Develop Reference

Is it possible to switch the layout to a different layout whilst an activity in running in Java?

Instead of moving views in a current layout, I was wondering if i could instead load a different layout whilst the program is running.
For example in the on create i would use:
setContentView(R.layout.layout1);
and then in an on click listener i would use:
setContentView(R.layout.layout2);
I say this since I am using a custom dialogue which prevents me from producing a dialog to overwrite it. I have attempted it but so far have only received errors. I would really like to know if this is possible.

This is possible, but risky and not recommended for a final product. The problem is, you cannot access already defined views once you have switched views. You need to assign them all again for the new layout. So once you switch the content view, re-initialize all of your views and anything that references the old layout. Calling a view from the old layout will cause a crash or error message.
Like CodeMagic said, it is best to use fragments and the FragmentManager for this. And really, this is not a stable way to produce good code. I recommend using separate fragments and using backstacks and such so that not only will your game work, but you can easily navigate back to the original fragment, rather than use makeshift code that may barely work.
After setContentView(R.id.yourLayout) is called, you need to re-instantiate all of your other views. So like say you used an ImageView view to show the color changes, well you need to instantiate that ImageView after you setContentView(R.id.yourLayout) so that it pulls from the new layout, and does not reference to the original layout.
Example:
ImageView imageView;
public void onCreate(Bundle b){
super.savedInstanceState(b);
setContentView(originalLayout);
//Instatiate all of your original Views.
imageView = (ImageView) R.id.yourImageView;
}
public void onButtonClick(View){
setContentView(newLayout);
imageView = (ImageView) R.id.yourNewImageView;
//All other views
}
If you need an example of the fragment manager solution go here: https://developer.android.com/training/basics/fragments/creating.html
and look through some of their examples on how to properly do what you are trying to do.

Is there a generic way to display progress bar over Views in Android?

I have seen numerous posts on how to display progress bar while the data loads in the background. All suggestions requires we manually place a ProgressBar in the layout xml and then use an AsyncTask to show and hide the ProgressBar and the View in question.
However, I would like to make a generic class which creates the ProgressBar programmatically at runtime and place it exactly over the view in question and maybe also slightly shade or blur the view while the ProgressBar is displayed. Had this been a Swing application I would have painted my progress bar on the "glass pane" of the view after slightly shading it with gray. In that case since the progress bar is the child of the same pseudo parent hence I could easily position that as centred.
In Android UI toolkit I am not aware of any such "glass panes". How do I achieve this effect?

Make a BaseActivity that you derive all your Activities from (same goes for Fragments).
Give it something like
protected void showLoading(){
ViewGroup content = findViewById(...);
content.setVisibility(Visibility.GONE);
ViewGroup root = findViewById(...);
root.addView(new ProgressBar());
}
Gotta make sure all your layouts have a ViewGroup for root and one for content, which otherwise might not be necessary and bloat layouts, but thats how I do it and it works fine.
Above is pseudocode of course, but you get the idea.
There's also this libary: http://www.androidviews.net/2013/04/progressfragment/, but I don't think it's necessary to import a library for that task.

Unfortunately you have to create this functionality. I always do this by creating a class from a framelayout and then place my imageview inside with my progressbar ontop. I then create an interface I use as a callback so that when said process is complete and the data is finished being processed I get my callback and I hide the progressbar. I use a framelayout because its the easiest view to use to "stack" views ontop of one another by simply placing them inside the FrameLayout. You may also need to place views inside the frame inside of a relativelayout with the width and height set to match parent so you can set the layout_centerInParent to true on your progressbar so it sits nicely inside your compound view.

Well, I'm not sure I get the question right, because it seems easier to me than it might be. But anyway:
To instantiate programmatically a progress bar, you need to do the following in your activity:
ProgressBar pb = new ProgressBar(this);
((ViewGroup) this.findViewById(R.id.view_that_will_contain_progressbar)).addView(pb);
This will add the view to the ViewGroup view_that_will_contain_progressbar. This ViewGroup should be a FrameLayout if you want to overlay over other information.
Tip: if you want to customize your ProgressBar, you can declare it in a layout file, and do the following to instantiate and attach the PB (still in your activity/fragment) :
this.getLayoutInflater().inflate(R.layout.progressbar,parent);
with parent refering to the parent you want to attach it to.

Relativelayout circual dependancy

I'm trying to create my android app for a lot of different devices so I'm trying to avoid using fixed heights and width and instead using the property WRAP_CONTENT.
Now I need to create a textview on top of a button and align that to the bottom. However the documentation states that you can't use WRAP_CONTENT in combination with ALIGN_PARENT_BOTTOM (which is obvious). Is there another way to achieve this?
The structure is something like this. A RelativeLayout which wraps a button and a textview.
RelativeLayout fl = new RelativeLayout(this);
fl.setLayoutParams(relativeWrapContentParams);
fl.addView(filterBtn);
fl.addView(filterCaption);
The buttons are also created dynamically so theres no xml. Instead the buttons are created in java code.
Also is this a good way of programming for multiple resolutions? Or is it ok to use fixed heights because then the problem is easy to fix and I can just give the relativelayout a fixed height and align its children with ALIGN_PARENT_BOTTOM

See this link this article is the bible for the newbies in android.
Now coming to your question you don't need to use relative layout just for this purpose
you can use linearlayout with vertical orientation place text and then button.
and you need to place this linearlayout inside relative layout with property alignparentbottom=true.
in such way you can have this layout of text and button at the bottom of the screen

How do I create an ImageView in java code, within an existing Layout?

I'm looking for an easy way for the user to see how many drinks they've had for a BAC calculator.
Picture of the app:
On button press, I would like an image to be added to the screen, directly under the spinner and with left alignment. When I press the button again, I want another image to be added to the screen.
So if I pressed the add beer button, a drawable of a beer would appear below the spinner. If I pressed the add beer button again, I want there to be TWO drawables of beers under the spinner, preferably with them being added from the right.
(Also, having them reach their width limit, wrapping around, and starting again on the left, but below a full line, would be AWESOME)
I can't figure out how to do this. I assume adding a ImageView in code to a relative layout (because it needs to be positioned to the right) would be the best route, but if it's possible in xml I'd be more than happy to use that. Any help?

In the button's click callback, create an ImageView object, set the bottle image, and position it. For example (I'm assuming the names of your elements):
ImageView imageView = new ImageView(this);
imageView.setImageResource(R.drawable.beerbottle);
RelativeLayout relativeLayout = (RelativeLayout) findViewById(R.id.RelativeLayout01);
RelativeLayout.LayoutParams layoutParams = new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.WRAP_CONTENT,
RelativeLayout.LayoutParams.WRAP_CONTENT
);
layoutParams.addRule(RelativeLayout.BELOW, R.id.ButtonRecalculate);
layoutParams.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);
relativeLayout.addView(imageView, layoutParams);
I haven't tested this, mind you, but it should give you a good start. You'll probably need to add other parameters to the ImageView and possibly to the LayoutParams to make it look good, plus tracking how many bottles are displayed, etc.

Android Update Layout Content

I'm looking for a way to update a layout's content with a new view. Is there any way to easily do this. It would be similar to how tabs work, but I don't want to have to get into extending the current tab structure if I don't have to.
The final result would be a few buttons that would switch the content in a specific linearlayout for each button.
Any help?

Have a look at ViewSwitcher. This is designed to help with the kind of things you are suggesting.
If you want the contents in entirely different layout files, you can use a LayoutInflater and add the inflated view to the parent view.