Develop Reference

How do I select a folder to save a file to in Jython using JFileChooser

I'm trying to use JFileChooser to select a folder to save a file to in Jython, but I'm not quite sure how to go about it.
The only example I've found so far was at this site: http://zetcode.com/gui/jythonswing/dialogs/, but its not really what I'm looking for.
I'm hoping to have just the file selection dialog open (the examples requires an awkward button press to activate the file dialog). I would also like to get the current directory of the selected folder instead of the filepath of a file.

Well I'm not going to claim this is the cleanest solution in the world, but it does work and thats close enough for me.
from java.awt import BorderLayout
from javax.swing import JFileChooser, JFrame, JPanel
class DropDown(JFrame):
def __init__(self):
super(DropDown, self).__init__()
self.initUI()
def initUI(self):
self.panel = JPanel()
self.panel.setLayout(BorderLayout())
choseFile = JFileChooser()
choseFile.setDialogTitle('Select Export Location')
choseFile.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY)
ret = choseFile.showSaveDialog(self.panel)
if ret == JFileChooser.APPROVE_OPTION:
if choseFile.getSelectedFile().isDirectory():
self.file_name = str(choseFile.getSelectedFile())
def get_file_name(self):
return self.file_name

How can I disable a dialog in ImageJ?

I'm using ImageJ a lot to look at image stacks composed of a number of single images sitting in one folder. I can just drag and drop the respective folder into the ImageJ GUI and it creates a scrollable visualization, which is very convenient. It could be even more convenient though since each time I do it, a dialog appears asking whether I want to open all images in the folder as a stack. Is it possible to make it default to "Yes"? Would I need to change the source code and compile it myself..? If that is the case, where could I start looking?

A suggestion would be to make a feature request to the author of Imagej Wayne rasband, e.g., at the Github repository:
https://github.com/imagej/imagej1
Or you can write a small macro (use the macro recorder with the menu actions!) which can be also be installed in ImageJ. Something like:
run("Image Sequence...", "open=C:\\images\\ sort");
Here the macro docs:
https://imagej.nih.gov/ij/developer/macro/macros.html
https://imagej.nih.gov/ij/docs/guide/146-14.html

To disable the dialog in the source code: Find the source file ij>plugin>DragAndDrop.java. From its openDirectory method, delete the dialog-related lines and assign boolean values to convertToRGB and virtualStack, both of which are normally defined by check boxes in the now defunct dialog window. The code should now look like this:
private void openDirectory(File f, String path) {
if (path==null) return;
if (!(path.endsWith(File.separator)||path.endsWith("/")))
path += File.separator;
String[] names = f.list();
names = (new FolderOpener()).trimFileList(names);
if (names==null)
return;
convertToRGB = false;
virtualStack = false;
String options = " sort";
if (convertToRGB) options += " convert_to_rgb";
if (virtualStack) options += " use";
IJ.run("Image Sequence...", "open=[" + path + "]"+options);
DirectoryChooser.setDefaultDirectory(path);
IJ.register(DragAndDrop.class);
}
I did this with ImageJ 1.51p. The source code can be downloaded here. After making these changes, just run the build.xml ant script.
Note that writing a macro might provide a cleaner and more portable way to achieve this--refer to Marcel's answer for further reading.

Windows native File chooser in java

Apparently, there are (at least?) two different native File choosers on Windows (10). There is this one, which is used by JFileChooser and other programs:
And there is that one, for example used by Chrome:
I like it much more than the first one because:
You can directly enter your file path at the top
Your can search the folder
The direct access on the left contains the whole file tree
How do I get it in Java?

Use the JavaFX library
FileChooser fileChooser = new FileChooser();
fileChoose.showOpenDialog(null);
To run it in a swing context, have a look at those two answers.
PlatformImpl.startup(() -> {
FileChooserd = new FileChooser();
d.showOpenDialog(null);
});
new JFXPanel();
Platform.runLater(() -> {
FileChooser d = new FileChooser();
d.showOpenDialog(null);
});
Note that other things like modality won't work when mixing JavaFX and Swing. Also, you will have to build some code that waits until the Runnable has finished to be able to fetch the results.
Use a special library
native file dialogs provides native file dialogs, and LWJGL 3 provides Java bindings for this library.

Need FileDialog with a file type filter in Java

I have a JDialog with a button/textfield for the user to select a file. Here's the code:
FileDialog chooser = new FileDialog(this, "Save As", FileDialog.SAVE );
String startDir = saveAsField.getText().substring( 0, saveAsField.getText().lastIndexOf('\\') );
chooser.setDirectory(startDir);
chooser.setVisible(true);
String fileName = chooser.getFile();
My problem is that instead of seeing an All Files filter, I want to provide a custom filter, e.g. for Word docs or something. I setup a custom FilenameFilter using setFilenameFilter(), but it didn't seem to work. I did notice that it says in the docs that the custom filter doesn't work in Windows (this runs in Windows XP/Vista/7). Here was my implementation of the filter:
chooser.setFilenameFilter( new geFilter() );
public class geFilter implements FilenameFilter {
public boolean accept(File dir, String name) {
return name.endsWith( ".doc" ) || name.endsWith( ".docx" );
}
}
Am I doing something wrong here? Also, I want a description to appear in the box, like "Microsoft Word (*.doc *.docx)" but I'm not sure how to do that.
Any and all help is appreciated.

AWT isn't really the preferred way of writing Java GUI apps these days. Sun seems to have mostly abandoned it. The two most popular options are Swing and SWT. So I think they didn't really develop the APIs very extensively to add modern features. (err, to answer your question: No you don't appear to be able to do that with AWT)
Swing has the advantage that it is truly write-once-run-anywhere and it can look exactly the same everywhere. There are Look & Feels that try to make Swing look native, some are better than others (Mac isn't terrible, Windows is okay, GTK isn't). Still, if you want an app that really looks and acts EXACTLY the same everywhere, Swing will let you do that. Plus it runs out-of-the-box without any extra libraries. Performance isn't great.
Swing's JFileChooser will let you do what you want. Create a subclass of FileFilter and call setFileFilter on the JFileChooser.
SWT takes the write-once-run-anywhere to the opposite extreme. You still have one codebase that you write against, but it actually uses the native widgets on each platform so it generally looks like a native app (not perfect everywhere, but still impressive). It's fast and pretty reliable in my experience. Eclipse (and other high profile software) uses SWT so it's in pretty heavy use. But it does require platform-specific JARs and DLLs.

since you are using JDialog, that is a swing class why not using JFileChooser?
JFileChooser fc = new JFileChooser("C:\\");
fc.setFileFilter(new FileNameExtensionFilter("Microsoft Word (*.doc, *.docx)", "doc", "docx"));
FileNameExtensionFilter is a nice Java 6 class that does exactly what you want.

I am also trying to do that. I want to use FileDialog instead of JFileChooser.
I found the answer here: http://www.rgagnon.com/javadetails/java-0247.html
He says that "on the Win platform, the setFilenameFilter method don't work. We must use the setFile method instead to set a filter."
There is source code at the specified link.
I tested and it works:
FileDialog fd = new FileDialog((Frame) null, "Save File", FileDialog.SAVE);
fd.setFile("*.txt");
fd.setVisible(true);
String file = fd.getFile();
System.out.println(file);
System.exit(0);

If you ever use JavaFX 2, the FileChooser class will do exactly what you need without any of JFileChooser/FileDialog problems. You can also embed JavaFX 2 components inside Swing applications, but you need JavaFX runtime.
Example:
FileChooser fc = new FileChooser();
FileChooser.ExtensionFilter filter;
filter = new FileChooser.ExtensionFilter("Text files (*.txt)", "*.txt");
fc.getExtensionFilters().add(filter);
File f = fc.showOpenDialog(primaryStage);
System.out.println(f);

You can call the native Windows Filedialog (CFileDialog) with JNI. Filters can be set for CFileDialog easily.
I wrote a simple wrapper class for CFileDialog several months ago, If you are interested, you can get the source and binary from
Xfiledialog project on google code

Just use setFilenameFilter method of the FileDialog instance fd:
fd.setFilenameFilter(new FilenameFilter()
{
#Override
public boolean accept(File file, String s)
{
// enter code to return TRUE or FALSE here
return s.contains(".txt");
}
});

How to play sound in JavaFX?

I'm experimenting with JavaFX making a small game.
I want to add sound.
How?
I tried MediaPlayer with media defined with relative source attribute like:
attribute media = Media{
source: "{__FILE__}/sound/hormpipe.mp3"
}
attribute player = MediaPlayer{
autoPlay:true
media:media
}
It doesn't play.
I get
FX Media Object caught Exception com.sun.media.jmc.MediaUnavailableException: Media unavailable: file: ... Sound.class/sound/hormpipe.mp3

Just a guess, but is that file "hornpipe.mp3" and not "hormpipe.mp3" (with an m)?

var player = javafx.scene.media.MediaPlayer {
repeatCount: javafx.scene.media.MediaPlayer.REPEAT_FOREVER
media: Media { source: "{\_\_DIR\_\_}clip.wav"
};
};
player.play();
You have to incluye the audio file in the build/compiled directory so Netbeans can pack it into the jar file.

Just a guess, but I think your {__FILE__} will expand to the name of your file. Try replacing it with {__DIR__}.

Also note that {__DIR__} includes the trailing /, so try this instead:
attribute media = Media{
source: "{__DIR__}sound/hormpipe.mp3"}
EDIT: I did some digging, and apparently, the source of a Media object has to be either a remote URL, or an absolute file path, since media files aren't allowed in JARs (something I hope gets changed with future releases, since I really like JavaFX and want to be able to make desktop apps with it). See: JavaFX FAQs.

This worked for me:
MediaPlayer audio = new MediaPlayer(
new Media(
new File("file.mp3").toURI().toString()));
Source file should be in project's root directory (not src, not dist).

OK, having used this question to get MP3 audio working (kinda), I've learned the following (not much).
1) Audio for compressed formats is very platform dependent. My continually upgraded Mint 17.1->18 machine plays mp3 fine using Media and MediaPlayer. Fresh installs of Mint 18 won't (with the dev tools).
So use .wav files.
Media sound=new Media(new File("noises/roll.wav").toURI().toString());
MediaPlayer mediaPlayer=new MediaPlayer(sound);
mediaPlayer.play();
2) One of the things you need to be aware of with Media/MediaPlayer is that in order to play multiple times (repeatedly or all at once ie, on a button press/whatever in a game) you have to spawn N number of MediaPlayer objects, and each one will play once and then stop.
So use javafx.scene.media.AudioClip
AudioClip soundMyNoise = new AudioClip(new File("noises/roll.wav").toURI().toString());
soundMyNoise.play();
AudioClip also has its issues, which include storing the raw audio data in RAM all at once instead of buffering. So there is the possibility of excessive memory use.
No matter which method you end up going with, one thing to be critically aware of was mentioned by daevon earlier - the path issue. With NetBeans, you have NetBeansProjects/yourproject/src/yourproject/foo.java. The sounds in the example above go in NetBeansProjects/yourproject/noises/roll.wav