Add public top level types to cache in java-imports-scan-file

Add new function java-imports-list-top-level and use it in
java-imports-scan-file to add public top level types to list
of classes to add to cache.

Useful when adding new types or working with a new project,
save having to specify the package on first import.
Only works if java-imports-scan-file runs after type is declared
in file so for new files it might be worth adding
(java-imports-scan-file) to define-auto-insert for example.

No kotlin-mode support yet, haven't figured out a good way
to do a "negative" match as "public" modifier is the default
in kotlin. Also the primary constructor syntax is tricky to include
and the regex is already rather horrible.

Author: thejk

java-imports.el

@@ -183,7 +183,8 @@ overwrites any existing cache entries for the file."
   (interactive)
   (when (member major-mode '(java-mode kotlin-mode))
     (let* ((cache (pcache-repository java-imports-cache-name)))
-      (dolist (import (java-imports-list-imports))
+      (dolist (import (append (java-imports-list-imports)
+                              (java-imports-list-top-levels)))
         (let ((pkg-class-list (java-imports-get-package-and-class import)))
           (when pkg-class-list
             (let* ((pkg (car pkg-class-list))
@@ -204,6 +205,25 @@ Java-mode or Kotlin-mode buffer"
    (cl-remove-if-not (lambda (str) (s-matches? "import[ \t]+.+?[ \t]*;?" str))
                      (s-lines (buffer-string)))))
 
+;;;###autoload
+(defun java-imports-list-top-levels ()
+  "Return a list of all public top-level type declarations in
+the current Java-mode buffer"
+  (interactive)
+  (let* ((package-match
+          (s-match "^package[ \t]+\\\(.+?\\\);?$" (buffer-string)))
+         ;; public is optional to always match the top-level entry and
+         ;; not the first public one (which might be a inner entry).
+         (identifier-match
+          (s-match "\\\(\\\<public[ \t\n]+\\\)?.*?\\\<\\\(?:class\\\|enum\\\|@?interface\\\)[ \t\n]+\\\([^. \t\n<]+\\\).*?[ \t\n]+{" (buffer-string))))
+    (when (and identifier-match
+             (cl-second identifier-match))
+        (let ((identifier (cl-third identifier-match)))
+          (cons (if package-match
+                    (concat (cl-second package-match) "." identifier)
+                  identifier)
+                nil)))))
+
 ;;;###autoload
 (defun java-imports-add-import-with-package (class-name package)
   "Add an import for the class for the name and package. Uses no caching."

test/java-imports-test.el

@@ -120,6 +120,100 @@
       (java-imports-list-imports)
       '("org.Thing" "java.util.List" "java.util.ArrayList")))))
 
+(ert-deftest t-list-top-levels ()
+  (with-temp-buffer
+    (insert "package mypackage;\n")
+    (insert "\n")
+    (insert "import org.Thing;\n")
+    (insert "\n")
+    (insert "import java.util.List;\n")
+    (insert "import java.util.ArrayList;\n")
+    (insert "\n")
+    (insert "public class Foo {}")
+    (should
+     (equal
+      (java-imports-list-top-levels)
+      '("mypackage.Foo"))))
+
+  (with-temp-buffer
+    (insert "public class Foo {}")
+    (should
+     (equal
+      (java-imports-list-top-levels)
+      '("Foo"))))
+
+  (with-temp-buffer
+    (insert "public abstract class Foo {}")
+    (should
+     (equal
+      (java-imports-list-top-levels)
+      '("Foo"))))
+
+  (with-temp-buffer
+    (insert "public class Foo extends Bar {}")
+    (should
+     (equal
+      (java-imports-list-top-levels)
+      '("Foo"))))
+
+  (with-temp-buffer
+    (insert "public class Foo implements Bar {}")
+    (should
+     (equal
+      (java-imports-list-top-levels)
+      '("Foo"))))
+
+  (with-temp-buffer
+    (insert "public class Foo<T> {}")
+    (should
+     (equal
+      (java-imports-list-top-levels)
+      '("Foo"))))
+
+  (with-temp-buffer
+    (insert "package mypackage;\n")
+    (insert "\n")
+    (insert "class Foo {\n")
+    (insert "public static class Bar {}\n")
+    (insert "}\n")
+    (should
+     (equal
+      (java-imports-list-top-levels)
+      '())))
+
+  (with-temp-buffer
+    (should
+     (equal
+      (java-imports-list-top-levels)
+      '())))
+
+  (with-temp-buffer
+    (insert "package mypackage;\n")
+    (insert "\n")
+    (insert "public\nenum\nFoo\n{}")
+    (should
+     (equal
+      (java-imports-list-top-levels)
+      '("mypackage.Foo"))))
+
+  (with-temp-buffer
+    (insert "package mypackage;\n")
+    (insert "\n")
+    (insert "public @interface Annotation {}")
+    (should
+     (equal
+      (java-imports-list-top-levels)
+      '("mypackage.Annotation"))))
+
+  (with-temp-buffer
+    (insert "package mypackage;\n")
+    (insert "\n")
+    (insert "public interface Foo {}")
+    (should
+     (equal
+      (java-imports-list-top-levels)
+      '("mypackage.Foo")))))
+
 (ert-deftest t-pkg-and-class-from-import ()
   (should
    (equal (java-imports-get-package-and-class "java.util.Map")
@@ -158,7 +252,11 @@
             (should
              (equal
               (pcache-get cache 'ArrayList)
-              "java.util"))))
+              "java.util"))
+            (should
+             (equal
+              (pcache-get cache 'Foo)
+              "mypackage"))))
       (pcache-destroy-repository java-imports-cache-name))))
 
 ;; End: