第七章 列表框和排序
在这一章中，将接触到一些新的控件和数据库操作技巧。我们先生成一个窗体来显示contact数据库中的所有记录，然后创建一个下拉框供选择排序标准，最后添加代码进行排序，并使新创建或修改过的记录也能够在列表中正确排列。
保存工程
按我们的习惯先保存工程，步骤如下：
1． 运行Windows浏览器；
2． 找到保存现有工程的文件夹；
3． 按下CTRL-C复制；
4． 选择目的文件夹；
5． 按下CTRL-V将现有工程粘贴到目的文件夹；
6． 将其重命名为容易记忆的名字，我将其命名为Contacts CH.6。
列表框
列表框能够显示许多文本条目并允许从中选择，我们可以对每个条目进行浏览或选择。我们还可以通过调用函数浏览列表或选择条目。当然，我们可以画出自己的列表框，在缺省情况下，列表框由Palm系统绘制。
Contacts.rsrc的内容添加
在这一部分中，我们将向应用程序添加一个新的窗体。此窗体将以列表的形式显示数据库记录，并允许我们浏览或选择。如果选中了其中的一条记录，记录内容将从Contact Detail 窗体上显示出来。
Contact Detail 窗体的内容添加
由于Contact Detail 窗体被调用来返回一条记录内容，所以我们需要添加一个Done按钮。步骤如下：
1． 运行构造器；
2． 打开资源文件Contact.rsrc，它位于工程文件夹的src文件夹里面；
3． 双击打开；
4． 选择Windows | Catalog打开控件模板；
5． 向Contact Detail 窗体拖动一个按钮；
6． 设置按钮属性Object Identifier为Done，Left Origin=1，Top Origin=147，Label为Done；
7． 添加完成后，所得按钮如下图所示，选择右上角的X按钮关闭编辑器。
在Contact List窗体上创建菜单栏
在创建Contact List窗体前，我们先创建一个菜单；这样当设置窗体的属性时，就可以直接写入此菜单栏的ID了。
1． 在Resource Type and Name 列表框中选择Menu Bars并按下CTRL-K，于是一个新的菜单就产生了，将其重命名为Contact List；
2． 双击打开；
3． 拖动Option菜单到Contact List菜单栏上；
4． 完成后应如下图所示，点击右上角的X按钮关闭菜单栏。
创建Contact List窗体
现在我们来创建Contact List 窗体，步骤如下：
1． 点击Forms，并按下CTRL-K创建一个新的窗体；
2． 点击窗体名称将其命名为Contact List；
3． 在窗体编辑器中双击打开Contact List 窗体；
4． 为Contact List 添加标题，并使菜单栏的ID和Contact List 窗体的菜单栏的ID相匹配。
创建列表框（List）
1． 从Catalog窗口中拖动一个列表框（List）到窗体上。它的属性如表7-1所示；
Object Identifier 在资源头文件中，构造器用之代表资源ID
List ID 列表框的资源ID
Left Origin 水平方向上控件的最左端位置
Top Origin 垂直方向上控件的最顶端位置
Width 列表的宽度
Usable 决定此控件是否可见能用，如果没有选中，也可在通过函数调用来实现其可见
Font 列表项的字体
Visible Items 列表框可显示的行数。注意，实际的列表条目数比此值可多可少
List Items 动态的初始化列表条目，如果想添加条目，按CTRL-K
2． 设置属性Object Identifier 为List，Left Origin=0,Top Origin=12,Width=160,Visible Items=12；
3． 完成后窗体如下图所示，按下右上角的X按钮关闭窗体，并选File | Save保存所做修改。
添加内存错误警告
在这一章里，我们将开始添加错误处理代码。在内存溢出时，系统将发出警告信息：
1． 点击Resource Type and Name列表中的Alerts 并按下CTRL-K创建一个新的警报；
2． 将其命名为MemoryError；
3． 双击，在编辑器中打开；
4． 设置属性Alert Type 为Error，标题（title）为Fatal Error，信息(message）为“I have run out of memory.”
5． 完成后，如下图所示：
Contact.c的内容添加
现在添加代码以完成新窗体的功能。首先，先在前几章中异常处理的忽略处添加代码进行异常处理。
异常处理
在这一章中，有很多地方可能会造成内存溢出。因此，我们必须添加严密的异常处理程序。下面我们将利用异常处理器（Error Manager）来完成，在The Palm OS SDK Reference 中对异常处理器有详细的论述。
首先，在PilotMain()前，定义异常退出（Exit）宏：
// CH.7 The error exit macro
#define errorExit(alert) { ErrThrow( alert ); }
异常处理函数ErrThrow()有些与众不同，它与宏ErrTry和ErrCatch()配合作用，类似C++和Java的形式给出异常处理。如果在ErrTry模块中的任何代码调用了ErrThrow()函数，控件就会立即调用ErrCatch()函数。下面我们看看在PilotMain()中做了哪些修改。
在事件loop 产生前先添加宏ErrTry：
// CH.7 Begin the try block
ErrTry {
// CH.2 Our event loop
do
{
结束宏ErrTry并添加ErrCatch() 函数：
// CH.7 End the try block and do the catch block
}
ErrCatch( errorAlert )
{
// CH.7 Display the appropriate alert
FrmAlert( errorAlert );
} ErrEndCatch
此函数将根据ErrThrow()传给ErrCatch()的ID号显示其相应的异常警报。然后，应用程序将在catch模块后正常退出，正常执行关闭数据库诸如此类的操作。最后，PilotMain()将控制权归还给Palm OS。
Contact List 窗体的切换
下面，我们添加代码来实现Contact List 窗体和Contact Detail窗体之间的切换。在PilotMain()中，修改初始化Contact Detail窗体的代码如下：
// CH.7 Choose our starting page
// CH.5 If there are no records, create one
if( numRecords == 0 )
{
newRecord();
FrmGotoForm( ContactDetailForm );
}
else
FrmGotoForm( ContactListForm );
在切换到Contact List窗体时，判断如果数据库中没有记录，就要创建一条新记录；一般情况下，数据库中都是有记录的，我们可以直接调用Contact List窗体。
为使Contact List窗体能正确的初始化，在loop事件中的frmLoadEvent处理代码中再添加case项：
// CH.7 Contact List form
case ContactListForm:
form = FrmInitForm( ContactListForm );
FrmSetEventHandler( form, contactListHandleEvent );
break;
下面的代码是如何处理Contact Detail 窗体中的Done按钮事件：
// CH.7 Done button
case ContactDetailDoneButton:
{
// CH.7 Load the contact list
FrmGotoForm( ContactListForm );
}
break;
为了在窗体间切换，而不是弹出窗体，我们使用了函数FrmGotoform()来初始化。这个函数首先调用frmCoseEvent关闭前一个窗体，然后调用frmLoadEvent和frmOpenEvent打开新的窗体。
Contact List窗体事件处理函数
下面我们为Contact List 窗体来添加事件处理函数。首先，在文件的开头加入原型：
static Boolean contactListHandleEvent( EventPtr event );
另外，还需要两个变量表示给列表框分配内存的句柄：
// CH.7 Contact list variables
static VoidHand hchoices; // CH.7 Handle to packed choices
static VoidHand hpchoices; // CH.7 Handle to pointers
下面是事件处理函数：
// CH.7 Our Contact List form event handler function
static Boolean contactListHandleEvent( EventPtr event )
{
FormPtr form; // CH.7 A form structure pointer
// CH.7 Get our form pointer
form = FrmGetActiveForm();
// CH.7 Parse events
switch( event->eType )
{
// CH.7 Form open event
case frmOpenEvent:
{
// CH.7 Draw the form
FrmDrawForm( form );
// CH.7 Build the list
buildList();
}
break;
// CH.7 Form close event
case frmCloseEvent:
{
// CH.7 Unlock and free things here
MemHandleUnlock( hpchoices );
MemHandleFree( hpchoices );
MemHandleUnlock( hchoices );
MemHandleFree( hchoices );
hchoices = 0;
}
break;
// CH.7 Respond to a list selection
case lstSelectEvent:
{
// CH.7 Set the database cursor to the selected contact
cursor = event->data.lstSelect.selection;
// CH.7 Go to contact details
FrmGotoForm( ContactDetailForm );
}
break;
// CH.7 Respond to a menu event
case menuEvent:
return( menuEventHandler( event ) );
// CH.7 Respond to the popup trigger
case popSelectEvent:
{
// CH.7 If there is no change, we're done
if( sortBy == event->data.popSelect.selection )
return( true );
// CH.7 Modify sort order variable
sortBy = event->data.popSelect.selection;
// CH.7 Sort the contact database by the new criteria
DmQuickSort( contactsDB, (DmComparF*)sortFunc, sortBy );
// CH.7 Rebuild the list
buildList();
}
break;
} // CH.7 End of the event switch statement
// CH.7 We're done
return( false );
}
事件处理函数以十分标准的形式开始：首先建立了一个窗体指针变量，它将在调用frmOpenEvent时被调用；然后窗体被绘制并调用了一个新的函数buildList()，这个函数在下一部分将详细讨论。
我们调用frmCloseEvent释放用来储存列表框内容的内存。之所以在关闭(close)事件中释放内存，是因为只要列表框可见、窗体在使用的时候，这一部分内存就一直被Palm OS使用。在这一点上，列表控件和其它控件有所不同，一般的控件都有自己的内存，而对于列表控件来说，它需要另外分配内存。
下面，讲述一个新的事件处理函数——lstSelectEvent。当列表的条目被选中时，此事件将被触发。变量selection标明哪一个条目被选中，列表得记录从0开始。这样我们使用起来就十分方便了，只要将当前记录等于列表变量selection的值，然后调用Contact Detail窗体，窗体就会使用前面所设置的变量cursor产生正确的记录。
最后，对本程序菜单事件的处理和对Contact Detail窗体的菜单处理几乎相同。这样，对Contact List窗体的处理程序就算完成了。
函数buildList()
下面我们来讨论这个实用函数buildList()，这个函数通过浏览数据库，为每条记录创建一文本字符串，然后使用这些字符串填充List对象的各个条目。
static void buildList( void )
{
FormPtr form; // CH.6 A form structure pointer
Int choice; // CH.7 The list choice we're doing
CharPtr precord; // CH.7 Pointer to a record
Char listChoice[dateStringLength + 1 + // CH.7 We
timeStringLength + 1 + // build
DB_FIRST_NAME_SIZE + // list
DB_LAST_NAME_SIZE]; // choices here
// CH.7 The current list choice
CharPtr pchoices; // CH.7 Pointer to packed choices
UInt offset; // CH.7 Offset into packed strings
VoidPtr ppchoices; // CH.7 Pointer to pointers to choices
// CH.6 Get our form pointer
form = FrmGetActiveForm();
在声明变量后，函数象往常一样获取窗体指针。这里面最有趣的变量是char array ，它将保证列表字符串的连续性。为使阵列（array）有足够的大小来保存任何Palm OS的系统时间和日期，可以使用Palm OS常量dateStringLength和timeStringLength。
// CH.7 Put the list choices in a packed string
for( choice = 0; choice < numRecords; choice++ )
{
// CH.7 Get the record
hrecord = DmQueryRecord( contactsDB, choice );
precord = MemHandleLock( hrecord );
// CH.7 Get the date and time
MemMove( &dateTime, precord + DB_DATE_TIME_START,
sizeof( dateTime ) );
首先，浏览数据库的所有记录，然后获取记录将变量dateTime设置为在所得记录中的时间和日期。注意到我们使用了DmQueryRecord（）函数来获取记录句柄。此函数只给我们提供一个只读的记录副本。
下面，我们创建表示记录的字符串：
// CH.7 Clear the list choice string
*listChoice = '\0';
// CH.7 Add the date string if any
if( dateTime.year != NO_DATE )
{
DateToAscii( dateTime.month, dateTime.day,
dateTime.year,
(DateFormatType)PrefGetPreference(
prefDateFormat ), listChoice );
StrCat( listChoice, " " );
}
// CH.7 Add the time string if any
if( dateTime.hour != NO_TIME )
{
TimeToAscii( dateTime.hour, dateTime.minute,
(TimeFormatType)PrefGetPreference(
prefTimeFormat ), listChoice +
StrLen( listChoice ) );
StrCat( listChoice, " " );
}
// CH.7 Append the first name
StrCat( listChoice, precord + DB_FIRST_NAME_START );
StrCat( listChoice, " " );
// CH.7 Append the last name
StrCat( listChoice, precord + DB_LAST_NAME_START );
在这里我们将date，time，first name和last name都写入了字符串。注意到函数DateToAscii（）和函数TimeToAscii（）运行需要花很多时间。对本程序来说调用这两个函数还算可以，但是如果要提高处理记录的速度，就必须考虑将时间和日期保存在单个记录来提高速度。
下一步，我们将为这些字符串分配内存，这样做是因为列表框在填充新条目时需要一定的格式。
// CH.7 Allocate memory for the list entry string
// CH.7 If this is the first choice
if( hchoices == 0 )
{
// CH.7 Allocate the storage for the choice
if( (hchoices = MemHandleNew(
StrLen( listChoice ) + 1 )) == 0 )
errorExit( MemoryErrorAlert );
// CH.7 Initial offset points to the start
offset = 0;
}
上面就是字符串没有创建时的代码，在给字符串分配内存时，如果失败了，就调用新的错误处理函数来处理。然后我们初始化偏移（offset）说明在哪里将字符串置零。
下面是字符串已经创建好的情况：
else
// CH.7 If this is a subsequent choice
{
// CH.7 Unlock
MemHandleUnlock( hchoices );
// CH.7 Resize
if( MemHandleResize( hchoices, offset +
StrLen( listChoice ) + 1 ) )
errorExit( MemoryErrorAlert );
}
在这里我们将锁定的内存解锁（Unlock），使之能储存下一个字符串。
接着我们将字符串写入包列表（Packed List）：
// CH.7 Lock
pchoices = MemHandleLock( hchoices );
// CH.7 Copy the string into the memory
StrCopy( pchoices + offset, listChoice );
offset += StrLen( listChoice ) + 1;
// CH.7 Unlock the record
MemHandleUnlock( hrecord );
}
首先我们锁定主块（chunk），然后将新建字符串拷入。做完这些工作后，解锁我们所使用的数据库记录句柄。注意，我们没有调用函数DmReleaseRecord（）是因为我们用函数DmQueryRecord（）代替了DmGetRecord（）。
循环操作完成后，我们已有了一个包含每个数据库记录的列表字符串包。现在我们将这些选项发送到列表对象显示：
// CH.7 Create a pointer array from the packed string list
if( (hpchoices = SysFormPointerArrayToStrings( pchoices,
numRecords )) == 0 )
errorExit( MemoryErrorAlert );
ppchoices = MemHandleLock( hpchoices );
// CH.7 Set the list choices
LstSetListChoices( getObject( form, ContactListListList ),
ppchoices, numRecords );
// CH.7 Draw the list
LstDrawList( getObject( form, ContactListListList ) );
// CH.7 We're done
return;
}
我们使用函数SysFormPointerArrayToStrings（）建立了一个指向所建包列表的指针。这样包列表的指针就确定了。
函数LstSetListChoice（）利用包列表的指针来填充每个条目。注意，此函数将清空所有已存在的条目，所以在向此函数发送列表项时，必须是完全的包列表条目。
记住在程序的最后，通过窗体关闭（Form Close）事件来释放所有的内存。
在这一部分的最后，我们绘出了列表框。
调试
在这一类程序的调试中，最好是使用单步调试来检查程序是否能够正常运行。首先调试刚创建的新函数builList（）。在函数的开始处设置一个断点，单步运行，看程序能否顺利运行，特别注意一下内存在最后是否得到释放。
从列表中选中一条记录，看是否能从Contact Detail窗体正确显示，再按下Contact Detail窗体上的Done按钮返回。在Contact Detail窗体上新添加一条记录，再从列表中选择此记录，看能否在Contact Detail窗体上正确显示。
排序
这一部分除了讲述排序外，还将接触到两个新控件，即弹出触发按钮（pop-up triggers）和弹出列表框（pop-up lists）。把弹出列表框加入Contact Detail窗体中可允许我们从其中选择不同的排序选项作为排序标准。最后，我们将添加代码创建或修改在Contact Detail窗体的相应记录，使之能够根据排序标准插入到正确的位置。
弹出触发按钮（pop-up triggers）
弹出触发按钮和普通按钮很相似。它们都有一个标签并响应触发事件。它的特殊之处在于它能够和一个弹出列表框相关联。当按下弹出触发按钮时，弹出列表框就会显示。如果选中列表框上的条目，就会产生事件popSelectEvent。当然，我们还可以利用弹出触发按钮和列表框相关联做一些其它的工作。
对Contacts.rsrc内容的添加
现在向Contact List窗体添加弹出列表框。它将允许我们依据三个排序标准进行排序：时间日期、姓（first name）、名（last name）。
1. 运行构造器；
2. 打开资源文件Contact.rsrc，它位于工程文件夹的Src文件夹中；
3. 双击打开Contact List窗体；
4. 选择Windows | Catalog打开控件面板；
5. 从Catalog窗口中拖动一个标签到窗体上。修改属性为：Left Origin=0，Top origin=149，Label为Sort By：；
6. 拖动一个弹出列表框到窗体上。修改属性维：Object Identifier 为SortList，Left Origin=40，Top Origin=125，Visible Items=3。在下面我们会看到它的位置和新添加的弹出触发按钮正好对齐；
7. 单击选中List Items，然后按下CTRL-K产生第一个条目。修改条目文本为Date and Time；
8. 单击选中List Items，然后按下CTRL-K产生第二个条目。修改条目文本为First Name；
9. 单击选中List Items，然后按下CTRL-K产生第三个条目。修改条目文本为Last Name。
创建弹出触发按钮
1. 拖动一个弹出触发按钮到Contact List 窗体上，其属性如表7-2所示；
Object Identifier 在资源头文件中，构造器用之代表资源ID
Popup ID 弹出触发按钮的资源ID
Left Origin 水平方向上控件的最左端位置
Top Origin 垂直方向上控件的最顶端位置
Width 按钮的宽度
Height 按钮的高度
Usable 用来定义控件是否可见及可用，如果不设置，也可在通过函数调用来实现其可见
Anchor Left 决定当文本长度改变时，按钮文本是以左侧还是右侧为锚点扩展，选中时，按钮文本将向右侧扩展。
Font 标签文本的字体
Label 标签上的文本内容
List ID 和弹出触发按钮相关联的弹出列表框的ID
2．修改属性为：Object Identifier为Trigger，Left Origin=40，Top Origin=149，Width=80，Label 为Date and Time，将List ID设置为刚创建的弹出列表框的ID；
3． 在对Contact List窗体修改完毕，其图如下所示。单击窗体编辑器右上角的X按钮关闭，选择File | Save 保存所做修改。
对Contacts.c内容的添加
首先，在文件头添加排序所必需的变量和常量：
// CH.7 The sort order variable and constants
static Int sortBy;
// CH.7 NOTE: These items match the popup list entries!
#define SORTBY_DATE_TIME 0
#define SORTBY_FIRST_NAME 1
#define SORTBY_LAST_NAME 2
变量sortBy表示在三个排序标准中的当前值。三个常量代表了弹出列表框中的三个排序标准，注意使它们和列表框的每个选项相对应。
排序的初始化
为了建立排序标准，必须添加代码来处理popSelectEvent事件，此事件在弹出列表框的列表选项被选中时触发。下面的代码是如何根据所选项进行排序：
case popSelectEvent:
{
// CH.7 If there is no change, we're done
if( sortBy == event->data.popSelect.selection )
return( true );
// CH.7 Modify sort order variable
sortBy = event->data.popSelect.selection;
// CH.7 Sort the contact database by the new criteria
DmQuickSort( contactsDB, (DmComparF*)sortFunc, sortBy );
// CH.7 Rebuild the list
buildList();
}
break;
首先，在排序标准没有改变时，避免重复排序。然后保存排序标准，因为在Contact Detail窗体中当有新记录或修改记录后，排序发生了改变，这时又用到了排序标准。最后调用函数DmQuickSort（），此函数将排序标准sortBy传递给函数sortFunc（）。在数据库排序完成后，绘制列表框显示。
下面我们研究一下函数sortFunc（）。这个函数可以比较前后两个条目的大小，在将数据库中的两条记录比较后，函数返回一个整数。如果此数大于零，则第一个记录排在前面；如果小于零则第二条记录排在前面；如果为零则说明两记录相同。
// CH.7 This function is called by Palm OS to sort records
static Int sortFunc( CharPtr precord1, CharPtr precord2, Int sortBy )
{
Int sortResult;
// CH.7 Switch based on sort criteria
switch( sortBy )
{
// CH.7 Sort by date and time
case SORTBY_DATE_TIME:
{
DateTimePtr pdateTime1;
DateTimePtr pdateTime2;
Long lDiff;
pdateTime1 = (DateTimePtr)(precord1 + DB_DATE_TIME_START);
pdateTime2 = (DateTimePtr)(precord2 + DB_DATE_TIME_START);
// CH.7 Compare the dates and times
lDiff = (Long)(TimDateTimeToSeconds( pdateTime1 ) / 60 ) -
(Long)(TimDateTimeToSeconds( pdateTime2 ) / 60 );
// CH.7 Date/time #1 is later
if( lDiff > 0 )
sortResult = 1;
else
// CH.7 Date/time #2 is later
if( lDiff < 0 )
sortResult = -1;
else
// CH.7 They are equal
sortResult = 0;
}
break;
代码中首先将时间和日期从所选记录中抽出，然后将其转换成秒进行比较。在这个算法中会将无日期的记录放在列表框的顶部，而将无时间的记录放在相同日期的最底部。由于所转换的秒值有可能超过16位整值，所以我们采用32位长整数来进行比较，相应的设置变量sortResult为16位。
// CH.7 Sort by first name
case SORTBY_FIRST_NAME:
{
sortResult = StrCompare( precord1 + DB_FIRST_NAME_START,
precord2 + DB_FIRST_NAME_START );
}
break;
// CH.7 Sort by last name
case SORTBY_LAST_NAME:
{
sortResult = StrCompare( precord1 + DB_LAST_NAME_START,
precord2 + DB_LAST_NAME_START );
}
break;
调用函数StrCompare（）为first name和last name 排序，此函数定义在Developing Palm OS 3.0 Applications Part II:Sytem Management中。它和ANSI C的函数strcmp（）十分相似，直接给Palm OS返回一个整值。
排序的记录写入列表框
在移动到另一个记录或退出Contact Detail窗体时，函数getField（）都要被调用，因此应该在此函数中添加代码，来保证在添加新记录或修改记录后重新排序。
为达到要求，这些代码应添加在记录内存已被释放但“脏（dirty）”位还没有清除的位置。
// CH.5 If the record has been modified
if( isDirty )
{
CharPtr precord; // CH.5 Points to the DB record
// CH.7 Detach the record from the database
DmDetachRecord( contactsDB, cursor, &hrecord );
// CH.5 Lock the record
precord = MemHandleLock( hrecord );
// CH.5 Get the text for the First Name field
getText( getObject( form, ContactDetailFirstNameField ),
precord, DB_FIRST_NAME_START );
// CH.5 Get the text for the Last Name field
getText( getObject( form, ContactDetailLastNameField ),
precord, DB_LAST_NAME_START );
// CH.5 Get the text for the Phone Number field
getText( getObject( form, ContactDetailPhoneNumberField ),
precord, DB_PHONE_NUMBER_START );
// CH.7 Find the proper position
cursor = DmFindSortPosition( contactsDB, precord, NULL,
(DmComparF*)sortFunc, sortBy );
// CH.5 Unlock the record
MemHandleUnlock( hrecord );
// CH.7 Reattach the record
DmAttachRecord( contactsDB, &cursor, hrecord, NULL );
}
既然只是在记录被改变时重新排序，因此可以先使用isDirty位来判断记录是否已被修改。然后将“脏”的记录从数据库中临时分离出来并将之锁定，最后调用函数DmFindSortPosition（）决定应该在列表框的什么地方插入。此函数的前提示列表已经有了正确的排序，由于我们一次只改变或添加一条记录，因此可以满足要求。最后解锁该记录并将之插入到数据库的新位置。
调试
分别在popSelectEvent事件的顶部、函数sortBy（）的顶部、函数getField（）的if语句的开始处设置断点。检查程序是否能正常运行。下面是一些功能的测试：
l 用三个排序标准分别排序，看数据库是否能根据各个标准正确的排序；
l 向数据库中添加一个记录，看其是否能排在正确的位置；
l 修改一个现存记录，看其是否能排在正确的位置。
下一步做什么
下一章我们将添加更多新的控件，例如表和浏览栏。这一章我们使用列表框显示程序的记录信息已是个不错的方法，下一章我们将修改程序，用表控件来做到这一点。
程序列表
// CH.2 The super-include for the Palm OS
#include <Pilot.h>
// CH.5 Added for the call to GrfSetState()
#include <Graffiti.h>
// CH.3 Our resource file
#include "Contacts_res.h"
// CH.4 Prototypes for our event handler functions
static Boolean contactDetailHandleEvent( EventPtr event );
static Boolean aboutHandleEvent( EventPtr event );
static Boolean enterTimeHandleEvent( EventPtr event );
static Boolean contactListHandleEvent( EventPtr event );
static Boolean menuEventHandler( EventPtr event );
// CH.4 Constants for ROM revision
#define ROM_VERSION_2 0x02003000
#define ROM_VERSION_MIN ROM_VERSION_2
// CH.5 Prototypes for utility functions
static void newRecord( void );
static VoidPtr getObject( FormPtr, Word );
static void setFields( void );
static void getFields( void );
static void setText( FieldPtr, CharPtr );
static void getText( FieldPtr, VoidPtr, Word );
static void setDateTrigger( void );
static void setTimeTrigger( void );
static void setTimeControls( void );
static void buildList( void );
static Int sortFunc( CharPtr, CharPtr, Int );
// CH.5 Our open database reference
static DmOpenRef contactsDB;
static ULong numRecords;
static UInt cursor;
static Boolean isDirty;
static VoidHand hrecord;
// CH.5 Constants that define the database record
#define DB_ID_START 0
#define DB_ID_SIZE (sizeof( ULong ))
#define DB_DATE_TIME_START (DB_ID_START +\
DB_ID_SIZE)
#define DB_DATE_TIME_SIZE (sizeof( DateTimeType ))
#define DB_FIRST_NAME_START (DB_DATE_TIME_START +\
DB_DATE_TIME_SIZE)
#define DB_FIRST_NAME_SIZE 16
#define DB_LAST_NAME_START (DB_FIRST_NAME_START +\
DB_FIRST_NAME_SIZE)
#define DB_LAST_NAME_SIZE 16
#define DB_PHONE_NUMBER_START (DB_LAST_NAME_START +\
DB_LAST_NAME_SIZE)
#define DB_PHONE_NUMBER_SIZE 16
#define DB_RECORD_SIZE (DB_PHONE_NUMBER_START +\
DB_PHONE_NUMBER_SIZE)
// CH.6 Storage for the record's date and time in expanded form
static DateTimeType dateTime;
static Word timeSelect;
#define NO_DATE 0
#define NO_TIME 0x7fff
// CH.7 The error exit macro
#define errorExit(alert) { ErrThrow( alert ); }
// CH.7 Contact list variables
static VoidHand hchoices; // CH.7 Handle to packed choices
static VoidHand hpchoices; // CH.7 Handle to pointers
// CH.7 The sort order variable and constants
static Int sortBy;
// CH.7 NOTE: These items match the popup list entries!
#define SORTBY_DATE_TIME 0
#define SORTBY_FIRST_NAME 1
#define SORTBY_LAST_NAME 2
// CH.2 The main entry point
DWord PilotMain( Word cmd, Ptr, Word )
{
DWord romVersion; // CH.4 ROM version
FormPtr form; // CH.2 A pointer to our form structure
EventType event; // CH.2 Our event structure
Word error; // CH.3 Error word
// CH.4 Get the ROM version
romVersion = 0;
FtrGet( sysFtrCreator, sysFtrNumROMVersion, &romVersion );
// CH.4 If we are below our minimum acceptable ROM revision
if( romVersion < ROM_VERSION_MIN )
{
// CH.4 Display the alert
FrmAlert( LowROMVersionErrorAlert );
// CH.4 PalmOS 1.0 will continuously re-launch this app
// unless we switch to another safe one
if( romVersion < ROM_VERSION_2 )
{
AppLaunchWithCommand( sysFileCDefaultApp,
sysAppLaunchCmdNormalLaunch, NULL );
}
return( 0 );
}
// CH.2 If this is not a normal launch, don't launch
if( cmd != sysAppLaunchCmdNormalLaunch )
return( 0 );
// CH.5 Create a new database in case there isn't one
if( ((error = DmCreateDatabase( 0, "ContactsDB-PPGU", 'PPGU', 'ctct',
false )) != dmErrAlreadyExists) && (error != 0) )
{
// CH.5 Handle db creation error
FrmAlert( DBCreationErrorAlert );
return( 0 );
}
// CH.5 Open the database
contactsDB = DmOpenDatabaseByTypeCreator( 'ctct', 'PPGU',
dmModeReadWrite );
// CH.5 Get the number of records in the database
numRecords = DmNumRecords( contactsDB );
// CH.5 Initialize the record number
cursor = 0;
// CH.7 Choose our starting page
// CH.5 If there are no records, create one
if( numRecords == 0 )
{
newRecord();
FrmGotoForm( ContactDetailForm );
}
else
FrmGotoForm( ContactListForm );
// CH.7 Begin the try block
ErrTry {
// CH.2 Our event loop
do
{
// CH.2 Get the next event
EvtGetEvent( &event, -1 );
// CH.2 Handle system events
if( SysHandleEvent( &event ) )
continue;
// CH.3 Handle menu events
if( MenuHandleEvent( NULL, &event, &error ) )
continue;
// CH.4 Handle form load events
if( event.eType == frmLoadEvent )
{
// CH.4 Initialize our form
switch( event.data.frmLoad.formID )
{
// CH.4 Contact Detail form
case ContactDetailForm:
form = FrmInitForm( ContactDetailForm );
FrmSetEventHandler( form, contactDetailHandleEvent );
break;
// CH.4 About form
case AboutForm:
form = FrmInitForm( AboutForm );
FrmSetEventHandler( form, aboutHandleEvent );
break;
// CH.6 Enter Time form
case EnterTimeForm:
form = FrmInitForm( EnterTimeForm );
FrmSetEventHandler( form, enterTimeHandleEvent );
break;
// CH.7 Contact List form
case ContactListForm:
form = FrmInitForm( ContactListForm );
FrmSetEventHandler( form, contactListHandleEvent );
break;
}
FrmSetActiveForm( form );
}
// CH.2 Handle form events
FrmDispatchEvent( &event );
// CH.2 If it's a stop event, exit
} while( event.eType != appStopEvent );
// CH.7 End the try block and do the catch block
}
ErrCatch( errorAlert )
{
// CH.7 Display the appropriate alert
FrmAlert( errorAlert );
} ErrEndCatch
// CH.5 Close all open forms
FrmCloseAllForms();
// CH.5 Close the database
DmCloseDatabase( contactsDB );
// CH.2 We're done
return( 0 );
}
// CH.4 Our Contact Detail form handler function
static Boolean contactDetailHandleEvent( EventPtr event )
{
FormPtr form; // CH.3 A pointer to our form structure
VoidPtr precord; // CH.6 Points to a database record
// CH.3 Get our form pointer
form = FrmGetActiveForm();
// CH.4 Parse events
switch( event->eType )
{
// CH.4 Form open event
case frmOpenEvent:
{
// CH.2 Draw the form
FrmDrawForm( form );
// CH.5 Draw the database fields
setFields();
}
break;
// CH.5 Form close event
case frmCloseEvent:
{
// CH.5 Store away any modified fields
getFields();
}
break;
// CH.5 Parse the button events
case ctlSelectEvent:
{
// CH.5 Store any field changes
getFields();
switch( event->data.ctlSelect.controlID )
{
// CH.5 First button
case ContactDetailFirstButton:
{
// CH.5 Set the cursor to the first record
if( cursor > 0 )
cursor = 0;
}
break;
// CH.5 Previous button
case ContactDetailPrevButton:
{
// CH.5 Move the cursor back one record
if( cursor > 0 )
cursor--;
}
break;
// CH.5 Next button
case ContactDetailNextButton:
{
// CH.5 Move the cursor up one record
if( cursor < (numRecords - 1) )
cursor++;
}
break;
// CH.5 Last button
case ContactDetailLastButton:
{
// CH.5 Move the cursor to the last record
if( cursor < (numRecords - 1) )
cursor = numRecords - 1;
}
break;
// CH.5 Delete button
case ContactDetailDeleteButton:
{
// CH.5 Remove the record from the database
DmRemoveRecord( contactsDB, cursor );
// CH.5 Decrease the number of records
numRecords--;
// CH.5 Place the cursor at the first record
cursor = 0;
// CH.5 If there are no records left, create one
if( numRecords == 0 )
newRecord();
}
break;
// CH.5 New button
case ContactDetailNewButton:
{
// CH.5 Create a new record
newRecord();
}
break;
// CH.7 Done button
case ContactDetailDoneButton:
{
// CH.7 Load the contact list
FrmGotoForm( ContactListForm );
}
break;
// CH.6 Date selector trigger
case ContactDetailDateSelTrigger:
{
// CH.6 Initialize the date if necessary
if( dateTime.year == NO_DATE )
{
DateTimeType currentDate;
// CH.6 Get the current date
TimSecondsToDateTime( TimGetSeconds(),
¤tDate );
// CH.6 Copy it
dateTime.year = currentDate.year;
dateTime.month = currentDate.month;
dateTime.day = currentDate.day;
}
// CH.6 Pop up the system date selection form
SelectDay( selectDayByDay, &(dateTime.month),
&(dateTime.day), &(dateTime.year),
"Enter Date" );
// CH.6 Get the record
hrecord = DmQueryRecord( contactsDB, cursor );
// CH.6 Lock it down
precord = MemHandleLock( hrecord );
// CH.6 Write the date time field
DmWrite( precord, DB_DATE_TIME_START, &dateTime,
sizeof( DateTimeType ) );
// CH.6 Unlock the record
MemHandleUnlock( hrecord );
// CH.6 Mark the record dirty
isDirty = true;
}
break;
// CH.6 Time selector trigger
case ContactDetailTimeSelTrigger:
{
// CH.6 Pop up our selection form
FrmPopupForm( EnterTimeForm );
}
break;
}
// CH.5 Sync the current record to the fields
setFields();
}
break;
// CH.5 Respond to field tap
case fldEnterEvent:
isDirty = true;
break;
// CH.3 Parse menu events
case menuEvent:
return( menuEventHandler( event ) );
break;
}
// CH.2 We're done
return( false );
}
// CH.4 Our About form event handler function
static Boolean aboutHandleEvent( EventPtr event )
{
FormPtr form; // CH.4 A pointer to our form structure
// CH.4 Get our form pointer
form = FrmGetActiveForm();
// CH.4 Respond to the Open event
if( event->eType == frmOpenEvent )
{
// CH.4 Draw the form
FrmDrawForm( form );
}
// CH.4 Return to the calling form
if( event->eType == ctlSelectEvent )
{
FrmReturnToForm( 0 );
// CH.4 Always return true in this case
return( true );
}
// CH.4 We're done
return( false );
}
// CH.6 Our Enter Time form event handler function
static Boolean enterTimeHandleEvent( EventPtr event )
{
FormPtr form; // CH.6 A form structure pointer
static DateTimeType oldTime; // CH.6 The original time
// CH.6 Get our form pointer
form = FrmGetActiveForm();
// CH.6 Switch on the event
switch( event->eType )
{
// CH.6 Initialize the form
case frmOpenEvent:
{
// CH.6 Store the time value
oldTime = dateTime;
// CH.6 Draw it
FrmDrawForm( form );
// CH.6 Set the time controls
setTimeControls();
}
break;
// CH.6 If a button was repeated
case ctlRepeatEvent:
// CH.6 If a button was pushed
case ctlSelectEvent:
{
Word buttonID; // CH.6 The ID of the button
// CH.6 Set the ID
buttonID = event->data.ctlSelect.controlID;
// CH.6 Switch on button ID
switch( buttonID )
{
// CH.6 Hours button
case EnterTimeHoursPushButton:
// CH.6 Minute Tens button
case EnterTimeMinuteTensPushButton:
// CH.6 Minute Ones button
case EnterTimeMinuteOnesPushButton:
{
// CH.6 If no time was set
if( dateTime.hour == NO_TIME )
{
// CH.6 Set the time to 12 PM
dateTime.hour = 12;
dateTime.minute = 0;
// CH.6 Set the controls
setTimeControls();
}
// CH.6 Clear the old selection if any
if( timeSelect )
CtlSetValue( getObject( form, timeSelect ),
false );
// CH.6 Set the new selection
CtlSetValue( getObject( form, buttonID ), true );
timeSelect = buttonID;
}
break;
// CH.6 Up button
case EnterTimeTimeUpRepeating:
{
// CH.6 If there's no time, do nothing
if( dateTime.hour == NO_TIME )
break;
// CH.6 Based on what push button is selected
switch( timeSelect )
{
// CH.6 Increase hours
case EnterTimeHoursPushButton:
{
// CH.6 Increment hours
dateTime.hour++;
// CH.6 If it was 11 AM, make it 12 AM
if( dateTime.hour == 12 )
dateTime.hour = 0;
// CH.6 If it was 11 PM, make it 12 PM
if( dateTime.hour == 24 )
dateTime.hour = 12;
}
break;
// CH.6 Increase tens of minutes
case EnterTimeMinuteTensPushButton:
{
// CH.6 Increment minutes
dateTime.minute += 10;
// CH.6 If it was 5X, roll over
if( dateTime.minute > 59 )
dateTime.minute -= 60;
}
break;
// CH.6 Increase minutes
case EnterTimeMinuteOnesPushButton:
{
// CH.6 Increment minutes
dateTime.minute++;
// CH.6 If it is zero, subtract ten
if( (dateTime.minute % 10) == 0 )
dateTime.minute -= 10;
}
break;
}
// Revise the controls
setTimeControls();
}
break;
// CH.6 Down button
case EnterTimeTimeDownRepeating:
{
// CH.6 If there's no time, do nothing
if( dateTime.hour == NO_TIME )
break;
// CH.6 Based on what push button is selected
switch( timeSelect )
{
// CH.6 Decrease hours
case EnterTimeHoursPushButton:
{
// CH.6 Decrement hours
dateTime.hour--;
// CH.6 If it was 12 AM, make it 11 AM
if( dateTime.hour == -1 )
dateTime.hour = 11;
// CH.6 If it was 12 PM, make it 11 PM
if( dateTime.hour == 11 )
dateTime.hour = 23;
}
break;
// CH.6 Decrease tens of minutes
case EnterTimeMinuteTensPushButton:
{
// CH.6 Decrement minutes
dateTime.minute -= 10;
// CH.6 If it was 0X, roll over
if( dateTime.minute < 0 )
dateTime.minute += 60;
}
break;
// CH.6 Decrease minutes
case EnterTimeMinuteOnesPushButton:
{
// CH.6 Decrement minutes
dateTime.minute--;
// CH.6 If it is 9, add ten
if( (dateTime.minute % 10) == 9 )
dateTime.minute += 10;
// CH.6 If less than zero, make it 9
if( dateTime.minute < 0 )
dateTime.minute = 9;
}
break;
}
// CH.6 Revise the controls
setTimeControls();
}
break;
// CH.6 AM button
case EnterTimeAMPushButton:
{
// CH.6 If no time was set
if( dateTime.hour == NO_TIME )
{
// CH.6 Set the time to 12 AM
dateTime.hour = 0;
dateTime.minute = 0;
// CH.6 Set the controls
setTimeControls();
}
// CH.6 If it is PM
if( dateTime.hour > 11 )
{
// CH.6 Change to AM
dateTime.hour -= 12;
// CH.6 Set the controls
setTimeControls();
}
}
break;
// CH.6 PM button
case EnterTimePMPushButton:
{
// CH.6 If no time was set
if( dateTime.hour == NO_TIME )
{
// CH.6 Set the time to 12 PM
dateTime.hour = 12;
dateTime.minute = 0;
// CH.6 Set the controls
setTimeControls();
}
// CH.6 If it is AM
if( dateTime.hour < 12 )
{
// CH.6 Change to PM
dateTime.hour += 12;
// CH.6 Set the controls
setTimeControls();
}
}
break;
// CH.6 No Time checkbox
case EnterTimeNoTimeCheckbox:
{
// CH.6 If we are unchecking the box
if( dateTime.hour == NO_TIME )
{
// CH.6 Set the time to 12 PM
dateTime.hour = 12;
dateTime.minute = 0;
// CH.6 Set the controls
setTimeControls();
// CH.6 Set the new selection
timeSelect = EnterTimeHoursPushButton;
CtlSetValue( getObject( form, timeSelect ),
true );
}
else
// CH.6 If we are checking the box
dateTime.hour = NO_TIME;
// CH.6 Set the controls
setTimeControls();
}
break;
// CH.6 Cancel button
case EnterTimeCancelButton:
{
// CH.6 Restore time
dateTime = oldTime;
// CH.6 Return to calling form
FrmReturnToForm( 0 );
}
// CH.6 Always return true
return( true );
// CH.6 OK button
case EnterTimeOKButton:
{
VoidPtr precord; // CH.6 Points to the record
// CH.6 Lock it down
precord = MemHandleLock( hrecord );
// CH.6 Write the date time field
DmWrite( precord, DB_DATE_TIME_START, &dateTime,
sizeof( DateTimeType ) );
// CH.6 Unlock the record
MemHandleUnlock( hrecord );
// CH.6 Mark the record dirty
isDirty = true;
// CH.6 Return to the Contact Details form
FrmReturnToForm( 0 );
// CH.6 Update the field
setTimeTrigger();
}
// CH.6 Always return true
return( true );
}
}
break;
}
// CH.6 We're done
return( false );
}
// CH.7 Our Contact List form event handler function
static Boolean contactListHandleEvent( EventPtr event )
{
FormPtr form; // CH.7 A form structure pointer
// CH.7 Get our form pointer
form = FrmGetActiveForm();
// CH.7 Parse events
switch( event->eType )
{
// CH.7 Form open event
case frmOpenEvent:
{
// CH.7 Draw the form
FrmDrawForm( form );
// CH.7 Build the list
buildList();
}
break;
// CH.7 Form close event
case frmCloseEvent:
{
// CH.7 Unlock and free things here
MemHandleUnlock( hpchoices );
MemHandleFree( hpchoices );
MemHandleUnlock( hchoices );
MemHandleFree( hchoices );
hchoices = 0;
}
break;
// CH.7 Respond to a list selection
case lstSelectEvent:
{
// CH.7 Set the database cursor to the selected contact
cursor = event->data.lstSelect.selection;
// CH.7 Go to contact details
FrmGotoForm( ContactDetailForm );
}
break;
// CH.7 Respond to a menu event
case menuEvent:
return( menuEventHandler( event ) );
// CH.7 Respond to the popup trigger
case popSelectEvent:
{
// CH.7 If there is no change, we're done
if( sortBy == event->data.popSelect.selection )
return( true );
// CH.7 Modify sort order variable
sortBy = event->data.popSelect.selection;
// CH.7 Sort the contact database by the new criteria
DmQuickSort( contactsDB, (DmComparF*)sortFunc, sortBy );
// CH.7 Rebuild the list
buildList();
}
break;
} // CH.7 End of the event switch statement
// CH.7 We're done
return( false );
}
// CH.3 Handle menu events
Boolean menuEventHandler( EventPtr event )
{
FormPtr form; // CH.3 A pointer to our form structure
Word index; // CH.3 A general purpose control index
FieldPtr field; // CH.3 Used for manipulating fields
// CH.3 Get our form pointer
form = FrmGetActiveForm();
// CH.3 Erase the menu status from the display
MenuEraseStatus( NULL );
// CH.4 Handle options menu
if( event->data.menu.itemID == OptionsAboutContacts )
{
// CH.4 Pop up the About form as a Dialog
FrmPopupForm( AboutForm );
return( true );
}
// CH.3 Handle graffiti help
if( event->data.menu.itemID == EditGraffitiHelp )
{
// CH.3 Pop up the graffiti reference based on
// the graffiti state
SysGraffitiReferenceDialog( referenceDefault );
return( true );
}
// CH.3 Get the index of our field
index = FrmGetFocus( form );
// CH.3 If there is no field selected, we're done
if( index == noFocus )
return( false );
// CH.3 Get the pointer of our field
field = FrmGetObjectPtr( form, index );
// CH.3 Do the edit command
switch( event->data.menu.itemID )
{
// CH.3 Undo
case EditUndo:
FldUndo( field );
break;
// CH.3 Cut
case EditCut:
FldCut( field );
break;
// CH.3 Copy
case EditCopy:
FldCopy( field );
break;
// CH.3 Paste
case EditPaste:
FldPaste( field );
break;
// CH.3 Select All
case EditSelectAll:
{
// CH.3 Get the length of the string in the field
Word length = FldGetTextLength( field );
// CH.3 Sound an error if appropriate
if( length == 0 )
{
SndPlaySystemSound( sndError );
return( false );
}
// CH.3 Select the whole string
FldSetSelection( field, 0, length );
}
break;
// CH.3 Bring up the keyboard tool
case EditKeyboard:
SysKeyboardDialogV10();
break;
}
// CH.3 We're done
return( true );
}
// CH.5 This function creates and initializes a new record
static void newRecord( void )
{
VoidPtr precord; // CH.5 Pointer to the record
// CH.7 Create the database record and get a handle to it
if( (hrecord = DmNewRecord( contactsDB, &cursor,
DB_RECORD_SIZE )) == NULL )
errorExit( MemoryErrorAlert );
// CH.5 Lock down the record to modify it
precord = MemHandleLock( hrecord );
// CH.5 Clear the record
DmSet( precord, 0, DB_RECORD_SIZE, 0 );
// CH.6 Initialize the date and time
MemSet( &dateTime, sizeof( dateTime ), 0 );
dateTime.year = NO_DATE;
dateTime.hour = NO_TIME;
DmWrite( precord, DB_DATE_TIME_START, &dateTime,
sizeof( DateTimeType ) );
// CH.5 Unlock the record
MemHandleUnlock( hrecord );
// CH.5 Clear the busy bit and set the dirty bit
DmReleaseRecord( contactsDB, cursor, true );
// CH.5 Increment the total record count
numRecords++;
// CH.5 Set the dirty bit
isDirty = true;
// CH.5 We're done
return;
}
// CH.5 A time saver: Gets object pointers based on their ID
static VoidPtr getObject( FormPtr form, Word objectID )
{
Word index; // CH.5 The object index
// CH.5 Get the index
index = FrmGetObjectIndex( form, objectID );
// CH.5 Return the pointer
return( FrmGetObjectPtr( form, index ) );
}
// CH.5 Gets the current database record and displays it
// in the detail fields
static void setFields( void )
{
FormPtr form; // CH.5 The contact detail form
CharPtr precord; // CH.5 A record pointer
Word index; // CH.5 The object index
// CH.5 Get the contact detail form pointer
form = FrmGetActiveForm();
// CH.5 Get the current record
hrecord = DmQueryRecord( contactsDB, cursor );
// CH.6 Initialize the date and time variable
precord = MemHandleLock( hrecord );
MemMove( &dateTime, precord + DB_DATE_TIME_START,
sizeof( dateTime ) );
// CH.6 Initialize the date control
setDateTrigger();
// CH.6 Initialize the time control
setTimeTrigger();
// CH.5 Set the text for the First Name field
setText( getObject( form, ContactDetailFirstNameField ),
precord + DB_FIRST_NAME_START );
// CH.5 Set the text for the Last Name field
setText( getObject( form, ContactDetailLastNameField ),
precord + DB_LAST_NAME_START );
// CH.5 Set the text for the Phone Number field
setText( getObject( form, ContactDetailPhoneNumberField ),
precord + DB_PHONE_NUMBER_START );
MemHandleUnlock( hrecord );
// CH.5 If the record is already dirty, it's new, so set focus
if( isDirty )
{
// CH.3 Get the index of our field
index = FrmGetObjectIndex( form, ContactDetailFirstNameField );
// CH.3 Set the focus to the First Name field
FrmSetFocus( form, index );
// CH.5 Set upper shift on
GrfSetState( false, false, true );
}
// CH.5 We're done
return;
}
// CH.5 Puts any field changes in the record
void getFields( void )
{
FormPtr form; // CH.5 The contact detail form
// CH.5 Get the contact detail form pointer
form = FrmGetActiveForm();
// CH.5 Turn off focus
FrmSetFocus( form, -1 );
// CH.5 If the record has been modified
if( isDirty )
{
CharPtr precord; // CH.5 Points to the DB record
// CH.7 Detach the record from the database
DmDetachRecord( contactsDB, cursor, &hrecord );
// CH.5 Lock the record
precord = MemHandleLock( hrecord );
// CH.5 Get the text for the First Name field
getText( getObject( form, ContactDetailFirstNameField ),
precord, DB_FIRST_NAME_START );
// CH.5 Get the text for the Last Name field
getText( getObject( form, ContactDetailLastNameField ),
precord, DB_LAST_NAME_START );
// CH.5 Get the text for the Phone Number field
getText( getObject( form, ContactDetailPhoneNumberField ),
precord, DB_PHONE_NUMBER_START );
// CH.7 Find the proper position
cursor = DmFindSortPosition( contactsDB, precord, NULL,
(DmComparF*)sortFunc, sortBy );
// CH.5 Unlock the record
MemHandleUnlock( hrecord );
// CH.7 Reattach the record
DmAttachRecord( contactsDB, &cursor, hrecord, NULL );
}
// CH.5 Reset the dirty bit
isDirty = false;
// CH.5 We're done
return;
}
// CH.5 Set the text in a field
static void setText( FieldPtr field, CharPtr text )
{
VoidHand hfield; // CH.5 Handle of field text
CharPtr pfield; // CH.5 Pointer to field text
// CH.5 Get the current field handle
hfield = FldGetTextHandle( field );
// CH.5 If we have a handle
if( hfield != NULL )
{
// CH.5 Resize it
if( MemHandleResize( hfield, StrLen( text ) + 1 ) != 0 )
errorExit( MemoryErrorAlert );
}
else
// CH.5 Allocate a handle for the string
{
hfield = MemHandleNew( StrLen( text ) + 1 );
if( hfield == NULL )
errorExit( MemoryErrorAlert );
}
// CH.5 Lock it
pfield = MemHandleLock( hfield );
// CH.5 Copy the string
StrCopy( pfield, text );
// CH.5 Unlock it
MemHandleUnlock( hfield );
// CH.5 Give it to the field
FldSetTextHandle( field, hfield );
// CH.5 Draw the field
FldDrawField( field );
// CH.5 We're done
return;
}
// CH.5 Get the text from a field
static void getText( FieldPtr field, VoidPtr precord, Word offset )
{
CharPtr pfield; // CH.5 Pointer to field text
// CH.5 Get the text pointer
pfield = FldGetTextPtr( field );
// CH.5 Copy it
DmWrite( precord, offset, pfield, StrLen( pfield ) );
// CH.5 We're done
return;
}
// CH.6 Set the Contact Detail date selector trigger
static void setDateTrigger( void )
{
FormPtr form; // CH.5 The contact detail form
// CH.6 Get the contact detail form pointer
form = FrmGetActiveForm();
// CH.6 If there is no date
if( dateTime.year == NO_DATE )
{
CtlSetLabel( getObject( form, ContactDetailDateSelTrigger ),
" " );
}
else
// CH.6 If there is a date
{
Char dateString[dateStringLength];
// CH.6 Get the date string
DateToAscii( dateTime.month, dateTime.day, dateTime.year,
(DateFormatType)PrefGetPreference( prefDateFormat ), dateString );
// CH.6 Set the selector trigger label
CtlSetLabel( getObject( form, ContactDetailDateSelTrigger ),
dateString );
}
// CH.6 We're done
return;
}
// CH.6 Set the Contact Detail time selector trigger
static void setTimeTrigger( void )
{
FormPtr form; // CH.5 The contact detail form
// CH.6 Get the contact detail form pointer
form = FrmGetActiveForm();
// CH.6 If there's no time
if( dateTime.hour == NO_TIME )
{
CtlSetLabel( getObject( form, ContactDetailTimeSelTrigger ),
" " );
}
else
// CH.6 If there is a time
{
Char timeString[timeStringLength];
// CH.6 Get the time string
TimeToAscii( dateTime.hour, dateTime.minute,
(TimeFormatType)PrefGetPreference( prefTimeFormat ), timeString );
// CH.6 Set the selector trigger label
CtlSetLabel( getObject( form, ContactDetailTimeSelTrigger ),
timeString );
}
// CH.6 We're done
return;
}
// CH.6 Set the controls in the Enter Time form based on dateTime
static void setTimeControls( void )
{
FormPtr form;
ControlPtr hourButton;
ControlPtr minuteTensButton;
ControlPtr minuteOnesButton;
ControlPtr amButton;
ControlPtr pmButton;
ControlPtr noTimeCheckbox;
Char labelString[3];
SWord hour;
// CH.6 Get the form
form = FrmGetActiveForm();
// CH.6 Get the control pointers
hourButton = getObject( form, EnterTimeHoursPushButton );
minuteTensButton = getObject( form,
EnterTimeMinuteTensPushButton );
minuteOnesButton = getObject( form,
EnterTimeMinuteOnesPushButton );
amButton = getObject( form, EnterTimeAMPushButton );
pmButton = getObject( form, EnterTimePMPushButton );
noTimeCheckbox = getObject( form, EnterTimeNoTimeCheckbox );
// CH.6 If there is a time
if( dateTime.hour != NO_TIME )
{
// CH.6 Update the hour
hour = dateTime.hour % 12;
if( hour == 0 )
hour = 12;
CtlSetLabel( hourButton,
StrIToA( labelString, hour ) );
// CH.6 Update the minute tens
CtlSetLabel( minuteTensButton,
StrIToA( labelString, dateTime.minute / 10 ) );
// CH.6 Update the minute ones
CtlSetLabel( minuteOnesButton,
StrIToA( labelString, dateTime.minute % 10 ) );
// CH.6 Update AM
CtlSetValue( amButton, (dateTime.hour < 12) );
// CH.6 Update PM
CtlSetValue( pmButton, (dateTime.hour > 11) );
// CH.6 Uncheck the no time checkbox
CtlSetValue( noTimeCheckbox, false );
}
else
// If there is no time
{
// CH.6 Update the hour
CtlSetValue( hourButton, false );
CtlSetLabel( hourButton, "" );
// CH.6 Update the minute tens
CtlSetValue( minuteTensButton, false );
CtlSetLabel( minuteTensButton, "" );
// CH.6 Update the minute ones
CtlSetValue( minuteOnesButton, false );
CtlSetLabel( minuteOnesButton, "" );
// CH.6 Update AM
CtlSetValue( amButton, false );
// CH.6 Update PM
CtlSetValue( pmButton, false );
// CH.6 Uncheck the no time checkbox
CtlSetValue( noTimeCheckbox, true );
}
// CH.6 We're done
return;
}
// CH.7 Builds the contact list
static void buildList( void )
{
FormPtr form; // CH.6 A form structure pointer
Int choice; // CH.7 The list choice we're doing
CharPtr precord; // CH.7 Pointer to a record
Char listChoice[dateStringLength + 1 + // CH.7 We
timeStringLength + 1 + // build
DB_FIRST_NAME_SIZE + // list
DB_LAST_NAME_SIZE]; // choices here
// CH.7 The current list choice
CharPtr pchoices; // CH.7 Pointer to packed choices
UInt offset; // CH.7 Offset into packed strings
VoidPtr ppchoices; // CH.7 Pointer to pointers to choices
// CH.6 Get our form pointer
form = FrmGetActiveForm();
// CH.7 Put the list choices in a packed string
for( choice = 0; choice < numRecords; choice++ )
{
// CH.7 Get the record
hrecord = DmQueryRecord( contactsDB, choice );
precord = MemHandleLock( hrecord );
// CH.7 Get the date and time
MemMove( &dateTime, precord + DB_DATE_TIME_START,
sizeof( dateTime ) );
// CH.7 Clear the list choice string
*listChoice = '\0';
// CH.7 Add the date string if any
if( dateTime.year != NO_DATE )
{
DateToAscii( dateTime.month, dateTime.day,
dateTime.year,
(DateFormatType)PrefGetPreference(
prefDateFormat ), listChoice );
StrCat( listChoice, " " );
}
// CH.7 Add the time string if any
if( dateTime.hour != NO_TIME )
{
TimeToAscii( dateTime.hour, dateTime.minute,
(TimeFormatType)PrefGetPreference(
prefTimeFormat ), listChoice +
StrLen( listChoice ) );
StrCat( listChoice, " " );
}
// CH.7 Append the first name
StrCat( listChoice, precord + DB_FIRST_NAME_START );
StrCat( listChoice, " " );
// CH.7 Append the last name
StrCat( listChoice, precord + DB_LAST_NAME_START );
// CH.7 Allocate memory for the list entry string
// CH.7 If this is the first choice
if( hchoices == 0 )
{
// CH.7 Allocate the storage for the choice
if( (hchoices = MemHandleNew(
StrLen( listChoice ) + 1 )) == 0 )
errorExit( MemoryErrorAlert );
// CH.7 Initial offset points to the start
offset = 0;
}
else
// CH.7 If this is a subsequent choice
{
// CH.7 Unlock
MemHandleUnlock( hchoices );
// CH.7 Resize
if( MemHandleResize( hchoices, offset +
StrLen( listChoice ) + 1 ) )
errorExit( MemoryErrorAlert );
}
// CH.7 Lock
pchoices = MemHandleLock( hchoices );
// CH.7 Copy the string into the memory
StrCopy( pchoices + offset, listChoice );
offset += StrLen( listChoice ) + 1;
// CH.7 Unlock the record
MemHandleUnlock( hrecord );
}
// CH.7 Create a pointer array from the packed string list
if( (hpchoices = SysFormPointerArrayToStrings( pchoices,
numRecords )) == 0 )
errorExit( MemoryErrorAlert );
ppchoices = MemHandleLock( hpchoices );
// CH.7 Set the list choices
LstSetListChoices( getObject( form, ContactListListList ),
ppchoices, numRecords );
// CH.7 Draw the list
LstDrawList( getObject( form, ContactListListList ) );
// CH.7 We're done
return;
}
// CH.7 This function is called by Palm OS to sort records
static Int sortFunc( CharPtr precord1, CharPtr precord2, Int sortBy )
{
Int sortResult;
// CH.7 Switch based on sort criteria
switch( sortBy )
{
// CH.7 Sort by date and time
case SORTBY_DATE_TIME:
{
DateTimePtr pdateTime1;
DateTimePtr pdateTime2;
Long lDiff;
pdateTime1 = (DateTimePtr)(precord1 + DB_DATE_TIME_START);
pdateTime2 = (DateTimePtr)(precord2 + DB_DATE_TIME_START);
// CH.7 Compare the dates and times
lDiff = (Long)(TimDateTimeToSeconds( pdateTime1 ) / 60 ) -
(Long)(TimDateTimeToSeconds( pdateTime2 ) / 60 );
// CH.7 Date/time #1 is later
if( lDiff > 0 )
sortResult = 1;
else
// CH.7 Date/time #2 is later
if( lDiff < 0 )
sortResult = -1;
else
// CH.7 They are equal
sortResult = 0;
}
break;
// CH.7 Sort by first name
case SORTBY_FIRST_NAME:
{
sortResult = StrCompare( precord1 + DB_FIRST_NAME_START,
precord2 + DB_FIRST_NAME_START );
}
break;
// CH.7 Sort by last name
case SORTBY_LAST_NAME:
{
sortResult = StrCompare( precord1 + DB_LAST_NAME_START,
precord2 + DB_LAST_NAME_START );
}
break;
}
// CH.7 We're done
return( sortResult );
}
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