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## 8 Date and Time Selector

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| Title - Palm OS® Programmer's API Reference Part I: User Interface 8 Date and Time Selector Date and Time Selections Data Structures SelectDayType DaySelectorType HMSTime Date and Time Selection Functions DayDrawDays DayDrawDaySelector DayHandleEvent SelectDay SelectDayV10 SelectOneTime SelectTime SelectTimeV33 SelectTimeZone |  |  |  | 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. |