hello.c

CD_PALM程序设计入门

#include <Pilot.h>
#include "hello.h"



static FieldPtr SetFieldTextFromHandle(Word fieldID, Handle txtH)
{
    Handle          oldTxtH;
    FormPtr         frm=FrmGetActiveForm();
    FieldPtr        fldP;
    

    // get the field and the field's current text handle.
    fldP =FrmGetObjectPtr(frm,FrmGetObjectIndex(frm,fieldID));
    ErrNonFatalDisplayIf(!fldP, "missing field");

     oldTxtH = FldGetTextHandle(fldP);

    // set the field's text to the new text.
    FldSetTextHandle(fldP, txtH);
    FldDrawField(fldP);

    // free the handle AFTER we call FldSetTextHandle().
    if (oldTxtH)
           MemHandleFree( (VoidHand) oldTxtH );

    return fldP;

}

// Allocates new handle and copies incoming string
static FieldPtr SetFieldTextFromStr(Word fieldID, CharPtr strP)
{
    Handle      txtH;

    // get some space in which to stash the string
    txtH = (Handle) MemHandleNew(StrLen(strP)+1);
    if (!txtH)
       return NULL;

    // copy the string to the locked handle.
    StrCopy(MemHandleLock( (VoidHand) txtH),strP);

    // unlock the string handle.
    MemHandleUnlock( (VoidHand) txtH);

    // set the field to the handle
    return SetFieldTextFromHandle(fieldID, txtH);
}

static void ClearFieldText(Word fieldID)
{
        SetFieldTextFromHandle(fieldID, NULL);
}

static Word MyAlert(void)
{
      FormPtr previousForm=FrmGetActiveForm();
      FormPtr frm = FrmInitForm(formAlert);
      Word hitButton;

      FrmSetActiveForm(frm);
      hitButton=FrmDoDialog(frm);
      
      if (previousForm)
              FrmSetActiveForm(previousForm);
      FrmDeleteForm(frm);
      return hitButton;

}

static Boolean HelloFormEventHandler(EventPtr event)
{
	Boolean handled = false;

   
	switch (event->eType) {

      case ctlSelectEvent:
           
                             
           if (event->data.ctlSelect.controlID==cmdButton1)
           {
               ClearFieldText(cmdField);
           }
           if (event->data.ctlSelect.controlID==cmdButton2)
           {
               SetFieldTextFromStr(cmdField, "gGgGg");
           }
           if (event->data.ctlSelect.controlID==cmdButton3)
           {
              // This example simply removes any uppercase characters in the field
                
              FormPtr    frm=FrmGetActiveForm();
              FieldPtr   fld;
              Handle     h;

              // get the field and the field's current text handle.
              fld     = FrmGetObjectPtr(frm, FrmGetObjectIndex(frm, cmdField));
              h=FldGetTextHandle(fld);
              if (h)
              {
                 CharPtr s;
                 FldSetTextHandle(fld, NULL);
                 s = MemHandleLock( (VoidHand) h);
                 // change contents of s
                 while (*s != '\0')
                 {
                    if (*s >= 'A' && *s <= 'Z')
                       StrCopy(s, s+1);
                    else
                       s++;
                 }
                 MemHandleUnlock( (VoidHand) h);
                 FldSetTextHandle(fld,h);
                 FldDrawField(fld);
            }
           
         
           }
        handled=true;
        break;

		case frmOpenEvent:

			FrmDrawForm(FrmGetActiveForm());
			handled = true;
			break;

      case menuEvent:
         if(event->data.menu.itemID==cmdMenu_1)
             SndPlaySystemSound(sndInfo);
         else
             SndPlaySystemSound(sndStartUp);
         handled=true;
         break;

	}

	return (handled);
}

static Boolean ApplicationHandleEvent(EventPtr event)
{
	FormPtr form;
	Word    formID;
	Boolean handled = false;

	if (event->eType == frmLoadEvent) {
		formID = event->data.frmLoad.formID;
		form   = FrmInitForm(formID);

		FrmSetActiveForm(form);

		switch (formID)  {
			case formID_hello:
            FrmSetEventHandler(form, HelloFormEventHandler);
				break;
		}

		handled = true;
	}

	return (handled);
}

static void StartApplication()
{
	FrmGotoForm(formID_hello);
}

static void EventLoop(void)
{
	short			err;
	int			formID;
	FormPtr		form;
	EventType		event;

	do {
		EvtGetEvent(&event, evtWaitForever);

		if (SysHandleEvent(&event)) continue;

		if (MenuHandleEvent(NULL, &event, &err))	continue;

		if (ApplicationHandleEvent(&event)) continue;

		FrmDispatchEvent(&event);

	} while (event.eType != appStopEvent);
}

static void StopApplication(void)
{
	FrmCloseAllForms();
}

DWord PilotMain (Word cmd, Ptr cmdPBP, Word launchFlags)
{
	if (cmd ==  sysAppLaunchCmdNormalLaunch) {
		StartApplication();
		EventLoop();
		StopApplication();
	}

	return (0);
}