Quickies for NSWindow

---

General

• Doing Sheets [permalink]
  To show a sheet in a window, use NSApplication to kick it off:

      [NSApp beginSheet: saveSheet
             modalForWindow: window
             modalDelegate: self
             didEndSelector: @selector(saveSheetDidEnd:returnCode:contextInfo:)
             contextInfo: NULL];

  In the controls in the sheet, use something like

      [NSApp endSheet: saveSheet  returnCode: NSOKButton];

  To invoke the didEndSelector. Inside of that method, you can check the return code and decide what to do:

  - (void) saveSheetDidEnd: (NSWindow *) sheet
                returnCode: (int) returnCode
               contextInfo: (void *) contextInfo
  {
      if (returnCode == NSOKButton) {
          // ...
      } else if (returnCode == NSCancelButton) {
          // ...
      } else {
          // ...
      }
  
      [sheet close];
  
  } // saveSheetDidEnd

• Finding the height of the title bar [permalink]
  When you setFrame: for a window, you have to account for the height of the title bar. In the Classic days it was 16 pixels. In Aqua-land, it's currently 22 pixels. But that's not safe to use, so try this instead:

  - (float) titleBarHeight
  {
      NSRect frame = NSMakeRect (0, 0, 100, 100);
  
      NSRect contentRect;
      contentRect = [NSWindow contentRectForFrameRect: frame
                              styleMask: NSTitledWindowMask];
  
      return (frame.size.height - contentRect.size.height);
  
  } // titleBarHeight

  Rainer Brockerhoff points out that this might miss any system-suppled window decorations at the bottom of the window. There aren't any now, but Mac OS X 10.37 Sabertooth might, so you may want to take into account the y positions of the original rectangle and the newly calculated content rect.

• Force an NSWindowController's nib to be loaded [permalink]
  The window controller nib doesn't get loaded until the window is manipulated. This can cause confusion if you do any kind of setup before the window is shown. If you call the window method, that will force the nib file to be loaded. Something like this:

  + (BWInspector *) sharedInspector
  {
      static BWInspector *s_inspector;
  
      if (s_inspector == nil) {
          s_inspector = [[BWInspector alloc]
                            initWithWindowNibName: @"BWInspector"];
          assert (s_inspector != nil);
  
          // force loading of nib
          (void) [s_inspector window];
      }
  
      return (s_inspector);
  
  } // sharedInspector

• Help! My Sheet won't go away [permalink]
  You may need to call [sheet close] in addition to your [NSApp endSheet: sheet returnCode:23]

• Making a floating palette [permalink]
  To make a floating palette with small controls, make the palette an NSPanel, and n IB make it a "Utility Window".

• Making a panel not eat the key [permalink]
  The default settings for an NSPanel in IB cause the panel to take the main window out of the responder chain, and so commands (like undo) don't propagate to the window the inspector is editing. In IB, make sure the settings "Utility window" and "Non Activating Panel" are selected.

• Preventing NSPanels from hiding on program deactivation [permalink]
  Sometimes you want an NSPanel for the nice skinny title bar, but don't want it to hide when another program is made active. Somewhere convenient (like in the awakeFromNib), do something like

  [panel setHidesOnDeactivate: NO];

• Resizing a window with animation [permalink]
  Use setFrame:display:animate: to resize a window, and have the window animate between the two sizes. Remember that Cocoa uses a bottom-left origin, which is a pain when dealing with windows. You want the window's top left to be the same between the old and new sizes, so you have to dink with the origin as well as the size:

      float delta = ... how much to make the window bigger or smaller ...;
      NSRect frame = [window frame];
  
      frame.origin.y -= delta;
      frame.size.height += delta;
  
      [window setFrame: frame
               display: YES
               animate: YES];
  

• Resizing a window with animation and cool cross-fade effect with views [permalink]
  NSViewAnimation lets you resize a window and cross-fade some views in one operation. (note I've had problems with the window size getting a couple of pixels off using this. Hopefully either I'm doing something dumb, or Apple fixes a bug). This code resizes the window, and changes the view that lives inside of a box. This is like how the Pages inspector works (except Pages doesn't do the gratuitous animation effect)

      NSRect newWindowFrame = ... the new window size;
  
      NSDictionary *windowResize;
      windowResize = [NSDictionary dictionaryWithObjectsAndKeys:
                                   window, NSViewAnimationTargetKey,
                                   [NSValue valueWithRect: newWindowFrame],
                                   NSViewAnimationEndFrameKey,
                                   nil];
  
      NSDictionary *oldFadeOut = nil;
      if (oldView != nil) {
          oldFadeOut = [NSDictionary dictionaryWithObjectsAndKeys:
                                     oldView, NSViewAnimationTargetKey,
                                     NSViewAnimationFadeOutEffect,
                                     NSViewAnimationEffectKey, nil];
      }
  
      NSDictionary *newFadeIn;
      newFadeIn = [NSDictionary dictionaryWithObjectsAndKeys:
                                    newView, NSViewAnimationTargetKey,
                                NSViewAnimationFadeInEffect,
                                NSViewAnimationEffectKey, nil];
  
      NSArray *animations;
      animations = [NSArray arrayWithObjects:
                                windowResize, newFadeIn, oldFadeOut, nil];
  
      NSViewAnimation *animation;
      animation = [[NSViewAnimation alloc]
                      initWithViewAnimations: animations];
  
      [animation setAnimationBlockingMode: NSAnimationBlocking];
      [animation setDuration: 0.5]; // or however long you want it for
  
      [animation startAnimation]; // because it's blocking, once it returns, we're done
  
      [animation release];

• Running a window modally [permalink]
  

    // I am the very modal of a modern major general.
    int blah = [NSApp runModalForWindow:[self window]];
  

  and then elsewhere, like in your OK or cancel button

    [NSApp stopModalWithCode:NSOKButton];

• Using an NSWIndowController to load a window [permalink]
  Here's how I like doing things. First make a subclass of NSWindowController:

  @interface BWInspector : NSWindowController
  {
      // ivars, IBOutlets, etc
  }
  
  // IBActions, etc
  
  + (BWInspector *) sharedInspector;
  @end // BWInspector
  

  Then make a nib file with the window, the controls, and other fun stuff you want. This one lives in English.lproj/BWInspector.nib

  Then in that class method load the window:

  + (BWInspector *) sharedInspector
  {
      static BWInspector *g_inspector;
  
      if (g_inspector == nil) {
          g_inspector = [[BWInspector alloc]
                            initWithWindowNibName: @"BWInspector"];
  
          assert (g_inspector != nil); // or other error handling
  
          [g_inspector showWindow: self];
      }
  
      return (g_inspector);
  
  } // sharedInspector

  That will load the nib file, set up the connections and then open the window for display

Hacks

• I want my window's background to be yellow [permalink]
  Why you'd want to do that, I don't know, but someone asked me how to turn the window background yellow. Since the window has a contentView NSView in it, this adds a category on it that draws the background with a transparent yellow. You also get the pinstripe effects. Just put this code anywhere.

  @implementation NSView (BWYellowView)
  
  - (void) drawRect: (NSRect) rect
  {
      NSColor *transparentYellow;
  
      rect = [self bounds];
  
      transparentYellow = [NSColor colorWithCalibratedRed: 1.0
                                   green: 1.0
                                   blue: 0.0
                                   alpha: 0.333];
      [transparentYellow set];
      [NSBezierPath fillRect: rect];
  
  } // rect
  
  @end // BWYellowView
  

  I have no idea how you colorize the titlebar.

Random

• Forwarding key events to another window [permalink]
  To forward key events to another window, make subclass of NSWindow and override sendEvent:

  - (void) sendEvent: (NSEvent *) anEvent
  {
      if ([anEvent type] == NSKeyDown) {
          [someOtherWindow sendEvent: anEvent];
  
      } else {
          [super sendEvent: anEvent];
      }
  
  } // sendEvent
  

  It's up to you to figure out what "someOtherWindow" is, whether it's a delegate or an instance variable that holds the other window.

---