Added resizing with keeping aspect ratio when dimension is 0.

[mcharmas]

I have added possibility to resize with keeping aspect ratio as discussed in #613 to be able to write alignTopCrop transformation efficiently. There are some issues like #226 that are solved with this pull request.

To resize keeping aspect ratio one should pass 0 as unknown resize dimension to resize method of builder.

[JakeWharton]

Thanks! We'll try to look soon. Both of us presenting at a conference this
weekend.

On Fri, Sep 19, 2014 at 9:50 AM, Michał Charmas notifications@github.com
wrote:

I have added possibility to resize with keeping aspect ratio as discussed
in #613 #613 to be able to write
alignTopCrop transformation efficiently. There are some issues like #226
#226 that are solved with this

pull request.

You can merge this Pull Request by running

git pull https://github.com/mcharmas/picasso master

Or view, comment on, or merge it at:

#663
Commit Summary

• Added resizing with keeping aspect ratio when dimension is 0.

File Changes

• M picasso/src/main/java/com/squareup/picasso/BitmapHunter.java
  https://github.com/square/picasso/pull/663/files#diff-0 (9)
• M picasso/src/main/java/com/squareup/picasso/Request.java
  https://github.com/square/picasso/pull/663/files#diff-1 (32)
• M picasso/src/main/java/com/squareup/picasso/RequestHandler.java
  https://github.com/square/picasso/pull/663/files#diff-2 (16)
• M picasso/src/main/java/com/squareup/picasso/Utils.java
  https://github.com/square/picasso/pull/663/files#diff-3 (2)
• M
  picasso/src/test/java/com/squareup/picasso/RequestCreatorTest.java
  https://github.com/square/picasso/pull/663/files#diff-4 (33)

Patch Links:

• https://github.com/square/picasso/pull/663.patch
• https://github.com/square/picasso/pull/663.diff

—
Reply to this email directly or view it on GitHub
#663.

[JakeWharton]

This looks great. I would like to see a test that exercises the actual resize logic though. I think there's four cases: resizing up and resizing down for both width-fixed and height-fixed aspect ratios. Do you think you can add those?

[JakeWharton]

Needs a rebase.

[mcharmas]

Glad it works for you. My implementation of crop that aligns to top transformation looks like this:

    private class CropAlignTopTransformation implements Transformation {
        private final int targetWidth;
        private final int targetHeight;

        public CropAlignTopTransformation(int targetWidth, int targetHeight) {
            this.targetWidth = targetWidth;
            this.targetHeight = targetHeight;
        }

        @Override
        public Bitmap transform(Bitmap source) {
            Bitmap transformed;
            if (source.getHeight() == targetHeight) {
                return source;
            } else if (source.getHeight() >= targetHeight) {
                transformed = Bitmap.createBitmap(source, 0, 0, targetWidth, targetHeight);
            } else {
                float scaleFactor = (float) targetHeight / source.getHeight();
                int drawWidth = (int) (source.getWidth() / scaleFactor);
                int xOffset = (source.getWidth() - drawWidth) / 2;
                Matrix matrix = new Matrix();
                matrix.preScale(scaleFactor, scaleFactor);
                transformed = Bitmap.createBitmap(source, xOffset, 0, drawWidth, source.getHeight(), matrix, false);
            }

            if (transformed != source) {
                source.recycle();
                source = transformed;
            }
            return source;
        }

        @Override
        public String key() {
            return "crop_align_top_" + targetWidth + "x" + targetHeight;
        }
    }

Api call that uses this transformation looks like this:

requestCreator.resize(width, 0).transform(new CropAlignTopTransformation(width, height))

So to sum up:

• image that is transformed has already size that is equal to desired width
• there are 3 cases:
  • image has desired height - returning original
  • image has bigger height - cropping from top
  • image has smaller heigh - image is scaled to match heigh and cropped on the sides

[JakeWharton]

Still missing tests that show the actual behavior (mentioned above).

[dnkoutso]

@mcharmas can you please add more tests? We are wrapping up 2.4 and I can't accept this change without more tests.

[mcharmas]

Yep, I'll add these tests in few hours.

[mcharmas]

Tests added.

[dnkoutso]

Thank you! looking now.