Question

I need some advice how to implement this situation in my application.

I have array of bitmpaps, which I’m using to store different states of my Canvas, so I can use them in the future. Here is the code which I’m using :

private Bitmap[] temp;
// on user click happens this ->
if(index<5){
            temp[index] = Bitmap.createBitmap(mBitmap);
            index++;
}

So basically I want to save only the last 5 bitmaps depending on user’s actions. The things which I want to learn is how can I update my array so I can always have the last 5 bitmaps.

Here is what I mean :

Bitmaps [1,2,3,4,5] -> after user clicks I want to delete the first bitmap, re-order the array and save the new one as the last..so my array should look like this : Bitmaps[2,3,4,5,6];

Any suggestions / advices which is the best way to do that?

Thanks in advance!

Answer 1

I just wrote this…
Use this code to initialise:

Cacher cach = new Cacher(5);
//when you want to add a bitmap
cach.add(yourBitmap);
//get the i'th bitmap using
cach.get(yourIndex);

Remember you can re implement the function get to return the ith “old” Bitmap

public class Cacher {
    public Cacher(int max) {

        this.max = max;
        temp = new Bitmap[max];
        time = new long[max];
        for(int i=0;i<max;i++)
            time[i] = -1;
    }
    private Bitmap[] temp;
    private long[] time;
    private int max = 5;
    public void add(Bitmap mBitmap) {
        int index = getIndexForNew();
        temp[index] = Bitmap.createBitmap(mBitmap);

    }
    public Bitmap get(int i) {
        if(time[i] == -1)
            return null;
        else
            return temp[i];
    }
    private int getIndexForNew() {
        int minimum = 0;
        long value = time[minimum];
        for(int i=0;i<max;i++) {
            if(time[i]==-1)
                return i;
            else {
                if(time[i]<value) {
                    minimum = i;
                    value = time[minimum];
                }
        }
        return minimum;
    }
}