any trick to combine 2 Item[] expressions to one expression for the purpose of use in a macro?

Question

V 8.04. This is in the context of Manipulate use only.

Here is a simple example of using an Item to place controls in different places in the UI using Manipulate

Manipulate[Plot[Sin[z], {z, -Pi, Pi}, ImageSize -> 100],
 Item[Control[{{x, 0, "x="}, 0, 10, 1,ImageSize->Tiny}],ControlPlacement->Left],
 Item[Control[{{y, 0, "y="}, 0, 10, 1,ImageSize->Tiny}],ControlPlacement->Right]
 ]

However, I am using Leonid's macro method (link here ) to help me build my UI controls, so I'd like to do something like

 Manipulate[Plot[Sin[z], {z, -Pi, Pi}],

 Evaluate@With[{im = ImageSize -> Tiny},

   Item[Control[{{x, 0, "x="}, 0, 10, 1, im}],ControlPlacement -> Left],
   Item[Control[{{y, 0, "y="}, 0, 10, 1, im}], ControlPlacement -> Right]

   ]    
 ]

The above does NOT work, because we no longer have ONE expression to make With happy, which has the syntax

 With[{x=x0}, expression ]

And in the above, the 2 Items are now not ONE expression, but 2.

This problem shows up only when I want to use Item to control placement. Otherwise, I would use Grid[] and combine my different things inside the Grid, and then the problem is solved.

But I can't of course use Item inside grid for purposes of making each Item locate in different place. The whole Grid has to be in one place.

I thought wrapping the 2 Items inside a Sequence[] might work but it does not.

question is: Any trick to combine the above 2 Items into ONE expression to make With happy?

Currently I solve this problem in my UI by simply breaking things into 2 separate Withs like this:

Manipulate[Plot[Sin[z], {z, -Pi, Pi}],

 Evaluate@With[{im = ImageSize -> Tiny},
   Item[Control[{{x, 0, "x="}, 0, 10, 1, im}], 
    ControlPlacement -> Left]
   ],

 Evaluate@With[{im = ImageSize -> Tiny},
   Item[Control[{{y, 0, "y="}, 0, 10, 1, im}], 
    ControlPlacement -> Right]
   ]

 ]

And it works fine.

But of course, in the above, I lose some of the benefits of using macro names to share among many control construction code.

update 12/26/11 8:37 PM

Here is an example, using one macro inside another. I think it is a Hold issue. The trick shown below is not working for this. Will try to figure it out: (In practice, I use 2 levels macros, as I define some macros at one level, and use them to build a higher level macros in the second level. here I only show very simple example of what I mean)

Manipulate[Plot[Sin[z], {z, -Pi, Pi}],

 Evaluate@With[{im = ImageSize -> Tiny},

   Evaluate@With[{},

     ## &[
      Item[Control[{{x, 0, "x="}, 0, 10, 1, im}], ControlPlacement -> Left],
      Item[Control[{{y, 0, "y="}, 0, 10, 1, im}], ControlPlacement -> Right]
      ]

     ]
   ]
 ]

I am almost sure I need a HoldAll thing to insert in the right place to sort this one out. Will try to figure it out and report here. Coffee is almost done ;)

update 9 pm

Ok, MrWizard showed me the problem with above. I should not have an Evaluate on the inner macros. I forgot about this. Here it is now, it works fine:

Manipulate[Plot[Sin[z], {z, -Pi, Pi}],

 Evaluate@With[{},

   With[{},
    ## &[
     Item[Control[{{x, 0, "x="}, 0, 10, 1}], ControlPlacement -> Left], 
     Item[Control[{{y, 0, "y="}, 0, 10, 1}], ControlPlacement -> Right]
     ]

    ](*close second With*)
   ](*close first With*)

 ](*close Manipulate*)

Thanks for the answer, both very useful.

Answer 1

Use Sequence, perhaps like:

Manipulate[
   Plot[Sin[z], {z, -Pi, Pi}], 
   Evaluate@With[{im = ImageSize -> Tiny}, 
      Sequence @@ {
         Item[Control[{{x, 0, "x="}, 0, 10, 1, im}], ControlPlacement -> Left], 
         Item[Control[{{y, 0, "y="}, 0, 10, 1, im}], ControlPlacement -> Right]
         }
      ]
   ]

Edit

Same approach, but with a different macro (warning, this way leads to madness...)

Manipulate[
   Plot[Sin[z], {z, -Pi, Pi}], 
   Evaluate @ With[{
      control = Function[{var, name, place}, 
         Item[Control[{{var, 0, name <> "="}, 0, 10, 1, ImageSize -> Tiny}],  ControlPlacement -> place], 
         HoldAll
         ]}, 
   Sequence @@ {control[x, "x", Left], control[y, "y", Right]}
   ]]