Add limitPath option

Author: Shougo

denops/ddu/base/source.ts

@@ -80,6 +80,7 @@ export function defaultSourceOptions(): SourceOptions {
     converters: [],
     defaultAction: "",
     ignoreCase: false,
+    limitPath: "",
     matcherKey: "word",
     matchers: [],
     maxItems: 10000,

denops/ddu/ddu.ts

@@ -1010,21 +1010,32 @@ export class Ddu {
     }
 
     // Check path is changed by action
-    if (itemAction.sourceOptions.path !== prevPath) {
+    const limitPath = itemAction.sourceOptions.limitPath;
+    const newPath = itemAction.sourceOptions.path;
+    if (
+      newPath !== prevPath && (
+        limitPath.length === 0 ||
+        treePath2Filename(newPath) === treePath2Filename(limitPath) ||
+        isParentPath(
+          convertTreePath(limitPath),
+          convertTreePath(newPath),
+        )
+      )
+    ) {
       itemAction.userSource = convertUserString(itemAction.userSource);
       // Overwrite current path
       if (!itemAction.userSource.options) {
         itemAction.userSource.options = {};
       }
-      itemAction.userSource.options.path = itemAction.sourceOptions.path;
+      itemAction.userSource.options.path = newPath;
       if (this.#context.path.length > 0) {
         this.#context.pathHistories.push(this.#context.path);
       }
 
       // Overwrite userSource
       this.#options.sources[itemAction.sourceIndex] = itemAction.userSource;
 
-      this.#context.path = itemAction.sourceOptions.path;
+      this.#context.path = newPath;
 
       // Clear input when path is changed
       await this.setInput(denops, "");

denops/ddu/types.ts

@@ -122,6 +122,7 @@ export type SourceOptions = {
   converters: UserFilter[];
   defaultAction: string;
   ignoreCase: boolean;
+  limitPath: TreePath;
   matcherKey: string;
   matchers: UserFilter[];
   maxItems: number;

doc/ddu.txt

@@ -861,6 +861,15 @@ ignoreCase		(boolean)
 
 		Default: v:false
 
+                                                 *ddu-source-option-limitPath*
+limitPath		(string | string[])
+		Specify limit path when current path is changed by actions.
+		The path must be under the limit path.
+		NOTE: You can represents a path by two way like below.
+			"/aa/bb/cc" (string)
+			["/", "aa", "bb", "cc"] (string[])
+		NOTE: It must be full path.
+
                                                 *ddu-source-option-matcherKey*
 matcherKey		(string)
 		Matcher compare key for items.