How to overlay an icon image on top of an exisiting view

This is a two part question.

I have an image of a warehouse that I would like to divide it into regions (A,B,C,D,E & F) where each letter represents a storage in the warehouse. If the user selects storage "B" then I would like to programmatically overlay an icon over the region on the i开发者_如何学Cmages that is designated for "B".

Question:

1. What is a good way to subdivide the image into regions that will describe each of the storage room?
2. How to programmatically place an icon over the correct region?

Thank you.

Answer to 1: You can use Framelayout; FrameLayout is the general mechanism for overlaying a view on top of another.

Here's an example:

 <?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">
<ImageView  
    android:id="@+id/image"
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:src="@drawable/my_image"/>
<View
    android:id="@+id/overlay"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"/>
</FrameLayout>

Then in your Java code you can dynamically set the transparency of your overlay:

View overlay = (View) findViewById(R.id.overlay);
int opacity = 200; // from 0 to 255
overlay.setBackgroundColor(opacity * 0x1000000); // black with a variable alpha
FrameLayout.LayoutParams params =
    new FrameLayout.LayoutParams(FrameLayout.LayoutParams.FILL_PARENT, 100);
params.gravity = Gravity.BOTTOM;
overlay.setLayoutParams(params);
overlay.invalidate(); // update the view

See here

Question 2: In framelayout, you can set the icons on top of where you want by dragging them:: So simple!

Hope this helped:: XD