how to display multiple image on one screen in android like layer of photoshop

Question

I am new to android development so I don't have much experience.

I want to develop an app for children in which I want display images (png or bitmap) of a sky, mountain, river in a combined manner and children can change the color of the sky ( that means only the sky bitmap will change ).

I want to display all bitmaps one over another like a Photoshop layer so children can add a tree or a small mountain to the view by clicking a button.

Please guide me on how I can work on such image manipulation. Which techniques do I have to use for this?

Answer 1

Just a starting point:

• All your bitmaps must have a transparent background.
• Use a RelativeLayout and add your Bitmap on it (RelativeLayout allows you to place childs overlapping each other)
• You can use margin to position bitmaps where you want in your RelativeLayout

EDIT

Here is a simple layout with 2 bitmaps (image1 and image2 both have a transparent background) overlapping each other.

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
            android:orientation="vertical"
            android:id="@+id/relativeLayout"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"

    >
     <ImageView
            android:background="@drawable/image1"
            android:layout_width="match_parent"
            android:layout_height="match_parent"/>

     <ImageView
            android:background="@drawable/image2"
            android:layout_width="match_parent"
            android:layout_height="match_parent"/>
</RelativeLayout>

Answer 2

It depends on your requirements. If you really want to create complex application I would recommend you to use a game engine. Like cocos-2dx, for example. It's free, cross-platform and there are a lot of graphics processing features out of box. There are layers, filters, animation... and it works very fast.

If you are android SDK fan then create a custom view and use it's canvas. It wont be easy. But if your app is simple enough you better stick with canvas.