protected void onCreate()
super.onCreate(); // will call the BaseActivitiy.onCreate()
// do something in the SecondActivity
}
The "hard work" will be the layouts. Have one baseLayout for the BaseActivity with a place holder for the Content View (the visible part of the Activities). For all other Activitys use this layout and include your Content View.

Android ActivityGroup Back Button

I have a small issue. I have looked all over the internet but I cannot find a solution to my problem. The problem I have is:
I have a TabHost that has 3 tabs. The first tab opens Activity A. In Activity A, I can press in a listview and it will change the setContent() to Activity B. When I press the back button in Activity B, the onBackPressed() function of Activity A gets called.
How can I close Activity B and go back to Activity A onBackPressed()?

This is how i did it
private void onBackPressed(){
RootActivity parentActivity;
parentActivity = (RootActivity) this.getParent();
parentActivity.switchToSecondActivity();
} // here RootActivity is the tabhost
in RootActivity
public void switchToSecondActivity(){
tabHost.setCurrentTab(SECOND);
} //SECOND is an integer pointing location of the second activity. it starts from 0

Clicking tab not showing Home activity

I have 3 tabs in my sample application with activity group. First tab contains search activity i.e.Home/Root activity and am displaying the results of search in another activity but under same tab i.e Tab1. When I press back button in result activity, it is going to search activity. Everything works fine till here. Now I want to go search activity by pressing tab1 instead of pressing back button. How can achieve this? I tried something like this
public class TabSample extends TabActivity {
public TabHost tabHost;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.tabHost = getTabHost();
tabHost.addTab(tabHost.newTabSpec("tab1").setIndicator("OPT")
.setContent(new Intent(this, TabGroup1Activity.class)));
tabHost.addTab(tabHost.newTabSpec("tab2").setIndicator("EDIT")
.setContent(new Intent(this, TabGroup2Activity.class)));
tabHost.setCurrentTab(1);
tabHost.setOnTabChangedListener(new OnTabChangeListener() {
public void onTabChanged(String arg0) {
if (tabHost.getCurrentTabTag().equals("tab1")) {
//What should I do to display search activity here
} else {
tabHost.setCurrentTab(1);
}
}
});
tabHost.setFocusable(true);
tabHost.requestFocus();
}
}
Can anyone please help let me know how to invoke search activity when tab is pressed? What will go into if part? Because if I use tabHost.setCurrentTab(index), it will display result activity but not search activity.
NOTE: I followed the tutorial given in this link.

I think what you want to do is this: when the 'tab1' tag is selected, go back to TabGroup1Activity if (and only if) the current activity is not that activity (basically you want to simulate a 'back' press).
If so, what you want is this:
if (getCurrentActivity().getClass() != TabGroup1Activity.class)
getCurrentActivity().finish()

I'm not 100% sure I understand you fully, but let's see :)
In your onTabChanged listener you can switch on which tab have been tabed, and then open the activity as normal inside an activitygroup:
public void onTabChanged(String tabId) {
if (tabId.contentEquals("tab1")) {
Intent intent = new Intent(tabHost.getContext(), TabGroup1Activity.class);
View view = StartGroup.group.getLocalActivityManager().startActivity("tab1", intent).getDecorView();
StartGroup.group.setContentView(view);
}
}
I just reviewed my code and think there's a bit more to explain here. The problem is that you don't stack activities as normal. Instead the workaround is to make a content stack and change these instead. So what I have done is to create a class StartGroup which extends
ButtonHandlerActivityGroup:
public class StartGroup extends ButtonHandlerActivityGroup {
// Keep this in a static variable to make it accessible for all the nested activities, lets them manipulate the view
public static StartGroup 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);
this.history = new ArrayList<View>();
group = this;
// Start the root activity within the group and get its view
View view = getLocalActivityManager().startActivity("UserList", new Intent(this, UserList.class).addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)).getDecorView();
replaceView(view);
}
public void back() {
if (history.size() > 0) {
// pop the last view
history.remove(history.size()-1);
setContentView(history.get(history.size()-1));
} else {
finish();
}
}
}
Then from the TabMaster class or what you call it you can use the StartGroup class to change the content view of an activity group.
This is something I wrote to work on devices from 2.2, so there might be an easier and more androidish way to accomplished it, but this works on almost all devices :)
Here is another thread where the use a similar approach:
Launching activities within a tab in Android
Let me know if I can help more.

There is an ArrayList in your ActivityGroup so override onPause() method in ActivityGroup and remove all the ids from ArrayList except the first one which must be your SearchActivity.
So when you go to other tab then comes back to SearchActivity( or on Tab1 ) Home will be displayed.