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Mithras · Jun 15, 2002, 04:00 PM

I need a simple command-line app that will return the current screen height and width (for main screen only, I guess).

(For the curious, it's to insert into a PHP web page running the VNC Java applet; that way, the page will give the applet the proper dimensions).

I'm comfortable with writing a Carbon "Tool" command-line app if that's the way to go about things. What system call do I use? I've dug around Developer Connection, but only turned up examples using ancient Toolbox calls.

I've also noticed that I could parse the file /Library/Preferences/com.apple.windowserver.plist, which contains keys for Height and Width, but I'm not sure if that's an okay way to go.

Appreciate any pointers
Mithras

Chuckit · Jun 15, 2002, 06:53 PM

I think the normal system call would be: <blockquote>code:<hr /><pre style="font-size:x-small; font-family: monospace;">CFDictionaryRef CGDisplayCurrentMode(CGDirectDisplayID display)</pre><hr /></blockquote>It's defined in /System/Library/Frameworks/ApplicationServices.framework/Frameworks/CoreGraphics.framework/Headers/CGDirectDisplay.h.
Of course, this is a C framework, so you probably will have to go the tool route if you use that. I'm not really familiar enough with Java to have any idea whether or not it has such a function.

[ 06-16-2002, 04:36 AM: Message edited by: Chuckit ]

Northform · Jun 15, 2002, 07:04 PM

Do you mean the resolution of the server's screen or the resolution of the screen of the user trying to access the website?

seb2 · Jun 16, 2002, 03:19 AM

<blockquote>quote:<hr />Originally posted by Chuckit:
I'm not really familiar enough with Java to have any idea whether or not it has such a function.<hr /></blockquote>it does:

<blockquote>code:<hr /><pre style="font-size:x-small; font-family: monospace;">import java.awt.*;

public class ScreenRes
{
public static void main (String[] args)
{
Rectangle b = GraphicsEnvironment.getLocalGraphicsEnvironment(). getDefaultScreenDevice().getDefaultConfiguration() .getBounds();
System.out.println("Width: " + b.width + " / Height: " + b.height);
System.exit(0);
}
}</pre><hr /></blockquote>i've not tested this with a secondary monitor connected, but it should give you the resolution of the main screen.

Ibson · Jun 16, 2002, 05:10 AM

For anyone who's interested, I thought I'd give a Cocoa/Obj-C example:
<blockquote>code:<hr /><pre style="font-size:x-small; font-family: monospace;">- (void)logScreenResolution
{
NSRect screenFrame;
NSSize screenSize;

screenFrame = [[NSScreen mainScreen] frame];
screenSize = screenFrame.size;

NSLog(@"Width: %f / Height: %f", screenSize.width, screenSize.height);
}</pre><hr /></blockquote>

[ 06-16-2002, 06:15 AM: Message edited by: Ibson ]

Chuckit · Jun 16, 2002, 07:29 AM

<blockquote>quote:<hr />Originally posted by Ibson:
For anyone who's interested, I thought I'd give a Cocoa/Obj-C example:
<blockquote>code:<hr /><pre style="font-size:x-small; font-family: monospace;">- (void)logScreenResolution
{
NSRect screenFrame;
NSSize screenSize;

screenFrame = [[NSScreen mainScreen] frame];
screenSize = screenFrame.size;

NSLog(@"Width: %f / Height: %f", screenSize.width, screenSize.height);
}</pre><hr /></blockquote><hr /></blockquote>Incidentally, CoreGraphics can make an almost exact equivalent for this method.
<blockquote>code:<hr /><pre style="font-size:x-small; font-family: monospace;">void logScreenResolution(void)
{
CGRect screenFrame;
CGSize screenSize;

screenFrame = CGDisplayBounds(kCGDirectMainDisplay);
screenSize = screenFrame.size;

printf("Width: %f / Height %f", screeenSize.width, screenSize.height);
}</pre><hr /></blockquote>Just so people can compare. The function I gave originally was much more general and returns a dictionary of all the information about the screen, and you can then retrieve the exact details you're looking for.
(And even more incidentally, you could actually achieve the same effect as the above function in one line. But then the similarities between the two frameworks wouldn't look as eerie. <img border="0" title="" alt="[Wink]" src="wink.gif" /> )

EDIT: Me no can type.

[ 06-16-2002, 08:31 AM: Message edited by: Chuckit ]

Mithras · Jun 16, 2002, 11:12 AM

Thanks a ton for all the helpful responses!
I went with Chuckit's CoreGraphics tool, since it most closely matched my simple needs; but I played with the Java version too.

Here's a little screenshot of the result (click for the big version):

<a href="http://homepage.mac.com/mybulkmail/screenshots/screeninfo.jpg" target="_blank"> <img src="http://homepage.mac.com/mybulkmail/screenshots/screeninfo-small.jpg" alt=" - " /></a>

That's an Internet Explorer window on one Mac, with resolution 1024x768. In the IE window is the PHP web page, displaying the contents of the server's screen at 800x600. The PHP puts up a nice Aqua-style window with blue background, which is why the picture might look rather confusing at first.

Without y'all's app to get the server's resolution, the applet and fake Aqua window on the web page wouldn't be properly sized.

By the way I'm hoping to release the project to the public within a couple of weeks. I'm still working on the iTunes interface part, and on making it super-easy to generate the self-signed SSL certificate.

For future reference, here's my complete code:
<blockquote>code:<hr /><pre style="font-size:x-small; font-family: monospace;">#include <ApplicationServices/ApplicationServices.h>

void showusage();

int main (int argc, const char * argv[]) {
# check for argument sanity
if (argc != 2)
showusage();

# return screen height or width as requested
if (strcmp(argv[1],"width&quot

== 0)
printf("%d\n",(int) CGDisplayBounds(kCGDirectMainDisplay).size.width);
else if (strcmp(argv[1],"height&quot

== 0)
printf("%d\n",(int) CGDisplayBounds(kCGDirectMainDisplay).size.height) ;
else
# complain if passed an incorrect argument
showusage();
return 0;
}

void showusage()
{
printf("Usage: screeninfo (height | width)\n&quot

;
exit(127);
}</pre><hr /></blockquote>