Develop Reference

Navigating between activities

I'm developing an app. for my semester project.App. is simple true&false game.I did something about it but i choked up one point.My problem is that handling activities.
Here is the quick view of the design.
http://imgur.com/2Fhsrn8
I created all activities and my codes working correct.But there is an issue.When i'm on third or fourth page(activity) and press back button on my phone it returns the second page then i automatically have another chance to answer question.All i want is turn the first screen when back button is pressed and clear all the data such as assign score as 0.
I'will be grateful for any kind of help.

Use
finish();
for your current activity when you start the new intent(e.g. when going from activity 3 to activity on your picture) and add this to your activity's 2-3 if you want to start again when you click back, otherwise it will close your app.
#Override
public boolean onKeyDown(int keyCode, KeyEvent event)
{
if ((keyCode == KeyEvent.KEYCODE_BACK))
{
//implement code to start 1st activity here!
}
return super.onKeyDown(keyCode, event);
}

you should override onBackPressed on your third, and fourth activity ->
#Override
public void onBackPressed() {
// here you should create intent to your firstActivity
// and assign variables -> e.g.
// score = 0;
}

Handling android back button

I have a basic question about android development. In my app i have a autocomplete box. When user click on a menu button, autocomplete become visible. When user clicks on an entry in autocomplete, the text views show it. I want to use back button such that when user presses it . Textview become invisible , on again click autocomplte disappears and than on third click app exits. But in my app on a single click app exits. I am a new to development so doesn't know much about it, so i ask here.

#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if ((keyCode == KeyEvent.KEYCODE_BACK)) {
//stuff
}
return super.onKeyDown(keyCode, event);
}
Since API 5 :
#Override
public void onBackPressed() {
//stuff
}

Android: show white background when search button pressed

When I press the search key on my device, I want it to show a white background. However, when I press the back button, I want the previous activity's background to be restored. ivBackground is a variable I added to my relativelayout which I turn VISIBLE to show the white background.
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_SEARCH) {
ivBackground.setVisibility(View.VISIBLE);//WHITE IMAGEVIEW
return false;
} else if (keyCode == KeyEvent.KEYCODE_BACK) {
ivBackground.setVisibility(View.GONE);
return true;
}
return super.onKeyDown(keyCode, event);
}
While the above code works, the problem is that when I press the back button, the white screen still remains. It only goes away if I press the back button once again. Any solutions?

On the relevant activity, you can get a reference to a SearchManager object. On this, you can set an OnDismissListener, which is called the when search UI is dismissed e.g.
this.searchMgr = (SearchManager)this.getSystemService(Context.SEARCH_SERVICE);
this.searchMgr.setOnDismissListener(new OnDismissListener() {
public void onDismiss() {
ivBackground.setVisibility(View.GONE);
}
});
To make the white background visible, you can override onSearchRequested inside your activity class, which is called when a user signals the desire to start a search
#Override
public boolean onSearchRequested() {
ivBackground.setVisibility(View.VISIBLE);
return super.onSearchRequested();
}
Hope this helps!

How about setting a SearchView.OnCloseListener or a SearchManager.OnDismissListener that also hides your view? This seems like the right solution anyway since the two events are logically connected. If you later dismiss the search view programmatically for example, you don't have to worry about separately dismissing the background view.

method to call when home button clicked?

In My android application, currently one of my activity is focused on the screen. If the user clicked on "HOME" button, which activity method gets invoked.

You cannot override anything about the Home activity. You can only use the Home intent category.
See this other question for more info:
Can I override the 'Home' button in my application?

There is no way to handle "Home" button click. And this is by design.
Read great post by CommonsWare: Please Ignore the HOME Button. Also see this and this threads on Android Developers group.

Works for me..
#Override
public void onAttachedToWindow() {
super.onAttachedToWindow();
this.getWindow().setType(WindowManager.LayoutParams.TYPE_KEYGUARD);
}
Then
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if(keyCode == KeyEvent.KEYCODE_HOME){
// Your code here.
return true;
}
return false;
}

What is the command to return to your main screen in an app?

How do I have an app return to the 'Home' screen when the user is on a different class and they click the back/return button on their phone?
Right now, when they access a different class and hit the back button, it goes back to the Home screen on the Droid rather than the Home screen on the app - how do I get it to go back to the Home Screen on the app?
Thanks!

Use OnBackPressed() method of Activity class.
Make conditions like :
public void onBackPressed(){
if(conditon)
{
detailInfoList.setVisibility(View.VISIBLE);//or anything that you want to show
}
}

you can't,
the home button is the only you can't prevent form closing your app. Its done so that you can't block the user inside your applications (like a virus).
the other keys like back menu and research are possible
in your activity
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if(event.getAction() == MotionEvent.ACTION_DOWN){
if(keyCode == 82){
Log.i("jason","released on menu");
//change view
//return so that the other behavior (leaving the activity) is not tirggered
return false;
}
}
Log.i("jason","actual key code "+keyCode);
return super.onKeyDown(keyCode, event);
}