Selection of multiple images from gallery view

Question

I want to create a gallery view, in which I want to select multiple images using an orange rectangular box.

It should look something like the following:

screen look like http://i.imgur.com/qAO0Q.jpg

Answer 1

Issues in your design:

Doing the selection by dragging the thumbs on either sides is going to be an extra headache. First of all, handling scrolling while doing selection. Secondly, handling touch/drag and deciding whether to include an item in the selection or not.

Design change:

Let me suggest a simpler way to extend your selection rectangle :

I assume the selection starts with a long click on any item. The orange selection rectangle appears over this initial item. Then a single tap on any neighboring item should include all items placed in-between the tapped and the initial item including the tapped one. That will make selection handling significantly simpler and less buggy.

Implementation:

Now this design shouldn't be too difficult to implement. Extend the Gallery widget and have members that indicate whether a selection is in progress and what is the range of selection (startIndex and endIndex) . Override the onDraw method and draw the selection rectangle from startIndex to endIndex items.