thanks a lot for all the updates,

I found some issues:
* when zooming in via the slider, the image is initially moved to the edge of the screen and is being stretched as the zoom level increases, it might be better looking to keep the image centered while zooming

* when viewing an image, if either the rotate left / rotate right buttons are used, then the image is zoomed in via slider / double click, part of the image cant be viewed in one direction and excess black areas on the edges are present on the other direction, but the image is viewed correctly if the device itself is rotated instead of pressing the rotate buttons.

* if the user views the info dialog, and marks the image then clicks back, the image will have a red square around it, and if the user touches and hold the image the red square will be gone, supposedly that means the image has been unmarked, however clicking again on the image and viewing it then clicking the info button, will still show that the image has been marked.

* if the user zooms in by double clicking the image, the slider position isn't updated, it is shown as if the image isn't zoomed at all.