DZone Snippets: cocoa code

Having Rails & Cocoa play together

pierlis (Pierlis) — Thu, 03 Jan 2008 14:47:45 GMT

// description of your code here
Play a Quartz composition from within a Rails application.



# Render a Quartz Composition ".qtz" file to buffer, as jpeg data

# Written by PLR from Pierlis (http://pierlis.com)

# Use at your own risk, reuse at will.



# Cocoa and the Quartz framework must have been included in config/environment.rb.



class Composition

  

  # creates a composition from a .qtz file whose path is qtz_path

  def initialize(qtz_path, width = 350, height = 100)

    @qtz = QCComposition.compositionWithFile(qtz_path)

    raise "Can't find a valid composition at “#{qtz_path}”." if @qtz.nil?

    @renderer = QCRenderer.alloc.initOffScreenWithSize_colorSpace_composition(

                        [width, height],

                        CGColorSpaceCreateWithName(KCGColorSpaceGenericRGB),

                        @qtz)

  end

  

  # renders the composition at time, with parameters, and return the jpeg data.

  def render(time = 0, parameters = {})

    # Only pass in parameters expected by the Qtz composition

    input_keys = @qtz.inputKeys

    parameters.each do |key, value|

      @renderer.setValue_forInputKey(value, key) if input_keys.include? key

    end

    # And render the composition

    rendering_ok = @renderer.renderAtTime_arguments(time, nil)

    raise "Unable to render Quartz Composition" unless rendering_ok == 1

    

    # now convert the result to jpeg

    bitmapRep = @renderer.createSnapshotImageOfType('NSBitmapImageRep')

    jpegimagedata = bitmapRep.representationUsingType_properties(NSJPEGFileType, 

      {NSImageCompressionFactor => 0.8}

      ).rubyString 

  end

end

See more on :

How to draw your own table header... (with borders)

aptiva (FjÃ¶lnir Ã?sgeirsson) — Sat, 28 Apr 2007 19:48:47 GMT

// It's a bit hacky at the beginning, but nstableheadercell wasn't exactly making things easy for me



- (void)_drawThemeContents:(NSRect)cellFrame highlighted:(BOOL)highlighted inView:(NSTableHeaderView *)view;

{

	int index = [view columnAtPoint:NSMakePoint(cellFrame.origin.x + 1,cellFrame.origin.y + 1)];

	NSRect headerRect;

	if(index != -1)

		headerRect = [view headerRectOfColumn:index];

	else

		headerRect = NSZeroRect;

	

	[headerImage drawInRect:cellFrame

				   fromRect:NSZeroRect

				  operation:NSCompositeSourceOver

				   fraction:1.0];

	

	[[NSColor colorWithCalibratedRed:207.0/255.0

							   green:207.0/255.0

								blue:207.0/255.0

							   alpha:1.0] set];

	NSRectFill(NSMakeRect(headerRect.origin.x, headerRect.origin.y + 1, headerRect.size.width, headerRect.size.height - 2));

	[headerImage drawInRect:NSMakeRect(headerRect.origin.x, headerRect.origin.y, headerRect.size.width - 1, headerRect.size.height)

				   fromRect:NSZeroRect

				  operation:NSCompositeSourceOver

				   fraction:1.0];

}

How to make the system notify you of audio cd insertion

aptiva (FjÃ¶lnir Ã?sgeirsson) — Mon, 23 Apr 2007 12:05:23 GMT

// Uses the DiskArbitration framework to notify ya of when new audio cds are inserted



NSDictionary *match = [NSDictionary dictionaryWithObjects:[NSArray arrayWithObjects:@"IOCDMedia", [NSNumber numberWithBool:YES], nil] forKeys:[NSArray arrayWithObjects:(NSString *)kDADiskDescriptionMediaKindKey, kDADiskDescriptionMediaWholeKey, nil]];

		

_session = DASessionCreate(kCFAllocatorDefault);

DASessionScheduleWithRunLoop(_session, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode);

DARegisterDiskAppearedCallback(_session, (CFDictionaryRef)match, diskAppearedCallback, NULL);

DARegisterDiskDisappearedCallback(_session, (CFDictionaryRef)match, diskDisappearedCallback, NULL);

Objective-C and Cocoa: Human-readable file size from number of bytes

maximile (Max Williams) — Sun, 26 Nov 2006 05:51:40 GMT

// Returns a human-readable string showing the file size from the number of bytes



- (NSString *)stringFromFileSize:(int)theSize

{

	float floatSize = theSize;

	if (theSize<1023)

		return([NSString stringWithFormat:@"%i bytes",theSize]);

	floatSize = floatSize / 1024;

	if (floatSize<1023)

		return([NSString stringWithFormat:@"%1.1f KB",floatSize]);

	floatSize = floatSize / 1024;

	if (floatSize<1023)

		return([NSString stringWithFormat:@"%1.1f MB",floatSize]);

	floatSize = floatSize / 1024;



	// Add as many as you like



	return([NSString stringWithFormat:@"%1.1f GB",floatSize]);

}

Calculate a NSView's frame in QuickDraw coordinates

rentzsch (Jonathan 'Wolf' Rentzsch) — Mon, 28 Nov 2005 14:34:31 GMT

@interface NSView (frameAsQuickDrawRect)

- (Rect)frameAsQuickDrawRect;

@end

@implementation NSView (frameAsQuickDrawRect)

- (Rect)frameAsQuickDrawRect {

    NSRect  nsrect = [self convertRect:[self bounds] toView:[[self window] contentView]];

    float   windowHeight = NSHeight( [[[self window] contentView] frame] );

    

    float   nsrectHeight = NSHeight( nsrect );

    

    Rect qdrect;

    qdrect.top = windowHeight - (nsrect.origin.y + nsrectHeight);

    qdrect.left = nsrect.origin.x;

    qdrect.bottom = qdrect.top + nsrectHeight;

    qdrect.right = qdrect.left + NSWidth( nsrect );

    

    return qdrect;

}

@end