IntelliJ IDEA plugin development: how to modify the Psi tree? - intellij-idea

I would like to know what the "proper" way to create new PsiElement instances and add them to the Psi tree is.
I looked at the tutorial provided by JetBrains (http://www.jetbrains.org/intellij/sdk/docs/tutorials/custom_language_support/quick_fix.html). The method they use there seems suitable for the simple properties language they introduce but I don't think it's the way to go with a more complicated syntax, where I want to add a child PsiElement that cannot appear at the root level of a PsiFile.
What would be best for me is to be able to parse a text snippet as an element and have it added to the tree. I tried to do something like this:
myLangTopElement.getNode().addLeaf(MyLangTypes.CHILD_EXPRESSION, "fish = '42'", null);
It actually seems to work - the text is added to the document and a node is created but when I edit the text inside the quotes in the editor - some exceptions are thrown...
What am I doing wrong? What is the correct way to add new elements?

PSI is complicated :(. A usual way is to create a whole file from a carefully prepared text (PsiFileFactory#createFileFromText), extract from it the PSI element you need to add into the tree, and then call PsiElement#add/addBefore/addAfter passing the extracted element as an argument. If your PSI element is a wrapper over AST (i.e. AstDelegatePsiElement), its add* methods already do the magic necessary for the exceptions not to be thrown.
You can study GrCreateSubclassAction#startTemplate from the IDEA CE source for an example, and the implementation of createCodeReferenceElementFromText that it calls.

Related

IntelliJ type error when using Geb static content DSL with parameters

Whenever I use a static-content defined closure that takes parameters, IntelliJ will complain that the types do not match (even if I specify the type inside the closure).
For example, if I use this static content block:
static content = {
myModule { $('myModule').module(CustomModule) }
namedModule { String name -> $(".$name").module(CustomModule) }
}
Both of the above items can be used successfully in my tests, but if I was to use 'namedModule' in one of my tests as follows:
page.namedModule("moduleName").moduleMethod("blah blah blah")
IntelliJ will highlight the parameter "moduleName" in yellow with the error:
'namedModule' cannot be applied to '(java.lang.String)'
We are trying to refactor our tests in a way that means you can navigate through the code easier (e.g. avoiding any Geb/Groovy 'magic' that IntelliJ can't resolve), and this is one of the last remaining issues preventing this from being possible.
This is a known limitation to Geb support in IntelliJ. IntelliJ always treats content definitions as properties of pages and modules even though they can be parametrised. Given that Geb support in IntelliJ is open sourced we could probably add support for this.
In the mean time, as a workaround you can use methods for parametrised content instead of content definitions and IntelliJ will be able to understand these and be able to refactor them:
void namedModule(String name) {
$(".$name").module(CustomModule)
}
There are some caveats, though:
you will loose ability to use content definition options; if you need to use these for a content definition then I suggest creating a parameterised "private" content definition (for example with a _ at the beginning of the name) that you will only ever access from within the page or module
RequiredPageContentNotPresent will not be thrown even if the returned content is empty; to work around it you will either need to add manual verification to each such method or use a strategy outlined in the first bullet point with using "private" content definitions

How do I go to the nth method of the eclipse editor's file?

I need to write a function goToNthMethod(int n) to let the user jump to the nth method in the file being edited.
Ideas so far:
I imagine the ContentOutline reads its tree from some sort of IContentSource (made up) or something, if I can read from the same source, that would probably be cleaner. Does something like this exist?
Read the contents of the outline view, and maybe simulate a double click on one of the Outline view's entries. This is as far as I got before I realized I was in over my head:
IWorkbenchPage page = PlatformUI.getWorkbench().getActiveWorkbenchWindow().getActivePage();
IViewPart part = page.findView("org.eclipse.ui.views.ContentOutline");
ContentOutline outline = (ContentOutline)part;
PageBook pageBook = outline.book; // Doesn't work, book is private
Tree root = pageBook.currentPage; // Doesn't work, currentPage is private
String label = root.getLabel(); // Nothing like getLabel exists
Read the entire IDocument's contents, parse the java source code within, get the offsets in the file, and feed that to the editor.selectAndReveal method. However, parsing the java source code within is a massive task, so this approach probably won't work.
Use outline.getCurrentPage(), which is a JavaOutlinePage, but I can't seem to import that class. I'm guessing I need to pull in the entire JDT project to do that. This approach also means I'm tied to a specific language, when I want my goToNthMethod to be language agnostic.
Any ideas on how I can jump to the nth method? Thanks!
Some context: I'm integrating Dragon NaturallySpeaking with eclipse to be able to program with my voice. It's working well so far, but one tedious part is navigating around the file, which would be made easier if I could say "go to 8th method". In fact, just "go to 8th entry" to just go to the 8th row in the outline view would be sufficient. Any other ideas appreciated!

how can I define strings in resource file and use them in qml

I want to define a number of xml formatted strings in resource file and use the strings in qml code. Is it possible? How to do it? I would be really appreciated any example.
As I know there is no way to store strings in resource file. But you still do that in another way.
First way: create language file with qt translation tool. As bonus you can store string in several languages.
Using in QML is very easy:
Text {
text: qsTr("myTextId");
}
See that link for more info.
Second way: store each string in different resource file.
But in this case you need to extend QML with C++ plugin to get ability to read files.
See that link for more info.

switching between languages in same file

I recently attended a user group meeting where the IntelliJ representative was demonstrating version 13.
He demonstrated how to switch the code completion view of a file. I do not exactly remember what the file extension of this particular file was, probably java.
The concept was that if the file is html with embedded javascript he could then switch the code completion between html and javascript with a shortcut. If he says treat the file as html then all code in file was treated for code completion purposes as html, and vice versa for javascript.
Does anybody know what shortcut he might have been using to enable the language switch?
Sounds like you may be referring to the IntelliLang feature. IntelliJ IDEA can be aware of other languages embedded within a file.
A simple example is in an HTML file that has CSS and JavaScript.
Notice when I am inside the HTML markup:
or inside an HTML element:
The code complete shows HTML completion options. However, when I am inside the style attribute, I get CSS code completion:
I also get CSS code completion if I am inside a <style> element. So even though I am in an HTML file, I see CSS code completion because of my location.
Same case with JavaScript. When I invoke code completion inside a <script> element, I get JavaScript completion, even though I am in an HTML file.
Anytime IntelliJ IDEA can determine that another embedded language is present, it provides, via IntelliLang, the appropriate syntax highlighting, error highlighting, and code completion. The same holds true for Java. Notice here that IDEA knows the method I am competing takes an SQL statement and therefore highlights the String value using SQL highlighting, and provides SQL code completion:
So even though I am in a .java file, I get SQL code completion. The reason is that IntelliLang comes pre-configured knowing the embedded language of some methods. You modify them, or add more, in File > Settings > [Project Settings] > Language Injections.
In addition, you can use an annotation to tell IntelliJ IDEA (as well as developers looking at the code) that a String must be valid in a particular language. For example, I can annotate a String field, variable, or parameter, to indicate it must be valid HTML:
Notice I get HTML syntax highlighting, HTML code completions, and the CSS color shows in the left gutter. If I annotate a method parameter, then any time I call the method, I get the appropriate syntax highlighting, code completion, and error/warning highlighting:
The #Language annotation is inside the annotations.jar that is contained in the redist directory inside the IntelliJ IDEA installation directory. It is also available in maven central, or IDEA will offer to attach it as a Library if you use the annotation without it being attached.
IntelliLang and the #Language annotation supports a large number of languages. Just use code Completion inside the quotes after typing #Language("") to see a list. (Inline search works in the list as well.) One of the most useful is Regexp. For example, if you have a method that expects the string passed in to be a valid Regular Expression, annotating it as such will give anyone that calls it Regex code completion and error highlighting if they are passing in an invalid Regex pattern. Even for developers using other IDEs it is useful as a form of documentation.
As for a shortcut to change the the language on the fly for code completion, the only thing I can think that you might be referring to is the "Inject Language" intention. If I am entering a String value, and I bring up the quick-fix/intention menu via Alt+Enter, I am given an option to inject a language:
If I select that, IntelliJ IDEA will ask me what language I want to use:
After making my selection, IntelliJ IDEA will give me temporary language injection (including code completion) for the selected language.
It also gives me an option to add the #Language annotation for permanent injection.
To the best of my knowledge (as a 10 year IntelliJ IDEA user) that is the only way to switch code completion language types. So hopefully that is what you are looking for. To me, IntelliLang is one of the coolest features in IntelliJ. (It actually started as a third party plug-in and JetBrains then absorbed it into the product.)

How can I add custom sorting to commonNavigator in an Eclipse plug-in?

I am trying to create an Eclipse plugin that contains a commonNavigator extension.
I can't figure out how to override the default alphabetical sorting. I want element type A to be before all the elements of type B. When I return the children of an element, I return them in the order that I want them, but they are displayed sorted.
I've seen a few really old tutorials that talk about a customSorter, but I am having trouble implementing it. This tutorial says to create it through plugin.xml, but when I try, I can only create a generic element, not a customSorter. I think it must be outdated because it didn't work even with the code that came with the tutorial.
Any tips?