Developer CD Series 1990: Discy Business

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Apple II Technical Notes _____________________________________________________________________________ Developer Technical Support Apple IIGS #3: Window Information Bar Use Revised by: Dan Oliver November 1988 Written by: Dan Oliver October 1986 This Technical Note details the use of a window's information bar, including a code sample which places a menu in an information bar. _____________________________________________________________________________ Apple IIGS window information bars are not as straightforward as other window features, and one reason for this is the small amount of space originally allocated for their processing. If you feel your application can benefit from the use of information bars, you can implement them, and this Technical Note explains how to do it and includes some suggestions for their use. The code samples below demonstrate how to place a menu bar in an information bar, but your use of information bars is not limited to those described here. Information Bar Initialization You can create an information bar in a window when you create the window by setting the following fields in the parameter list you pass to NewWindow: wFrame Set bit 4. wInfoHeight Set to the height of the information bar (should not exceed window height). wInfoDefProc Set to the address of the information bar definition procedure (see below). If you create a window as visible, the Window Manager will call your information bar definition procedure (InfoDefProc) before returning from NewWindow. If you have to create the contents of the information bar after the window, you will have a problem since the Window Manager will expect your InfoDefProc to draw things which do not yet exist. You can solve this problem by creating the window as invisible, creating the contents of the information bar, then showing the window. Another solution would be to detect, in the InfoDefProc, that the contents of the information bar do not yet exist. Below is an example of initializing a window's information bar to contain a menu bar. The three key fields of the parameter list which you pass to NewWindow are as follows: wFrame Set bit 4 = 1 and bit 5 = 0 for an invisible window; the other bits do not affect the information bar, so you can set them as you wish. wInfoHeight Assuming you are using a system menu bar and initializing it before the window, set to the height FixMenuBar returned when you created the system menu bar. If you would rather use an absolute value, which we do not advise, you could use 14 which should be about right for the current system font. wInfoDefProc Set to the address of the InfoDefProc, in this case draw_info. After you create the window, but before you show it, you can create the menu bar to place in the information bar. The code to create the menu bar might look like the following: window Direct page location that contains pointer to window's port. ; ; --- Create a menu bar -------------------------------------------------------------------- ; pha Space for result. pha pea $FFFF Set "use current port" flag. pea $FFFF _NewMenuBar Create a menu bar. pla Get returned menu bar handle. sta <menuBar Remember menu bar handle. pla sta <menuBar+2 ; ; ; --- Store menu bar's handle in the window's InfoRefCon ----------------------------------- ; pei <menuBar+2 Pass menu bar handle. pei <menuBar pei <window+2 Window to set refCon. pei <window _SetInfoRefCon Store menu bar handle in window's infoRefCon. ; ; ; --- Make the window's menu bar the current menu bar -------------------------------------- ; pei <menuBar+2 Pass menu bar handle. pei <menuBar _SetMenuBar Make new menu bar the current menu bar. ; ; ; --- Get the RECT of the window's information bar ----------------------------------------- ; pea tempRect|-16 Pass pointer of RECT. pea tempRect pei <window+2 Pass pointer of window. pei <window _GetRectInfo tempRect = interior RECT of window's Info Bar. ; --- Dereference menu bar handle ---------------------------------------------------------- ; ldy #2 lda [menuBar],y tay lda [menuBar] sta <menuBar Now menuBar is the pointer to the Menu Bar. sty <menuBar+2 ; ; ; --- Set size of menu bar ----------------------------------------------------------------- ; ; lda <tempRect+y1 dec a Overlap top side. ldy #CtlRect+y1 sta [menuBar],y ; lda <tempRect+x1 dec a Overlap left side. ldy #CtlRect+x1 sta [menuBar],y ; lda <rect+y2 inc a Overlap bottom side. ldy #CtlRect+y2 sta [menuBar],y ; ; ; --- Set flag to tell Menu Manager to draw menu in current port --------------------------- ; ldy #CtlOwner+2 Set high bit in CtlOwner. lda [menuBar],y ora #$8000 sta [menuBar],y ; ; ; --- Create the menus and add them to the window's menu bar ------------------------------- ; lda #4 loop pha Save index into menu list. tay Switch index to Y. ; pha Space for return value. pha lda menu_list+2,y Pass address of menu/item lines. pha lda menu_list,y pha _NewMenu ; Menu handle already on stack. pea 0 Insert menu list at front of list. _InsertMenu Add my menus to the system menu bar. ; pla sec sbc #4 bpl loop ; ; ; --- Initialize the size of the menu bar and menus ---------------------------------------- ; pha Space for returned bar height. _FixMenuBar Fix up positions in the menu bar. pla Discard height of menu bar. ; ; ; --- Restore the system menu bar as the current menu -------------------------------------- ; pea 0 Pass flag for system menu bar. pea 0 _SetMenuBar Make system menu bar current. The window's menu bar is now initialized, and you can make the window visible with a call to ShowWindow; the InfoDefProc will draw the menu bar. Information Bar Definition Procedure (InfoDefProc) The InfoDefProc is slightly misleading; it is only responsible for drawing the interior, above the background, of the information bar. The InfoDefProc is not responsible for defining the information bar, drawing the frame and background, testing for hits, or tracking the user. The InfoDefProc is located inside your application, and the Window Manager calls it whenever it needs to draw the part of the window frame that contains the information bar. Each window with an information bar can have its own InfoDefProc, or they can call share a common InfoDefProc. When the Window Manager calls your InfoDefProc, it sets the proper port, the Window Manager's port, and the proper state, an origin local to the window frame and clipped to any windows above. The direct page and data bank are not defined and should be considered unknown. The Window Manager passes your InfoDefProc the following information: o Pointer to the information bar's interior rectangle (less frame), local coordinates. o Value of the window's wInfoRefCon, set and used only by your application. o Pointer to the window's port (do not switch to this port for drawing). A window that has an information bar containing a menu bar (handle stored in the window's InfoRefCon) might have a InfoDefProc as follows: draw_info START ; theWindow equ 6 Offset to the information bar owner window. infoRefCon equ theWindow+4 Offset to the window's information bar RefCon. infoRect equ infoRefCon+4 Offset to the information bar's enclosing RECT. ; phd Save original direct page. tsc Switch to direct page in stack. tcd ; ; ; --- Draw the window's menu bar in the window's information bar --------------------------- ; pei infoRefCon+2 Pass handle of window's menu bar handle. pei infoRefCon _SetMenuBar Make the window's menu bar the current menu bar. ; _DrawMenuBar Draw the window's menu bar, as requested. ; lda #0 Zero is the flag for the system menu bar. pha pha _SetMenuBar Make the system menu bar current again. ; ; ; --- Remove input parameters from the stack ----------------------------------------------- ; ldx #12 ply Pull original direct page off stack, save in Y. ; tsc Move direct page point to stack. tcd lda 2,s Move return address down over input parameters. sta 2,x lda 0,s sta 0,x ; tsc Adjust stack for stripped input parameters. phx Number of bytes of input parameters. clc adc 1,s Add number of input parameters to stack pointer. tcs And reset stack. ; tya Restore original direct page. tcd ; rtl Return to Window Manager. END Information Bar Environment An information bar is part of a window's frame, that is, not part of the window's content region. Because it is part of the frame, an information bar is in the Window Manager's port, so before an interaction (drawing or mouse selecting), the proper port (Window Manager's) must be in the proper state. The proper state means the origin must be at the window's upper-left corner and clipped to any windows above. When the Window Manager calls the InfoDefProc it sets the proper port to the proper state; however, to interact with the information bar outside the InfoDefProc, you must set the proper port the the proper state. You can accomplish this with a call to StartInfoDrawing. When the interaction is completed, you must allow the Window Manager to return its port to a general state via a call to EndInfoDrawing. You are in a special state that requires some constraints (discussed later) between the calls to StartInfoDrawing and EndInfoDrawing. Here is an example of interacting with our window's menu bar. ; poll pha Space for return value. pea %0000111101101110 Pass event mask to use. pea TaskRec|-16 Pass pointer to Task record. pea TaskRec _TaskMaster pla Get returned value. beq poll Does event need further processing? ; ; ; --- Handle button down in window's information bar --------------------------------------- ; cmp #InInfo In Information bar? bne poll ; pha Space for result. pha lda TaskRec+TaskData+2 Pass pointer of window. pha lda TaskRec+TaskData pha _GetInfoRefCon Get menu bar handle from window's InfoRefCon. pla sta menuBar pla sta menuBar+2 ; ; ; --- Switch to proper port in proper coordinate system ------------------------------------ ; pea tempRect|-16 Pass pointer to RECT to store info bar RECT. pea tempRect lda TaskRec+TaskData+2 Pass pointer of window. pha lda TaskRec+TaskData pha _StartInfoDrawing ; ; ; --- Handle menu selection from window's menu bar ----------------------------------------- ; pea TaskRec|-16 Pass pointer to Task record for MenuSelect. pea TaskRec pei menuBar+2 Pass handle of menu bar. pei menuBar _MenuSelect Let user make selection. ; lda event+TaskData Get the item's ID number. beq exit Was a selection made? ; _EndInfoDrawing Switch back to original port. ; ; (Handle the menu selection.) ; ; The EndInfoDrawing followed by the StartInfoDrawing call is only ; needed when code between them calls the Window Manager. ; pea tempRect|-16 Pass pointer to RECT to store info bar RECT. pea tempRect lda TaskRec+TaskData+2 Pass pointer of window. pha lda TaskRec+TaskData pha _StartInfoDrawing Switch to the proper port in the proper state. ; pea 0 Pass unhilite flag. lda TaskRec+TaskData+2 Pass menu's ID number. pha _HiliteMenu Unhilite menu's title. ; ; ; --- Clean up and return to polling ------------------------------------------------------- ; exit _EndInfoDrawing Switch back to original port. ; pea 0 Make system menu bar current. pea 0 _SetMenuBar ; jmp poll Return to polling user. ; Information Bar Shutdown When the Window Manager closes the window, it is up to you to resolve any shutdown necessities associated with the information bar. Using our window menu bar example, the close window might look like the following: ; pei menuBar+2 Pass handle of menu bar pei menuBar _SetMenuBar ; pha Space for returned menu handle. pha pea 2 ID number of second menu. _GetMHandle Get the menu's handle. _DisposeMenu Free menu record and associated data. ; pha Space for returned menu handle. pha pea 1 ID number of first menu. _GetMHandle Get the menu's handle. _DisposeMenu Free menu record and associated data. ; pea 0 Make system menu bar current. pea 0 _SetMenuBar ; pha Space for menu bar's handle. pha pei <window+2 Pass pointer of window to close. pei <window _GetInfoRefCon Get the InfoRefCon from the window. _DisposeHandle Free menu bar record. ; pei <window+2 Pass pointer of window to close. pei <window _CloseWindow Now the window can be closed. ; The type of shutdown you use depends upon the contents of the information bar. Why didn't I put a DisposeMenuBar call in the Menu Manager? I didn't think of it until a week too late. Sorry. Other Information Bar Uses The following suggestions are only theories and have not been tested. o Display text information, as in Macintosh Finder windows. o Split window. Like the content region, the information bar could be large enough to hold data. o Hold controls. You could scroll data in the content region while keeping the controls which affect the display in place and within the user's] reach. (Note: The Control Manager currently will not allow controls it creates in an information bar. In this case, NewControl would be using a port that is not in your window's port, namely the Window Manager's port.) Further Reference o Apple IIGS Toolbox Reference, Volumes 1 & 2