WE_Dockscreens.xml

<?xml version="1.0" encoding="utf-8"?>

<TranscendenceModule>

<Globals>
(block Nil
 (setq intComputeSellPrice (lambda (thisItem)
				 (if (objGetSellPrice gSource thisItem)
				   (itmGetActualPrice thisItem)
				  )
				))

 (setq intComputeBuyPrice (lambda (thisItem)
        (block (tempPrice)
         
         (setq tempPrice (objGetBuyPrice gSource thisItem))
         (if (and (not (itmIsDamaged thisItem)) (not (itmIsKnown thisItem)))
         (switch
                  (not tempPrice)
                    tempPrice
									(leq (subtract (itmGetLevel thisItem) (sysGetLevel)) 2)
										(setq tempPrice (divide (itmGetActualPrice thisItem) 1))
									(eq (subtract (itmGetLevel thisItem) (sysGetLevel)) 3)
										(setq tempPrice (divide (itmGetActualPrice thisItem) 2))
									(geq (subtract (itmGetLevel thisItem) (sysGetLevel)) 4)
										(setq tempPrice (divide (itmGetActualPrice thisItem) 10))
								))
				 tempPrice
				)))

)
</Globals>


	<DockScreen UNID="&dsExchangeSell;"
			name=				"=(if gTitle gTitle (objGetName gSource))"
			type=				"itemPicker"
			backgroundID=		"&rsItemListScreen;"
			nestedScreen=		"true"
			>

		<ListOptions
				dataFrom=	"player"
				list=		"*"
				>
			(switch
				(not gMargin)
					(scrSetListFilter gScreen intComputeBuyPrice)

				(isfunction gMargin)
					(scrSetListFilter gScreen gMargin)

				(scrSetListFilter gScreen "*")	
				)
		</ListOptions>

		<Panes>
			<Default
					desc=			"There are no items here.">

				<OnPaneInit>
					(block (thisItem)
						(setq thisItem (scrGetItem gScreen))
						(if thisItem
							(block (affordCount availCount currencyUsed desc priceText existingCount averageAppearing)
							
								(if (not gTitle)
									(setq gTitle (objGetName gSource 0x41))
									)

								; Set the currency

								(setq currencyUsed (objGetDefaultCurrency gSource))
								
								; Compute the cost of this item.
								; The cost is in the currency used by the station

								(switch
									; If gMargin is a function, then we call the function
									; to evaluate the price.

									(isfunction gMargin)
										(setq gCost (apply gMargin thisItem Nil))
										
									; Otherwise we let the station price the item
									
									(setq gCost (objGetBuyPrice gSource thisItem))
									)
									
								(if (not gCost) (setq gCost 0))

								(if (not (itmIsKnown thisItem))
								 (switch
									(leq (subtract (itmGetLevel thisItem) (sysGetLevel)) 2)
										(setq gCost (divide gCost 1))
									(eq (subtract (itmGetLevel thisItem) (sysGetLevel)) 3)
										(setq gCost (divide gCost 2))
									(geq (subtract (itmGetLevel thisItem) (sysGetLevel)) 4)
										(setq gCost (divide gCost 10))
								 )
									)

								; If the station already has lots of these, lower the price
								(setq existingCount (objHasItem gSource thisItem))
								(setq averageCount (itmGetAverageAppearing thisItem))
								(switch
									(not existingCount)
										Nil

									(geq existingCount (multiply averageCount 5))
										(setq gCost 0)

									(geq existingCount (multiply averageCount 4))
										(setq gCost (divide (multiply gCost 25) 100))

									(geq existingCount (multiply averageCount 3))
										(setq gCost (divide (multiply gCost 50) 100))

									(geq existingCount (multiply averageCount 2))
										(setq gCost (divide (multiply gCost 75) 100))
									)

								; Compute how many items are available
								(setq availCount (itmGetCount thisItem))

								; Compute how many items the station is willing to buy
								(if (gr gCost 0)
									(switch
										(not gMaxPrice)
											(block Nil
												(setq affordCount (divide (objGetBalance gSource) gCost))
												(if (gr affordCount availCount)
													(setq affordCount availCount)
													)
												)

										(gr gCost gMaxPrice)
											(setq affordCount 0)

										(setq affordCount availCount)
										)
									)

								(setq gMaxCount affordCount)

								; Set the price and description
								(setq priceText (cat "Unit offer: " (if (eq gCost 0) "N/A" (fmtCurrency currencyUsed gCost))))
								(if (gr availCount 1)
									(setq priceText (cat priceText " (" availCount " for " (fmtCurrency currencyUsed (multiply gCost availCount)) ")"))
									)

								(setq priceText (cat priceText "\nUnit mass: " (intMassString (itmGetMass thisItem))))
								(if (gr availCount 1)
									(setq priceText (cat priceText " (" availCount " at " (intMassString (multiply (itmGetMass thisItem) availCount)) ")"))
									)

								(setq priceText (cat priceText "\n\n"))

								(switch
									(eq gCost 0)
										(setq desc (cat gTitle " is not interested in buying " (itmGetName thisItem 0x02) "."))
									(eq affordCount 0)
										(setq desc (cat gTitle " cannot afford to buy " (itmGetName thisItem 0x04) "."))
									(eq availCount 1)
										(setq desc (cat priceText gTitle " offers " (fmtCurrency currencyUsed gCost) " for your " (itmGetName thisItem 0) "."))
									(eq affordCount 1)
										(setq desc (cat priceText gTitle " offers " (fmtCurrency currencyUsed gCost) " for a single " (itmGetName thisItem 0) "."))
									(ls affordCount availCount)
										(setq desc (cat priceText gTitle " offers " (fmtCurrency currencyUsed gCost) " for each " (itmGetName thisItem 0) " (up to a maximum of " affordCount ")."))
									(setq desc (cat priceText gTitle " offers " (fmtCurrency currencyUsed gCost) " for each " (itmGetName thisItem 0) "."))
									)

								(scrSetDesc gScreen desc)
								)
							
							; If there are no items, then set to 0
							(block Nil
								(setq gCost 0)
								(setq gMaxCount 0)
								)
							)

						; Enable/disable actions
						(scrEnableAction gScreen 0 (and (gr gCost 0) (gr gMaxCount 0)))
						)
				</OnPaneInit>

				<Actions>
					<Action name="Sell this item" default="1" key="S">
						(if (gr gCost 0)
							(if (gr gMaxCount 1)
								(scrShowPane gScreen "SellQuantity")
								(if (eq gMaxCount 1)
									(block Nil
										(intSellItems 1 gCost)
										(setq gResult (add gResult gCost))
										(scrShowPane gScreen "Default")
										)
									)
								)
							)
					</Action>

					<Action name="Done" cancel="1" key="D">
						(scrExitScreen gScreen)
					</Action>

				</Actions>

			</Default>

			<SellQuantity
					showCounter=	"true">

				<OnPaneInit>
					(block Nil
						(scrSetDesc gScreen (cat "How many items do you wish to sell at " (fmtCurrency (objGetDefaultCurrency gSource) gCost) " each?"))
						(scrSetCounter gScreen gMaxCount)
						)
				</OnPaneInit>

				<Actions>
					<Action name="Sell" default="1" key="S">
						(block (count)
							(setq count (scrGetCounter gScreen))
							(if (gr count gMaxCount)
								(scrSetCounter gScreen gMaxCount)
								(block Nil
									(intSellItems count gCost)
									(setq gResult (add gResult (multiply count gCost)))
									(scrShowPane gScreen "Default")
									)
								)
							)
					</Action>

					<Action name="Cancel" cancel="1" key="C">
						<ShowPane pane="Default"/>
					</Action>

				</Actions>

			</SellQuantity>
		</Panes>

	</DockScreen>

</TranscendenceModule>