lang/java: fix java namespace resolution #1098

Now uses slightly more sophisticated namespace resolution when
populating the *.java file template.

modules/feature/file-templates/templates/java-mode/.yas-setup.el

@@ -1,11 +1,9 @@
 (defun yas-java-project-package ()
-  (if (eq major-mode 'java-mode)
-    (s-chop-suffix "." (s-replace "/" "." (f-dirname (f-relative (buffer-file-name)
-                                                                 (concat (narf/project-root) "/src/")))))
+  (or (and (eq major-mode 'java-mode)
+           (+java-current-package))
       ""))
 
 (defun yas-java-class-name ()
-  (if (eq major-mode 'java-mode)
-      (f-no-ext (f-base (buffer-file-name)))
+  (or (and (eq major-mode 'java-mode)
+           (+java-current-class))
       ""))
-

modules/lang/java/autoload.el

@@ -30,3 +30,42 @@
     (android-mode +1)
     (doom/set-build-command "./gradlew %s" "build.gradle")))
 
+;;;###autoload
+(defun +java-current-package ()
+  "Converts the current file's path into a namespace.
+
+For example: ~/some/project/src/net/lissner/game/MyClass.java
+Is converted to: net.lissner.game
+
+It does this by ignoring everything before the nearest package root (see
+`+java-project-package-roots' to control what this function considers a package
+root)."
+  (unless (eq major-mode 'java-mode)
+    (user-error "Not in a java-mode buffer"))
+  (let* ((project-root (file-truename (doom-project-root)))
+         (file-path (file-name-sans-extension
+                     (file-truename (or buffer-file-name
+                                        default-directory))))
+         (src-root (cl-loop for root in +java-project-package-roots
+                            if (and (stringp root)
+                                    (locate-dominating-file file-path root))
+                            return (file-name-directory (file-relative-name file-path (expand-file-name root it)))
+                            if (and (integerp root)
+                                    (> root 0)
+                                    (let* ((parts (split-string (file-relative-name file-path project-root) "/"))
+                                           (fixed-parts (reverse (nbutlast (reverse parts) root))))
+                                      (when fixed-parts
+                                        (string-join fixed-parts "/"))))
+                            return it)))
+    (when src-root
+      (string-remove-suffix "." (replace-regexp-in-string "/" "." src-root)))))
+
+;;;###autoload
+(defun +java-current-class ()
+  "Get the class name for the current file."
+  (unless (eq major-mode 'java-mode)
+    (user-error "Not in a java-mode buffer"))
+  (unless buffer-file-name
+    (user-error "This buffer has no filepath; cannot guess its class name"))
+  (or (file-name-sans-extension (file-name-base (buffer-file-name)))
+      "ClassName"))

modules/lang/java/config.el

@@ -1,5 +1,26 @@
 ;;; lang/java/config.el -*- lexical-binding: t; -*-
 
+(defvar +java-project-package-roots (list "java/" "test/" "main/" "src/" 1)
+  "A list of relative directories (strings) or depths (integer) used by
+`+java-current-package' to delimit the namespace from the current buffer's full
+file path. Each root is tried in sequence until one is found.
+
+If a directory is encountered in the file path, everything before it (including
+it) will be ignored when converting the path into a namespace.
+
+An integer depth is how many directories to pop off the start of the relative
+file path (relative to the project root). e.g.
+
+Say the absolute path is ~/some/project/src/java/net/lissner/game/MyClass.java
+The project root is ~/some/project
+If the depth is 1, the first directory in src/java/net/lissner/game/MyClass.java
+  is removed: java.net.lissner.game.
+If the depth is 2, the first two directories are removed: net.lissner.game.")
+
+
+;;
+;; java-mode
+
 (add-hook 'java-mode-hook #'rainbow-delimiters-mode)
 
 (cond ((featurep! +meghanada) (load! "+meghanada"))