Web site:  http://openamiga.org  Open Amiga - Projects20241122 17:40
Content ID:  23
Content title:  Global pointers
Guideline - Mouse pointers
<- Back to guidelines

Content
    
- Intro
- Example of use
- Load and Discard functions
- Example fallback bitmap


Intro
Openamiga encourages its developers to use the mouse pointers defined in the Extended default mouse pointer types project where ever possible to heighten the user experience.

You can download the pointers here.

Below is some example code that can be used for this purpose.

Points to remember:
- Always reset the mouse pointer before closing your window.
    This includes iconification of your window
- Always reset the mouse pointer before discarding your loaded pointers.

This will reset your pointer to the normal system pointer: 
IIntuition->SetWindowPointer(window, TAG_DONE);


Example of use 

 ...

 struct DiskObject *diskObject;
 struct Object *pointrObj;
 STRPTR name = "cellpointer";  // do not specify pointer filename or path
                               // simply state the name

 ...

 LoadPointer(name,
             &diskObject,
             &pointerObj,
             &fallbackPointer,
             screen);

 ...
 
 IIntuition->SetWindowPointer(window, WA_Pointer, pointerObj, TAG_DONE);

 ...

 IIntuition->SetWindowPointer(window, TAG_DONE); // reset pointer

 ...

 DiscardPointer(&diskObject,&pointerObj); // Must discard the loaded data

 ...


Load and Discard functions 
void LoadPointer(STRPTR name, struct DiskObject **diskObject,
                 struct Object **pointerObj, struct BitMap *fallback,
                 struct Screen *screen)
{
 *pointerObj=NULL;

 *diskObject = IIcon->GetIconTags(NULL, ICONGETA_GetDefaultName, name, ICONGETA_FailIfUnavailable, TRUE, TAG_DONE);

 if(*diskObject)
 {
  UBYTE *image = NULL;
  int32 w,h;
  char *xoffset_tool,*yoffset_tool;
  int32 xoffset=0, yoffset=0;
  IIcon->LayoutIcon(*diskObject,screen,TAG_DONE);
  IIcon->IconControl(*diskObject,ICONCTRLA_GetImageData1,&image,
                                 ICONCTRLA_GetWidth,&w,
                                 ICONCTRLA_GetHeight,&h,
                     TAG_DONE);
                          
  if((xoffset_tool = (char *)IIcon->FindToolType((*diskObject)->do_ToolTypes, (STRPTR)"XOFFSET")))
  {
   char *tmp;
   xoffset = strtol(xoffset_tool,&tmp,0);
  }
  
  if((yoffset_tool = (char *)IIcon->FindToolType((*diskObject)->do_ToolTypes, (STRPTR)"YOFFSET")))
  {
   char *tmp;
   yoffset = strtol(yoffset_tool,&tmp,0);
  }
  
  if(image)
  {
   *pointerObj = (struct Object *)IIntuition->NewObject(NULL,(STRPTR)"pointerclass",
    POINTERA_BitMap,fallback,
    POINTERA_ImageData,image,
    POINTERA_Width,w,
    POINTERA_Height,h,
    POINTERA_XOffset,-xoffset,
    POINTERA_YOffset,-yoffset,TAG_DONE);
  }
  else
  {
   *pointerObj = NULL;
  }
 }
}

void DiscardPointer(struct DiskObject **diskObject, struct Object **pointerObj)
{
 if(*pointerObj)
 {
  IIntuition->DisposeObject(*pointerObj);
 }
 
 if(*diskObject)
 {
  IIcon->FreeDiskObject(*diskObject);
 }
}


Example fallback bitmap 
static UWORD fallbackPointerData[]=
{
 0x0400,0x0e00,0x0e00,0x0e00,0x0e00,0x0f80,0x0fe0,0x4ff8,
 0xeff8,0x7ff8,0x3ff8,0x1ff8,0x1ff8,0x1ff8,0x0ff0,0x00f0,
 
 0x0400,0x0a00,0x0a00,0x0a00,0x0a00,0x0b80,0x0ae0,0x4ab8,
 0xa828,0x5808,0x2808,0x1008,0x1008,0x1008,0x0810,0x0ff0
};

static struct BitMap fallbackPointer=
{
 2,16,0,2,0,{(PLANEPTR)fallbackPointerData,(PLANEPTR)(fallbackPointerData+16)}
};