imageview - How to TOP CROP Image using PhotoView Android? -

i have 1 imageview layout_width & layout_height match_parent, 2 of them screen width , height size. need display photo fill full width , when image higher imageview height, can scroll , down. i'm using photoview library zoom, scroll, tap... i'm using centercrop scale type not solution need. show part of center image , need scroll view beginning.

i tried lot of custom view extended imageview display top crop style when touch image, changed default photoview scale type. work when not use photoviewattacher

how can make top crop , scroll + zoom + touch... image using photoview library ?

you can achieve topcrop scale changing center_crop scale under updatebasematrix() in photoviewattacher of chris banes`s photoview.

here code:

else if (mscaletype == scaletype.center_crop) {    float scale = math.max(widthscale, heightscale);     mbasematrix.postscale(scale, scale);     //changed dy = 0 top crop     mbasematrix.posttranslate((viewwidth - drawablewidth * scale) / 2f, 0); 

source: http://www.widecodes.com/fxsznwpevx/android-image-view-top-crop.html

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since people requesting more scaletypes in imageview: https://code.google.com/p/android/issues/detail?id=58468 added custom scale types chris banes`s photoview.

i send pr him. since don't know if accept pr(or when), can project in github: https://github.com/jonathanrz/photoview/ , add aar project manually.

you can see example of usage in croptypeactivity in sample project inside library.