bug#21662: 25.0.50; visible-bell causes display artifacts on OS X 10.11

bug#21662: 25.0.50; visible-bell causes display artifacts on OS X 10.11

[Steve Purcell]

I'm using snapshot builds from emacsformacosx.com on my Macbook, and I
have `visible-bell' set to t. Since upgrading OS X from 10.10 to 10.11 I
see display artifacts: specifically, there appears to be no redraw after
the visible bell square flashes in the centre of the frame, so the frame
contents are left obscured or blurred.

I had initially noticed this with an older snapshot build, and have
verified that it still occurs using the latest snapshot (dated Oct
10).

Happy to provide further info upon request.



In GNU Emacs 25.0.50.1 (x86_64-apple-darwin13.4.0, NS appkit-1265.21 Version 10.9.5 (Build 13F1112))
 of 2015-10-10
Windowing system distributor 'Apple', version 10.3.1404
Configured using:
 'configure --with-ns '--enable-locallisppath=/Library/Application
 Support/Emacs/${version}/site-lisp:/Library/Application
 Support/Emacs/site-lisp''

Configured features:
ACL LIBXML2 ZLIB TOOLKIT_SCROLL_BARS NS

Important settings:
  value of $LC_CTYPE: en_US.UTF-8
  value of $LANG: en_US
  locale-coding-system: utf-8

Major mode: Emacs-Lisp

Minor modes in effect:
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  redshank-mode: t
  aggressive-indent-mode: t
  rainbow-delimiters-mode: t
  highlight-quoted-mode: t
  highlight-symbol-nav-mode: t
  highlight-symbol-mode: t
  diff-hl-mode: t
  diff-auto-refine-mode: t
  bug-reference-prog-mode: t
  paredit-mode: t
  goto-address-prog-mode: t
  auto-insert-mode: t
  auto-compile-on-load-mode: t
  auto-compile-on-save-mode: t
  auto-compile-mode: t
  ipretty-mode: t
  global-rinari-mode: t
  guide-key-mode: t
  hes-mode: t
  global-page-break-lines-mode: t
  page-break-lines-mode: t
  delete-selection-mode: t
  cua-mode: t
  show-paren-mode: t
  global-undo-tree-mode: t
  undo-tree-mode: t
  global-whitespace-cleanup-mode: t
  whitespace-cleanup-mode: t
  global-auto-revert-mode: t
  electric-pair-mode: t
  savehist-mode: t
  desktop-save-mode: t
  winner-mode: t
  global-auto-complete-mode: t
  auto-complete-mode: t
  ido-ubiquitous-mode: t
  ido-everywhere: t
  recentf-mode: t
  global-anzu-mode: t
  anzu-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  global-prettify-symbols-mode: t
  prettify-symbols-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent messages:
Desktop: 26.79ms to restore nil
Desktop: 24.35ms to restore nil
Wrote /Users/steve/.emacs.d/.emacs.desktop.lock
Desktop: 1 frame, 72 buffers restored.
Desktop restored in 12698.73ms
For information about GNU Emacs and the GNU system, type C-h C-a.
Evaluating...
t
Quit [3 times]
Press key for agenda command:

Load-path shadows:
/Users/steve/.emacs.d/elpa/helm-20151009.1117/helm-multi-match hides /Users/steve/.emacs.d/elpa/helm-core-20151009.905/helm-multi-match
/Users/steve/.emacs.d/elpa/emms-20150810.832/tq hides /Applications/Emacs.app/Contents/Resources/lisp/emacs-lisp/tq

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Memory information:
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 (symbols 48 57378 0)
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bug#21662: 25.0.50; visible-bell causes display artifacts on OS X 10.11

[Spike Ilacqua]

I can confirm this issue exists in 24.5.50 (build from source) as well. It appear with the upgrade to El Capitan and persists after rebuilding from scratch.

bug#21662: 25.0.50; visible-bell causes display artifacts on OS X 10.11

[Mustafa Kocaturk]

Hi,

The current implementation of the visual bell on NextStep is to cache and redraw a rectangle on the current Emacs frame *from outside the NextStep run loop*. It seems this was good enough so far but is no longer a particularly supported one for the latest Mac OS X version.
Maintaining it might still be possible, only with sufficient effort and caution.

Alternative: Switch to an implementation that is particularly supported in this release of OS X, as follows:
Create a temporary NSView object and attach it to the selected EmacsView object.
This new subview draws itself, starts an NSTimer, with a callback in the current NS run loop. 
When the timer expires the callback is entered, which updates, hides, and finally removes the subview from its superview.
The view is garbage collected, all as part of the NS run loop. 
The required change is small: Add a NSView-derived class in nsterm.m and replace old cache/draw/restore code with new temporary local instance of this new class.

Best regards,
Mustafa

bug#21662: 25.0.50; visible-bell causes display artifacts on OS X 10.11

[Mustafa Kocaturk]

Implemented a patch with a few small corrections to the proposed solution:
> Create a temporary NSView object and attach it to the selected EmacsView object.

Not temporary, but a shared instance, a singleton.

> This new subview draws itself, starts an NSTimer, with a callback in the 
> current NS run loop. 

Instead of starting a timer, the subview sends itself a message with delay.

> When the timer expires the callback is entered, which updates, hides, and 
> finally removes the subview from its superview.
> The view is garbage collected, all as part of the NS run loop. 

The view is retained for re-use.

> The required change is small: Add a NSView-derived class in nsterm.m and 
> replace old cache/draw/restore code with new temporary local instance of this 
> new class.

As already mentioned, not temporary, but retained.

Patch follows.

diff --git a/src/nsterm.m b/src/nsterm.m
index c4bfd7c..f16ebe2 100644
--- src/nsterm.m~
+++ src/nsterm.m
@@ -987,6 +987,59 @@ ns_clip_to_row (struct window *w, struct glyph_row *row,
 }
 
 
+@interface BellView : NSImageView {
+    NSColor *bellColor;
+}
+
+@property(readwrite,copy) NSColor *bellColor;
+
+- (IBAction)ring:(id)sender;
+@end
+
+@implementation BellView
+@synthesize bellColor;
+
+- (id)initWithFrame:(NSRect)frame {
+  self = [super initWithFrame:frame];
+  if (self) { self.image=[NSApp applicationIconImage]; }
+  return self;
+}
+
++ (instancetype)sharedInstance {
+  static id _si=nil;
+  static dispatch_once_t onceT;
+  dispatch_once(&onceT, ^{ _si=[[self alloc] init]; });
+  return _si;
+}
+
+- (BOOL)isOpaque {
+  return NO;
+}
+
+static const CGFloat BELL_T = 0.2;
+
+- (IBAction)ring:(NSView*)nv color:(NSColor*)fg {
+  self.hidden=NO;
+  self.image=[NSImage imageNamed:NSImageNameCaution];
+  NSRect dr=[nv bounds];
+  dr.origin.x+=(dr.size.width-self.image.size.width)/2;
+  dr.origin.y+=(dr.size.height-self.image.size.height)/2;
+  [self setFrameOrigin:dr.origin];
+  [self setFrameSize:self.image.size];
+  /* find a use for color fg */
+  [nv addSubview:self];
+  [self setNeedsDisplay:YES];
+  [self performSelector:@selector(dismiss) withObject:self afterDelay:BELL_T];
+}
+
+- (void)dismiss {
+    self.hidden=YES;
+    [self setNeedsDisplay:YES];
+    [self removeFromSuperview];
+}
+
+@end
+
 static void
 ns_ring_bell (struct frame *f)
 /* --------------------------------------------------------------------------
@@ -996,41 +1049,18 @@ ns_ring_bell (struct frame *f)
   NSTRACE (ns_ring_bell);
   if (visible_bell)
     {
-      NSAutoreleasePool *pool;
       struct frame *frame = SELECTED_FRAME ();
       NSView *view;
 
       block_input ();
-      pool = [[NSAutoreleasePool alloc] init];
 
       view = FRAME_NS_VIEW (frame);
-      if (view != nil)
-        {
-          NSRect r, surr;
-          NSPoint dim = NSMakePoint (128, 128);
-
-          r = [view bounds];
-          r.origin.x += (r.size.width - dim.x) / 2;
-          r.origin.y += (r.size.height - dim.y) / 2;
-          r.size.width = dim.x;
-          r.size.height = dim.y;
-          surr = NSInsetRect (r, -2, -2);
-          ns_focus (frame, &surr, 1);
-          [[view window] cacheImageInRect: [view convertRect: surr toView:nil]];
-          [ns_lookup_indexed_color (NS_FACE_FOREGROUND
-                                      (FRAME_DEFAULT_FACE (frame)), frame) set];
-          NSRectFill (r);
-          [[view window] flushWindow];
-          ns_timeout (150000);
-          [[view window] restoreCachedImage];
-          [[view window] flushWindow];
-          ns_unfocus (frame);
+      if (view != nil) {
+	  [BellView.sharedInstance ring:view color:ns_lookup_indexed_color(NS_FACE_FOREGROUND(FRAME_DEFAULT_FACE (frame)), frame)];
         }
-      [pool release];
+      
       unblock_input ();
-    }
-  else
-    {
+    } else {
       NSBeep ();
     }
 }
diff --git a/src/nsterm.m b/src/nsterm.m
index c4bfd7c..f16ebe2 100644
--- a/src/nsterm.m
+++ b/src/nsterm.m
@@ -987,6 +987,59 @@ ns_clip_to_row (struct window *w, struct glyph_row *row,
 }
 
 
+@interface BellView : NSImageView {
+    NSColor *bellColor;
+}
+
+@property(readwrite,copy) NSColor *bellColor;
+
+- (IBAction)ring:(id)sender;
+@end
+
+@implementation BellView
+@synthesize bellColor;
+
+- (id)initWithFrame:(NSRect)frame {
+  self = [super initWithFrame:frame];
+  if (self) { self.image=[NSApp applicationIconImage]; }
+  return self;
+}
+
++ (instancetype)sharedInstance {
+  static id _si=nil;
+  static dispatch_once_t onceT;
+  dispatch_once(&onceT, ^{ _si=[[self alloc] init]; });
+  return _si;
+}
+
+- (BOOL)isOpaque {
+  return NO;
+}
+
+static const CGFloat BELL_T = 0.2;
+
+- (IBAction)ring:(NSView*)nv color:(NSColor*)fg {
+  self.hidden=NO;
+  self.image=[NSImage imageNamed:NSImageNameCaution];
+  NSRect dr=[nv bounds];
+  dr.origin.x+=(dr.size.width-self.image.size.width)/2;
+  dr.origin.y+=(dr.size.height-self.image.size.height)/2;
+  [self setFrameOrigin:dr.origin];
+  [self setFrameSize:self.image.size];
+  /* find a use for color fg */
+  [nv addSubview:self];
+  [self setNeedsDisplay:YES];
+  [self performSelector:@selector(dismiss) withObject:self afterDelay:BELL_T];
+}
+
+- (void)dismiss {
+    self.hidden=YES;
+    [self setNeedsDisplay:YES];
+    [self removeFromSuperview];
+}
+
+@end
+
 static void
 ns_ring_bell (struct frame *f)
 /* --------------------------------------------------------------------------
@@ -996,41 +1049,18 @@ ns_ring_bell (struct frame *f)
   NSTRACE (ns_ring_bell);
   if (visible_bell)
     {
-      NSAutoreleasePool *pool;
       struct frame *frame = SELECTED_FRAME ();
       NSView *view;
 
       block_input ();
-      pool = [[NSAutoreleasePool alloc] init];
 
       view = FRAME_NS_VIEW (frame);
-      if (view != nil)
-        {
-          NSRect r, surr;
-          NSPoint dim = NSMakePoint (128, 128);
-
-          r = [view bounds];
-          r.origin.x += (r.size.width - dim.x) / 2;
-          r.origin.y += (r.size.height - dim.y) / 2;
-          r.size.width = dim.x;
-          r.size.height = dim.y;
-          surr = NSInsetRect (r, -2, -2);
-          ns_focus (frame, &surr, 1);
-          [[view window] cacheImageInRect: [view convertRect: surr toView:nil]];
-          [ns_lookup_indexed_color (NS_FACE_FOREGROUND
-                                      (FRAME_DEFAULT_FACE (frame)), frame) set];
-          NSRectFill (r);
-          [[view window] flushWindow];
-          ns_timeout (150000);
-          [[view window] restoreCachedImage];
-          [[view window] flushWindow];
-          ns_unfocus (frame);
+      if (view != nil) {
+	  [BellView.sharedInstance ring:view color:ns_lookup_indexed_color(NS_FACE_FOREGROUND(FRAME_DEFAULT_FACE (frame)), frame)];
         }
-      [pool release];
+      
       unblock_input ();
-    }
-  else
-    {
+    } else {
       NSBeep ();
     }
 }

This displays an image named NSImageNameCaution, a small yellow triangle with an exclamation mark, for ~200 ms in the center of the selected frame.
It is possible to choose another image from the workspace, wide open to improvement (e.g., select favorite image by name in lisp ?).
The current foreground color is also sent to the BellView object, but no use case is implemented (ignored) in this patch, also wide open to improvement.

For use as appropriate,
Mustafa

bug#21662: 25.0.50; visible-bell causes display artifacts on OS X 10.11

[Mustafa Kocaturk]

The patch file had a duplicate of itself; the first half is sufficient.

> diff --git a/src/nsterm.m b/src/nsterm.m
> index c4bfd7c..f16ebe2 100644
> --- src/nsterm.m~
> +++ src/nsterm.m
> @@ -987,6 +987,59 @@ ns_clip_to_row (struct window *w, struct glyph_row *row,
> 
[…]
> -          ns_timeout (150000);

[…]
> }

The rest of the patch, starting with the lines below, should be removed:
> diff --git a/src/nsterm.m b/src/nsterm.m
> index c4bfd7c..f16ebe2 100644
> --- a/src/nsterm.m
> +++ b/src/nsterm.m
> @@ -987,6 +987,59 @@ ns_clip_to_row (struct window *w, struct glyph_row *row,
[…]
> 


The affected file, nsterm.m, defines a function called ns_timeout (int usecs), whose only use case appears to be removed by this change.
I think there is no other use of this function, but will verify by recompiling and send an updated patch, also removing the definition of ns_timeout if unused.

Best regards,
Mustafa

bug#21662: visible-bell causes display artifacts on OS X 10.11

[Anders Lindgren]

[-- Attachment #1: Type: text/plain, Size: 790 bytes --]

Hi,

Today I tested suggested patch on an 10.11 and on 10.6.8.

The good news is that, visually, the patch looks really good! It replaced
the boring black square with the standard OS X icon "Caution" icon -- an
exclamation mark on a triangle. It is less intrusive, which I consider a
good thing.

Unfortunately, the code doesn't compile under 10.6.8. The code use the
"hidden" property of NSView (introduced in 10.10), and it the compiler
complains about the "." in the "[BellView.instance ..." construct.

I notices a minor problem under 10.11 as well. The icon is shadowed by
scroll bars, if they happen to be displayed in the middle of the frame,
like when having two side-by-side windows.

I will make an attempt to rewrite to code to work under 10.6.8.

Sincerely,
    Anders Lindgren

[-- Attachment #2: Type: text/html, Size: 1035 bytes --]

bug#21662: visible-bell causes display artifacts on OS X 10.11

[Anders Lindgren]

[-- Attachment #1.1: Type: text/plain, Size: 1356 bytes --]

Hi again,

I decided to reimplement Mustafas ideas in a 10.6.8 compatible manner, and
to address the problem with the image being covered by scroll bars I
mentioned before. In addition, my implementation is aware that several
bell:s may be active at once and won't remove the image until the last one
times out, which eliminated flickering.

Unless anyone objects, I will publish this in the beginning of next week.

Sincerely,
    Anders Lindgren

On Wed, Nov 18, 2015 at 9:27 PM, Anders Lindgren <andlind@gmail.com> wrote:

> Hi,
>
> Today I tested suggested patch on an 10.11 and on 10.6.8.
>
> The good news is that, visually, the patch looks really good! It replaced
> the boring black square with the standard OS X icon "Caution" icon -- an
> exclamation mark on a triangle. It is less intrusive, which I consider a
> good thing.
>
> Unfortunately, the code doesn't compile under 10.6.8. The code use the
> "hidden" property of NSView (introduced in 10.10), and it the compiler
> complains about the "." in the "[BellView.instance ..." construct.
>
> I notices a minor problem under 10.11 as well. The icon is shadowed by
> scroll bars, if they happen to be displayed in the middle of the frame,
> like when having two side-by-side windows.
>
> I will make an attempt to rewrite to code to work under 10.6.8.
>
> Sincerely,
>     Anders Lindgren
>
>

[-- Attachment #1.2: Type: text/html, Size: 1941 bytes --]

[-- Attachment #2: bell-3.diff --]
[-- Type: text/plain, Size: 4382 bytes --]

diff --git a/src/nsterm.m b/src/nsterm.m
index 58ace48..5f22405 100644
--- a/src/nsterm.m
+++ b/src/nsterm.m
@@ -584,28 +584,6 @@ ns_load_path (void)
   return NULL;
 }
 
-static void
-ns_timeout (int usecs)
-/* --------------------------------------------------------------------------
-     Blocking timer utility used by ns_ring_bell
-   -------------------------------------------------------------------------- */
-{
-  struct timespec wakeup = timespec_add (current_timespec (),
-					 make_timespec (0, usecs * 1000));
-
-  /* Keep waiting until past the time wakeup.  */
-  while (1)
-    {
-      struct timespec timeout, now = current_timespec ();
-      if (timespec_cmp (wakeup, now) <= 0)
-	break;
-      timeout = timespec_sub (wakeup, now);
-
-      /* Try to wait that long--but we might wake up sooner.  */
-      pselect (0, NULL, NULL, NULL, &timeout, NULL);
-    }
-}
-
 
 void
 ns_release_object (void *obj)
@@ -1161,6 +1139,77 @@ ns_clip_to_row (struct window *w, struct glyph_row *row,
 }
 
 
+/* ==========================================================================
+
+    Visibel bell and beep.
+
+   ========================================================================== */
+
+
+@interface EmacsBell : NSImageView
+{
+  // Number of currently active bell:s.
+  unsigned int nestCount;
+}
+- (void)show:(NSView *)view;
+- (void)hide;
+@end
+
+@implementation EmacsBell
+
+- (id)init;
+{
+  if ((self = [super init]))
+    {
+      nestCount = 0;
+      self.image = [NSImage imageNamed:NSImageNameCaution];
+    }
+  return self;
+}
+
+- (void)show:(NSView *)view
+{
+  NSTRACE ("[EmacsBell show:]");
+  NSTRACE_MSG ("nestCount: %u", nestCount);
+
+  // Show the image, unless it's already shown.
+  if (nestCount == 0)
+    {
+      NSRect rect = [view bounds];
+      NSPoint pos;
+      pos.x = rect.origin.x + (rect.size.width  - self.image.size.width )/2;
+      pos.y = rect.origin.y + (rect.size.height - self.image.size.height)/2;
+
+      [self setFrameOrigin:pos];
+      [self setFrameSize:self.image.size];
+
+      [[[view window] contentView] addSubview:self
+                                   positioned:NSWindowAbove
+                                   relativeTo:nil];
+    }
+
+  ++nestCount;
+
+  [self performSelector:@selector(hide) withObject:self afterDelay:0.5];
+}
+
+
+- (void)hide
+{
+  // Note: Trace output from this method isn't shown, reason unknown.
+  // NSTRACE ("[EmacsBell hide]");
+
+  --nestCount;
+
+  // Remove the image once the last bell became inactive.
+  if (nestCount == 0)
+    {
+      [self removeFromSuperview];
+    }
+}
+
+@end
+
 static void
 ns_ring_bell (struct frame *f)
 /* --------------------------------------------------------------------------
@@ -1170,37 +1219,24 @@ ns_ring_bell (struct frame *f)
   NSTRACE ("ns_ring_bell");
   if (visible_bell)
     {
-      NSAutoreleasePool *pool;
       struct frame *frame = SELECTED_FRAME ();
       NSView *view;
 
+      static EmacsBell * bell_view = nil;
+      if (bell_view == nil)
+        {
+          bell_view = [[EmacsBell alloc] init];
+          [bell_view retain];
+        }
+
       block_input ();
-      pool = [[NSAutoreleasePool alloc] init];
 
       view = FRAME_NS_VIEW (frame);
       if (view != nil)
         {
-          NSRect r, surr;
-          NSPoint dim = NSMakePoint (128, 128);
-
-          r = [view bounds];
-          r.origin.x += (r.size.width - dim.x) / 2;
-          r.origin.y += (r.size.height - dim.y) / 2;
-          r.size.width = dim.x;
-          r.size.height = dim.y;
-          surr = NSInsetRect (r, -2, -2);
-          ns_focus (frame, &surr, 1);
-          [[view window] cacheImageInRect: [view convertRect: surr toView:nil]];
-          [ns_lookup_indexed_color (NS_FACE_FOREGROUND
-                                      (FRAME_DEFAULT_FACE (frame)), frame) set];
-          NSRectFill (r);
-          [[view window] flushWindow];
-          ns_timeout (150000);
-          [[view window] restoreCachedImage];
-          [[view window] flushWindow];
-          ns_unfocus (frame);
+          [bell_view show:view];
         }
-      [pool release];
+
       unblock_input ();
     }
   else
@@ -1209,6 +1245,7 @@ ns_ring_bell (struct frame *f)
     }
 }
 
+
 /* ==========================================================================
 
     Frame / window manager related functions

bug#21662: Fixed

[Anders Lindgren]

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Fixed, see
http://git.savannah.gnu.org/cgit/emacs.git/commit/?h=emacs-25&id=345a9c8cd07111a8c8367e59404688544e8b8b1d
for details.

    -- Anders Lindgren

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