drawable

A drawable is a general term for any object that can be drawn onto a screen. In computing, a drawable is typically an image or vector-like element that a graphics system can render. In Android, Drawable specifically refers to an object that can be drawn on a Canvas and used by UI widgets.

Drawable resources in Android are stored in the res/drawable directory and may be either binary assets or XML definitions. The framework exposes a base class android.graphics.drawable.Drawable. Subclasses render different content, including BitmapDrawable (bitmaps), ShapeDrawable (basic shapes), ColorDrawable, GradientDrawable, LayerDrawable, InsetDrawable, ClipDrawable, ScaleDrawable, StateListDrawable, TransitionDrawable, NinePatchDrawable, and VectorDrawable.

XML drawable resources let you declare visuals declaratively using elements such as <shape>, <gradient>, and <selector>. These resources can be referenced as backgrounds, source images in ImageView, or programmatically via drawable resources.

Drawables support theming and state changes; they can be tinted, scaled, or animated and are designed to be memory-efficient when used appropriately. Performance considerations include avoiding large bitmaps, reusing drawables, and using vector drawables for scalable icons on modern platforms.