diff --git a/zero-framework.el b/zero-framework.el
index 60cb33c7e6b12e8e2fa1ab9b7375c621e2f3e7fa..e198262bc06f0c219c6433fe20a37e173e0234e9 100644
--- a/zero-framework.el
+++ b/zero-framework.el
@@ -191,7 +191,13 @@ if t, `zero-debug' will output debug msg in *zero-debug* buffer")
 							 zero-candidates))))
     (zero-panel-show-candidates
      (funcall zero-get-preedit-str-for-panel-func)
-     (length candidates-on-page) candidates-on-page)
+     (length candidates-on-page)
+     candidates-on-page
+     `(("in_emacs" t)
+       ("filename" ,(or (buffer-file-name) ""))
+       ("page_number" ,zero-current-page)
+       ("has_next_page" ,(or (> (length (or candidates zero-candidates)) (* zero-candidates-per-page (1+ zero-current-page))) (< zero-fetch-size (* zero-candidates-per-page (+ 2 zero-current-page)))))
+       ("has_previous_page" ,(> zero-current-page 0))))
     (zero-debug "candidates:\n  %s\n  " (s-join "\n  " candidates-on-page))
     (destructuring-bind (x y) (zero-get-point-position)
       (zero-panel-move x y))))
@@ -202,7 +208,7 @@ if t, `zero-debug' will output debug msg in *zero-debug* buffer")
   (unless (functionp zero-build-candidates-func)
     (signal 'wrong-type-argument (list 'functionp zero-build-candidates-func)))
   (prog1 (funcall zero-build-candidates-func preedit-str fetch-size)
-    (setq zero-fetch-size fetch-size)))
+    (setq zero-fetch-size (max fetch-size (length zero-candidates)))))
 
 (defun zero-build-candidates-complete (candidates)
   "called when `zero-build-candidates-async' returns"
@@ -300,7 +306,8 @@ return ch's Chinese punctuation if ch is converted. return nil otherwise"
 		 new-fetch-size
 		 (lambda (candidates)
 		   (zero-build-candidates-complete candidates)
-		   (setq zero-fetch-size new-fetch-size)
+		   (setq zero-fetch-size (max new-fetch-size
+					      (length candidates)))
 		   (zero-just-page-down)))
       (zero-just-page-down))))
 
diff --git a/zero-panel.el b/zero-panel.el
index 741e060a92fe7cf7dc6116524b2f7f1f364ecfdf..abb007bf1a1d597fd4d5d87aecd42a7947acfe77 100644
--- a/zero-panel.el
+++ b/zero-panel.el
@@ -19,11 +19,45 @@
 (defun zero-panel-async-call (method _handler &rest args)
   "call Method on zero-panel service asynchronously. This is a wrapper around `dbus-call-method-asynchronously'"
   (apply 'dbus-call-method-asynchronously
-	 :session "com.emacsos.zero.Panel"
-	 "/com/emacsos/zero/Panel"
-	 "com.emacsos.zero.Panel"
+	 :session
+	 "com.emacsos.zero.Panel1"	; well known name
+	 "/com/emacsos/zero/Panel1"	; object path
+	 "com.emacsos.zero.Panel1.PanelInterface" ; interface name
 	 method nil :timeout 500 args))
 
+;;=========================
+;; public utility function
+;;=========================
+
+(defun zero-alist-to-asv (hints)
+  "convert lisp alist to dbus a{sv} data structure.
+alist should be of form '((k1 [v1type] v1) (k2 [v2type] v2)).
+
+For example,
+(zero-alist-to-asv
+  '((\"name\" \"foo\")
+    (\"timeout\" :int32 10)))
+=>
+'(:array
+  (:dict-entry \"name\" (:variant \"foo\"))
+  (:dict-entry \"timeout\" (:variant :int32 10)))
+"
+  (if (null hints)
+      '(:array :signature "{sv}")
+    (let ((result '(:array)))
+      (dolist (item hints)
+	(push (list :dict-entry (car item) (cons :variant (cdr item))) result))
+      (reverse result))))
+
+(ert-deftest zero-alist-to-asv ()
+  (should (equal (zero-alist-to-asv nil) '(:array :signature "{sv}")))
+  (should (equal (zero-alist-to-asv
+		  '(("name" "foo")
+		    ("timeout" :int32 10)))
+		 '(:array
+		   (:dict-entry "name" (:variant "foo"))
+		   (:dict-entry "timeout" (:variant :int32 10))))))
+
 ;;============
 ;; public API
 ;;============
@@ -33,12 +67,13 @@
 (x, y) are coordinates, (0, 0) is at screen top left corner"
   (zero-panel-async-call "Move" nil :int32 x :int32 y))
 
-(defun zero-panel-show-candidates (preedit_str candidate_length candidates)
+(defun zero-panel-show-candidates (preedit_str candidate_length candidates &optional hints)
   "show candidates"
   (zero-panel-async-call "ShowCandidates" nil
 			 :string preedit_str
 			 :int32 candidate_length
-			 (or candidates '(:array))))
+			 (or candidates '(:array))
+			 (zero-alist-to-asv hints)))
 
 (defun zero-panel-show ()
   "show panel"
@@ -50,6 +85,7 @@
 
 (defun zero-panel-quit ()
   "quit panel application"
+  (interactive)
   (zero-panel-async-call "Quit" nil))
 
 (provide 'zero-panel)
diff --git a/zero-pinyin.el b/zero-pinyin.el
index 72b128e6544bd404aeb0a667814c79804124ab57..ba817eed8909d3290551f6b5dc9e205ac5b4ba5e 100644
--- a/zero-pinyin.el
+++ b/zero-pinyin.el
@@ -47,10 +47,10 @@
   (if zero-pinyin--build-candidates-use-test-data
       (progn
 	(zero-pinyin-build-candidates-test preedit-str)
-	(setq zero-fetch-size fetch-size))
+	(setq zero-fetch-size (max fetch-size (length zero-candidates))))
     (zero-debug "zero-pinyin building candidate list synchronously\n")
     (let ((result (zero-pinyin-service-get-candidates preedit-str fetch-size)))
-      (setq zero-fetch-size fetch-size)
+      (setq zero-fetch-size (max fetch-size (length (first result))))
       (setq zero-pinyin-used-preedit-str-lengths (second result))
       (first result))))
 
@@ -62,7 +62,7 @@
    fetch-size
    (lambda (candidates matched_preedit_str_lengths)
      (setq zero-pinyin-used-preedit-str-lengths matched_preedit_str_lengths)
-     (setq zero-fetch-size fetch-size)
+     (setq zero-fetch-size (max fetch-size (length candidates)))
      ;; Note: with dynamic binding, this command result in (void-variable
      ;; complete-func) error.
      (funcall complete-func candidates))))