Develop Reference

Grid of Views with unequal size

I have an Android app with an image detail screen. Images have tags, and these need to be displayed at the bottom of the screen. When the horizontal space for tags is exhausted, they wrap to the next line up. Each tag should only occupy the minimum necessary horizontal space. Here is an image of the effect I need, from an iOS app:
How can I achieve this effect in Android?

You will need to implement such FlowLayout yourself or use some library. Have a look at this question.

Arranging Components in App Inventor?

Is there a more precise way of arranging components in App Inventor than using the Vertical/Horizontal/Table Arrangement formatting elements?
I want to sparsely position about six buttons across my app screen - all different sizes.
Thank you in advance.

the short answer is: no
well, additionally you also could use empty labels as delimiter between components...
another answer is: you could use a canvas and sprite components instead of buttons. You can define sprite positions exactly at x/y coordinates of your canvas.
However keep in mind, that there are different Android devices with different screens sizes and resolutions, so normally you wouldn't set buttons exactly at x/y coordinates to avoid strange layouts for e.g. smaller or larger devices.

The bit longer answer is to use labels as spacers.
Example:
Need to center a button at the top of the screen.
Add horizontal layout with 2 label texts and button in center inside of the layout.
Click each text label and remove the actual text from right side properties menu and choose fill parent width and height.
This centers the button because the layout automatically assigns one third size to each.
Labels are the best, but longer coding answer.

Which layout to use and how to achieve the following?

I have been struggling to figure out which layout to use and how to achieve what I am looking for. I've tried gridlayouts, linear and relative layouts as well as scroll views in many different combinations. What I want is something like Google now.
I have two buttons to launch the two modes in my app. I have an imagebutton in the top right which they press for more information and when they do so a text view slides out. I have made the layout work, and to overlay the imagebutton on my mode buttons I require a relative layout. However my problem comes from trying to optimise for different screen sizes. I would like it to centre the buttons to rest a quarter of the way down and the layout to pop out underneath towards the half way mark. For the bottom button I want it three quarters of the way down with a text view that drops down towards the bottom. If there isn't sufficient space to fit everything I want a scroll view for when the text views appear, but otherwise it should fit comfortably and not require scrolling.
How do I do this? Two nested relative layouts within a linearlayout, both with equal weight? Then some how I need to address that if the length of the height (taking in account orientation) does not allow it to fit, adapt it so the buttons are closer and scrollable.

You can use sepperate res/layout folders for different screen sizes just like with drawables, examples: layout-small, layout-large etc.
More explained here http://developer.android.com/training/multiscreen/screensizes.html#TaskUseWrapMatchPar

Android: creating custom 2D avatar

I am creating an app that allows a user to build a custom 2D avatar by specifying things like shoes, socks, skin color, etc...
Currently my solution has been to create a .PNG of each item and then to 'stack' them all on top of each other in a RelativeLayout. So for example, I create an ImageView of two shoes and align the ImageView to the center of the relative layout and the bottom of the Relative Layout. Next I 'stack' the bottom edge of the socks to the top edge of the shoe. And on and on.
This method works, but I feel like I don't have much control over where the parts sit and would much rather be able to calculate the x,y coordinates at run time and place the images that way. For instance, this works well if all of the ImageViews are stacked, but if I need to place one ImageView 10 pixels below the top edge of another ImageView I can't do it (or at least I haven't figured out how yet).
I am looking for a solution that will allow me to control the x,y position of ImageViews and allow ImageView to be offset from each other.

If you'd rather place the images by x,y coordinates, then you should consider using a single view and simply drawing the images on top. See this doc on custom drawing. You'll find drawBitmap and some of its overloads useful.

Android: How do you scale multiple views together?

I'm trying to layer graphics one top of each other, like an icon over a background, with the second layer (icon) at a certain pixel offset from the top left corner of first layer (background). Since each layer will eventually have its own animation, I'm placing each in its own View.
For my implementation I have two ImageViews, one for each layer, inside a RelativeLayout, which in turn is inside a ScrollView. ImageViews are positioned using layout_margin relative to the top left corner (0,0). The first ImageView is larger than the screen (background), while the second ImageView is smaller than it (icon). ScrollView automatically resizes the first ImageView (background) since it is larger than the screen, it does not resize the second since it is smaller (icon).
I need both of them to scale together, and I also need the positioning of the second layer over the first layer to adjust itself accordingly. This actually works well in a layer-list, but due to the animations I am forced to use Views. How can I scale and position multiple Views together, or do I need to build my own class for something that seems like it should be fairly basic?
Thanks in advance.

I had a similar problem in my android application. Android has introduced new set of API's to help us on this, setScaleX() and setScaleY().
Just call layout.getParent().setScaleX(); and layout.getParent().setScaleY();