Drag-Drop Android Launcher / GridView Issue - Android / Java

Question

I have a gridView I've created from an online example/tutorial and I'm trying to figure out how to change the behavior when a new item is dragged over a previously existing item in the GridView. Currently when a new item is dragged over the gridView it removes the current icon in place (leaving it with the red empty square [icon.png is a grid of empty squares the code uses as a background image])

I've poured through the example's source quite a few times and I can't figure out how to change the behavior of what happens when one item is dragged over the other

Screenshot:

Source code:

https://drive.google.com/file/d/0B6jCh_IJdtoFYWFJMlk5MHhlX3c/edit?usp=sharing

P.S.

I believe the issue may be in either the DragView or DropTarget class. (feel free to download the entire project - I've made the entire thing available for an easy download)

Answer 1

Look at methods onDragEnter and onDragExit in ImageCell. Those two methods are the ones called as your finger passes over a cell on the grid. They set the background of the image view.

onDragEnter: int bg = mEmpty ? R.color.cell_empty_hover : R.color.cell_filled_hover; setBackgroundResource (bg);

onDragExit: int bg = mEmpty ? R.color.cell_empty : R.color.cell_filled; setBackgroundResource (bg);

The color definitions are in mycolor.xml.

Reference: http://blahti.wordpress.com/2012/03/03/improved-drag-drop-for-gridview/