Develop Reference

Best way to activate/deactivate two layouts on top of each other in Android Studio?

I want to put two Linear Layouts containing ImageButtons in my app, where depending on the choice of a spinner, one layout with all its buttons would appear and be "active", while the other layout will be "inactive", meaning you can't see any of its buttons and they obviously won't be visible/clickable.
What's the best way to approach this?
<LinearLayout
android:id="#+id/linearLayout"
android:orientation="horizontal">
<ImageButton
android:id="#+id/btn1" />
<ImageButton
android:id="#+id/btn2"/>
<ImageButton
android:id="#+id/btn3"
/>
</LinearLayout>
I have seen examples online using relative layout, and placing the two linear layouts inside on relative layout, but is doing that and then manually switching everything inside to be invisible and deactivated the best way to go about this?
Thanks!

One way is to do that using XML:
android:visibility="invisible"
However, you can also do it in the Java (in case you want to make it visible again ):
linearLayout.setVisibility(View.INVISIBLE / VISIBLE / GONE );

How to get spacing between two edit text boxes as the below attached image

The texts can be entered into them . Only these two text widgets are possible in the given activity. I would want to know the structure , I would have to employ to get result as such.
I am still in learning phase.

There's a lot of ways how to achieve that. I suggest you to start with reading this thoroughly to learn how to build layouts on Android.
In general, you can add spacing among views by adding some margin and/or padding.
If you want to replicate the particular design quickly, do this:
Have vertical LinearLayout as your root layout (with gray background).
Add two CardViews (one for each box). That will add the
background and spacing.
Add other views to those CardViews.

To give you something to work on
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"> //Elements inside this will be added vertically on the screen
<EditText
android:layout_width="match_parent"
android:layout_height="100dp"
android:layout_margin="10dp"
android:hint="First edittext"/>
<EditText
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="10dp"
android:hint="Second edittext"/>
</LinearLayout>
This is the basic structure on the image you showed. Expirement with it. Add your desired borders by using shapes and etc.

Most Performant Android ViewGroup to Use For Independantly Positioned Children? - RelativeLayout vs FrameLayout

I'm no Android expert but I am aware of discussions regarding the appropriate use of LinearLayout and RelativeLayout, keeping the view hierarchy as small as possible, avoid unnecessary passes of onMeasure(), etc.
Lets imagine I have two ImageView's that I want to position completely INDEPENDENTLY, the first in the center of the parent and the second in the bottom left of the parent. (note this is a vastly simplified example of far more complex real life requirements).
The obvious way to solve this is using a RelativeLayout...
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent" >
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:src="#drawable/first_image" />
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignRight="true"
android:layout_alignBottom="true"
android:src="#drawable/second_image" />
</RelativeLayout>
However something keeps telling me that a RelativeLayout isn't appropriate in this situation because I don't want to organise the children relative to each other. All I want to do is position the children according to the parent and I wonder if using a RelativeLayout causes some unnecessary layout calculations that I don't really require.
I am wondering if there is another ViewGroup type that would perform better? Its totally possible to achieve what I want with a FrameLayout for example but I've no idea if this is more performant or if I am abusing the intent of a FrameLayout etc...
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent" >
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:src="#drawable/first_image" />
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="right|bottom"
android:src="#drawable/second_image" />
</FrameLayout>
Maybe there is another Layout type I am unaware of?

Short answer
Given the information you have provided, the FrameLayout has a good chance of performing better. As you may have learned already watching (Adam Powell quote in Google I/O 2013 conference),
[...] RelativeLayouts will measure child views more than once in order to solve some of the constraints you give it. So, being generic has a cost [...]
From what I read and understood, this is not guaranteed and it depends on the constraints you give it.
Long answer
It really depends.
We all read Romain Guy blog post : Android Layout Tricks #1, who said that most people misinterpret his post and started using RelativeLayout everywhere.
This post, if you haven't read it, talks about how removing one hierarchy level using a RelativeLayout instead of a LinearLayout which saves loading time in a list.
Basically, it means that if you don't need them, as you described it yourself
[...] I have two ImageViews that I want to position completely INDEPENDENTLY [...] I don't want to organize the children relative to each other
you should not use them because of that reason.
Concrete example of : "Don't use them if you don't need to."
For instance, in one of our applications, we have serious performance issues on devices running Gingerbread -- which we want to support.
Our most complex layout involves a vertical ScrollView, attached to the current activity, in which we have several containers and one HorizontalScrollView that displays images and information which are contained in a complex LinearLayout.
We started to replace the LinearLayout by RelativeLayout. The result: no obvious improvement -- equivalent or maybe worse.
Since that layout is fairly complex, adding more RelativeLayouts embedded in each other just increased the onMeasure() calls that were made for a single draw.
Even a small circular ProgressBar was now spamming the UI thread with several measure calls because it was in one of those embedded RelativeLayout which triggered recalculations of the whole view.

Android Eclipse placing a text view in specific places

I'm creating this in a XML file and want a text view to be placed in a specific spot.
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="200dp"
android:text="Text"
android:textColor="#color/blue"
/>
It's underneath the last button that was placed so it's around in the middle of the screen. I want it to be at the bottom of the screen of to the right.

Easy if you're using a RelativeLayout as parent.
android:layout_alignParentRight
android:layout_alignParentBottom
(check the capitalization, I'm not anywhere I can double check).

Using a RelativeLayout would be perfect if you would be specifying each views' positions. It is the most flexible layout among the Android Layouts.
Take a look at this tutorial. It discussed how to position views in a RelativeLayout.
I hope you can get ideas from it in solving your problem.

Best solution to merge/include an xml layout file multiple times in an activity layout

I'm building a flashcards app as a college project, and wanted a horizontally scrolling display of the cards. I've built an xml file for the flashcard design itself:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/relativeLayout1"
android:layout_width="fill_parent"
android:layout_height="fill_parent" android:background="#drawable/whitenote" android:padding="3dp">
<ImageButton
android:id="#+id/imageButtonPins"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true" android:background="#color/transparent" android:src="#drawable/pinselector"/>
<TextView
android:id="#+id/textViewWord"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/imageButton1"
android:layout_centerHorizontal="true"
android:text="Word" android:textColor="#color/black" android:paddingTop="30dp" android:textSize="20dp"/>
<TextView
android:id="#+id/textViewMeaning"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/textViewWord"
android:layout_centerHorizontal="true"
android:text="Meaning" android:textColor="#color/black"/>
</RelativeLayout>
I've also created the Class file.
In the activity layout, I have a few more elements and as such a linearlayout at the root level is necessary. I've been able to display a single flashcard for test purposes using and using layout inflater.
Question
In both the ways, in and layout inflater I've been unable to get the ImageButton working. My question is how do I get the button to work.
Update: Managed to get the ImageButton working using . Realised that I have to handle the onclick event in the activity, and not the Custom Adapter class. This should allow me to obtain the words too, as long as I can keep track of the "current" flashcard on display
Also, whats the best way to handle the scrolling for a flashcard app? My current plans so far is to use a HorizontalScrollView and customise it a bit, because I need (a) a swipe should make the flashcard move only to the next one (b) I need to focus on the "current" flashcard since I need some data from its children views (ie, the word).

Are you considering Fragments?
You can get some help with the ViewPager here.This is supported in Android 3.0 or above or Android 1.6 with the compatibility package.
http://geekyouup.blogspot.com/2011/07/viewpager-example-from-paug.html
If you do not wish to use the fragments, you can simply use the Gallery. This way, you can achieve the horizontal scrolling. (like in the Amazon app) without complex ViewPager.

For the second part of your question, take a look at the ViewPager.

A HorizontalScrollView or a Gallery are probably the most direct way of implementing this. I don't use Gallery-- but it is good to at least know it exists.
If you want a much more robust implementation, I agree with dcanh121 and think you should check out a Fragment based ViewPager. This will allow more options than just a View , but might be overkill depending on the goal. A fragment is basically the bizarre offspring of an Activity and a View, but don't quote me on that.
Also,
Inflating layouts is costly, so try to only inflate the XML into a View once, and reuse that View object. Try not to re-inflate the XML every time a new flashcard is drawn.