The Palm OS® UI provides two system resources for accepting date and time input values. These resources are dialog boxes that contain UI gadgetry for entering dates and times. The Palm OS UI also provides routines to manage the interaction with these resources. This chapter describes those functions.
The API described in this chapter is declared in the header files Day.h, SelDay.h, SelTime.h, and SelTimeZone.h.
Date and Time Selections Data Structures

SelectDayType

typedef enum {
selectDayByDay, // return d/m/y
selectDayByWeek, // return d/m/y with d as
// same day of the week
selectDayByMonth // return d/m/y with d as
// same day of the month
} SelectDayType;
DaySelectorType

typedef struct DaySelectorType {
RectangleType bounds;
Boolean visible;
UInt8 reserved1;
Int16 visibleMonth; // month actually
// displayed
Int16 visibleYear; // year actually
// displayed
DateTimeType selected;
SelectDayType selectDayBy;
UInt8 reserved2;
} DaySelectorType;
HMSTime

typedef struct {
UInt8 hours;
UInt8 minutes;
UInt8 seconds;
UInt8 reserved;
} HMSTime;
Date and Time Selection Functions

DayDrawDays

Purpose
Draw only the days-of-the-month portion of a day selector control object.
Prototype
void DayDrawDays (const DaySelectorType *selectorP)
Parameters
-> selectorP | Pointer to the control object to draw. |
Result
Nothing.
Comments
This function is used when the year or month changes. Only drawing the portion of the control that presents the days of the month avoids the flicker that would occur if the week titles were redrawn.
See Also
DayDrawDaySelector
DayDrawDaySelector

Purpose
Draw a day selector control object on screen.
Prototype
void DayDrawDaySelector (const DaySelectorType *selectorP)
Parameters
-> selectorP | Pointer to the control object to draw. |
Result
Nothing.
Comments
The control is drawn only if it is usable.
See Also
DayDrawDays
DayHandleEvent

Purpose
Handle event in the specified control. This routine handles two types of events, penDownEvent and ctlEnterEvent.
Prototype
Boolean DayHandleEvent (DaySelectorType *selectorP, const EventType *pEvent)
Parameters
-> selectorP | Pointer to control object. |
-> pEvent | Pointer to an EventType structure. |
Result
true if the event was handled or false if it was not.
Posts a daySelectEvent with information on whether to use the date.
Comments
A date is used if the user selects a day in the visible month.
When this routine receives a penDownEvent, it checks if the pen position is within the bounds of the control object. If it is, a dayEnterEvent is added to the event queue and the routine exits.
When this routine receives a dayEnterEvent, it checks that the control id in the event record matches the id of the control specified. If they match, this routine will track the pen until it comes up in the bounds in which case daySelectEvent is sent.
If the pen exits the bounds a dayExitEvent is sent.
SelectDay

Purpose
Display a form showing a date; allow user to select a different date.
Prototype
Boolean SelectDay (const SelectDayType selectDayBy, Int16 *month, Int16 *day, Int16 *year, const Char *title)
Parameters
selectDayBy | The method by which the user should choose the day. Possible values are selectDayByDay, | | | selectDayByWeek, and selectDayByMonth. See SelectDayType |
<-> month, day, year | Month, day, and year selected. |
-> title | String title for the dialog. |
Result
true if the OK button was pressed. If true, month, day, and year contain the new date.
Compatibility
Implemented only if 2.0 New Feature Set is present.
See Also
SelectDayV10
SelectDayV10

Purpose
Display a form showing a date, allow user to select a different date.
Prototype
Boolean SelectDayV10 (Int16 *month, Int16 *day, Int16 *year, const Char *title)
Parameters
<-> month, day, year | Month, day, and year selected. The initial values passed in these parameters must be valid. |
-> title | String title for the dialog. |
Result
Returns true if the OK button was pressed. In that case, the parameters passed are changed.
Compatibility
This function corresponds to the 1.0 version of SelectDay.
See Also
SelectDay
SelectOneTime

Purpose
Display a form showing the time and allow the user to select a different time.
Prototype
Boolean SelectOneTime (Int16 *hour, Int16 *minute, const Char *titleP)
Parameters
<-> hour | The hour selected in the form. |
<-> minute | The minute selected in the form. |
-> titleP | A pointer to a string to display as the title. Doesn't change as the function executes. |
Result
Returns true if the user selects OK and false otherwise. If true is returned, the values in hour and minute have probably been changed.
Comments
Use this function instead of SelectTime if you want to display a dialog that specifies a single point in time, not a range of time from start to end.
Compatibility
Implemented only if 3.1 New Feature Set is present.
See Also
SelectTimeV33
SelectTime

Purpose
Display a form showing a start and end time. Allow the user to select a different time.
Prototype
Boolean SelectTime (TimeType *startTimeP, TimeType * EndTimeP, Boolean untimed, const Char *titleP, Int16 startOfDay, Int16 endOfDay, Int16 startOfDisplay)
Parameters
<-> startTimeP, EndTimeP | Pointers to values of type TimeType. Pass values to display in these two parameters. If the user makes a selection and taps the OK button, the selected values are returned here. |
-> untimed | Pass in true to indicate that no time is selected. If the user sets the time to no time then startTimeP and EndTimeP are both set to the constant noTime (-1). |
-> titleP | A pointer to a string to display as the title. Doesn't change as the function executes. |
-> startOfDay | The hour that the hour list displays at its top. To see earlier hours, the user can scroll the list up. The value must be between 0 to 12, inclusive. |
-> endOfDay | The hour used when the "All Day" button is selected. |
-> startOfDisplay | First hour initially visible. |
Result
Returns true if the user selects OK and false otherwise. If true is returned, the values in hour and minute have probably been changed.
Comments
This version of SelectTime adds the endOfDay and startOfDisplay functionality.
Compatibility
Implemented if 3.5 New Feature Set is present.
See Also
SelectDay, SelectOneTime
SelectTimeV33

Purpose
Display a form showing the time and allow the user to select a different time.
This function is obsolete and should not be used.
Prototype
Boolean SelectTimeV33 (TimeType *startTimeP, TimeType *EndTimeP, Boolean untimed, const Char *titleP, Int16 startOfDay)
Parameters
<-> startTimeP, EndTimeP | Pointers to values of type TimeType. Pass values to display in these two parameters. If the user makes a selection and taps the OK button, the selected values are returned here. |
-> untimed | Pass in true to indicate that no time is selected. If the user sets the time to no time then startTimeP and EndTimeP are both set to the constant noTime (-1). |
-> titleP | A pointer to a string to display as the title. Doesn't change as the function executes. |
-> startOfDay | The hour that the hour list displays at its top. To see earlier hours, the user can scroll the list up. The value must be between 0 to 12, inclusive. |
Result
Returns true if the user selects OK and false otherwise. If true is returned, the values in hour and minute have probably been changed.
Comments
NOTE: Obsolete functions are provided ONLY for backward compatibility; for example, so a 1.0 application will work on 3.x OS releases. New code should not call these routines!
See Also
SelectDay, SelectOneTime
New SelectTimeZone

Purpose
Display a form that allows the user to select a different time zone.
Prototype
Boolean SelectTimeZone (Int16 *ioTimeZoneP, LmLocaleType *ioLocaleInTimeZoneP, const Char *titleP, Boolean showTimes, Boolean anyLocale)
Parameters
<-> ioTimeZoneP | A pointer to the time zone, given as minutes east of Greenwich Mean Time (GMT). The initial value is used as the initial selection in the form. Upon return, this parameter contains a pointer to the new time zone that the user selected. |
<-> ioLocaleInTimeZoneP | A pointer to a locale (see LmLocaleType) that identifies the time zone country. This parameter is used for countries that share a time zone, such as Canada and Chile. |
| If the time zone specified by ioTimeZoneP is specific to a particular country, you do not have to initialize this parameter. Instead, set the anyLocale parameter to true to have this parameter ignored upon entry. |
-> titleP | A string to use as the title for the dialog. Pass NULL to use the default title, which is "Set Time Zone". |
-> showTimes | If true, the dialog shows the correct times in both the current and newly selected time zones. If false, the dialog doesn't show the current time. Using false provides a larger area for the list of time zones. |
-> anyLocale | If true, ignore ioLocaleInTimeZoneP upon entry. |
Result
Returns true if the user clicked the OK button in the dialog to change the time zone, or false if the user clicked the Cancel button.
Comments
The time zones displayed in the form are listed by country. For this reason, if the time zone specified by ioTimeZoneP is shared by several countries, you need to supply a value for ioLocaleTimeZoneP to identify which country should be selected when the list is first displayed. You can use the constant lmAnyLanguage as the value for the language field of the structure pointed to by this parameter.
If you don't care which value is initially selected, pass true for the anyLocale parameter. In this case, the first country that matches the GMT offset given in ioTimeZoneP is selected.
You might want to use the current time zone stored in the system preferences as the initial value for the ioTimeZoneP parameter. To obtain this time zone, do the following:
Int16 timeZone =
(Int16)PrefGetPreference(prefTimeZone);
CountryType timeZoneCountry = (CountryType)
PrefGetPreference(prefTimeZoneCountry);
LmLocaleType timeZoneLocale;
Boolean change;
timeZoneLocale.country = timeZoneCountry;
timeZoneLocale.language = lmAnyLanguage;
change = SelectTimeZone(&timeZone,
&timeZoneLocale, NULL, true, false);
Compatibility
Implemented if 4.0 New Feature Set is present.
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