Android Draggable View
An implementation of a draggable Android View that can be modified as it moves.
The standard approach to implementing a draggable/movable View in Android is to rely on DragShadowBuilder. For many situations, this would be the easiest approach. However, in some cases, where, for example, you need to modify the view as it is being dragged, DragShadowBuilder won't do, as it's just not flexible enough.
This is an example of an alternate implementation of a simulated draggable View, without the dependency on DragShadowBuilder. With this approach you have full access to the view being dragged (actually, the cached Bitmap image of the view), and, as such, the view can be modified while moving.
To reduce flicker and improve animation performance, this implementation simulates the movement of a View by moving a cached Bitmap rendition of the View, instead of the View itself. This technique results in a much smoother effect.
In this example project, the transparency of the view is modified as the View is dragged around the screen.
The MIT License (MIT)
Copyright (c) 2014-2015, Andrey Butov. All Rights Reserved.
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