I am developing a custom launcher/home-screen, thus I am able to hand home-press events.
Sometimes I want it to intercept Home-presses without affecting the visible activity-stack so to speak. When I press home, however, I get to the launcher stack I suppose, but what I want to do then is get back to the last visited activity stack that was shown right before I pressed home. How can I do that?
How can I retrieve and show the activity that was visible right before I pressed home?
Related
I am following the tutorial here:
http://developer.android.com/training/basics/firstapp/starting-activity.html
When I enter some text into the field and press Send, it goes to the second screen with the larger text, so that part works.
When I click the "back" button on my phone, the text I inputted is still in the text field. But if I press the back button on the screen near the top of the program, the text I inputted is gone.
Why is this and how can I control / change this?
Reason for your issue - Your app creates a new instance of activity when you click the back button in your app.
To fix this
In the back button where you call your first activity, add this line of code
intent.setFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
What happens with this flag ?
When you use this flag, Android looks for an instance of the desired activity in your activity stack, starting from the front of the stack and scanning until it gets to the root/back of the stack. As soon as it finds an instance of the specified activity, it brings that one to the front (ie: if there are multiple instances of the specified activity it will bring to the front the most recent instance).
I have noticed the splash screen does not display when user clicks the middle button on a real device to quit an application but if user selects back button from main menu to quit app and relaunches the splash screen will display.
Question is what function is the middle button performing compared to the back pressed and is there a way to ensure the splash screen is displayed when the middle button is used to quit an application.
Thanks.
The HOME button takes the user to the home screen (also called the Launcher). The BACK button by default finishes the current activity, which usually results in the user ending up on the previous activity he was in, until he reaches the home screen. The difference is BACK will explicitly finish an Activity, whereas HOME will not.
I've got an app with two screens, we can call them List and Details.
If an user is at Details and presses Home to minimize the app and then switches back I want to stay in the view and just restore, but if he presses Back I want to go back to List, I figure I can save a "Done"-button this way. But...what's the proper way to do this?
Currently I've overriden onPause and onSaveInstance but it seems they're both called in both cases.
I'm thinking about overriding onKeyDown instead, like he did; How to control Activity flow - Back button versus Home button, but that doesn't seem like a "nice" way to do it so I thought I'd check if anybody else has another idea.
Make two activities, for list and for details. When you will press the back key in the details activity it will finish and will show up the list activity.
I have read into the finish(); commands and the FLAG_ACTIVITY_CLEAR_TOP commands and also checked out Common Ware's answer on killing app, but I am not sure how to put this into my app.
Basically, I have a user click a button that takes them to the camera. The user then snaps a photo and it brings them to a layout view. The user then clicks a button that takes them to one of 2 views, depending on a some conditions.
The user is then allowed to either retake a photo, or go to the main menu (depending). My problem is, if the user goes back to the main menu, and snaps another, then another, etc...the activities stack, so when I click the 'Main Menu' button the app goes back through eached stack activity until finally it goes back to the main menu. Is there a way to kill each activity with one of these lines, so even if a user retakes a photo, they will only need to go back once to get to the main menu?
Thanks for anyhelp.
You could use the noHistory flag which would end each activity once you're away from it.
Probably though, what you really want is singleTop launch mode, that will return to your previously opened activity rather than making a new instance of it.
How do I go to previous screen from current screen in Android app? I know there is a back button on phone, but it takes me to beginning screen of my app and I want my buttons on app to work for going back to previous screen.
Back button indeed takes you to previously seen activity on screen, that launched the current one (not by means of back button). If back button takes you to beggining screen of your app means that navigation to your last activity was done from it. Try launching an activity from another one different from start activity.
What really can be problematic is ending application once at start activity by pressing back button and discovering the application switching to activity that lauched start activity (not by means of back button). In this case you should just call finish() inside onDestroy() listener method of your start activity.