ChoiceButtons.mesa
Copyright © 1985 by Xerox Corporation. All rights reserved.
Written by Linda Gass on August 20, 1982 2:36 pm
Last Edit by Linda Gass September 24, 1982 2:26 pm
Last Edited by: Maxwell, December 17, 1982 10:08 am
Last Edited by: Paul Rovner, July 20, 1983 2:02 pm
Doug Wyatt, April 14, 1985 11:35:19 pm PST
Enumerated Types
EnumTypeRef: TYPE = REF EnumTypeRec;
EnumTypeRec:
TYPE =
RECORD [
proc: SelectionNotifierProc ← NIL, -- procedure called everytime a button's selected (optional)
permission: EnumPermissionProc ← NIL, -- (optional) permission proc called before doing anything
namesOfButtons: ButtonList ← NIL, -- list of names of buttons in this Enumerated type
nextx: CARDINAL, -- next x position in container that client may begin displaying info so that it wont overwrite the buttons
nexty: CARDINAL, -- similar to nextx
type: DisplayStyle,
buttonOn: Buttons.Button ← NIL, -- the button currently on for a given enumerated type
flipLabel: Viewer ← NIL, -- points to the Viewer to re-label
clientdata: REF ANY ← NIL -- optional data provided by the client and used when the selection notifier procedure is called
];
(NOTE: It would have seemed natural to make the above record a variant record but because
of language constraints, it would have been more trouble than it was worth to
implement it)
ButtonList:
TYPE =
LIST
OF
ROPE;
A ButtonList is a list of the names of the buttons to be displayed as Choices.
StyleChoice: TYPE = {menuSelection, flipThru};
DisplayStyle: TYPE = {menuStyle, flipThruWithTitle, flipThruNoTitle};
BuildEnumTypeSelection:
PROC [viewer: Viewer, x, y:
CARDINAL ← 0, title:
ROPE ←
NIL,
buttonNames: ButtonList, default:
ROPE ←
NIL, borderOnButtons:
BOOL ←
TRUE,
notifyClientProc: SelectionNotifierProc ←
NIL, permit: EnumPermissionProc ←
NIL, clientdata:
REF
ANY ←
NIL, style: StyleChoice,
allInOneRow:
BOOL ←
TRUE, maxWidth:
INTEGER ←
LAST[
INTEGER]
]
RETURNS [EnumTypeRef];
SIGNALS DefaultDoesntExist
See documentation below
GetSelectedButton:
PROC [handle: EnumTypeRef]
RETURNS [
ROPE];
Using the handle, it returns the currently selected button
UpdateChoiceButtons:
PROC [viewer: Viewer, enumTypeInfo: EnumTypeRef, newName:
ROPE];
SIGNALS ChoiceDoesntExist and ButtonsCannotBeUpdated
SelectionNotifierProc: TYPE = PROC [name: ROPE, clientdata: REF ANY];
EnumPermissionProc:
TYPE =
PROC [handle: EnumTypeRef]
RETURNS [
BOOL];
client returns true if "giving permission", false otherwise.
Three state buttons
ThreeStateRef: TYPE = REF ThreeState;
ThreeState: TYPE = RECORD [
button: Buttons.Button ← NIL,
state: StateType ← off
];
StateType: TYPE = {off, on, default};
BuildTriStateButton: PROC [viewer: Viewer, x,y: INTEGER ← 0, name: ROPE] RETURNS [stateInfo: ThreeStateRef, nextX: INTEGER];
SetButtonState: PROC [buttonSelected: Buttons.Button, state: StateType];
Text Prompts
PromptDataRef: TYPE = REF PromptDataRec;
PromptDataRec: TYPE = RECORD [
promptButton: Buttons.Button,
textViewer: Viewer,
newy, newx: CARDINAL,
clientdata: REF ANY ← NIL,
permission: PromptPermissionProc,
notify: SelectionNotifierProc
];
PromptPermissionProc: TYPE = PROC [handle: PromptDataRef] RETURNS [BOOL];
BuildTextPrompt:
PROC [viewer: Viewer, x,y:
CARDINAL ← 0, title:
ROPE,
default:
ROPE ←
NIL, font: Imager.Font ←
NIL,
textViewerWidth:
INTEGER ←
LAST[
INTEGER], clientdata:
REF
ANY ←
NIL,
notify: SelectionNotifierProc ←
NIL, permit: PromptPermissionProc ←
NIL
]
RETURNS [promptData: PromptDataRef];
See documentation below
DefaultDoesntExist: SIGNAL;
ChoiceDoesntExist: SIGNAL;
ButtonsCannotBeUpdated: SIGNAL;
**** BuildEnumTypeSelection ****
Takes an enumerated type in the form of a list and displays it either as a menu selection of
buttons or a sequence of labels displayed when a button is selected.
"container" is the Container that this selection of buttons is to be displayed in
"x, y" are the x and y positions in the Container at which this menu is to be displayed
"title" is the name to be displayed before the selection. It can be left empty.
"buttonNames" is the list of names to appear in the buttons
"default" is the button which will originally be turned "on" when this menu is first
displayed.
NOTE: Signals "DefaultDoesntExist" if specified default wasn't found in button list
"borderOnButtons" indicates if a border should be placed around the buttons in the
enumerated type selection. NOTE: the labels will never have a border.
"permit" is a procedure which is called when a button is selected. It is intended to be some sort
of "permission" which enables the button switching procedure to continue with its task.
There are times when the client may want to prevent anything from happening when a
button is selected
"notifyClientProc" is a procedure which is called when a button is selected. It makes
available to the client a rope containing the name associated with that button.
"clientdata" optional information for use by the client. Returned when the notifyClientProc is
called.
"style" allows the user to choose different display styles for the EnumTypeSelection
menuSelection - displays all the different button names but only one button can be
"on" at a given point in time.
flipThru - displays only one button name at a time, "flipping through" all the
different possibilities. Optional title preceding it.
"allInOneRow - optional. When menu selection is used, tell whether all should be in one row.
"maxWidth - optional. When menu selection is used and allInOneRow is FALSE. Tells how
wide to make each row of the menu.
Returns a SelectionRef which contains information about the button which is currently "on"
This Ref may be used in conjunction with the "GetSelectedButton" procedure to find out
which button is currently "on" rather than using the notifyClientProc everytime a new
button is selected. (i.e. - the client actually has two options for using BuildEnumType-
Selection: (1) The client can be notified everytime a new button is selected by providing
a notifyClientProc or (2) The client can save the SelectionRef returned from BuildEnum-
TypeSelection and use this Ref and GetSelectedButton to inquire which button is on at a
given time. NOTE: the SelectionRef.buttonOn returned by BuildEnumTypeSelection
initially is the default value provided, it does NOT necessarily contain the CURRENT
button on.
**** BuildTriStateButton ****
Builds a button which cycles through three states. The states are indicated by different color backgrounds. The state may be initialized by using the procedure "SetButtonState"
**** BuildTextPrompt ****
Builds a "label" and a corresponding text viewer. The "label" is really a button such that when
the "label" is selected it forces the selection into the corresponding text field. If the "label" was selected with red mouse button then this causes the text viewer to become pending delete.
Otherwise displays the default if one was specified initially. If no default was specified initially then sets contents of text viewer to NIL.
"container" is the parent container that this text prompt will be displayed in
"x, y" are the x and y positions in the container at which this text prompt is to be displayed
"title" is the text displayed on the "label"
"default" (optional) text to be displayed initially and when text prompt is selected with yellow or
blue mouse button
"font" is the font that the "label" will be displayed in
"textViewerWidth" is how wide to make the text viewer. If not specified then will make the text
viewer as wide as the container.