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Android: one fragment turning into two fragments on one page

I have an activity that has within it one fragment that takes up the whole screen. At some point in the app flow, the user can go to another screen in the same activity that is composed of two seperate fragments. So you can imagine it as:
Fragment A (100% of the screen) -> Fragment B (50%) + Fragment C (50%)
I can think of two ways of doing this and neither one of them is particularly good. The first is to set a layout for the activity that has in it one container that will hold Fragment A, and then have Fragment A open subfragments B and C inside it. I'm trying to avoid using subfragments because it leads to unusual lifecycle bugs and it also isn't supported by all version of the api.
The second way is to have two layouts for the activity - one layout having a single container, and the second one having two containers and then switch between them at the appropriate moment with setcontentview. I have to admit that I'm not too happy about that solution either, since it means the user will see the screen redraw white instead of a nice transition effect.
Does anyone have any suggestions on how to do this most efficiently? Note that I do want everything to remain under one activity - logically it should be this way. There's no logical point in having two seperate activities for this UI movement.

solved by having two containers and setting the top one to wrap_content height, visibility=invisible and not populating it at all. When I need to move to the two pane setup I populate the invisibile container and set it's visibility to visible which causes it to remeasure. When moving back from the two pane to the single pane call remove on the fragment that populates the top pane.

RelativeLayout required to display fragment on top of each activity?

I want to make it possible to display a fragment on top of every activity (if the right action is called). It should look like a window on top of everything. This works fine so far, but I am a bit confused about how to get the layout integration working.
When I wanted to display something like a fragment on top of everything, I had to use a RelativeLayout as the root element, then nesting maybe LinearLayout (containing the activity's layout) and fragment.
Is that the only way to achieve this? Do I have to refactor now every activity layout to use RelativeLayout as the base? Or is there a more straightforward way?

I cannot comment, so will write here. Please provide some code to express what you mean, much easier to understand it than. If i understood you correct, u want to have a window on top of another window?
Cannot see why this would be voted down, and not even a comment for the reason :/.
You might achieve what you want with an overlapping fragment. I have had this side effect when making my app, i.e. that a fragment view is transparent on top of another fragment. To achieve this, just skip if(savedInstanceState != null){return;} in your onCreate() in your activity. And instead of replacing a fragment (transaction.replace) use (transaction.add)

Android - Fragments or custom views? Which should I be using?

I am trying to create a layout in an activity that will look different in landscape and portrait, however it will contain the same sections, just in different places on the screen.
Most examples I find on fragments is always the list and detail, which is not what I'm looking at.
In my example I have, amongst others,
a scrolling image section (carousel)
a page title with some brief details
a carousel of thumbnails
two buttons
full details of the page
Now in the landscape layout, the image section will always be on the left side with down the right side, the page title, carousel of thumbs, two buttons and full details.
In the Portrait the title will appear at top, with image carousel beneath, then thumbs, then buttons etc.
The way it works in my head, is that each section should be a fragment, and then depending on the layout file in the respective res/layout folder corresponding to land/port, the fragments are arranged accordingly. But I'm also thinking is each section a whole fragment? Or could it be a separate view that get's loaded in, but just in a different order depending on the screen orientation.
I hope that made sense?
Does anyone have any good tutorials that explain exactly when you should and shouldn't use fragments. All the usual suspects just list the list/detail example, which is not applicable in my case.
tl;dr Can I use fragments as modules/blocks in various layouts or should I just create other layouts and display them inside the main layouts.

Fragments can be used to have split screen and to store previous state unlike views. It is difficult to manage back button with views

If you just want to change how the screen is laid out, the answer is neither. You can define orientation-specific resources (either a separate layout file for each orientation or different dimensions/constraints for each orientation) and the system will just provide you with the correct resource set for the current orientation.
That said, it sounds like you may be describing a modified version of master/detail flow. If this is the case, fragments are a good way to go since the landscape view is actually several separate screens in the portrait version of the app, so each section needs it's own state and lifecycle, which fragments provide.
Now, I know you said you wanted an example beyond a list and detail view, so here's some more details on when to use fragments:
Fragment, like activities, have state and lifecycle. Custom views do not have lifecycle and are completely dependent on the activity or fragment containing them.
You might use a custom view when you have a widget on screen that is used in multiple places and is just like any other view – bound to the activity when the layout is inflated and controlled from there. It's a way to either reduce duplicating combinations of views in your layout or to draw a custom view that doesn't exist yet.
Fragments are good when you need some state or lifecycle for a section of the app that might get used in multiple places or shouldn't be logically connected to the activity it is contained in. If you use the new Navigation Component, you actually just define one activity and then each screen in the navigation tree is a fragment that gets swapped out as the user navigates around the app. Here each child component on the screen (each "screen" that the user navigates to) has it's own lifecycle, business logic, etc, so mixing the code for all of that in the activity wouldn't make sense.
So the question comes down to what you are trying to build, and this may be a case where the best way to learn the difference is to try each option out as bit. The differences become more clear with practice using them. As a general rule of thumb, personally, I only really use custom views when I am trying to make a new view that doesn't exist elsewhere. If what I'm trying to do is simply a matter of laying out existing views in a new way, the answer is probably some trick in the layout file or layout code inside the activity. If I'm trying to make a stand-alone piece of the app that does stuff, especially if it also appears in multiple places in the app, I'll probably be building a fragment.

Android Honeycomb: layout problem - hide/show FrameLayouts

in my Activity, I have a layout containing 3 FrameLayouts, one at the top, one at the left and one at the "center".
Now, I sometimes only want to display one or two of them. Atm I am doing it this way:
FrameLayout frame = (FrameLayout) findViewById(R.id.framelayout_menu_left);
frame.setVisibility(...);
frame = (FrameLayout) findViewById(R.id.framelayout_content);
frame.setVisibility(...);
frame = (FrameLayout) findViewById(R.id.framelayout_menu_top);
frame.setVisibility(...);
However this can get really ugly results, e.g. when I switch the "content" Fragment and hide the top and/or left FrameLayout. It all starts flickering as the "content" Fragment jumps to the top and/or left and only afterwards is replaced.
Also, I can obviously not navigate back to another setup, so is there any other way to do this?
Kind regards,
jellyfish
Edit:
Maybe a little drawing makes my question clearer...
A shows a Layout of 3 FrameLayouts containing 3 different Fragments. Each color represents one distinct Fragment.
Now what I want to do is to switch from A to D.
I am doing this by replacing the blue Fragment with the yellow Fragment via a FragmentTransaction.
However, this still keeps the other Frames visible, so I hide them via the code above.
Now, Frame.setVisibility() is called way before commit(), so in B and C the blue Fragment "jumps" to the left and the top and only afterwards (in D) is replaced with the yellow Fragment. This produces a nasty flickering.
As a workaround, I now hide all three FrameLayouts before the transaction and re-show the ones I need once the transaction has finished. But there still is the problem that I can't go back via the back button as this isn't a real transaction.

I would have two suggestions. Firstly, if you both add a fragment transition effect and do the visibility changes after the transaction, that would probably substantially reduce much of your flicker effect
ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
Secondly, I've simply given up on having the system manage the fragment stack for me -- it seems that this only works well with simple transactions. Override onBackPressed and do your own logic there.
--randy

Android: layout problem on starting an activity

I have a layout.. The 70% of it occupies a view then i have a button on the 30% left.. on click of the button, i have an activity that should be displayed only on that 30%. what happened is, it displays in full screen since i used startActivity(myIntent)... can anyone help me how to start an activity by getting only a certain portion of the layout and not as a full screen? Thanks you!

You may want to look at the Fragments API.
A Fragment represents a behavior or a portion of user interface in an Activity. You can combine multiple fragments in a single activity to build a multi-pane UI and reuse a fragment in multiple activities. You can think of a fragment as a modular section of an activity, which has its own lifecycle, receives its own input events, and which you can add or remove while the activity is running.
Check this post to use it on android < 3.0: http://mobile.tutsplus.com/tutorials/android/android-compatibility-working-with-fragments/

Activities starts in fullscreen always. You may create layout where 70% of screen will be transparent and 30% of screen will be filled by views.

The question you are asking is may be to hide the required view while starting the activity .
so for that just set the visibility of that view as invisible.
so to just hide.
reqview.setVisibilty(View.INVISIBLE)
in this case your view will be invisible . but it still takes up space for layout purposes.
reqview.setVisibilty(View.GONE)
in this case your view will be invisible . and it doesn't take any space for layout purposes.
may be this help you.

you can give the next activity as transparent activity so that it will be displayed in 30 % of the previous activity.But the problem is that you will not get any event for the remaining 70% actvity. if you want like this then go with the transparent activity.
If you want this then look into How do I create a transparent Activity on Android?

TODO
btn1.setVisibility(View.INVISIBLE);
Controls the initial visibility of the view.
Must be one of the following constant values.
Constant Value Description
visible 0 Visible on screen; the default value.
invisible 1 Not displayed, but taken into account during layout (space is left for it).
gone 2 Completely hidden, as if the view had not been added.
This corresponds to the global attribute resource symbol visibility.
Related Methods
setVisibility(int)