Default DnD Support
Technically speaking, the framework for drag and drop supports all Swing components — the data transfer mechanism is built into every
JComponent. If you wanted, you could implement drop support for a
JSlider so that it could fully participate in data transfer. While
JSlider does not support drop by default, the components you would want (and expect) to support drag and drop do provide specialized built-in support.
The following components recognize the drag gesture once the
setDragEnabled(true) method is invoked on the component. For example, once you invoke
myColorChooser.setDragEnabled(true) you can drag colors from your color chooser:
The following components support drop out of the box. If you are using one of these components, your work is done.
The framework for drop is in place for the following components, but you need to plug in a small amount of code to customize the support for your needs.
For these critical components, Swing performs the drop location calculations and rendering; it allows you to specify a drop mode; and it handles component specific details, such as tree expansions. Your work is fairly minimal.
You can also install drop support on top-level containers, such as
JDialog. You can learn more about this in Top-Level Drop.