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8    Date and Time Selector

Palm OS® Programmer's API Reference

Palm OS® 68K SDK

     

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 functions 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 ^TOP^

SelectDayType Struct ^TOP^

Prototype

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 Struct ^TOP^

Prototype

typedef struct DaySelectorType {
RectangleTypebounds;
Booleanvisible;
UInt8reserved1;
Int16visibleMonth; // month actually
// displayed
Int16visibleYear;// year actually
// displayed
DateTimeTypeselected;
SelectDayTypeselectDayBy;
UInt8reserved2;
} DaySelectorType;

HMSTime Struct ^TOP^

Prototype

typedef struct {
UInt8 hours;
UInt8 minutes;
UInt8 seconds;
UInt8 reserved;
} HMSTime;

Date and Time Selection Functions ^TOP^

DayDrawDays Function ^TOP^

Purpose

Draw only the days-of-the-month portion of a day selector control object.

Declared In

Day.h

Prototype

void DayDrawDays(
   constDaySelectorType*selectorP
)

Parameters

selectorP
Pointer to the control object to draw.

Returns

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.

Compatibility

If either 5.0 New Feature Set or Palm OS Cobalt Feature Set is present this function is unimplemented.

See Also

DayDrawDaySelector()

DayDrawDaySelector Function ^TOP^

Purpose

Draw a day selector control object on screen.

Declared In

Day.h

Prototype

void DayDrawDaySelector(
   constDaySelectorType*selectorP
)

Parameters

selectorP
Pointer to the control object to draw.

Returns

Nothing.

Comments

The control is drawn only if it is usable.

Compatibility

If either 5.0 New Feature Set or Palm OS Cobalt Feature Set is present this function is unimplemented.

See Also

DayDrawDays()

DayHandleEvent Function ^TOP^

Purpose

Handle event in the specified control. This function handles two types of events, penDownEvent and ctlEnterEvent. It is primarily intended for use by the operating system; applications do not typically use this function.

Declared In

Day.h

Prototype

Boolean DayHandleEvent(
   DaySelectorType*selectorP,
   constEventType*pEvent
)

Parameters

selectorP
Pointer to control object.
pEvent
Pointer to an EventType structure.

Returns

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 function 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 function exits.

When this function receives a dayEnterEvent, it checks that the control id in the event record matches the id of the control specified. If they match, this function 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.

Compatibility

If Palm OS Cobalt Feature Set is present this function is unimplemented.

SelectDay Function ^TOP^

Purpose

Display a form showing a date; allow user to select a different date.

Declared In

SelDay.h

Prototype

Boolean SelectDay(
   constSelectDayTypeselectDayBy,
   Int16*month,
   Int16*day,
   Int16*year,
   constChar*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.

Returns

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 Function ^TOP^

Purpose

Display a form showing a date, allow user to select a different date.

Declared In

SelDay.h

Prototype

Boolean SelectDayV10 (
   Int16*month,
   Int16*day,
   Int16*year,
   constChar*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.

Returns

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 Function ^TOP^

Purpose

Display a form showing the time and allow the user to select a different time.

Declared In

SelTime.h

Prototype

Boolean SelectOneTime (
   Int16 *hour,
   Int16*minute,
   constChar*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.

Returns

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 Function ^TOP^

Purpose

Display a form showing a start and end time. Allow the user to select a different time.

Declared In

SelTime.h

Prototype

Boolean SelectTime (
   TimeType *startTimeP,
   TimeType*EndTimeP,
   Boolean untimed,
   const Char*titleP,
   Int16 startOfDay,
   Int16 endOfDay,
   Int16startOfDisplay
)

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.

Returns

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 Function ^TOP^

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.

Declared In

SelTime.h

Prototype

Boolean SelectTimeV33 (
   TimeType*startTimeP,
   TimeType*EndTimeP,
   Booleanuntimed,
   constChar*titleP,
   Int16startOfDay
)

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.

Returns

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 functions!

See Also

SelectDay(), SelectOneTime()

SelectTimeZone Function ^TOP^

Purpose

Display a form that allows the user to select a different time zone.

Declared In

SelTimeZone.h

Prototype

Boolean SelectTimeZone (
   Int16*ioTimeZoneP,
   LmLocaleType*ioLocaleInTimeZoneP,
   constChar*titleP,
   BooleanshowTimes,
   BooleananyLocale
)

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.

Returns

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.