Resize image to full width and variable height wit

问题:

I have a listView with an adapter that contains ImageView of variable size (width and height). I need resize the pictures load with Picasso to the max width of layout and a variable height given by the aspect ratio of the picture.

I have checked this question: Resize image to full width and fixed height with Picasso

The fit() works but I haven't found nothing to keep the aspect ratio of the picture.

This code partially works if I fixed the height in the layout of the adapter:

Picasso.with(this.context).load(message_pic_url)
.placeholder(R.drawable.profile_wall_picture)
.fit().centerInside()
.into(holder.message_picture);

But it generates blank spaces between the pictures of the listView because the pictures may be that not have that height.

Thanks in advance.

回答1:

As of Picasso 2.4.0, this operation is now directly supported. Simply add a .resize() request with one of the dimensions as 0. For example, to have a variable width, your call would become:

Picasso.with(this.context)
       .load(message_pic_url)
       .placeholder(R.drawable.profile_wall_picture)
       .resize(0, holder.message_picture.getHeight()),
       .into(holder.message_picture);

Note that this call uses .getHeight() and therefore assumes the message_picture has already been measured. If that isn't the case, such as when you have inflated a new view in a ListAdapter, you can delay this call until after measurement by adding an OnGlobalLayoutListener to the view:

holder.message_picture.getViewTreeObserver()
      .addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
            // Wait until layout to call Picasso
            @Override
            public void onGlobalLayout() {
                // Ensure we call this only once
                imageView.getViewTreeObserver()
                         .removeOnGlobalLayoutListener(this);


                Picasso.with(this.context)
                       .load(message_pic_url)
                       .placeholder(R.drawable.profile_wall_picture)
                       .resize(0, holder.message_picture.getHeight())
                       .into(holder.message_picture);
            }
        });

回答2:

I came across the same issue and it took me a while to track down a solution but I finally came across something that works for me.

Firstly I changed the Picasso call to

Picasso.with(this.context).load(message_pic_url)
.placeholder(R.drawable.profile_wall_picture)
.into(holder.message_picture);

Removing the fit and the centerInside. Next you need to add the following lines to the ImageView in your XML

android:scaleType="fitStart"
android:adjustViewBounds="true"

Hopefully it will work for you as well.

回答3:

Finally I solved it doing a transformation of Picasso, here is the snippet:

    Transformation transformation = new Transformation() {

        @Override
        public Bitmap transform(Bitmap source) {
            int targetWidth = holder.message_picture.getWidth();

            double aspectRatio = (double) source.getHeight() / (double) source.getWidth();
            int targetHeight = (int) (targetWidth * aspectRatio);
            Bitmap result = Bitmap.createScaledBitmap(source, targetWidth, targetHeight, false);
            if (result != source) {
                // Same bitmap is returned if sizes are the same
                source.recycle();
            }
            return result;
        }

        @Override
        public String key() {
            return "transformation" + " desiredWidth";
        }
    };

    mMessage_pic_url = message_pic_url;

    Picasso.with(this.context)
        .load(message_pic_url)
        .error(android.R.drawable.stat_notify_error)
        .transform(transformation)
        .into(holder.message_picture, new Callback() {
            @Override
            public void onSuccess() {
                holder.progressBar_picture.setVisibility(View.GONE);
            }

            @Override
            public void onError() {
                Log.e(LOGTAG, "error");
                holder.progressBar_picture.setVisibility(View.GONE);
            }
    });

This line is for customize with your desired width:

int targetWidth = holder.message_picture.getWidth();

Additionally this snipped include Callback for loading hide and error drawable built-in Picasso.

If you need more information to debug any error, you MUST implement a custom listener (Picasso builder) beacuse the onError Callback information is "null". You only know that there is an error for UI behavior.

I hope this helps someone to save many hours.

回答4:

May Accepted Answer is Useful to all but If you are binding Multiple ViewHolder for Multiple Views then you can reduce your code by Creating Class for Transformation and passing ImageView from ViewHolder.

/**
 * Created by Pratik Butani
 */
public class ImageTransformation {

    public static Transformation getTransformation(final ImageView imageView) {
        return new Transformation() {

            @Override
            public Bitmap transform(Bitmap source) {
                int targetWidth = imageView.getWidth();

                double aspectRatio = (double) source.getHeight() / (double) source.getWidth();
                int targetHeight = (int) (targetWidth * aspectRatio);
                Bitmap result = Bitmap.createScaledBitmap(source, targetWidth, targetHeight, false);
                if (result != source) {
                    // Same bitmap is returned if sizes are the same
                    source.recycle();
                }
                return result;
            }

            @Override
            public String key() {
                return "transformation" + " desiredWidth";
            }
        };
    }
}

Calling from ViewHolder:

Picasso.with(context).load(baseUrlForImage)
                     .transform(ImageTransformation.getTransformation(holder.ImageView1))
                     .error(R.drawable.ic_place_holder_circle)
                     .placeholder(R.drawable.ic_place_holder_circle)
                     .into(holder.mMainPhotoImageView1);

Hope it will Help you.

回答5:

    Picasso.with(this).load(url).resize(1800, 1800).centerInside().into(secondImageView)

    <ImageView
        android:id="@+id/SecondImage"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentStart="true"
        android:layout_alignParentLeft="true"
        android:adjustViewBounds="true"
        android:layout_margin="10dp"
        android:visibility="gone"/>

This will help you with variable height of images for all devices

回答6:

I've wrote simple helper that take care about adding layout complete listener and call into(imageView) when layout process complete.

public class PicassoDelegate {

private RequestCreator mRequestCreator;

public PicassoDelegate(ImageView target, RequestCreator requestCreator) {
    if (target.getWidth() > 0 && target.getHeight() > 0) {
        complete(target, requestCreator);
    } else {
        mRequestCreator = requestCreator;
        target.addOnLayoutChangeListener(new View.OnLayoutChangeListener() {
            @Override
            public void onLayoutChange(View v, int left, int top, int right, int bottom, int oldLeft, int oldTop, int oldRight, int oldBottom) {
                v.removeOnLayoutChangeListener(this);
                complete((ImageView) v, mRequestCreator);
            }
        });

    }

}

private void complete(ImageView target, RequestCreator requestCreator) {
    if (target.getWidth() > 0 && target.getHeight() > 0) {
        requestCreator.resize(target.getWidth(), target.getHeight());
    }

    requestCreator.into(target);
}

}

So you can easily use it like this for example in fragment's onViewCreated()

new PicassoDelegate(customerPhoto, Picasso.with(getActivity()).load(user.getPhotoUrl()).centerCrop());

回答7:

imageView.post(new Runnable() {
      @Override public void run() {
        Picasso.with(context)
            .resize(0, imageView.getHeight())
            .onlyScaleDown()
            .into(imageView, new ImageCallback(callback, null));
      }
    });

回答8:

public class CropSquareTransformation implements Transformation {

  private int mWidth;
  private int mHeight;

  @Override public Bitmap transform(Bitmap source) {
    int size = Math.min(source.getWidth(), source.getHeight());

    mWidth = (source.getWidth() - size) / 2;
    mHeight = (source.getHeight() - size) / 2;

    Bitmap bitmap = Bitmap.createBitmap(source, mWidth, mHeight, size, size);
    if (bitmap != source) {
      source.recycle();
    }

    return bitmap;
  }

  @Override public String key() {
    return "CropSquareTransformation(width=" + mWidth + ", height=" + mHeight + ")";
  }

More transformations: https://github.com/wasabeef/picasso-transformations

回答9:

extend ImageView then override onMeasure method like the following.

@Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec){
        Drawable d = getDrawable();

        if(d!=null && fittingType == FittingTypeEnum.FIT_TO_WIDTH){
            int width = MeasureSpec.getSize(widthMeasureSpec);
            int height = (int) Math.ceil((float) width * (float) d.getIntrinsicHeight() / (float) d.getIntrinsicWidth());
            setMeasuredDimension(width, height);
        }else{
            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        }
    }

回答10:

Actually i was getting in while loading image in CustomImageView which had zoomable functionality

Error was

java.lang.RuntimeException: Transformation transformation desiredWidth crashed with exception.

I solved it by editing code given from accepted answer i got the max width of my display as if my imageview width was already match_parent.

if (!imgUrl.equals("")) {

        DisplayMetrics displayMetrics = new DisplayMetrics();
        ((Activity) context).getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
        int height = displayMetrics.heightPixels;
        int width = displayMetrics.widthPixels;

        Picasso.with(context).load(imgUrl)
                .transform(getTransformation(width, imageView))
                .into(imageView, new Callback() {
                    @Override
                    public void onSuccess() {
                        if (progressBar != null) {
                            progressBar.setVisibility(View.GONE);
                        }
                    }

                    @Override
                    public void onError() {
                        if (progressBar != null) {
                            progressBar.setVisibility(View.GONE);
                        }
                    }
                });
    }

    public static Transformation getTransformation(final int width, final ImageView imageView) {
        return new Transformation() {
            @Override
            public Bitmap transform(Bitmap source) {
                int targetWidth = width;
                double aspectRatio = (double) source.getHeight() / (double) source.getWidth();
                int targetHeight = (int) (targetWidth * aspectRatio);
                Bitmap result = Bitmap.createScaledBitmap(source, targetWidth, targetHeight, false);
                if (result != source) {
                    // Same bitmap is returned if sizes are the same
                    source.recycle();
                }
                return result;
            }

            @Override
            public String key() {
                return "transformation" + " desiredWidth";
            }
        };
    }

回答11:

Picasso.get()
.load(message_pic_url)
.fit()
.centerCrop()
.placeholder(R.drawable.profile_wall_picture)
.into(holder.message_picture);

Try this code, Worked for me.