How to implement the ScrollImageView class in my Android application

I found this class:

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.Display;
import android.view.MotionEvent;
import android.view.View;
import android.view.WindowMan开发者_C百科ager;


// borrowed from https://sites.google.com/site/androidhowto/how-to-1/custom-scrollable-image-view
public class ScrollImageView extends View {
    private final int DEFAULT_PADDING = 10;
    private Display mDisplay;
    private Bitmap mImage;

    /* Current x and y of the touch */
    private float mCurrentX = 0;
    private float mCurrentY = 0;

    private float mTotalX = 0;
    private float mTotalY = 0;
    /* The touch distance change from the current touch */
    private float mDeltaX = 0;
    private float mDeltaY = 0;

    int mDisplayWidth;
    int mDisplayHeight;
    int mPadding;

    public ScrollImageView(Context context) {
        super(context);
        initScrollImageView(context);
    }

    public ScrollImageView(Context context, AttributeSet attributeSet) {
        super(context);
        initScrollImageView(context);
    }

    private void initScrollImageView(Context context) {
        mDisplay = ((WindowManager)context.getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay();
        mPadding = DEFAULT_PADDING;
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int width = measureDim(widthMeasureSpec, mDisplay.getWidth());
        int height = measureDim(heightMeasureSpec, mDisplay.getHeight());
        setMeasuredDimension(width, height);
    }

    private int measureDim(int measureSpec, int size) {
        int result = 0;
        int specMode = MeasureSpec.getMode(measureSpec);
        int specSize = MeasureSpec.getSize(measureSpec);

        if (specMode == MeasureSpec.EXACTLY) {
            result = specSize;
        } else {
            result = size;
            if (specMode == MeasureSpec.AT_MOST) {
               result = Math.min(result, specSize);
            }
        }
        return result;
    }

    public Bitmap getImage() {
        return mImage;
    }

    public void setImage(Bitmap image) {
        mImage = image;
    }

    public int getPadding() {
        return mPadding;
    }

    public void setPadding(int padding) {
        this.mPadding = padding;
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        if (event.getAction() == MotionEvent.ACTION_DOWN) {
            mCurrentX = event.getRawX();
            mCurrentY = event.getRawY();
        } 
        else if (event.getAction() == MotionEvent.ACTION_MOVE) {
            float x = event.getRawX();
            float y = event.getRawY();

            // Update how much the touch moved
            mDeltaX = x - mCurrentX;
            mDeltaY = y - mCurrentY;

            mCurrentX = x;
            mCurrentY = y;

            invalidate();
        }
        // Consume event
        return true;
    }

    @Override
    protected void onDraw(Canvas canvas) {
        if (mImage == null) {
            return;
        }

        float newTotalX = mTotalX + mDeltaX;

        // Don't scroll off the left or right edges of the bitmap.
        if (mPadding > newTotalX && newTotalX > getMeasuredWidth() - mImage.getWidth() - mPadding)
            mTotalX += mDeltaX;

        float newTotalY = mTotalY + mDeltaY;

        // Don't scroll off the top or bottom edges of the bitmap.
        if (mPadding > newTotalY && newTotalY > getMeasuredHeight() - mImage.getHeight() - mPadding)
            mTotalY += mDeltaY;

        Paint paint = new Paint();
        canvas.drawBitmap(mImage, mTotalX, mTotalY, paint);
    }
}

and am stumped how to use it with my application.

I want my application when in landscape orientation to display a bitmap image that is scrollable vertically and horizontally. I pull my image from a URL and programatically make it a bitmap. I call a method that returns my bitmap image.

Any ideas?

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The setImage methods takes a Bitmap. So, you should be able to programmatically create this view in your activity, set the image with your Bitmap and place the view into your layout.

I've never seen this class before, so your mileage may vary ;)