/*

    File:       DrawCalendar.c

    Contains:   Module for displaying the calendar (Gregorian).

    Written by: Martin Minow

    Copyright:  © 1994-1997 by Apple Computer, Inc., all rights reserved.

    Change History (most recent first):

    You may incorporate this sample code into your applications without

    restriction, though the sample code has been provided "AS IS" and the

    responsibility for its operation is 100% yours.  However, what you are

    not permitted to do is to redistribute the source as "DSC Sample Code"

    after having made changes. If you're going to re-distribute the source,

    we require that you make it clear in the source that the code was

    descended from Apple Sample Code, but that you've made changes.

    DrawCalendar displays the calendar (Gregorian) for the selected date. The

    algorithm has been simplified and consequently will only work for dates within

    the Macintosh epoch.

    Note that DrawCalendar is common to the Control Strip and Setup application.

    If you change it, you must rebuild both modules.

*/

/////////////////////////////////////////////////////////////////////////

// Pick up some common stuff, specifically the height and width macros.

#include "MacCalendarCommon.h"

/////////////////////////////////////////////////////////////////////////

// Pick up prototypes for our exported routines.

#include "DrawCalendar.h"

/////////////////////////////////////////////////////////////////////////

// Pick up system types.

#include <Fonts.h>

#include <IntlResources.h>

#include <Memory.h>

#include <OSUtils.h>

#include <Packages.h>

#include <QuickDraw.h>

#include <Script.h>

#include <TextUtils.h>

/////////////////////////////////////////////////////////////////////////

// Some global constants.

#define kFebruary       2                       /* The magic month                  */

/*

 * This character vector contains the number of days in a month. Because compilers

 * do not necessarily allow pc-relative addressing of generic vectors, we define

 * it as a character string.

 *  034     28

 *  035     29

 *  036     30

 *  037     31

 */                 /*    Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec           */

#define kDayInMonth "\000\037\034\037\036\037\036\037\037\036\037\036\037"

/////////////////////////////////////////////////////////////////////////

static short GetFontNumber(

        SavedSettingsHandle     settings        /* Current font etc         */

    )

{

        Str255                  fontName;

        short                   fontNumber;

        pstrcpy(fontName, (**settings).fontName);

        GetFNum(fontName, &fontNumber);

        return (fontNumber);

}

/////////////////////////////////////////////////////////////////////////

// GetCalendarDisplaySize

// Return the width and height of a rectangle needed to display the calendar in the

// specified font and font size. This is needed to draw the calendar and to position

// the calendar display with respect to the Control Strip.

Point                       GetCalendarDisplaySize(

        SavedSettingsHandle     settings        /* Current font etc         */

    )

{

        FontInfo                fontInfo;

        short                   dateWidth;

        short                   lineHeight;

        Point                   result;

        short                   saveTextFont;

        short                   saveTextSize;

        short                   saveTextFace;

        GrafPtr                 currentPort;

        GetPort(&currentPort);

        saveTextFont = currentPort->txFont;

        saveTextSize = currentPort->txSize;

        saveTextFace = currentPort->txFace;

        TextFont(GetFontNumber(settings));

        TextSize((**settings).fontSize);

        TextFace(normal);

        GetFontInfo(&fontInfo);

        lineHeight = fontInfo.ascent + fontInfo.descent + fontInfo.leading;

        dateWidth = StringWidth("\p 00");

        result.h = (dateWidth * 7) + 4;     /* 7 == days in the week                */

        result.v = (lineHeight * 8) + 4;    /* 8 == lines of text in the calendar   */

        TextFont(saveTextFont);

        TextSize(saveTextSize);

        TextFace(saveTextFace);

        return (result);

}

/////////////////////////////////////////////////////////////////////////

// GetCalendarMonthRect

//

// Given a display rectangle, font, and font size, create the actual display area.

void                        GetCalendarMonthRect(

        SavedSettingsHandle     settings,       /* Current font etc         */

        const Rect              *displayRect,   /* Where to draw the text   */

        Rect                    *monthRect      /* Returns drawing rect     */

    )

{

        Point                   monthSize;

        monthSize = GetCalendarDisplaySize(settings);

        /*

         * Center the month rectangle within the drawing rectangle.

         * >> 1 is used to divide by two without loading a library routine.

         */

        monthRect->left = displayRect->left

                    + ((width(*displayRect) - monthSize.h) >> 1);

        monthRect->top = displayRect->top

                    + ((height(*displayRect) - monthSize.v) >> 1);

        monthRect->right = monthRect->left + monthSize.h;

        monthRect->bottom = monthRect->top + monthSize.v;

}

/////////////////////////////////////////////////////////////////////////

// DrawCalendar

//

// Draw the month - the port is set to the drawing port. Text font, size, and style

// are not preserved. dayName is a Pascal string with the following format, repeated

// seven times, once for each day:

//  { nByte, Byte1, Byte2, etc }. For example, if dates are represented

// by "S M Tu W Th F S", dayName would be specified in a pascal string as

//      "\p\001S\001M\002Tu\001W\002Th\001F\001S\000"

// Note: the day names must correspond to the firstDayOfWeek parameter. I.e. if the

// first day is Monday, the first word in the string is "M".

void                        DrawCalendar(

        SavedSettingsHandle     settings,       /* Current font etc         */

        short                   year,           /* 1904 ..                  */

        short                   month,          /* January == 1             */

        const Rect              *displayRect    /* Where to draw the text   */

    )

{

        DateTimeRec             now;

        unsigned long           nowSeconds;

        short                   weekday;

        short                   daysInMonth;

        short                   today;

        short                   lineHeight;

        short                   dateWidth;

        short                   spaceWidth;

        short                   digitWidth;

        FontInfo                fontInfo;

        Rect                    monthRect;

        short                   hPos;

        short                   vPos;

        register unsigned char  *dayNamePtr;

        short                   dayWidth;

        Intl1Hndl               intlHdl;

        Str255                  work;

        Boolean                 isThisMonth;

        short                   thisDate;

        Rect                    dayRect;

        PenState                penState;

        short                   hOffset;

        short                   vOffset;

        short                   penSize;

        /*

         * Get the drawing parameters for this month. This duplicates the logic of

         * GetCalendarDisplaySize above.

         */

        GetCalendarMonthRect(settings, displayRect, &monthRect);

        TextFont(GetFontNumber(settings));

        TextSize((**settings).fontSize);

        TextFace(normal);

        GetFontInfo(&fontInfo);

        lineHeight = fontInfo.ascent + fontInfo.descent + fontInfo.leading;

        spaceWidth = CharWidth(' ');

        digitWidth = CharWidth('0');

        dateWidth = spaceWidth + (digitWidth * 2);

        /*

         * If we're displaying the current month, we want to hilite today's date.

         * 1.0d3

         */

        GetDateTime(&nowSeconds);

        SecondsToDate(nowSeconds, &now);

        isThisMonth = (year == now.year && month == now.month);

        thisDate = now.day;

        /*

         * Get the parameters for this particular month. We convert day 1 to seconds,

         * then back to the date in order to locate the weekday corresponding to the

         * first day of the month.

         */

        now.year = year;

        now.month = month;

        now.day = 1;

        now.hour = 0;

        now.minute = 0;

        now.second = 0;

        DateToSeconds(&now, &nowSeconds);

        SecondsToDate(nowSeconds, &now);

        vPos = monthRect.top + 2 + fontInfo.ascent;

        /*

         * Draw the month and year names.

         */

        intlHdl = (Intl1Hndl) GetIntlResource(1);

        if (intlHdl != NULL) {

            /*

             * 1.0d4: Don't modify the actual data.

             */

            if (HandToHand((Handle *) &intlHdl) == noErr) {

                /*

                 * Convert the date to "month, year" (myd + supress day)

                 */

                (**intlHdl).suppressDay = 3;

                IUDatePString(nowSeconds, myd, work, (Handle) intlHdl);

                hPos = monthRect.left + 2

                    + ((width(monthRect) - StringWidth(work)) >> 1);

                MoveTo(hPos, vPos);

                DrawString(work);

                vPos += lineHeight;

            }

            DisposeHandle((Handle) intlHdl);

        }   

        /*

         * Draw the days in the week. dayName is a vector of Pascal strings hiding

         * inside a Pascal string.

         */

        pstrcpy(work, (**settings).dayNameString);

        dayNamePtr = (unsigned char *) &work[1];

        hPos = monthRect.left + 2;

        TextFace(bold);                                     /* 1.0d3                */

        for (weekday = 0; weekday < 7; weekday++) {

            dayWidth = StringWidth((StringPtr) dayNamePtr);

            MoveTo(hPos + dateWidth - dayWidth, vPos);

            DrawString((StringPtr) dayNamePtr);

            dayNamePtr += dayNamePtr[0] + 1;

            hPos += dateWidth;

        }

        TextFace(normal);                                   /* 1.0d3                */

        vPos += lineHeight;

        /*

         * How far do we go in this month, with a leap year hack.

         */

        daysInMonth = kDayInMonth[month];

        if ((year & 0x3) == 0 && month == kFebruary)

            ++daysInMonth;

        /*

         * now.dayOfWeek is the weekday corresponding to the first day of the month.

         * For example, if the first day of the month is on a Sunday, now.dayOfWeek

         * will equal one. firstDayOfWeek will equal one for Sunday, two for Monday.

         */

        weekday = now.dayOfWeek - (**settings).firstDayOfWeek;

        if (weekday < 0)

            weekday = 6;

        hPos = monthRect.left + 2 + (weekday * dateWidth);

        for (today = 1; today <= daysInMonth; today++, weekday++) {

            if (weekday >= 7) {     /* Wrap around to a new week.                   */

                hPos = monthRect.left + 2;

                vPos += lineHeight;

                weekday = 0;

            }

            /*

             * hOffset locates the left edge of the date -- this will cover one

             * digit for dates 1 to 9, and two digits for 10 to 31.

             */

            hOffset = hPos + spaceWidth;

            if (today < 10) {

                hOffset += digitWidth;      /* Space over the leftmost digit space  */

                MoveTo(hOffset, vPos);

                DrawChar(today + '0');

            }

            else {

                MoveTo(hOffset, vPos);

                DrawChar((today / 10) + '0');

                DrawChar((today % 10) + '0');

            }

            if (isThisMonth && today == thisDate) {         /* 1.0d3                */

                /*

                 * We are drawing an oval around this date. There is quite a bit of

                 * eyeball adjustment that could be re-adjusted by someone with

                 * more (or less) visual taste.

                 */

                GetPenState(&penState);

                penSize = (fontInfo.ascent >= 12) ? fontInfo.ascent / 6 : 1;

                vOffset = vPos - fontInfo.ascent - penSize;

                PenSize(penSize, penSize);

                SetRect(

                    &dayRect,

                    hOffset - penSize,

                    vOffset,

                    hPos + dateWidth + penSize,

                    vOffset + lineHeight + penSize

                );

                FrameRoundRect(

                    &dayRect,

                    (dateWidth * 3) / 4,

                    (lineHeight * 3) / 4

                );

                SetPenState(&penState);

            }

            hPos += dateWidth;

        }

}