83Plus:Hooks:9BC0 - Revision history

PT: /* Example */

2016-07-11T17:31:15Z

‎Example

Zeda at 19:38, 25 April 2012

2012-04-25T19:38:03Z

Zeda: Added some info about A = 01h

2012-04-25T19:37:18Z

Added some info about A = 01h

Mmartin: added menu table example

2006-07-11T07:39:18Z

added menu table example

Gambit: revert vandalism

2005-10-28T04:16:26Z

revert vandalism

24.1.42.41: /* Using the Hook */

2005-10-27T16:53:02Z

‎Using the Hook

FloppusMaximus: /* Synopsis */

2005-04-02T03:29:43Z

‎Synopsis

FloppusMaximus at 03:27, 2 April 2005

2005-04-02T03:27:58Z

JasonM at 03:27, 2 April 2005

2005-04-02T03:27:41Z

JasonM at 03:27, 2 April 2005

2005-04-02T03:27:00Z

New page

[[Category:83Plus:Hooks:By Address|9BC0 - Menu Hook]]
[[Category:83Plus:Hooks:By Name|9BC0]]
== Synopsis ==
'''Name:''' Menu Hook

'''Hook Pointer Block Address:''' [[83Plus:RAM:9BC0|9BC0]]

'''Hook Enable BCALL:''' [[83Plus:BCALLs:5083|5083]]

'''Hook Disable BCALL:''' [[83Plus:BCALLs:5086|5086]]

'''Hook Call BCALL:''' ''(Unknown)''

'''Hook Active Flag:''' [[83Plus:Flags:36|6, (iy + 36h)]]

The menu hook allows for modification of any of the system menus that are presented through the system monitor.

== Using the Hook ==
This hook, like most, is called for several events, each identified by A. In general, it appears that returning with the zero flag set will cause the OS to execute its normal behavior.

I've ordered the events in the order that they are called by the OS.

* '''A = 04h:''' This is the first event called. B contains the value of the menu about to be displayed. When this event is triggered, [[83Plus:RAM:85DE|MenuCurrent]] currently contains the ID referring to the menu that was previously displayed (if you went from one menu directly to another), or 0 if previously there was no menu displayed (you were seeing the context itself.)
* '''A = 00h:''' This is the second event, called after event 04h. This event allows you to provide your own menu table. B contains the menu ID. If you want to provide your own table, copy it to RAM, point HL to it, and return with the zero flag reset. It's called a second time, but with B being zero. The outputs appear to be the same, so handle it the same way.
* '''A = 02h:''' This event is called before the OS draws the menu header. C is the index of the header (zero based.) Returning with zero set will draw the header, returning with zero reset will cause it to not draw the header. It's also called after it's done drawing the headers, with C is the number of headers (basically, last index plus one). Return flag seems to be ignored.
* '''A = 01h:''' The OS is about to draw the text corresponding to a menu item. The number prefix has already been drawn. C contains the index of the item (zero indexed.) Returning with zero set will cause the OS to draw the string, returning with zero reset will cause it just to draw a blank line (but it does draw something!)
* '''A = 03h:''' The user selected an item from the menu that is about to cause a context switch. B contains the ID of the context the calculator might switch to. You can return with zero set to execute the app, or zero reset to cancel the execution. If you're switching to a flash app (B is cxextapps), then DE also points to the end of the name of the flash app in RAM. You can cancel the execution of a flash app (this could prove useful for a security app.)

@@ Line 35: / Line 35: @@
 	db 0,kZOut	;these are 2-byte keypresses of each entry
 	db 0,kStd</nowiki>
 == Credits and Contributions ==
 * '''Kirk Meyer:''' For providing an example of this hook in graph3

← Older revision		Revision as of 07:39, 11 July 2006
Line 25:		Line 25:
	* '''A = 01h:''' The OS is about to draw the text corresponding to a menu item. The number prefix has already been drawn. C contains the index of the item (zero indexed.) Returning with zero set will cause the OS to draw the string, returning with zero reset will cause it just to draw a blank line (but it does draw something!)		* '''A = 01h:''' The OS is about to draw the text corresponding to a menu item. The number prefix has already been drawn. C contains the index of the item (zero indexed.) Returning with zero set will cause the OS to draw the string, returning with zero reset will cause it just to draw a blank line (but it does draw something!)
	* '''A = 03h:''' The user selected an item from the menu that is about to cause a context switch. B contains the ID of the context the calculator might switch to. You can return with zero set to execute the app, or zero reset to cancel the execution. If you're switching to a flash app (B is cxextapps), then DE also points to the end of the name of the flash app in RAM. You can cancel the execution of a flash app (this could prove useful for a security app.)		* '''A = 03h:''' The user selected an item from the menu that is about to cause a context switch. B contains the ID of the context the calculator might switch to. You can return with zero set to execute the app, or zero reset to cancel the execution. If you're switching to a flash app (B is cxextapps), then DE also points to the end of the name of the flash app in RAM. You can cancel the execution of a flash app (this could prove useful for a security app.)
		+
		+	== Example ==
		+	This is an example of a menu table taken from graph3.
		+	<nowiki>ZoomMenu:
		+	db 1 ;how many headers?
		+	db 3 ;how many choices under 1st header?
		+	db 5Eh ;string table entry for "ZOOM"
		+	db 0,kZIn
		+	db 0,kZOut ;these are 2-byte keypresses of each entry
		+	db 0,kStd</nowiki>
		+
		+	== Credits and Contributions ==
		+	* '''Kirk Meyer:''' For providing an example of this hook in graph3

← Older revision		Revision as of 04:16, 28 October 2005
Line 25:		Line 25:
	* '''A = 01h:''' The OS is about to draw the text corresponding to a menu item. The number prefix has already been drawn. C contains the index of the item (zero indexed.) Returning with zero set will cause the OS to draw the string, returning with zero reset will cause it just to draw a blank line (but it does draw something!)		* '''A = 01h:''' The OS is about to draw the text corresponding to a menu item. The number prefix has already been drawn. C contains the index of the item (zero indexed.) Returning with zero set will cause the OS to draw the string, returning with zero reset will cause it just to draw a blank line (but it does draw something!)
	* '''A = 03h:''' The user selected an item from the menu that is about to cause a context switch. B contains the ID of the context the calculator might switch to. You can return with zero set to execute the app, or zero reset to cancel the execution. If you're switching to a flash app (B is cxextapps), then DE also points to the end of the name of the flash app in RAM. You can cancel the execution of a flash app (this could prove useful for a security app.)		* '''A = 03h:''' The user selected an item from the menu that is about to cause a context switch. B contains the ID of the context the calculator might switch to. You can return with zero set to execute the app, or zero reset to cancel the execution. If you're switching to a flash app (B is cxextapps), then DE also points to the end of the name of the flash app in RAM. You can cancel the execution of a flash app (this could prove useful for a security app.)
−
−	~~I do not like SAM I AM~~

← Older revision		Revision as of 16:53, 27 October 2005
Line 25:		Line 25:
	* '''A = 01h:''' The OS is about to draw the text corresponding to a menu item. The number prefix has already been drawn. C contains the index of the item (zero indexed.) Returning with zero set will cause the OS to draw the string, returning with zero reset will cause it just to draw a blank line (but it does draw something!)		* '''A = 01h:''' The OS is about to draw the text corresponding to a menu item. The number prefix has already been drawn. C contains the index of the item (zero indexed.) Returning with zero set will cause the OS to draw the string, returning with zero reset will cause it just to draw a blank line (but it does draw something!)
	* '''A = 03h:''' The user selected an item from the menu that is about to cause a context switch. B contains the ID of the context the calculator might switch to. You can return with zero set to execute the app, or zero reset to cancel the execution. If you're switching to a flash app (B is cxextapps), then DE also points to the end of the name of the flash app in RAM. You can cancel the execution of a flash app (this could prove useful for a security app.)		* '''A = 03h:''' The user selected an item from the menu that is about to cause a context switch. B contains the ID of the context the calculator might switch to. You can return with zero set to execute the app, or zero reset to cancel the execution. If you're switching to a flash app (B is cxextapps), then DE also points to the end of the name of the flash app in RAM. You can cancel the execution of a flash app (this could prove useful for a security app.)
		+
		+	I do not like SAM I AM

@@ Line 23: / Line 23: @@
 * '''A = 00h:''' This is the second event, called after event 04h. This event allows you to provide your own menu table. B contains the menu ID. If you want to provide your own table, copy it to RAM, point HL to it, and return with the zero flag reset. It's called a second time, but with B being zero. The outputs appear to be the same, so handle it the same way.
 * '''A = 02h:''' This event is called before the OS draws the menu header. C is the index of the header (zero based.) Returning with zero set will draw the header, returning with zero reset will cause it to not draw the header. It's also called after it's done drawing the headers, with C is the number of headers (basically, last index plus one). Return flag seems to be ignored.
-* '''A = 01h:''' The OS is about to draw the text corresponding to a menu item. The number prefix has already been drawn. C contains the index of the item (zero indexed.) Returning with zero set will cause the OS to draw the string, returning with zero reset will cause it just to draw a blank line (but it does draw something!). To change the string to be drawn to another token, you will need DE to be an extended keycode.
+* '''A = 01h:''' The OS is about to draw the text corresponding to a menu item. The number prefix has already been drawn. C contains the index of the item (zero indexed.) Returning with zero set will cause the OS to draw the string, returning with zero reset will cause it just to draw a blank line (but it does draw something!). To draw another token, you will need DE to be an extended keycode.
 * '''A = 03h:''' The user selected an item from the menu that is about to cause a context switch. B contains the ID of the context the calculator might switch to. You can return with zero set to execute the app, or zero reset to cancel the execution. If you're switching to a flash app (B is cxextapps), then DE also points to the end of the name of the flash app in RAM. You can cancel the execution of a flash app (this could prove useful for a security app.)

@@ Line 11: / Line 11: @@
 '''Hook Call BCALL:''' ''(Unknown)''
-'''Hook Active Flag:''' [[83Plus:Flags:36|6, (iy + 36h)]]
+'''Hook Active Flag:''' [[83Plus:Flags:36#Bit_6|6, (iy + 36h)]]
 The menu hook allows for modification of any of the system menus that are presented through the system monitor.

@@ Line 1: / Line 1: @@
-[[Category:83Plus:Hooks:By Address|9BC0 - Menu Hook]]
+[[Category:83Plus:Hooks:By Address|9BC0 - Menu Hook]] [[Category:83Plus:Hooks:By Name|Menu Hook]]
 [[Category:83Plus:Hooks:By Name|Menu Hook]]
 == Synopsis ==
 '''Name:''' Menu Hook