Develop Reference

Android Gallery View Semi Circle Theme

Hi friends i am planned to work on user interface part, i wanted to make my own user interface for my gallery application. for example gallery view should be in semi circular view. can any one suggest me on this
Thanks in advance

Do you want something like this!!
you can find it in this link
sorry but the link is in french language but you can find sources in the bottom of the page Mirror links

You should start by learning more about the Gallery in general. This link would make a good start.
Understand that code, go through the tutorials and begin experimenting on making incremental changes and seeing if they work.
Using this knowledge and prototype code start thinking about how you might go about creating your custom semi-circle gallery. Experiment and try some different things.
When/if you run into any issues or specific problems, post your question on a new thread and I'm sure you will find people willing to help you out.

Android User Interface - Are tabs at the bottom the best approach?

I am creating an app that provides users information about a building that the app is being designed for. For example it will tell the user the location of the building, hotels/restaurants/cafes nearby and some other useful information.
I will be creating seperate activities to carry this out, so an activity to tell user the location and maybe contain a map, an activity listing hotels and an activity listing nearby cafes etc.
My problem is that I am not sure how to design the interface for this. I was thinking of having tabs at the botton of the screen where each tab opens the corresponding activity. Is this a good way to do it or is there a better way?
Thanks

This is really a UX (user experience) decision, not a coder decision. You are probably asking this question on a wrong site.
I recommend you look around how other apps have solved a similar problem, to get ideas what is possible. Then pick a solution that you like best.

You might want to ask that at UX
Personally I think Tabs are a quite intuitive way to let the user choose between dedicated views/activities - especially if they are labelled with distinct icons

Tabs is always a clean solution.
Maybe something like a dashboard would also be nice. (Pattern 3 in my link)
This link covers some things that may be useful in further development.
Android Dev UI Development

Right now i can think of some other solutions
Use a gesture to swap to another activity
Use a pair of arrow buttons at the bottom
But your solution seems nicer

Slide images the screen. Do I really need to write my own "game engine" or use someone elses?

I'm thinking about writing a pretty basic game, which mostly involves sliding images around on the screen when tapped. So tap an image and it slides to one side. Doesn't seem like Android Animations will help me here since those don't actually move the images, just makes it appear moved.
So even though this seems like pretty basic functionality, it seems like I have to write a game loop,etc and implement my own code to handle the "animation" (including some acceleration/deceleration), etc. Not hugely hard or anything, but just seems like overkill. Also using a 3rd party game engine also seems like overkill, just in the time it would take to learn that, and so on.
Am I off base here?
If anyone has any suggestions that might get me pointed in the right direction (links, etc) that would be great. Is there a good way to use Android Animation functionality in this case that I am missing?

If you are developing for Honeycomb, it may be as easy with animations. With Honeycomb, there is a whole new strategy to animation. Check out the blog. The premises is that any property or value can be animated, and that includes the view's actual position (and not just look like it moved).

I have built a couple of games using AndEngine (http://andengine.org) I would recommend it for making games for android. And since it is all written in java, it is relativiely easy to integrate it with layouts and other activities.

Android -- is there anything wrong with doing the user interface almost entirely in OpenGL?

What considerations should one be mindful of when constructing a GLSurfaceView-centric UI?
This is for a game and the bulk of the UI will be an intro screen (start, options, about, exit) and a level selector screen. I've put a lot of time into the rendering/animation for the game using OpenGL, and I'm no graphic artist, so taking the OGL UI route seems to make sense to me. But I'm an Android novice and need some outside input. Thanks for reading.

There is nothing wrong with that, especially for a game. The only problem is that you will have to do everything yourself. Most games seem to be doing this.

Due to the ease from which one activity can start another, I would say it is worthwhile to abstract your options and level selection from the game itself. If you're unfamiliar with starting activities and/or passing information between activities, there are plently of good tutorials and examples to help. You could try the ubiquitous Notepad tutorial if you haven't already ( http://developer.android.com/resources/tutorials/notepad/index.html ).
The advantages of this method would be to leave your OpenGL/game Activity less cluttered, and that you would be able to use tried-and-true Android UI elements instead of building your own from scratch.

Android - first launch interactive tutorial

I'm writing a new app for android and I would like to implement also a first launch tutorial. In particular, the tutorial has to be interactive. Basically, after a user registers to the service, a minimum settings will be required.
I'd like something like today we have into Google Apps, like Sheets, Docs and so far. The exception there is that those tutorials have the aim to explain how the app works. Here I want to have something where user can input some data.
I was looking at ShowcaseView but seems to be deprecated and old in style.
So here the question is: what is the best way to implement that? ViewPager?
I also had a look to this other question, but it did not help too much.
Any advice is really appreciated.
EDIT: I have found this other nice alternative. AppIntro It seems what I was looking for. :)

There are few I found by quick searching Github:
https://github.com/Seishin/showcaseview-android
https://github.com/worker8/TourGuide
https://github.com/amlcurran/ShowcaseView
I'm pretty sure you can find the right one for you ;)

You can do it in several ways that really depends on you and your app. Basically you can create a "Boarding" experience with ViewPager that will go thru the main screen of your app (with static images for example) where you explain the user what goes on in your app. The other way way is an interactive tutorial as the user already landed into your app - you can achieve this with something like Showcase (I'm pretty sure that there are libs on GitHub that are still maintained).

I would recommend Roman Nuriks Wizard Pager code on Github as a starting point. It's not so much a library as a sample code showing you how to do what you want.
The general approach is to use a ViewPager with some form of navigation buttons to move the user forwards and backwards through the pager Fragments.
https://github.com/romannurik/Android-WizardPager