In my last article, I described how to access a QC Tiger Era-esque Editor and Patch Creator (patcherator), via the hidden preference option, QCEditCompositions. Now, I'm going to describe how to get a Viewer that links with this composition edit mode.
Please note that this is merely documentation of Quartz Composer functionality. I am in no way implying that anyone should use these modes as opposed to the more fully featured normal QC Editor app. However, knowing of the existence of this functionality may prove useful in limited scenarios.
Inside of the contents of the Quartz Composer app Runtimes/Leopard folder is an application that is a Viewer for Quartz Composer files called QCPlayer.app. This view app can be opened in either 64 or 32 bit runtimes by Control+Clicking and choosing Get Info.
If one opens the QCPlayer.app, one is presented with the option to open a file. If you have enabled QCEditCompositions, then you will see a list with your loaded file. Clicking on the file in that list will open up the Tiger-style QC Editor, and this Editor instance will actually be tied to what is going on in your QCPlayer.app viewer. Any editing of the composition is reflected in the QCPlayer.app window.
Further, another way to gain a Viewer is by selecting a composition icon in Finder and holding down Spacebar, activates a Quicklook preview. Opening a composition editor from the Quicklook loaded list also results in a linked editing environment - that instance of the Editor forwards all events to Quicklook's Viewer.
A small note; if one already has opened a composition in QCEditComposition mode, and is looking at the editor view, dragging the qtz alias at the top of the editor onto the QCPlayer.app file finder interface will instantly locate your file, which is convenient. However, when it is opened, your editor instance will not be linked to the QCPlayer.app viewer. The editor is only linked to the Viewer when it is triggered from the composition list for the QCPlayer.app, with the QC Player.app being open first.
Another interesting tidbit... if you were to keep dragging the qtz icon from the QCEditCompositions title bar onto itself, you would see duplicate instances of the same composition in the QCEditCompositions list, but each one is distinct in memory.
For example, if you take the composition, disconnect a cable, then open a second instance of the same file (through any method), then close both, clicking on the first instance in your file list will reveal that the edited state is saved, even if your Edit window disappears when you have brought focus to the Viewer or another app. So, editing can actually be successfully done, and on multiple instances of the same file at once. If you've made changes that you wish to keep, keep track of where it is in the list, and Option+DoubleClick; this will present you with the opportunity to do a Save As, with the file in edited state.