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Android - Switching multiple layouts within single activity

I am developing application which requires many (more than 80) screen layouts (each layout having different image views, buttons, textviews and so on) and I have to be able to switch between them (upon button clicks). I am also using SlidingMenu so I would very much like to have only one Activity (I am currently using ActionBarActivity and the SlidingMenu serves as expandable navigation TreeView).
So my question is, what is the best practice to be able to switch between a lot of unique screen layouts within one activity ?

I suggest two ways:
1) Use FrameLayout, and Fragment
2) Use ViewFlipper in main.xml that in this one every child of ViewFliper is one of your 80 views like:
<ViewFlipper ...>
<!-- first view -->
<LinearLayout ...>
</LinearLayout>
<!-- second view -->
<LinearLayout ...>
</LinearLayout>
<!-- third view -->
<LinearLayout ...>
</LinearLayout>
<!-- and so on -->
</ViewFlipper>
Of course you can create 80 separate xml files and include them in ViewFlipper.

Get id's when click (ANDROID)

Simple question, i have this code
<HorizontalScrollView
android:id="#+id/horizontalScrollView1"
...
<LinearLayout
android:id="#+id/insideLinearLayout1"
...
<TextField>
android:text='beforeClick'
...
<Button
android:id="#+id/button1"
android:onClick="updateExpression"
...
</Linear Layout
<LinearLayout
android:id="#+id/insideLinearLayout2"
...
<TextField>
android:text='beforeClick'
...
<Button
android:id="#+id/button1"
android:onClick="updateExpression"
...
</Linear Layout
</LinearLayout>
</HorizontalScrollView>
The idea, is to change the textField text property, when clicking the button on the same layout!
Ok for 2 is easy, just need the reference of each button and each textfield and change use the get and set method!
But i want to add more layouts dynamically, and grab each one's reference would be a hard task.
So two questions :
How can i grab the id of the Linear layout, that have the clicked button?
I want to handle the 'insideLinearLayout(1 or 2 depending on the clicked button)'id in the 'updateExpression'!
How can i add more layouts with the same widgets as the ones created manually?
Thank you in advance.
Best of codings!

1)Your onClick function is passed the view that was clicked. Every view has a getParent() function. You can use it to get the LinearLayout, then get the id.
2)Create them with the new keyword then add them to the parent layout. For something like this I would probably make a custom compund view holding everything you want to instantiate at once, so you can treat the entire set of widgets as one.

Custom sub menu in android

I have created custom tab bars by following the post given below:
How to create a Tab-like UI in Android?
No I need to display a set on sub menu when the center tab (actually it is a button) is clicked. I need the sub menu to pop up like in this drawing (sub menu should be above my main layout):
I believe that this can be achieved by putting an additional layout above the custom tab bar in which a set of buttons can be placed one after another. But I am not sure which layout needs to be used and how I can get the same style in the drawing. Please help me to find a solution.

you're correct with just adding another layout above the button you want to open it, and then setting its visibility to gone until you want to animate in it.
a regular LinearLayout would work fine, and then adding 4 buttons to it would work as well, then you would want to make sure those buttons used the same styles as the built-in android menu buttons (or style it yourself) but check out some of the built in styles here
example:
your activity
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">
//all your other activity layout stuff goes here
<!--add your new menu-->
<LinearLayout
android:id="#+id/my_menu_layout"
android:visibility="gone"
... />
<Button
android:id="#+id/menu_btn_1"
style="#android:style/Widget.Holo.ActionButton.TextButton" //as example of built-in style
... />
//more buttons
</LinearLayout>
then in your activity class, assign an onClickListener to the button that will toggle the menu and animate the view in
//animation xml you make
Animation inFromBottom = AnimationUtils.loadAnimation(this, R.anim.layout_in_bottom);
mMenuLayout.startAnimation(inFromBottom);
mMenuLayout.setVisibility(View.VISIBLE);
now your view will animate in and you can go about adding onClick listeners to the buttons

Complex Android UI design guidance needed (fragments)

I am developing an applications that is aimed at Tablets and Google TVs. It will be like many standard Google TV applications with a LeftNavBar and a top Search bar that is common to all application screens. It will look something like the following image:
Main Screen
The RED area will be different for all other screens. It may contain data like following screens mockups:
Activity One loaded into main container
Activity Two loaded into main container
So you can see that completely different sections can be loaded in the main area.
Screen 3 can be loaded as a detailed section when selecting any list item in Screen 2 (say in fragment list) OR it can be loaded as a result of selecting a tab (which will appear in LeftNavBar).
Here is how I am trying to implement it.
Step 1. I Created a main Activity with the following XML:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="50dp"
android:background="#9ccc" >
<!-- Top Bar -->
</LinearLayout>
<FrameLayout
android:id="#+id/mainContainer"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1">
<!-- main Red Container that will load other Activities -->
</FrameLayout>
</LinearLayout>
mainContainer is the RED container where I want to load the Activities. LeftNavBar will be added to this Activity as its the parent of All.
Step 2 I created ActivityOne & ActivityTwo with two & three Fragments in them respectively (as shown in above second & third image).
*Step 3 I am trying to load the ActivityOne in main page's mainContainer FrameLayout... But I cannot add it.
I tried by adding the ActivityOne to mainContainer as follows:
View v = (new ActivityOne()).getWindow().getDecorView();
FrameLayout mainContainer = (FrameLayout) findViewById(R.id.mainContainer);
mainContainer.addView(v);
but the getWindow() returns null....
Other issue occurs because all the data comes from a remote services .. so please also suggest how would I be able to hold references to all the loaded Activities in mainContainer in a some kind of stack ... so I can just reload the already loaded activity instead of creating its new instance.. This will be used on BACK button press.
OR
Instead of loading an activity into the above RED container, I should create two Activities each with their own Fragments & a LeftNavBar. This might be easier than the aforementioned approach. or this might be the only solution.... however I feel that saving state for BACK buttons might get messy .. but I will try implementing this
What would you do if you had to create this type of application?
How would you design the UI layout for best performance/practice?
Your suggestions in helping me setting this app's layout are much appreciated.

Disclaimer
This is where fragments can get tricky. The problem would be simple if Activity 1 & 2 had identical layouts so that you could simply attach/detach fragments and use the fragment back stack to unwind.
Because you want 2 unique layouts to house your fragments, things are going to be a little more involved. If at all possible I would try to use the same layout so that you can take the easy path.
As another option, you could use two activities as you outline above and send data back and forth with Intents.
That said, if I really had to implement this solution as written, here is what I would do. Note that I am not advocating this solution but myself do not know of a better way of doing things.
The Solution
Create a FragmentActivity whose view would be Main Screen as you've defined above. The layout for the Main Screen would contain:
Left nav bar
Top bar
2 layouts. layout1 and layout2. These would be contained in a parent layout i.e. RelativeLayout or LinearLayout and would contain the necessary FrameLayout elements for your fragments.
Example using your XML (note, tags are a bit brief):
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="50dp"
android:background="#9ccc" >
<!-- Top Bar -->
</LinearLayout>
<LinearLayout android:id="#+id/layout1">
<FrameLayout android:id="#+id/listFragment" />
<FrameLayout android:id="#+id/contentFragment" />
</LinearLayout>
<LinearLayout android:id="#+id/layout2">
<FrameLayout android:id="#+id/imageFragment" />
<FrameLayout android:id="#+id/boxFragment1" />
<FrameLayout android:id="#+id/boxFragment2" />
<FrameLayout android:id="#+id/boxFragment3" />
</LinearLayout>
</LinearLayout>
The main idea is that you then show/hide layout1 & layout2 i.e. set android:visibility="gone" based on the state of your app.
The disadvantages of this method are:
Using fragment backstack may be impossible, instead you'll have to track where the user is in your UI flow and manage the back button to show/hide layout
You may need to take special care to attach/detach fragments when you show/hide their parent view to reduce resource consumption while the fragments are invisible
The advantages are:
Easy communication between fragments and the base activity since only 1 activity is used

Re: The nested Fragments problem
To get around the 'nested Fragments' problem in our application where (as you correctly note) Fragments cannot add Fragments I hosted a single templating Fragment under the activity whose only purpose was to define a set of place holders for other fragments to anchor to. When adding further Fragments to the activity past this point I used the templating Fragment's view place holder +#ids to identify the "root" or parent view Id for the Fragment being added.
getSupportFragmentManager().beginTransaction().add(#someIdFromTheTemplateFrag, fragment, fragmentTag).commit();
The Fragment I was adding then knew where to anchor itself in the current layout and of course then went about it's merry way of add it's view. This had the effect of attaching a Fragment to another Fragment hence achieving the desired visual 'nesting'...

Android: fixed button in each view

Is there a way to make a button fix in the whole application views? I mean instead of adding the button to every xml file and code it.
Thank you.

You can keep your button xml code a different xml file. And to every other activity xml layout you can use the xml tag include like
<LinearLayout android:layout_width="fill_parent" android:layout_height="fill_parent">
<include layout="#layout/okcancelbar_button"/>
</LinearLayout>
Or like jack said, create a base activity that creates the buttons and the rest of the activities can extend from it.

you can create a custom activity in which you create one time button and every activity you will call, extended to your custom activity will have that button