Inside Macintosh: QuickTime Components
Listing 7-1 supplies the component dispatchers for the sequence grabber panel component together with the required functions for open, close, can do, and version.
Listing 1 Implementing the required functions
#define sgcPictShowTicksType 'TICK'
typedef struct {
ComponentInstance self;
ControlHandle ch;
} PictPanelGlobalsRecord, *PictPanelGlobals;
/* only for PICT channels */
pascal ComponentResult SGSetShowTickCount (SGChannel c,
Boolean show) = {0x2f3c,2,0x100,0x7000,0xA82A};
pascal ComponentResult SGGetShowTickCount (SGChannel c,
Boolean *show) = {0x2f3c,4,0x101,0x7000,0xA82A};
pascal ComponentResult PictPanelDispatcher
(ComponentParameters *params, Handle storage)
{
OSErr err = badComponentSelector;
ComponentFunction componentProc = 0;
switch (params->what) {
case kComponentOpenSelect:
componentProc = PictPanelOpen; break;
case kComponentCloseSelect:
componentProc = PictPanelClose; break;
case kComponentCanDoSelect:
componentProc = PictPanelCanDo; break;
case kComponentVersionSelect:
componentProc = PictPanelVersion; break;
case kSGCPanelGetDitlSelect:
componentProc = PictPanelPanelGetDitl; break;
case kSGCPanelInstallSelect:
componentProc = PictPanelPanelInstall; break;
case kSGCPanelItemSelect:
componentProc = PictPanelPanelItem; break;
case kSGCPanelRemoveSelect:
componentProc = PictPanelPanelRemove; break;
case kSGCPanelGetSettingsSelect:
componentProc = PictPanelPanelGetSettings; break;
case kSGCPanelSetSettingsSelect:
componentProc = PictPanelPanelSetSettings; break;
}
if (componentProc)
err = CallComponentFunctionWithStorage (storage, params,
componentProc);
return err;
}
pascal ComponentResult PictPanelCanDo (PictPanelGlobals store,
short ftnNumber)
{
switch (ftnNumber) {
case kComponentOpenSelect:
case kComponentCloseSelect:
case kComponentCanDoSelect:
case kComponentVersionSelect:
case kSGCPanelGetDitlSelect:
case kSGCPanelInstallSelect:
case kSGCPanelItemSelect:
case kSGCPanelRemoveSelect:
case kSGCPanelGetSettingsSelect:
case kSGCPanelSetSettingsSelect:
return true;
default:
return false;
}
}
pascal ComponentResult PictPanelVersion (PictPanelGlobals store)
{
return 0x00020001;
}
pascal ComponentResult PictPanelOpen (PictPanelGlobals store,
ComponentInstance self)
{
OSErr err;
/* allocate global variables */
store = (PictPanelGlobals) NewPtrClear
(sizeof(PictPanelGlobalsRecord));
if (err = MemError()) goto bail;
SetComponentInstanceStorage (self, (Handle)store);
/* remember the component instance identification number */
store->self = self;
bail:
return err;
}
pascal ComponentResult PictPanelClose (PictPanelGlobals store,
ComponentInstance self)
{
if (store) DisposePtr ((Ptr)store);
return noErr;
}