I have the following project on my hands, and I am banging my head to the wall for this "little" caveat.
In the project Matlab classes are used. Due to the structure of the project, I have the folders structured as follows:
+a/+b/+c/
Then, on c there are a bunch of other subfolders declared:
+a/+b/+c/+d
+a/+b/+c/+e
+a/+b/+c/+f
+a/+b/+c/+g
On one of those folders (let's sat +e) is where I am implementing my .m classes, which contain properties, as well as Static methods:
+a/+b/+c/+e/my_class_1.m
+a/+b/+c/+e/my_class_2.m
+a/+b/+c/+e/my_class_3.m
+a/+b/+c/+e/my_class_4.m
So let's take a look into my startup.m file:
% add the path to the class
addpath(genpath('<previous_path_to_a>'));
% import the module
import a.b.c.e.*
What I would like to do now is to be able to press my_class_1. + Tab on the Matlab prompt and be shown the properties and methods available for that given class.
I know I could just use Matlab's methods() function for this, or the properties() one, but it would be really nice to be able to just type:
help my_class_1. + Tab
to be able to select the given method and see it's documentation.
Otherwise I have, as I said, to call methods() first to see what the names of the class's own methods are for this particular class, to be able to access its documentation.
Edit:
Of course, what does work is typing the whole path, in my example:
help a.b.c.e.my_class_1. + Tab
The question is how to get rid off those previously annoying a.b.c.e.
Hmm, looks like you're right. Tab completion of methods and properties only seems to work with fully qualified class names, even if the class is on the path and imported.
I don't know of a workaround. If I were you, I'd enter an enhancement request with MathWorks for that. It would seem like an obvious and nice thing to have.
Related
Can't find anything on this and sort of would like a report on it and not going through all of this code. Here's the question.
I am analyzing a method that calls about 45 other methods that calls other methods. I need to find out all calls that ends up with a specific package from this specific method. How could I do this?
An option I have is to to use "call hierarchy" and drill down one method at a time (but there is no filter option as I can see to just see methods from one given package).
Actually you can do filtering when using the call hierarchy (CTRL - ALT - H). On the newly opened pane, there is a drop-down list with the name "Scope:". Here you can add a new scope where you can include/exclude filter not only on packages but also on classes or to search given a certain regex.
I checked this on the latest Intellij version (14.1.5).
I am working on a program, which is supposed to have "Modules" which people can make their own code from an API, and they can then add one of their Modules, let's say it's called ModuleNicerText, they add it to the MyProgram\Modules folder as a .java class (the source), and the class implements Module.
The Module class has one method (well, it has more but for the sake of this post I'll say one), called onUpdate(), and I want to be able to somehow import that class to my code, and then run the .onUpdate() whenever I need to, I hope I explained it well enough, if I haven't then here is another example:
I have an interface, named Module
this is the body of Module:
public interface Module {
void onUpdate();
}
Now, I have my main class named MyProgram, and in that class I have this method:
public void onUpdate(){
for (Module module : modules){
module.onUpdate();
}
}
I use this kind of system, so I can easily add or remove components without having to mess with a bunch of stuff, if it is all crowded in one class/method.
Now, there is a directory that gets created when the program is run which is MyProgram\Modules and anyone who wants can add a .java file which extends the Module interface there.
I want to be able to look through the .java files in that directory and be able to call the .onUpdate() method for them, so that my users can have as much customization as they possibly can!
Any help at all is very much appreciated, and I thank you in advance for taking your time to read this enormous wall of text :)
There is a good article (a little old, but great explanation).
It provides detailed information about how to use the Proxy Pattern through UpToDate file check.
By the time you keep the same methods inside your interface, and change only implementation of it, you can make use of this technique only in classes which implements the interface.
Check it out: Dynamic Java code to your Application
You can use Java Simple Plugin Framework. It does something similiar to what you want and is ready to use.
I'm reading Thinking in Java and it's frustrating to declare each class in a separate window in Eclipse, as the examples often contain 6-7 very simple classes.
I can just make a new class file, make one class public in this class file and the others with default access, but I don't know what should be the class' name I created. For example, I do the following:
New -> Class -> and then I must choose a class name, let's say it's Dog.
Now, in this file, I have this:
public class Dog {
}
class Cat {
}
But since I have two classes, it's a little weird to have this class file (I don't know if it's the right word here?) to be named Dog in Eclipse (The name in the src folder).
Is there a better way to declare multiple classes in the same window(?) in Eclipse?
A java file can have at most only one public class into it. And the name of that file should be same as of that public class.
I would say the frustration are not genuine because:
This is the how Java is designed and makes all sense to define each
class in a separate file. (Unless you want to write your own compiler)
You may want to use some shortcuts e.g.
Cntrl + Shift + R` to search a class
Alt + Shift + R to rename
You can update Eclipse to use shortcut for switching within classes.
What you're doing isn't going to compile. Each top level java class must be declared in a file with the same name. It will give you an error "Cat must be declared in its own file" or something like that. If you really want to, you can put the Cat class inside of the Dog class, which is called an inner class. However since they aren't related classes you shouldn't do that. Just declare each one in its own file.
Keep each class in it's own position. If your class is small and data can be exposed you can consider using nested (inner) class.
By the way, in Eclipse you can show multiple class at same time. Just drag you file title to some place.
To actually answer your question, rather than leave a bunch of comments stating why you shouldn't (which you seem to understand already), no. There isn't really a better way to do what you want. I don't know if it will compile or not (I seem to recall seeing that in the past in Java 5), but KyleM seems to think not so we'll go with that.
Short answer: no, there is not a better way to declare multiple classes in the same file.
(I don't want to suggest inner classes because that is kind of complicated for someone just starting java, as your post suggests).
Don't mix Eclipse window with files, you can understand a .java file as a container for a java class. It's the standard way and it would help you to have a more clear project when it becomes bigger.
You can have more information about this here
If you want 2 classes in the screen you can split the eclipse editor window by dragging the opened tab file and drop it on the tabs zone.
Unfortunately you do have to do this the long way, as everyone else has suggested / insisted. If the problem is a matter of clicking around through tabs, though, eclipse does allow you to drag tabs into new windows on the screen, which lets you view potentially all of them at once.
You also end up with an "overview" of the classes in the file explorer on the left of the screen, if that's more along the lines of what you're looking for.
Good luck (:
Is there a way to hook into the Eclipse compiler to specify custom class reading/resolving/loading logic while a Java source file is being compiled? I'm not sure what the correct term is, but essentially the compile-time equivalent of "class loading" that happens at run-time.
For example, say I have the Java source:
package foo;
import bar.Bar;
public final class Foo {
// getQux() returns type: qux.Qux
private final Bar bar = baz.Baz.getQux().getBar();
[...]
}
The compiler should request that 3 classes are read while compiling the source file foo/Foo.java:
bar.Bar - It is specified as an import.
baz.Baz - It is used in its fully qualified form (... = baz.Baz.getQux()...).
qux.Qux - It is an "indirect" dependency (it is returned by the call to baz.Baz.getQux(), which in turn is used to access a bar.Bar through the call to its getBar() method).
I'd like to be able intercept each of these "class requests" so that I can provide custom logic to obtain the class in question (perhaps it lives in a database, perhaps it it served up by some server somewhere, etc).
Also, I'd like it if no attempt was made to compile any of the source files in the Eclipse project until they are explicitly opened by the user. So in the example above, the 3 class requests (bar.Bar, baz.Baz, qux.Qux) aren't made until the user actually opens the source file foo/Foo.java. Ideally the list of source files in the project needn't be actual files on the filesystem (perhaps they too live in a database, etc) and a compile attempt is made only when a user opens/loads a source file.
I realize that, if possible, this has some drawbacks. For example, if I edit source file foo/Foo.java to make the class "package private", this will silently break any class that depends on foo.Foo until a "full" compile is done of the project. For now, that is fine for my purposes (there are things that I can do later to solve this).
Any ideas/suggestions?
Thank you!
Probably not, this would fall under the Java build path part of the JDT and I don't think it has that level of customization. There does not appear to be a documented extension point for this. To get a definitive answer you would need to look at the source. You could probably add this capability and it would mean that your would need to use an alternate version of the JDT, which might be difficult or impossible.
I often refactor code first by creating an inner class inside the class I'm working on--When I'm done, I move the entire thing into a new class file. This makes refactoring code into the new class extremely easy because A) I'm only dealing with a single file, and B) I don't create new files until I have a pretty good idea of the name/names (Sometimes it ends up as more than one class).
Is there any way Eclipse can help me with the final move? I should just be able to tell it what package I want the class in, it can figure out the filename from the class name and the directory from the package.
This seems like a trivial refactor and really obvious, but I can't figure out the keystrokes/gestures/whatever to make it happen. I've tried dragging, menus, context menus, and browsing through the keyboard shortcuts.
Anyone know this one?
[edit] These are already "Top Level" classes in this file, not inner classes, and "Move" doesn't seem to want to create a new class for me. This is the hard way that I usually do it--involves going out, creating an empty class, coming back and moving. I would like to do the whole thing in a single step.
I'm sorry I gave the wrong answer before. I rechecked, and it didn't do quite want you want. I did find a solution for you though, again, in 3.4.
Highlight the class, do a copy CTRL-C or cut CTRL-X, click on the package you want the class do go into, and do a paste, CTRL-V. Eclipse will auto generate the class for you.
Convert Member Type to Top Level doesn't quite work. Doing that will create a field of the outer class and generate a constructor that takes the outer class as a parameter.
In Eclipse 3.6, you can do: Refactor -> Move type to new file
Right-click the class name (in the source code) and choose Refactor -> Convert Member Type to Top Level. It doesn't let you choose the package, though.
For IntelliJ IDEA / Android Studio:
Refactor -> Move -> Move inner class MyInnerClass to upper level
Can be done in 2 refactorings :
Convert Member type to top level
Move