Hafni is a java swing wrapper for the clojure language focusing on how components change. This does not only mean that the content displayed should be easy to change, but also that events coming from that content should be handled in a convenient way.
This is a small taste of Hafni, for a more thorough explanation of the parts of Hafni, see Usage below. The following example comes from
(frame :content (comp-and-events (button :text "*") :act (flow (output-arr this :text) >>> (arr #(str % "*")) >>> (input-arr this :text))) :size 200 200 :dont_exit_on_close)
This creates a frame (a window if you so will), with a button as content, size 200x200 and which doesn't close when the frame is closed (useful when working in the repl).
(comp-and-events (button :text "*") :act (flow (output-arr this :text) >>> (arr #(str % "*")) >>> (input-arr this :text)))
We first create a button with the text "*".
(button :text "*")
Then, when the button is pressed, the buttons text is extracted, another "*" is added to the end of that text, and set as the current text of the button.
(flow (output-arr this :text) >>> (arr #(str % "*")) >>> (input-arr this :text)))
What happens is that
(output-arr this :name) receives the current text, which is then sent to the function
#(str % "*") (the
arr can be ignored for now). The result of that function is then sent to the buttons text with
(input-arr this :text). The result is that the text of the button changes in the following way:
"*" "**" "***" "****"
To accomplish this, Hafni uses the datatypes Event and Arrow which are both explained in the wiki.
Add [hafni "1.0.3-SNAPSHOT"] as a dependency in leiningen.
To the left is the java class or function that is wrapped, to the right is the corresponding function used in Hafni.
AbstractAction action ButtonGroup button-group JButton button JCheckBox check-box JCheckBoxMenuItem check-box-menu-item JMenuItem menu-item JRadioButton radio-button JRadioButtonMenuItem radio-button-menu-item JToggleButton toggle-button
JComboBox combo-box JList jlist JSpinner spinner JTabbedPane tabbed-pane
JFileChooser/showOpenDialog open-file JFileChooser/showSaveDialog save-file JOptionPane/showMessageDialog error-message info-message message plain-message warning-message JOptionPane/showInputDialog adv-input-dialog text-input-dialog
BorderLayout border-layout BoxLayout box-layout CardLayout card-layout FlowLayout flow-layout GridLayout grid-layout
JMenu menu popup-menu JMenuBar menu-bar JToolBar tool-bar
JTable table table-model
JPasswordField password-field JTextArea text-area JTextField text-field JTextPane text-pane
File file *path-separator* Font font *available-fonts* Color color
JFrame frame JIcon icon JLabel label JProgressBar progress-bar JScrollPane scroll-pane MouseInfo mouse-position
Copyright (c) 2011 Jonathan Fischer Friberg
This software is provided 'as-is', without any express or implied warranty. In no event will the authors be held liable for any damages arising from the use of this software.
Permission is granted to anyone to use this software for any purpose, including commercial applications, and to alter it and redistribute it freely, subject to the following restrictions:
1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.