fix #107, Menu flickers when no custom tool is defined

src/ce_interfaces.pas

@@ -172,6 +172,8 @@ type
     procedure menuDeclare(item: TMenuItem);
     // item is the mainMenu entry declared previously. the sub items can be updated, deleted.
     procedure menuUpdate(item: TMenuItem);
+    // indicates if menuDeclare should be called.
+    function menuHasItems: boolean;
   end;
   (**
    * An implementer collects and updates its observers menus.

src/ce_main.pas

@@ -1894,31 +1894,42 @@ procedure TCEMainForm.updateMainMenuProviders;
 var
   i, j: Integer;
   itm: TMenuItem;
-  doneUpdate: boolean = false;
+  hasItems: boolean;
+  doneUpdate: boolean;
 begin
   if not assigned(mainMenu.Images) then
     exit;
   for j := 0 to fMainMenuSubj.observersCount-1 do
   begin
+    doneUpdate := false;
+    hasItems := (fMainMenuSubj.observers[j] as ICEMainMenuProvider).menuHasItems;
     // try to update existing entry.
-    for i := 0 to mainMenu.Items.Count-1 do
+    for i := mainMenu.Items.Count-1 downto 0 do
       if PtrInt(fMainMenuSubj.observers[j]) = mainMenu.Items[i].Tag then
+    begin
+      if not hasItems then
+      begin
+        doneUpdate:=true;
+        mainMenu.Items[i].Clear;
+        mainMenu.Items.Delete(i);
+        break;
+      end
+      else
       begin
         (fMainMenuSubj.observers[j] as ICEMainMenuProvider).menuUpdate(mainMenu.Items[i]);
         doneUpdate := true;
         break;
       end;
-    if doneUpdate then
+    end;
+    if doneUpdate or not hasItems then
       continue;
     // otherwise propose to create a new entry
     itm := TMenuItem.Create(Self);
     mainMenu.Items.Add(itm);
     (fMainMenuSubj.observers[j] as ICEMainMenuProvider).menuDeclare(itm);
     itm.Tag:= PtrInt(fMainMenuSubj.observers[j]);
-    case itm.Count > 0 of
-      true: ;
-      false: itm.Free;
-    end;
+    if itm.Count = 0 then
+      itm.Free;
   end;
 end;
 

src/ce_tools.pas

@@ -76,6 +76,7 @@ type
     //
     procedure menuDeclare(item: TMenuItem);
     procedure menuUpdate(item: TMenuItem);
+    function menuHasItems: boolean;
     procedure executeToolFromMenu(sender: TObject);
     //
     procedure docNew(document: TCESynMemo);
@@ -339,6 +340,11 @@ begin
       mnuitm.shortcut := colitm.shortcut;
   end;
 end;
+
+function TCETools.menuHasItems: boolean;
+begin
+  result := tools.Count <> 0;
+end;
 {$ENDREGION}
 
 {$REGION ICEEditableShortcut ---------------------------------------------------}