Putting a 'terminal' in my application? - objective-c

Are there any frameworks for say, putting a display like in Terminal.app in MY app, and then displaying text on it like usual output to STDOUT? Complete with scrollback and etc.?

You may want to look at iTerm, an open-source terminal emulator written in Cocoa. If you really want terminal emulation, you might be able to lift from that framework.

This thread has a couple suggestions. The first is very UNIX'y - you use pipe() to map stdout to a new location. Then you'd need another process or a thread that reads that pipe and displays it into an NSTextView. The other approach that I liked as it seems cleaner and less resource intensive is to replace the File_writer_t _write proc in the stdout() FILE pointer with the hook that you want, which write the output into an NSTextView.

Related

Sizeable screenshot UI code

I am in need of someway to access the UI for the screenshot command in OSX (Cmd+Shft+4) and I would like to be able to activate the UI with a UI button that will screenshot the region selected and save it to a temp location.
Thanks in advance ;)
If there's a direct way to do this from Cocoa, maybe someone will chime in... but I doubt it exists. You can, however, get any behavior you want from the "screencapture" command line utility; it does exactly the same as Cmd-Shift-3 or 4 with a gazillion options. Just type "man screencapture" in Terminal to see all the flags.
But this would require you to run a bash script from your app. If you haven't done that before, well, google it, or check out the many threads here on SO... Opinions vary on how complicated it should be, from a one-liner call to system() to fully thread-safe error reporting NSTask and all kinds of answers in between.
I'd recommend using one of the NSTask answers which keep themselves to half a dozen lines, but YMMV.

KQueue wrapper for Cocoa

So I want to monitor a single file and as far as I can tell KQueue is the way to do it in Cocoa. I have a partially functioning FSEvents code running, but that monitors the whole folder.
Can anyone recommend a good Cocoa wrapper that I might use to monitor when a file is altered? Preferably something along the lines it receiving the file path, then a block of code is run when it senses a change.
Any suggestions would be appreciated.
I'm also surprised cocoa doesn’t have something like this built in??
I ended up going with VDKQueue, an updated version of UKKQueue

Programmatically Controlling Playback in FCP

I ran the Unix "strings" command on the Final Cut Pro binary and it returns some stuff like this:
nextEdit:
previousEdit:
stepForward:
stepBackward:
playPause:
Is there any way that I can tell Final Cut to run these functions while it's running? Could this possibly have to do with NSNotifications? I can't find any Apple Documentation on it.
If I'm going about this the wrong way, is there any way I can programmatically control playback (play/pause/rewind/etc.) in Final Cut?
Take a look here: https://discussions.apple.com/thread/6430030
The arguably lame approach is to send keyboard short cuts. Works for me.

Track all ObjC method calls?

Sometimes when looking at someone else's large Objective-C program, it is hard to know where to begin.
In such situations, I think it would be helpful to log every call to every non-Apple method.
Is there a way to do that? Basically, make one change in some central place, and log every method that is called. Preferably limited to non-Apple methods.
You can set the environment variable NSObjCMessageLoggingEnabled to YES. This will write a log of all message sends in the folder /tmp/msgSends-xxx.
You could add a symbolic breakpoint to objc_msgSend(), and have it log the second parameter without stopping.
How to do it for your own methods only though is a toucher task. Maybe if you could inspect the class name being called and do some magic to have a conditional breakpoint for only calls where the class' prefix matches your own?
I don't think logging every single call is practical enough to be useful, but here's a suggestion in that direction.
On a side note, if it's a large program, it better have some kind of documentation or an intro comment for people to get started with the code.
In any case, every Cocoa application has an applicationDidFinishLaunching... method. It's a good place to start from. Some apps also have their principal (or 'main window') class defined in the Info.plist file. Both these things might give you a hint as to what classes (specifically, view controllers) are the most prominent ones and what methods are likely to have long stack-traces while the program is running. Like a game-loop in a game engine, or some other frequently called method. By placing a breakpoint inside such a method and looking at the stack-trace in the debugger, you can get a general idea of what's going on.
If it's a UI-heavy app, looking at its NIB files and classes used in them may also help identify parts of app's functionality you might be looking for.
Another option is to fire up the Time Profiler instrument and check both Hide missing symbols and Hide system libraries checkboxes. This will give you not only a bird's eye view on the methods being called inside the program, but also will pin-point the most often called ones.
By interacting with your program with the Time Profiler recording on, you could also identify different parts of the program's functionality and correlate them with your actions pretty easily.
Instruments allows you to build your own "instruments", which are really just DTrace scripts in disguise. Use the menu option Instrument >> Build New Instrument and select options like which library you'd like to trace, what you'd like to record when you hit particular functions, etc. Go wild!
That's an interesting question. The answer would be more interesting if the solution supported multiple execution threads and there were some sort of call timeline that could report the activity over time (maybe especially with user events plotted in somehow).
I usually fire up the debugger, set a breakpoint at the main entry point (e.g. - applicationDidFinishLaunching:withOptions:) and walk it in the debugger.
On OSX, there are also some command-line tools (e.g. sample and heap) that can provide some insight.
It seems like some kind of integration with instruments could be really cool, but I am not aware of something that does exactly what you're wanting (and I want it now too after thinking about it).
If one were to log a thread number, and call address, and some frame details, it seems like the pieces would be there to plot the call timeline. The logic for figuring out the appropriate library (Apple-provided or third party) should exist in Apple's symbolicatecrash script.

Automatic screenshot uploading on Mac like Cloud App

Cloud App has this neat feature wherein it automatically uploads new screenshots as they are added to the Desktop. Any ideas how this is done?
You can do similar things yourself without much in the way of programming. In OSX, you can configure "Folder Actions" to run a script, for example, when a new item appears in a folder, including the Desktop. You can then use the script to do whatever you want with the new files.
This article at TUAW includes an example of uploading files to a web server when they hit a particular folder.
So, basically, the answer is "Folder Actions", or "something's keeping an eye on the folder and sending notifications", at some level. Whether Cloud App uses Folder Actions or watches the folder itself at a lower level, using FSEvents/NSWorkspace, or the kqueue mechanisms (for which there's a nice wrapper class called UKKQueue, if I remember correctly -- don't know how current my knowledge is on that one though!) is another matter...
You could implement this at several different levels, depending on the outcome you want, how you want to design whatever it is you're actually doing, and even what kind of filesystem you're targeting. Fundamentally, in Cocoa/Objective C, I think you probably want to start looking at FSEvents.
Once you've got notifications of the file changes, I'd probably use something like ConnectionKit to do the uploading -- any library at all, really, that means you don't have to bother with the sockets level yourself -- but again, there's a lot of different ways.
Depends, really, what level you're looking to solve the problem at, and whether you want to build something for other people or get something working for yourself. If I just wanted to bash something together for myself, I could probably have something cobbled together using Coda's Transmit app, and Folder Actions, or maybe Hazel, and a minimal bit of Applescript, in a half-hour at most, that would do the job well enough for me...
I am not sure what you are asking for exactly. If you are asking for a way to take a screenshot programmatically in MacOSX, I suggest you have a look at the "screencapture" command (in the terminal, type "man screencapture" for doc).
If you want to do it the "hard" way, you should look at this.