Question

I’ve been programming for a while, but just recently decided to start developing for Mac OS X. I feel like I’ve come to grips with the basics of Objective-C and Cocoa development over the past week. I’m planning on making graphics apps, and as such am currently in the process of learning how to control Quartz compositions through a Cocoa app. I went through the tutorial that apple offers (with the Mac Engravings composition), and was able to create that just fine. In order to make sure that I truly understood what I learned, I decided to create my own composition and link it to a slightly more complicated Cocoa application.

Essentially, I have a composition that loads a movie or image through a Movie Loader patch, at which point it applies various filters to the frames before outputting it. In my Cocoa app, I’ve written code (or rather copied and pasted from other apple examples) that lets a user pick a file using an NSOpenPanel object. The filepath of the file they pick gets placed in a text-box that I placed in the app’s window using Interface Builder. I binded the value of said text-box to the “Movie_Location” key in my composition, which is a published input in the Movie Loader patch that I’m using. However, no matter what I do, movies and images aren’t loaded into this composition no matter what I try. The only thing that gets displayed is the default image that I have saved in that input from Quartz Composer (or nothing if I leave it blank before publishing).

I’ve added a Clear Color patch to the composition and binded that to a colorwell in my UI, and that successfully changes the color in my display, so I know that the composition and my Cocoa app are communicating. I’ve spent numerous hours at this point trying to figure out what’s going on, and I’ve just about given up. Does the Movie Loader have any weird behaviors that I’m not aware of, or is there something obvious that I seem to be missing? I’d really appreciate any help or advice from anybody.

Thanks for reading through this…

Best,
Sami

Answer 1

There are two things I can think of as reasons why it is doing this:

1. The file path isn’t formatted incorrectly. Try checking backslashes, colons, etc.
2. The box isn’t updating the value. Try literally clicking in the text field and hitting enter.

That’s all I can think of without seeing your quartz composition and/or code.

EDIT:

Check the other continuous box, in the general properties.