Need to simulate screen-shooting a window

Question

Hi there
I need to simulate a screenshot of a window of Safari. Basically: CMD+SHIFT+4+SPACE+click.
I have a script that works for a screenshot of the entire screen, but since my screen is only 1200x800 I need to take an SS of the window while it's resized and a part of it is not visible. If I do it manually it works like a charm, but I need a script because I need to do it a few hundred times.
I've tried using cliclick but I ran into some trouble and I'm stuck. The site loads, the window gets selected, the screen goes gray in anticipation of a click, but no clicking happens. Anyway, here's my script, hope you can help me.
p.s. I'm not sure if my CODE tags will wrap my code in code tags, I'm a bit daft today
[CODE]
set myURL to "X"
repeat with myPage from 1 to 325
          tell application "Safari"
                         set the URL of the front document to (myURL & myPage)
       activate
                         do shell script "/Users/macjohn/Desktop/cliclick d:400,100"
          end tell
  delay 5
          set myPath to ((POSIX path of (path to desktop)) & "screenshots/" & myPage & ".jpg") as string
          do shell script "screencapture -W " & quoted form of myPath
end repeat
[/CODE]

Answer 1

Hello
Here's a simple command line utility written in C to caputure specified window's image and save it as png. I first tried to do this in rubycocoa for convenience but in vain because the used function CGWindowListCreateImageFromArray() always returns nil in rubycocoa for some reason. So here's C version.
# Recipe.
A) To compile and test the C programme.
A1) Copy the code listed below as main.c into new document of text editor (e.g. TextEdit) and save it as plain text named "main.c" on desktop.
A2) In Terminal.app, run the following commands (type each line followed by return):
cd ~/Desktop
gcc -framework ApplicationServices -o windowcapture main.c
and it will create an executable file named "windowcapture" on desktop.
A3) For brief test, first in Ssfari, have a window open and then in Terminal.app, type the following satements (each followed by return):
wid=$(osascript -e 'tell application "Safari" to get id of window 1')
./windowcapture $wid out.png
This will capture the front window of Safari and save it as out.png on desktop.
B) To create an AppleScript wrapper to call this utility.
B1) Create a new AppleScript script with the following contents and save it as a script bundle or an application bundle:
tell application "Safari" to set wid to window 1's id
set p to (path to resource "windowcapture")'s POSIX path
do shell script "cmd=" & p's quoted form & "; wid=" & wid & "
out=~/Desktop/$(date +'%F %H.%M.%S.png')
\"$cmd\" \"$wid\" \"$out\""
B2) Show package contents (via contextual menu) of the saved bundle and put the executable file "windowcapture" loose in its Contents/Resources directory. Now you can run the script bundle or the application bundle to capture the front window of Safari and save it as a time-stamped png file on desktop.
# Notes.
• You need to have Developer Tools (Xcode and its command line tools) installed to build the programme.
• Tested under 10.6.8 but no warranties of any kind.
• This is free software you may use and modify as you like.
# File
main.c
    file
        main.c
    function
        capture image from window specified by window id (CGWindowID) and save it as png file.
    compile
        gcc -framework ApplicationServices -o windowcapture main.c
    usage e.g.
        ./windowcapture 251 outfile.png
#include <ApplicationServices/ApplicationServices.h>
#include <libgen.h>    // basename
int
main (int argc, char * argv[])
    if ( argc != 3 )
        fprintf(stderr, "Usage: %s <window ID> <outfile>\n", basename(argv[0]));
        return 1;
    CGWindowID wid = (CGWindowID) atoi(argv[1]);
    CFStringRef outfile = CFStringCreateWithCString(kCFAllocatorDefault, argv[2], kCFStringEncodingUTF8);
    CFURLRef url = CFURLCreateWithFileSystemPath(kCFAllocatorDefault, outfile, kCFURLPOSIXPathStyle, false);
    CFRelease(outfile);
    CGWindowID wids[] = { wid };
    CFArrayRef widarray = CFArrayCreate(kCFAllocatorDefault, (const void **)wids, 1, NULL);
    CGImageRef img = CGWindowListCreateImageFromArray(CGRectNull, widarray, kCGWindowImageDefault);
    CFRelease(widarray);
    if ( !img )
        fprintf(stderr, "Failed to create image from window id: %d\n", (int) wid);
        return 1;
    CGImageDestinationRef idst = CGImageDestinationCreateWithURL(url, CFSTR("public.png"), (size_t) 1, NULL);
    CFRelease(url);
    CGImageDestinationAddImage(idst, img, NULL);
    bool b = CGImageDestinationFinalize(idst);
    CFRelease(idst);
    return b ? 0 : 1;
Hope this may help,
H