Form not updated in PalmOS 3.5 and bus errors if I try to fix it

[McCollister, Mike]

Hi,

I have a program that does not get its form properly updated with Palm OS
3.5 DR4.

I am responding to frmUpdateEvent and calling my MainUpdateForm() routine
that calls FrmDrawForm(pForm); However, within the MainUpdateForm, I call my
UpdateBatteryLevel() function that puts a bitmap on the form to show the
current battery level. When this is called, I get a bus error in POSE.

Any ideas on what the problem might be?

Here is some code of interest.


// from MainEventHandler()
      case frmUpdateEvent:
         MainUpdateForm();
         break;


static void MainUpdateForm(void)
{
   // ??? FormPtr pForm = FrmGetActiveForm();
   FormPtr pForm = FrmGetFormPtr(formID_main);

   FrmDrawForm(pForm);

   // update battery level
   UpdateBatteryLevel(true);
}

static void UpdateBatteryLevel(Boolean forceUpdate)
{
   VoidHand hBitmap;
   WinHandle hScreen;
   Int batteryBitmapID = bitmapID_battery100;
   Byte batteryLevelPercent;
   Boolean pluggedIn;
   RectangleType rect;
   static int lastBatteryLevel = -1;
   int currentBatteryLevel;

   GetVoltage(NULL, &batteryLevelPercent, &pluggedIn);

   if(batteryLevelPercent <= 10)
      batteryBitmapID = bitmapID_battery000;
   else if(batteryLevelPercent <= 20)
      batteryBitmapID = bitmapID_battery020;
   else if(batteryLevelPercent <= 40)
      batteryBitmapID = bitmapID_battery040;
   else if(batteryLevelPercent <= 60)
      batteryBitmapID = bitmapID_battery060;
   else if(batteryLevelPercent <= 80)
      batteryBitmapID = bitmapID_battery080;
   else if(batteryLevelPercent <= 100)
      batteryBitmapID = bitmapID_battery100;

   // update only if level has changed
   currentBatteryLevel = batteryBitmapID + (pluggedIn ? 1000 : 0);
   if(lastBatteryLevel == currentBatteryLevel && !forceUpdate)
      return;
   lastBatteryLevel = currentBatteryLevel;

   hScreen = WinSetDrawWindow(hOffscreen);

   // draw battery level
   hBitmap = DmGet1Resource('Tbmp', batteryBitmapID);
   WinDrawBitmap(MemHandleLock(hBitmap), 0, 0);
   MemHandleUnlock(hBitmap);

   // drawing charging
   if(pluggedIn) {
      if(batteryLevelPercent < 100)
         hBitmap = DmGet1Resource('Tbmp', bitmapID_charging);
      else
         hBitmap = DmGet1Resource('Tbmp', bitmapID_chargingComplete);
      WinDrawBitmap(MemHandleLock(hBitmap), CHARGING_LEFT, CHARGING_TOP);
      MemHandleUnlock(hBitmap);
   }

   // set display back to screen
   hOffscreen = WinSetDrawWindow(hScreen);

   // copy battery level to screen
   rect.topLeft.x = 0;
   rect.topLeft.y = 0;
   rect.extent.x  = BATTERY_WIDTH;
   rect.extent.y  = BATTERY_HEIGHT;
   WinCopyRectangle(hOffscreen, hScreen, &rect,
                    BATTERY_LEFT, BATTERY_TOP, scrCopy);
}

// note here that hOffscreen is created with my StartApplication code.
// Here is a portion.

   hOffscreen = WinCreateOffscreenWindow(BATTERY_WIDTH, BATTERY_HEIGHT,
                                         screenFormat, &err);

Thanks,

Mike McCollister

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