Summary #

Library providing easy to use mouse or touch (for mobile devices) based drag-and-drop capabilities to Google Web Toolkit (GWT) projects.

Questions? #

If you have questions, please post them on http://groups.google.com/group/gwt-dnd and I (or someone else) will try to answer them as best as possible. Using the forum means that others can benefit from any answers and feedback you get. It is always the fastest way to get an answer to a new question.

Is your project using drag and drop? #

I'd like to know if you're using gwt-dnd on your project, and how useful (or not) this library is to you. You can send me an email at fredsa@gmail.com.

Getting started with your own drag-and-drop projects #

Read the wiki here: https://github.com/fredsa/gwt-dnd/wiki/GettingStarted

Working examples #

Try the working demo:

Features #

Drag-and-Drop - classic drag/drop operations for your existing widgets and panels

Drag-and-Move - allows user to rearrange widgets within a Panel

Non-invasive - No need to extend or implement special library classes or interfaces; just use your existing widgets and panels

Any Widget that implements SourcesMouseEvents is draggable. For today's version of GWT that means FocusPanel, HTML, Image and Label are immediately draggable. Listening for mouse events on other widgets is relatively straight forward.

Any Panel can become a drop target. If you need absolute positioning on the drop target, use AbsolutePanel.

Quirks mode and Strict mode fully support

Inline and Block elements are supported for dragging and as drop targets

AbsolutePanel, IndexedPanel, FlowPanel and FlexTable drop targets

Drag Handles - grab hold of small part of a larger widget

Drag Proxies - Leave the original widget in place while you drag a proxy widget around

Veto Capability - Prevent certain operations from happening, causing the draggable to snap back to its original location

EventListener for drag-and-drop events via DragHandler interface

Many examples with source code

OOTB (Out of the Box) provided drag-and-drop or drag-and-move behaviors #

`DropController`	Description	Example Use
`AbsolutePositionDropController`	Drag-and-Move widgets around an `AbsolutePanel`.	Moving drawing elements around on a flow chart.
`AbstractDropController`	Create your own controllers from this base class.	Anything you can dream up.
`BoundaryDropController`	All drag operations are ultimately constrained by a panel you specify. By default this panel is `RootPanel.get()` which means you can drag widgets over the entire page.	For use as part of the gwt-dnd implementation.
`FlexTableRowDropController`	Rearrange rows in a `FlexTable`.	Users rearrange results of a query.
`FlowPanelDropController`	Drop controller for instances of `FlowPanel`.	Moving elements around in flowed text.
`HorizontalPanelDropController`	Drop controller for instances of `HorizontalPanel`.	Moving widgets in a horizontal list.
`GridConstrainedDropController`	Similar to `AbsolutePositionDropController`, but constrains the position of the draggable widgets to a specified grid.	Allows for 'snap to grid' functionality.
`SimpleDropController`	For simple drop targets which allows a widget to be dropped on them.	A trash can icon.
`VerticalPanelDropController`	Drop controller for instances of `VerticalPanel`.	Moving widgets in a vertical list.

Feedback #

Please let me know what you think. Suggestions are always welcome.

Other GWT projects by the same author #

Project	Description
gwt-voices	Provides sound support for your GWT applications.
gwt-log	Provides logging support for your GWT applications.