Quote from Forum Archives on November 6, 2012, 9:07 pm

Posted by: svanvoorst <svanvoorst@...>

This demo gives the illusion of line numbers in a text view by utilizing two synchronized scroll views; one containing text and the other containing line numbers.  Both are embedded into a single view to make it easier to 'group' the components and move them en masse.  The window is resizable.

'------- start ----------

/*

   Adds line numbers to an NSTextView by utilizing synchronized NSScrollViews.

   Reference: Apple Doc "Scroll View Programming Guide for Mac", 2010-06-19, pp. 17-20.

   Adapted for FB by S.Van Voorst   {20121024}  Modifications by Bernie Wylde.

*/

BeginCDeclaration

@interface EmbedderView : NSView

//methods automatically called

@end  //interface

EndC

BeginCFunction

@implementation EmbedderView : NSView;

- (id)initWithFrame:(NSRect)frameRect

{

 if ((self = [super initWithFrame:frameRect]) != nil) 

 {

  self = [super initWithFrame:frameRect];

  // Add initialization code here

 }

 return self;

}

- (void)drawRect:(NSRect)rect

{

// ****** Background ***** //

[[NSColor orangeColor] set];

[NSBezierPath fillRect:rect];

}

// ----- Use this if you want 0,0 (origin) to be top, left ---- //

// ----- Otherwise origin will be at bottom, left (Unflipped) ----- //

-(BOOL)isFlipped

{

 return YES;

}

@end //implementation

EndC

BeginCDeclaration

@interface MyDelegate : NSObject

{

  NSWindow *window;

  NSScrollView *rightScrollView;

  NSScrollView *leftScrollView;

  NSTextView *txtView1;

  NSTextView *txtView2;

  NSRect embedderR;

}

- (void) createMenu;

- (void) createWindow;

- (void) calcLineNumbers;

@end

EndC

BeginCFunction

@implementation MyDelegate : NSObject 

- (void) dealloc

{

  [window release];

  [super dealloc];

}

- (void)calcLineNumbers 

{

  NSMutableString *txtView1String = [[NSMutableString alloc] initWithCapacity:0];

  NSLayoutManager *layoutManager = [txtView2 layoutManager];

  unsigned numberOfLines, index, numberOfGlyphs = [layoutManager numberOfGlyphs];

  NSRange lineRange;

  for (numberOfLines = 0, index = 0; index < numberOfGlyphs; numberOfLines++)

  {

   (void) [layoutManager lineFragmentRectForGlyphAtIndex:index effectiveRange: &lineRange];

   index = NSMaxRange(lineRange);

   [txtView1String appendFormat:@"%dn", numberOfLines+1];    

   [txtView1 setString:txtView1String];

  }

   [txtView1String release]; 

}

- (void)textDidChange:(NSNotification *)notification

{

  [self calcLineNumbers];

}

- (void)scrollViewContentBoundsDidChange:(NSNotification *)notification

{

 NSPoint leftOrigin = [[leftScrollView contentView] bounds].origin;

 NSPoint rightOrigin = [[rightScrollView contentView] bounds].origin;

 if ( [notification object] == [rightScrollView contentView] ) {

   leftOrigin.y = rightOrigin.y;

   [[leftScrollView contentView] scrollToPoint:leftOrigin];

  } else {

   rightOrigin.y = leftOrigin.y;

   [[rightScrollView contentView] scrollToPoint:rightOrigin];

       [rightScrollView reflectScrolledClipView:[rightScrollView contentView]];

  }

}

- (void) createMenu

{

// ******** Menu and menubar ********//

  id menubar = [[NSMenu new] autorelease];

  id appMenuItem = [[NSMenuItem new] autorelease];

  [menubar addItem:appMenuItem];

  [NSApp setMainMenu:menubar];

  id appMenu = [[NSMenu new] autorelease];

  id quitMenuItem = [[[NSMenuItem alloc] initWithTitle:@"Quit"

        action:@selector(terminate:) keyEquivalent:@"q"] autorelease];

  [appMenu addItem:quitMenuItem];

  [appMenuItem setSubmenu:appMenu];

}

- (void) createWindow

{

  // ***** window ***** //

  #define _wndW  600

  #define _wndH  550

  window = [[NSWindow alloc] initWithContentRect: NSMakeRect( 0, 0, _wndW, _wndH )

    styleMask: NSTitledWindowMask | NSMiniaturizableWindowMask | NSClosableWindowMask | NSResizableWindowMask

             backing: NSBackingStoreBuffered

                   defer: NO];

  [window center];

  [window setMinSize:NSMakeSize(152,220)];

  [window setTitle: @"NSTextView with line numbers."];

// ------- Create an instance of EmbedderView (NSView) ------ //

 embedderR = NSMakeRect( 20, 80, _wndW - 40, _wndH - 100 );

 EmbedderView *baseView = [[EmbedderView alloc]initWithFrame:embedderR];

 [baseView setAutoresizingMask:NSViewHeightSizable | NSViewWidthSizable];

 [baseView setAutoresizesSubviews:YES];

 [[window contentView] addSubview:baseView];

 [baseView release];

// ****** Left NSTextView with Scroll ****** //

 NSRect leftScrollViewR = NSMakeRect( 10, 10, 50, embedderR.size.height - 20 );

 leftScrollView = [[NSScrollView alloc] initWithFrame: leftScrollViewR];

 [baseView addSubview:leftScrollView];

 [leftScrollView setHasVerticalScroller:NO];

 [leftScrollView setAutoresizingMask:NSViewHeightSizable];

 txtView1 = [[NSTextView alloc] initWithFrame:NSMakeRect( 0, 0, leftScrollViewR.size.width, leftScrollViewR.size.height )];

 [txtView1 setEditable:NO]; 

 [txtView1 setAlignment:NSRightTextAlignment];

 [txtView1 setBackgroundColor:[NSColor lightGrayColor]];

 [txtView1 setHorizontallyResizable:NO];

 [txtView1 setAutoresizingMask:NSViewWidthSizable | NSViewHeightSizable];

 [leftScrollView setDocumentView: txtView1];

 [leftScrollView release];

 [txtView1 release];

// ****** Right NSTextView with Scroll ****** //

 NSRect rightScrollViewR = NSMakeRect( 62, 10, embedderR.size.width - 72, embedderR.size.height - 20 );

 rightScrollView = [[NSScrollView alloc] initWithFrame: rightScrollViewR];

 [baseView addSubview:rightScrollView];

 [rightScrollView setHasVerticalScroller: YES];

 [rightScrollView setAutoresizingMask:NSViewWidthSizable | NSViewHeightSizable];

 txtView2 = [[NSTextView alloc] initWithFrame:NSMakeRect( 0, 0, rightScrollViewR.size.width, rightScrollViewR.size.height )];

 [txtView2 setMinSize:NSMakeSize( 0.0, [rightScrollView contentSize].height)];

 [txtView2 setMaxSize:NSMakeSize(FLT_MAX, FLT_MAX)];

 [txtView2 setVerticallyResizable:YES];

 [txtView2 setHorizontallyResizable:YES];

 [txtView2 setAutoresizingMask:NSViewWidthSizable | NSViewHeightSizable ];

 [[txtView2 textContainer]setContainerSize:NSMakeSize(FLT_MAX, FLT_MAX)];

 [[txtView2 textContainer] setWidthTracksTextView:NO];

 [txtView2 setDelegate:[NSApp delegate]];

 [rightScrollView setDocumentView: txtView2];

 [[txtView2 enclosingScrollView] setHasHorizontalScroller:YES];

 [txtView2 insertText:@"Enter text - Right click for menu."];

 [rightScrollView release];

 [txtView2 release];

// ******* Synchronize the two Scroll Views ******** //

  [[rightScrollView contentView] setPostsBoundsChangedNotifications:YES];

  [[NSNotificationCenter defaultCenter] addObserver:self

                                             selector:@selector(scrollViewContentBoundsDidChange:)

                                                 name:NSViewBoundsDidChangeNotification

                                               object:[rightScrollView contentView]];

  [[leftScrollView contentView] setPostsBoundsChangedNotifications:YES];

  [[NSNotificationCenter defaultCenter] addObserver:self

                                             selector:@selector(scrollViewContentBoundsDidChange:)

                                                 name:NSViewBoundsDidChangeNotification

                                               object:[leftScrollView contentView]];

[window setInitialFirstResponder:txtView2];

// ***** Quit btn ***** //

 NSButton *quitBtn = [[NSButton alloc]initWithFrame:NSMakeRect( _wndW - 130, 30, 95, 30 )];

 [quitBtn setBezelStyle:NSRoundedBezelStyle ];

 [quitBtn setAutoresizingMask:NSViewMinXMargin];

 [quitBtn setTitle: @"Quit" ];

 [quitBtn setAction:@selector(terminate:)];

 [[window contentView] addSubview: quitBtn];

 [quitBtn release];

}

- (void) applicationWillFinishLaunching: (NSNotification *)notification

{

  [self createMenu];

  [self createWindow];

}

- (void) applicationDidFinishLaunching: (NSNotification *)notification

{

  [window makeKeyAndOrderFront: nil];

}

@end

EndC

BeginCCode

  NSAutoreleasePool *pool = [[NSAutoreleasePool alloc]init];

  [NSApplication sharedApplication];

  [NSApp setDelegate: [MyDelegate new]];

  [NSApp run];

  [pool drain];

EndC

'-------- end ----------

Steve Van Voorst

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