Found 12 entries, viewing 1 through 5.
Building Cocoa GUIs in Python with PyObjC, Part Six
Handling Images
Cocoa provides an easy interface for dealing with images, NSImage. It can be a bit tricky in Python, but once you get it right the first time, it is fairly easy. For our application we have the images stored inside the audio tags and need to populate an NSImage object from binary data stored as a Python byte-string.
There are a number of methods for initializing an NSImage object from various sources. A few of note:
initWithContentsofFile:
initWithData:
initWithPasteboard:
All of these are worth reading about in the developer documentation. We will be using initWithData:. This accepts a NSData object to make the NSImage. This is a multiple step process, so we'll create a method to make things easier:
def buildNSImage(bytes):
data = NSData.dataWithBytes_length_(bytes, len(bytes))
return NSImage.alloc().initWithData_(data)
bytes is a Python byte-string containing the image. NSImage will automatically handle the formatting ...
Audio of My UTOSC Presentation
I gave a presentation this past fall at UTOSC about various programming tips I've learned while I worked on Oggify. The audio from this was recorded and is now available. Enjoy.
Building Cocoa GUIs in Python with PyObjC, Part Five
Adding Python Modules to the Bundle
If you try to use Python modules on the standard OS X Python path import statements will work fine. However, if you have non-standard modules that might be in a different location, or ones that you want to ship with, you will notice you can't just import them.
To bring them into the application bundle you'll have to go through a couple steps, but when it is all done the application will be able to use the modules, and you don't have to require the end user to install anything extra.
Add the files to the Xcode project.
- Select 'Project -> Add to Project' (option-command-a)
- Select the Python module (directory) that you want to add.
-
On the next screen select "Copy items into destination group's folder (if needed)
- Select the correct targets in 'Add to Targets'
- Select "Create Folder References for ...
Rambling on Git
So during my UTOSC presentation I add some spare time, and ended up doing a "Git in Five Minutes" demo. I've done a written version for everyone to enjoy. So yes, I've written a Git tutorial.
Oh, and this Git Magic tutorial is pretty good too.
Building Cocoa GUIs in Python with PyObjC, Part Four
Creating an Open Dialog
Our controller doesn't really do anything at this point. We'll begin by adding an open dialog for the user. This will require us to really delve into the Objective C bridge provided by PyObjC. We'll start by reading some documentation that ships with Xcode.
Let's launch the local documentation browser in Xcode. Under "Help" click "Documentation". In the newly opened documentation browser select the "Mac OS X 10.5" documentation set and search for NSOpenPanel. This is the class we'll be working with to create our open dialog. Have a look through the documentation, then let's code.
First we do some basic stuff, creating the object and setting some permissions. A modified open method on our controller.py looks like this:
filetypes = ('mp3', 'ogg', 'mp4', 'flac', 'm4a', 'm4p')
@IBAction
def open_(self, sender):
panel = NSOpenPanel.openPanel()
panel.setCanChooseDirectories_(NO)
panel ...
