ardour/gtk2_ardour/au_pluginui.mm

#undef  Marker
#define Marker FuckYouAppleAndYourLackOfNameSpaces

#include <sys/time.h>
#include <gtkmm/button.h>
#include <gdk/gdkquartz.h>

#include "pbd/convert.h"
#include "pbd/error.h"

#include "ardour/audio_unit.h"
#include "ardour/debug.h"
#include "ardour/plugin_insert.h"

#undef check // stupid gtk, stupid apple

#include <gtkmm2ext/utils.h>
#include <gtkmm2ext/window_proxy.h>

#include "au_pluginui.h"
#include "gui_thread.h"
#include "processor_box.h"

#include "CAAudioUnit.h"
#include "CAComponent.h"

#import <AudioUnit/AUCocoaUIView.h>
#import <CoreAudioKit/AUGenericView.h>
#import <objc/runtime.h>
#include <dispatch/dispatch.h>

#undef Marker

#include "keyboard.h"
#include "utils.h"
#include "public_editor.h"
#include "i18n.h"

#include "gtk2ardour-config.h"

#ifdef COREAUDIO105
#define ArdourCloseComponent CloseComponent
#else
#define ArdourCloseComponent AudioComponentInstanceDispose
#endif
using namespace ARDOUR;
using namespace Gtk;
using namespace Gtkmm2ext;
using namespace std;
using namespace PBD;

vector<string> AUPluginUI::automation_mode_strings;
int64_t AUPluginUI::last_timer = 0;
bool    AUPluginUI::timer_needed = true;
CFRunLoopTimerRef AUPluginUI::cf_timer;
uint64_t AUPluginUI::timer_callbacks = 0;
uint64_t AUPluginUI::timer_out_of_range = 0;

static const gchar* _automation_mode_strings[] = {
	X_("Manual"),
	X_("Play"),
	X_("Write"),
	X_("Touch"),
	0
};

static void
dump_view_tree (NSView* view, int depth, int maxdepth)
{
	NSArray* subviews = [view subviews];
	unsigned long cnt = [subviews count];

	if (depth == 0) {
		NSView* su = [view superview];
		if (su) {
			NSRect sf = [su frame];
			cerr << " PARENT view " << su << " @ " <<  sf.origin.x << ", " << sf.origin.y
			     << ' ' << sf.size.width << " x " << sf.size.height
			     << endl;
		}
	}

	for (int d = 0; d < depth; d++) {
		cerr << '\t';
	}
	NSRect frame = [view frame];
	cerr << " view " << view << " @ " <<  frame.origin.x << ", " << frame.origin.y
		<< ' ' << frame.size.width << " x " << frame.size.height
		<< endl;

	if (depth >= maxdepth) {
		return;
	}
	for (unsigned long i = 0; i < cnt; ++i) {
		NSView* subview = [subviews objectAtIndex:i];
		dump_view_tree (subview, depth+1, maxdepth);
	}
}

/* This deeply hacky block of code exists for a rather convoluted reason.
 *
 * The proximal reason is that there are plugins (such as XLN's Addictive Drums
 * 2) which redraw their GUI/editor windows using a timer, and use a drawing
 * technique that on Retina displays ends up calling arg32_image_mark_RGB32, a
 * function that for some reason (probably byte-swapping or pixel-doubling) is
 * many times slower than the function used on non-Retina displays.
 *
 * We are not the first people to discover the problem with
 * arg32_image_mark_RGB32.
 *
 * Justin Fraenkel, the lead author of Reaper, wrote a very detailed account of
 * the performance issues with arg32_image_mark_RGB32 here:
 * http://www.1014.org/?article=516
 *
 * The problem was also seen by Robert O'Callahan (lead developer of rr, the
 * reverse debugger) as far back as 2010:
 * http://robert.ocallahan.org/2010/05/cglayer-performance-trap-with-isflipped_03.html
 *
 * In fact, it is so slow that the drawing takes up close to 100% of a single
 * core, and the event loop that the drawing occurs in never sleeps or "idles".
 *
 * In AU hosts built directly on top of Cocoa, or some other toolkits, this
 * isn't inherently a major problem - it just makes the entire GUI of the
 * application slow.
 *
 * However, there is an additional problem for Ardour because GTK+ is built on
 * top of the GDK/Quartz event loop integration. This integration is rather
 * baroque, mostly because it was written at a time when CFRunLoop did not
 * offer a way to wait for "input" from file descriptors (which arrived in OS X
 * 10.5). As a result, it uses a hair-raising design involving an additional
 * thread. This design has a major problem, which is that it effectively
 * creates two nested run loops.
 *
 * The GTK+/GDK/glib one runs until it has nothing to do, at which time it
 * calls a function to wait until there is something to do. On Linux or Windows
 * that would involve some variant or relative of poll(2), which puts the
 * process to sleep until there is something to do.
 *
 * On OS X, glib ends up calling [CFRunLoop waitForNextEventMatchingMask] which
 * will eventually put the process to sleep, but won't do so until the
 * CFRunLoop also has nothing to do. This includes (at least) a complete redraw
 * cycle. If redrawing takes too long, and there are timers expired for another
 * redraw (e.g. Addictive Drums 2, again), then the CFRunLoop will just start
 * another redraw cycle after processing any events and other stuff.
 *
 * If the CFRunLoop stays busy, then it will never return to the glib
 * level at all, thus stopping any further GTK+ level activity (events,
 * drawing) from taking place. In short, the current (spring 2016) design of
 * the GDK/Quartz event loop integration relies on the idea that the internal
 * CFRunLoop will go idle, and totally breaks if this does not happen.
 *
 * So take a fully functional Ardour, add in XLN's Addictive Drums 2, and a
 * Retina display, and Apple's ridiculously slow blitting code, and the
 * CFRunLoop never goes idle. As soon as Addictive Drums starts drawing (over
 * and over again), the GTK+ event loop stops receiving events and stops
 * drawing.
 *
 * One fix for this was to run a nested GTK+ event loop iteration (or two)
 * whenever a plugin window was redrawn. This works in the sense that the
 * immediate issue (no GTK+ events or drawing) is fixed. But the recursive GTK+
 * event loop causes its own (very subtle) problems too.
 *
 * This code takes a rather radical approach. We use Objective C's ability to
 * swizzle object methods. Specifically, we replace [NSView displayIfNeeded]
 * with our own version which will skip redraws of plugin windows if we tell it
 * too. If we haven't done that, or if the redraw is of a non-plugin window,
 * then we invoke the original displayIfNeeded method.
 *
 * After every 10 redraws of a given plugin GUI/editor window, we queue up a
 * GTK/glib idle callback to measure the interval between those idle
 * callbacks. We do this globally across all plugin windows, so if the callback
 * is already queued, we don't requeue it.
 *
 * If the interval is longer than 40msec (a 25fps redraw rate), we set
 * block_plugin_redraws to some number. Each successive call to our interposed
 * displayIfNeeded method will (a) check this value and if non-zero (b) check
 * if the call is for a plugin-related NSView/NSWindow. If it is, then we will
 * skip the redisplay entirely, hopefully avoiding any calls to
 * argb32_image_mark_RGB32 or any other slow drawing code, and thus allowing
 * the CFRunLoop to go idle. If the value is zero or the call is for a
 * non-plugin window, then we just invoke the "original" displayIfNeeded
 * method.
 *
 * This hack adds a tiny bit of overhead onto redrawing of the entire
 * application. But in the common case this consists of 1 conditional (the
 * check on block_plugin_redraws, which will find it to be zero) and the
 * invocation of the original method. Given how much work is typically done
 * during drawing, this seems acceptable.
 *
 * The correct fix for this is to redesign the relationship between
 * GTK+/GDK/glib so that a glib run loop is actually a CFRunLoop, with all
 * GSources represented as CFRunLoopSources, without any nesting and without
 * any additional thread. This is not a task to be undertaken lightly, and is
 * certainly substantially more work than this was. It may never be possible to
 * do that work in a way that could be integrated back into glib, because of
 * the rather specific semantics and types of GSources, but it would almost
 * certainly be possible to make it work for Ardour.
 */

static IMP original_nsview_drawIfNeeded;
static std::vector<id> plugin_views;
static uint32_t block_plugin_redraws = 0;
static const uint32_t minimum_redraw_rate = 25; /* frames per second */
static const uint32_t block_plugin_redraw_count = 10; /* number of combined plugin redraws to block, if blocking */

static void add_plugin_view (id view)
{
	if (plugin_views.empty()) {
		AUPluginUI::start_cf_timer ();
	}

	plugin_views.push_back (view);

}

static void remove_plugin_view (id view)
{
	std::vector<id>::iterator x = find (plugin_views.begin(), plugin_views.end(), view);
	if (x != plugin_views.end()) {
		plugin_views.erase (x);
	}
	if (plugin_views.empty()) {
		AUPluginUI::stop_cf_timer ();
	}
}

static void interposed_drawIfNeeded (id receiver, SEL selector, NSRect rect)
{
	if (block_plugin_redraws && (find (plugin_views.begin(), plugin_views.end(), receiver) != plugin_views.end())) {
		block_plugin_redraws--;
		std::cerr << "Plugin redraw blocked\n";
		/* YOU ... SHALL .... NOT ... DRAW!!!! */
		return;
	}
	(void) ((int (*)(id,SEL,NSRect)) original_nsview_drawIfNeeded) (receiver, selector, rect);
}

@implementation NSView (Tracking)
+ (void) load {
	static dispatch_once_t once_token;

	/* this swizzles NSView::displayIfNeeded and replaces it with
	 * interposed_drawIfNeeded(), which allows us to interpose and block
	 * the redrawing of plugin UIs when their redrawing behaviour
	 * is interfering with event loop behaviour.
	 */

	dispatch_once (&once_token, ^{
			Method target = class_getInstanceMethod ([NSView class], @selector(displayIfNeeded));
			original_nsview_drawIfNeeded = method_setImplementation (target, (IMP) interposed_drawIfNeeded);
		});
}

@end

/* END OF THE PLUGIN REDRAW HACK */

@implementation NotificationObject

- (NotificationObject*) initWithPluginUI: (AUPluginUI*) apluginui andCocoaParent: (NSWindow*) cp andTopLevelParent: (NSWindow*) tlp
{
	self = [ super init ];

	if (self) {
		plugin_ui = apluginui;
		top_level_parent = tlp;

		if (cp) {
			cocoa_parent = cp;

			[[NSNotificationCenter defaultCenter]
			     addObserver:self
			        selector:@selector(cocoaParentActivationHandler:)
			            name:NSWindowDidBecomeMainNotification
			          object:NULL];

			[[NSNotificationCenter defaultCenter]
			     addObserver:self
			        selector:@selector(cocoaParentBecameKeyHandler:)
			            name:NSWindowDidBecomeKeyNotification
			          object:NULL];
		}
	}

	return self;
}

- (void)cocoaParentActivationHandler:(NSNotification *)notification
{
	NSWindow* notification_window = (NSWindow *)[notification object];

	if (top_level_parent == notification_window || cocoa_parent == notification_window) {
		if ([notification_window isMainWindow]) {
			plugin_ui->activate();
		} else {
			plugin_ui->deactivate();
		}
	}
}

- (void)cocoaParentBecameKeyHandler:(NSNotification *)notification
{
	NSWindow* notification_window = (NSWindow *)[notification object];

	if (top_level_parent == notification_window || cocoa_parent == notification_window) {
		if ([notification_window isKeyWindow]) {
			plugin_ui->activate();
		} else {
			plugin_ui->deactivate();
		}
	}
}

- (void)auViewResized:(NSNotification *)notification
{
	(void) notification; // stop complaints about unusued argument
	plugin_ui->cocoa_view_resized();
}

@end

@implementation LiveResizeNotificationObject

- (LiveResizeNotificationObject*) initWithPluginUI: (AUPluginUI*) apluginui
{
	self = [ super init ];
	if (self) {
		plugin_ui = apluginui;
	}

	return self;
}

- (void)windowWillStartLiveResizeHandler:(NSNotification*)notification
{
	plugin_ui->start_live_resize ();
}

- (void)windowWillEndLiveResizeHandler:(NSNotification*)notification
{
	plugin_ui->end_live_resize ();
}
@end

AUPluginUI::AUPluginUI (boost::shared_ptr<PluginInsert> insert)
	: PlugUIBase (insert)
	, automation_mode_label (_("Automation"))
	, preset_label (_("Presets"))
	, resizable (false)
	, req_width (0)
	, req_height (0)
	, cocoa_window (0)
	, au_view (0)
	, in_live_resize (false)
	, plugin_requested_resize (0)
	, cocoa_parent (0)
	, _notify (0)
	, _resize_notify (0)
{
	if (automation_mode_strings.empty()) {
		automation_mode_strings = I18N (_automation_mode_strings);
	}

	set_popdown_strings (automation_mode_selector, automation_mode_strings);
	automation_mode_selector.set_active_text (automation_mode_strings.front());

	if ((au = boost::dynamic_pointer_cast<AUPlugin> (insert->plugin())) == 0) {
		error << _("unknown type of editor-supplying plugin (note: no AudioUnit support in this version of ardour)") << endmsg;
		throw failed_constructor ();
	}

	/* stuff some stuff into the top of the window */

	HBox* smaller_hbox = manage (new HBox);

	smaller_hbox->set_spacing (6);
	smaller_hbox->pack_start (preset_label, false, false, 4);
	smaller_hbox->pack_start (_preset_modified, false, false);
	smaller_hbox->pack_start (_preset_combo, false, false);
	smaller_hbox->pack_start (add_button, false, false);
#if 0
	/* Ardour does not currently allow to overwrite existing presets
	 * see save_property_list() in audio_unit.cc
	 */
	smaller_hbox->pack_start (save_button, false, false);
#endif
#if 0
	/* one day these might be useful with an AU plugin, but not yet */
	smaller_hbox->pack_start (automation_mode_label, false, false);
	smaller_hbox->pack_start (automation_mode_selector, false, false);
#endif
	smaller_hbox->pack_start (reset_button, false, false);
	smaller_hbox->pack_start (bypass_button, false, true);

	VBox* v1_box = manage (new VBox);
	VBox* v2_box = manage (new VBox);

	v1_box->pack_start (*smaller_hbox, false, true);
	v2_box->pack_start (focus_button, false, true);

	top_box.set_homogeneous (false);
	top_box.set_spacing (6);
	top_box.set_border_width (6);

	top_box.pack_end (*v2_box, false, false);
	top_box.pack_end (*v1_box, false, false);

	set_spacing (6);
	pack_start (top_box, false, false);
	pack_start (low_box, true, true);

	preset_label.show ();
	_preset_combo.show ();
	automation_mode_label.show ();
	automation_mode_selector.show ();
	bypass_button.show ();
	top_box.show ();
	low_box.show ();

	cocoa_parent = 0;
	cocoa_window = 0;

#ifdef WITH_CARBON
	_activating_from_app = false;
	_notify = 0;
	au_view = 0;
	editView = 0;
	carbon_window = 0;
#endif

	/* prefer cocoa, fall back to cocoa, but use carbon if its there */

	if (test_cocoa_view_support()) {
		create_cocoa_view ();
#ifdef WITH_CARBON
	} else if (test_carbon_view_support()) {
		create_carbon_view ();
#endif
	} else {
		create_cocoa_view ();
	}

	low_box.add_events (Gdk::VISIBILITY_NOTIFY_MASK | Gdk::EXPOSURE_MASK);

	low_box.signal_realize().connect (mem_fun (this, &AUPluginUI::lower_box_realized));
	low_box.signal_visibility_notify_event ().connect (mem_fun (this, &AUPluginUI::lower_box_visibility_notify));
	if (au_view) {
		low_box.signal_size_request ().connect (mem_fun (this, &AUPluginUI::lower_box_size_request));
		low_box.signal_size_allocate ().connect (mem_fun (this, &AUPluginUI::lower_box_size_allocate));
		low_box.signal_map ().connect (mem_fun (this, &AUPluginUI::lower_box_map));
		low_box.signal_unmap ().connect (mem_fun (this, &AUPluginUI::lower_box_unmap));
	}
}

AUPluginUI::~AUPluginUI ()
{
	if (_notify) {
		[[NSNotificationCenter defaultCenter] removeObserver:_notify];
	}

	if (_resize_notify) {
		[[NSNotificationCenter defaultCenter] removeObserver:_resize_notify];
	}

	NSWindow* win = get_nswindow();
	if (au_view) {
		remove_plugin_view ([[win contentView] superview]);
	}

#ifdef WITH_CARBON
	if (cocoa_parent) {
		[win removeChildWindow:cocoa_parent];
	}

	if (carbon_window) {
		/* not parented, just overlaid on top of our window */
		DisposeWindow (carbon_window);
	}
#endif

	if (editView) {
		ArdourCloseComponent (editView);
	}

	if (au_view) {
		/* remove whatever we packed into low_box so that GTK doesn't
		   mess with it.
		 */
		[au_view removeFromSuperview];
	}
}

bool
AUPluginUI::test_carbon_view_support ()
{
#ifdef WITH_CARBON
	bool ret = false;

	carbon_descriptor.componentType = kAudioUnitCarbonViewComponentType;
	carbon_descriptor.componentSubType = 'gnrc';
	carbon_descriptor.componentManufacturer = 'appl';
	carbon_descriptor.componentFlags = 0;
	carbon_descriptor.componentFlagsMask = 0;

	OSStatus err;

	// ask the AU for its first editor component
	UInt32 propertySize;
	err = AudioUnitGetPropertyInfo(*au->get_au(), kAudioUnitProperty_GetUIComponentList, kAudioUnitScope_Global, 0, &propertySize, NULL);
	if (!err) {
		int nEditors = propertySize / sizeof(ComponentDescription);
		ComponentDescription *editors = new ComponentDescription[nEditors];
		err = AudioUnitGetProperty(*au->get_au(), kAudioUnitProperty_GetUIComponentList, kAudioUnitScope_Global, 0, editors, &propertySize);
		if (!err) {
			// just pick the first one for now
			carbon_descriptor = editors[0];
			ret = true;
		}
		delete[] editors;
	}

	return ret;
#else
	return false;
#endif
}

bool
AUPluginUI::test_cocoa_view_support ()
{
	UInt32 dataSize   = 0;
	Boolean isWritable = 0;
	OSStatus err = AudioUnitGetPropertyInfo(*au->get_au(),
						kAudioUnitProperty_CocoaUI, kAudioUnitScope_Global,
						0, &dataSize, &isWritable);

	return dataSize > 0 && err == noErr;
}

bool
AUPluginUI::plugin_class_valid (Class pluginClass)
{
	if([pluginClass conformsToProtocol: @protocol(AUCocoaUIBase)]) {
		if([pluginClass instancesRespondToSelector: @selector(interfaceVersion)] &&
		   [pluginClass instancesRespondToSelector: @selector(uiViewForAudioUnit:withSize:)]) {
				return true;
		}
	}
	return false;
}

int
AUPluginUI::create_cocoa_view ()
{
	bool wasAbleToLoadCustomView = false;
	AudioUnitCocoaViewInfo* cocoaViewInfo = NULL;
	UInt32               numberOfClasses = 0;
	UInt32     dataSize;
	Boolean    isWritable;
	NSString*	    factoryClassName = 0;
	NSURL*	            CocoaViewBundlePath = NULL;

	OSStatus result = AudioUnitGetPropertyInfo (*au->get_au(),
						    kAudioUnitProperty_CocoaUI,
						    kAudioUnitScope_Global,
						    0,
						    &dataSize,
						    &isWritable );

	numberOfClasses = (dataSize - sizeof(CFURLRef)) / sizeof(CFStringRef);

	// Does view have custom Cocoa UI?

	if ((result == noErr) && (numberOfClasses > 0) ) {

		DEBUG_TRACE(DEBUG::AudioUnits,
			    string_compose ( "based on %1, there are %2 cocoa UI classes\n", dataSize, numberOfClasses));

		cocoaViewInfo = (AudioUnitCocoaViewInfo *)malloc(dataSize);

		if(AudioUnitGetProperty(*au->get_au(),
					kAudioUnitProperty_CocoaUI,
					kAudioUnitScope_Global,
					0,
					cocoaViewInfo,
					&dataSize) == noErr) {

			CocoaViewBundlePath	= (NSURL *)cocoaViewInfo->mCocoaAUViewBundleLocation;

			// we only take the first view in this example.
			factoryClassName	= (NSString *)cocoaViewInfo->mCocoaAUViewClass[0];

			DEBUG_TRACE (DEBUG::AudioUnits, string_compose ("the factory name is %1 bundle is %2\n",
									[factoryClassName UTF8String], CocoaViewBundlePath));

		} else {

			DEBUG_TRACE (DEBUG::AudioUnits, string_compose ("No cocoaUI property cocoaViewInfo = %1\n", cocoaViewInfo));

			if (cocoaViewInfo != NULL) {
				free (cocoaViewInfo);
				cocoaViewInfo = NULL;
			}
		}
	}

	// [A] Show custom UI if view has it

	if (CocoaViewBundlePath && factoryClassName) {
		NSBundle *viewBundle	= [NSBundle bundleWithPath:[CocoaViewBundlePath path]];

		DEBUG_TRACE (DEBUG::AudioUnits, string_compose ("tried to create bundle, result = %1\n", viewBundle));

		if (viewBundle == NULL) {
			error << _("AUPluginUI: error loading AU view's bundle") << endmsg;
			return -1;
		} else {
			Class factoryClass = [viewBundle classNamed:factoryClassName];
			DEBUG_TRACE (DEBUG::AudioUnits, string_compose ("tried to create factory class, result = %1\n", factoryClass));
			if (!factoryClass) {
				error << _("AUPluginUI: error getting AU view's factory class from bundle") << endmsg;
				return -1;
			}

			// make sure 'factoryClass' implements the AUCocoaUIBase protocol
			if (!plugin_class_valid (factoryClass)) {
				error << _("AUPluginUI: U view's factory class does not properly implement the AUCocoaUIBase protocol") << endmsg;
				return -1;
			}
			// make a factory
			id factory = [[[factoryClass alloc] init] autorelease];
			if (factory == NULL) {
				error << _("AUPluginUI: Could not create an instance of the AU view factory") << endmsg;
				return -1;
			}

			DEBUG_TRACE (DEBUG::AudioUnits, "got a factory instance\n");

			// make a view
			au_view = [factory uiViewForAudioUnit:*au->get_au() withSize:NSZeroSize];

			DEBUG_TRACE (DEBUG::AudioUnits, string_compose ("view created @ %1\n", au_view));

			// cleanup
			[CocoaViewBundlePath release];
			if (cocoaViewInfo) {
				UInt32 i;
				for (i = 0; i < numberOfClasses; i++)
					CFRelease(cocoaViewInfo->mCocoaAUViewClass[i]);

				free (cocoaViewInfo);
			}
			wasAbleToLoadCustomView = true;
		}
	}

	if (!wasAbleToLoadCustomView) {
		// load generic Cocoa view
		DEBUG_TRACE (DEBUG::AudioUnits, string_compose ("Loading generic view using %1 -> %2\n", au,
								au->get_au()));
		au_view = [[AUGenericView alloc] initWithAudioUnit:*au->get_au()];
		DEBUG_TRACE (DEBUG::AudioUnits, string_compose ("view created @ %1\n", au_view));
		[(AUGenericView *)au_view setShowsExpertParameters:1];
	}

	// Get the initial size of the new AU View's frame
	NSRect  frame = [au_view frame];
	req_width  = frame.size.width;
	req_height = frame.size.height;

	resizable  = [au_view autoresizingMask];

	low_box.queue_resize ();

	return 0;
}

void
AUPluginUI::update_view_size ()
{
	last_au_frame = [au_view frame];
}


void
au_cf_timer_callback (CFRunLoopTimerRef timer, void* info)
{
	reinterpret_cast<AUPluginUI*> (info)->cf_timer_callback ();
}

void
AUPluginUI::cf_timer_callback ()
{
	int64_t now = ARDOUR::get_microseconds ();
	timer_callbacks++;

	if (!last_timer) {
		last_timer = now;
		return;
	}

	const int64_t usecs_slop = 7500; /* 7.5 msec */

	std::cerr << "Timer elapsed : " << now - last_timer << std::endl;

	if ((now - last_timer) > (usecs_slop + (1000000/minimum_redraw_rate))) {
		timer_out_of_range++;
	}

	/* check timing roughly every second */

	if ((timer_callbacks % minimum_redraw_rate) == 0) {
		std::cerr << "OOR check: " << timer_out_of_range << std::endl;
		if (timer_out_of_range > (minimum_redraw_rate / 4)) {
			/* more than 25 % of the last second's worth of timers
			   have been late. Take action.
			*/
			block_plugin_redraws = block_plugin_redraw_count;
			std::cerr << "Timer too slow, block plugin redraws\n";
		}
		timer_out_of_range = 0;
	}

	last_timer = now;
}

void
AUPluginUI::start_cf_timer ()
{
	if (!timer_needed) {
		return;
	}

	CFTimeInterval interval = 1.0/25.0; /* secs => 40msec or 25fps */

	cf_timer = CFRunLoopTimerCreate (kCFAllocatorDefault,
	                                 CFAbsoluteTimeGetCurrent() + interval,
	                                 interval, 0, 0,
	                                 au_cf_timer_callback,
	                                 0);

	CFRunLoopAddTimer (CFRunLoopGetCurrent(), cf_timer, kCFRunLoopCommonModes);
	timer_needed = false;
}

void
AUPluginUI::stop_cf_timer ()
{
	if (timer_needed) {
		return;
	}

	CFRunLoopRemoveTimer (CFRunLoopGetCurrent(), cf_timer, kCFRunLoopCommonModes);
	timer_needed = true;
	last_timer = 0;
}

void
AUPluginUI::cocoa_view_resized ()
{
        /* we can get here for two reasons:

           1) the plugin window was resized by the user, a new size was
           allocated to the window, ::update_view_size() was called, and we
           explicitly/manually resized the AU NSView.

           2) the plugin decided to resize itself (probably in response to user
           action, but not in response to an actual window resize)

           We only want to proceed with a window resizing in the second case.
        */

	if (in_live_resize) {
		/* ::update_view_size() will be called at the right times and
		 * will update the view size. We don't need to anything while a
		 * live resize in underway.
		 */
		return;
	}

	if (plugin_requested_resize) {
		/* we tried to change the plugin frame from inside this method
		 * (to adjust the origin), which changes the frame of the AU
		 * NSView, resulting in a reentrant call to the FrameDidChange
		 * handler (this method). Ignore this reentrant call.
		 */
		std::cerr << plugin->name() << " re-entrant call to cocoa_view_resized, ignored\n";
		return;
	}

	plugin_requested_resize = 1;

	ProcessorWindowProxy* wp = insert->window_proxy();
	if (wp) {
		/* Once a plugin has requested a resize of its own window, do
		 * NOT save the window. The user may save state with the plugin
		 * editor expanded to show "extra detail" - the plugin will not
		 * refill this space when the editor is first
		 * instantiated. Leaving the window in the "too big" state
		 * cannot be recovered from.
		 *
		 * The window will be sized to fit the plugin's own request. Done.
		 */
		wp->set_state_mask (WindowProxy::Position);
	}

        NSRect new_frame = [au_view frame];

	/* from here on, we know that we've been called because the plugin
	 * decided to change the NSView frame itself.
	 */

	/* step one: compute the change in the frame size.
	 */

	float dy = new_frame.size.height - last_au_frame.size.height;
        float dx = new_frame.size.width - last_au_frame.size.width;

        NSWindow* window = get_nswindow ();
        NSRect windowFrame= [window frame];

	/* we want the top edge of the window to remain in the same place,
	   but the Cocoa/Quartz origin is at the lower left. So, when we make
	   the window larger, we will move it down, which means shifting the
	   origin toward (x,0). This will leave the top edge in the same place.
	*/

        windowFrame.origin.y    -= dy;
        windowFrame.origin.x    -= dx;
        windowFrame.size.height += dy;
        windowFrame.size.width  += dx;

        NSUInteger old_auto_resize = [au_view autoresizingMask];

        /* Some stupid AU Views change the origin of the original AU View when
           they are resized (I'm looking at you AUSampler). If the origin has
           been moved, move it back.
        */

        if (last_au_frame.origin.x != new_frame.origin.x ||
            last_au_frame.origin.y != new_frame.origin.y) {
                new_frame.origin = last_au_frame.origin;
                [au_view setFrame:new_frame];
                /* also be sure to redraw the topbox because this can
                   also go wrong.
                 */
                top_box.queue_draw ();
	}

	/* We resize the window using Cocoa. We can't use GTK mechanisms
	 * because of this:
	 *
	 * http://www.lists.apple.com/archives/coreaudio-api/2005/Aug/msg00245.html
	 *
	 * "The host needs to be aware that changing the size of the window in
	 * response to the NSViewFrameDidChangeNotification can cause the view
	 * size to change depending on the autoresizing mask of the view. The
	 * host may need to cache the autoresizing mask of the view, set it to
	 * NSViewNotSizable, resize the window, and then reset the autoresizing
	 * mask of the view once the window has been sized."
	 *
	 */

        [au_view setAutoresizingMask:NSViewNotSizable];
	[window setFrame:windowFrame display:1];
        [au_view setAutoresizingMask:old_auto_resize];

	/* keep a copy of the size of the AU NSView. We didn't set it - the plugin did */
	last_au_frame = new_frame;
	req_width  = new_frame.size.width;
	req_height = new_frame.size.height;

	plugin_requested_resize = 0;
}

int
AUPluginUI::create_carbon_view ()
{
#ifdef WITH_CARBON
	OSStatus err;
	ControlRef root_control;

	Component editComponent = FindNextComponent(NULL, &carbon_descriptor);

	OpenAComponent(editComponent, &editView);
	if (!editView) {
		error << _("AU Carbon view: cannot open AU Component") << endmsg;
		return -1;
	}

	Rect r = { 100, 100, 100, 100 };
	WindowAttributes attr = WindowAttributes (kWindowStandardHandlerAttribute |
						  kWindowCompositingAttribute|
						  kWindowNoShadowAttribute|
						  kWindowNoTitleBarAttribute);

	if ((err = CreateNewWindow(kUtilityWindowClass, attr, &r, &carbon_window)) != noErr) {
		error << string_compose (_("AUPluginUI: cannot create carbon window (err: %1)"), err) << endmsg;
	        ArdourCloseComponent (editView);
		return -1;
	}

	if ((err = GetRootControl(carbon_window, &root_control)) != noErr) {
		error << string_compose (_("AUPlugin: cannot get root control of carbon window (err: %1)"), err) << endmsg;
		DisposeWindow (carbon_window);
	        ArdourCloseComponent (editView);
		return -1;
	}

	ControlRef viewPane;
	Float32Point location  = { 0.0, 0.0 };
	Float32Point size = { 0.0, 0.0 } ;

	if ((err = AudioUnitCarbonViewCreate (editView, *au->get_au(), carbon_window, root_control, &location, &size, &viewPane)) != noErr) {
		error << string_compose (_("AUPluginUI: cannot create carbon plugin view (err: %1)"), err) << endmsg;
		DisposeWindow (carbon_window);
	        ArdourCloseComponent (editView);
		return -1;
	}

	// resize window

	Rect bounds;
	GetControlBounds(viewPane, &bounds);
	size.x = bounds.right-bounds.left;
	size.y = bounds.bottom-bounds.top;

	req_width = (int) (size.x + 0.5);
	req_height = (int) (size.y + 0.5);

	SizeWindow (carbon_window, req_width, req_height,  true);
	low_box.set_size_request (req_width, req_height);

	return 0;
#else
	error << _("AU Carbon GUI is not supported.") << endmsg;
	return -1;
#endif
}

NSWindow*
AUPluginUI::get_nswindow ()
{
	Gtk::Container* toplevel = get_toplevel();

	if (!toplevel || !toplevel->is_toplevel()) {
		error << _("AUPluginUI: no top level window!") << endmsg;
		return 0;
	}

	NSWindow* true_parent = gdk_quartz_window_get_nswindow (toplevel->get_window()->gobj());

	if (!true_parent) {
		error << _("AUPluginUI: no top level window!") << endmsg;
		return 0;
	}

	return true_parent;
}

void
AUPluginUI::activate ()
{
#ifdef WITH_CARBON
	ActivateWindow (carbon_window, TRUE);
#endif
}

void
AUPluginUI::deactivate ()
{
#ifdef WITH_CARBON
	ActivateWindow (carbon_window, FALSE);
#endif
}

int
AUPluginUI::parent_carbon_window ()
{
#ifdef WITH_CARBON
	NSWindow* win = get_nswindow ();
	Rect windowStructureBoundsRect;

	if (!win) {
		return -1;
	}

	/* figure out where the cocoa parent window is in carbon-coordinate space, which
	   differs from both cocoa-coordinate space and GTK-coordinate space
	*/

	GetWindowBounds((WindowRef) [win windowRef], kWindowStructureRgn, &windowStructureBoundsRect);

	/* compute how tall the title bar is, because we have to offset the position of the carbon window
	   by that much.
	*/

	NSRect content_frame = [NSWindow contentRectForFrameRect:[win frame] styleMask:[win styleMask]];
	NSRect wm_frame = [NSWindow frameRectForContentRect:content_frame styleMask:[win styleMask]];

	int titlebar_height = wm_frame.size.height - content_frame.size.height;

	int packing_extra = 6; // this is the total vertical packing in our top level window

	/* move into position, based on parent window position */
	MoveWindow (carbon_window,
		    windowStructureBoundsRect.left,
		    windowStructureBoundsRect.top + titlebar_height + top_box.get_height() + packing_extra,
		    false);
	ShowWindow (carbon_window);

	// create the cocoa window for the carbon one and make it visible
	cocoa_parent = [[NSWindow alloc] initWithWindowRef: carbon_window];

	SetWindowActivationScope (carbon_window, kWindowActivationScopeNone);

	_notify = [ [NotificationObject alloc] initWithPluginUI:this andCocoaParent:cocoa_parent andTopLevelParent:win ];

	[win addChildWindow:cocoa_parent ordered:NSWindowAbove];
	[win setAutodisplay:1]; // turn of GTK stuff for this window

	return 0;
#else
	return -1;
#endif
}

int
AUPluginUI::parent_cocoa_window ()
{
	NSWindow* win = get_nswindow ();

	if (!win) {
		return -1;
	}

	//[win setAutodisplay:1]; // turn off GTK stuff for this window

	NSView* view = gdk_quartz_window_get_nsview (low_box.get_window()->gobj());
	[view addSubview:au_view];
	/* despite the fact that the documentation says that [NSWindow
	   contentView] is the highest "accessible" NSView in an NSWindow, when
	   the redraw cycle is executed, displayIfNeeded is actually executed
	   on the parent of the contentView. To provide a marginal speedup when
	   checking if a given redraw is for a plugin, use this "hidden" NSView
	   to identify the plugin, so that we do not have to call [superview]
	   every time in interposed_drawIfNeeded().
	*/
	add_plugin_view ([[win contentView] superview]);

	/* this moves the AU NSView down and over to provide a left-hand margin
	 * and to clear the Ardour "task bar" (with plugin preset mgmt buttons,
	 * keyboard focus control, bypass etc).
	 */

	gint xx, yy;
	gtk_widget_translate_coordinates(
			GTK_WIDGET(low_box.gobj()),
			GTK_WIDGET(low_box.get_parent()->gobj()),
			8, 6, &xx, &yy);
	[au_view setFrame:NSMakeRect(xx, yy, req_width, req_height)];

	last_au_frame = [au_view frame];
	// watch for size changes of the view
	_notify = [ [NotificationObject alloc] initWithPluginUI:this andCocoaParent:NULL andTopLevelParent:win ];

	[[NSNotificationCenter defaultCenter] addObserver:_notify
		selector:@selector(auViewResized:) name:NSViewFrameDidChangeNotification
		object:au_view];

	// catch notifications that live resizing is about to start

#if HAVE_COCOA_LIVE_RESIZING
	_resize_notify = [ [ LiveResizeNotificationObject alloc] initWithPluginUI:this ];

	[[NSNotificationCenter defaultCenter] addObserver:_resize_notify
		selector:@selector(windowWillStartLiveResizeHandler:) name:NSWindowWillStartLiveResizeNotification
		object:win];

	[[NSNotificationCenter defaultCenter] addObserver:_resize_notify
		selector:@selector(windowWillEndLiveResizeHandler:) name:NSWindowDidEndLiveResizeNotification
		object:win];
#else
	/* No way before 10.6 to identify the start of a live resize (drag
	 * resize) without subclassing NSView and overriding two of its
	 * methods. Instead of that, we make the window non-resizable, thus
	 * ending confusion about whether or not resizes are plugin or user
	 * driven (they are always plugin-driven).
	 */

	Gtk::Container* toplevel = get_toplevel();
	Requisition req;

	resizable = false;

	if (toplevel && toplevel->is_toplevel()) {
		toplevel->size_request (req);
		toplevel->set_size_request (req.width, req.height);
		dynamic_cast<Gtk::Window*>(toplevel)->set_resizable (false);
	}

#endif
	return 0;
}

void
AUPluginUI::grab_focus()
{
	if (au_view) {
		[au_view becomeFirstResponder];
	}
}
void
AUPluginUI::forward_key_event (GdkEventKey* ev)
{
	NSEvent* nsevent = gdk_quartz_event_get_nsevent ((GdkEvent*)ev);

	if (au_view && nsevent) {

		/* filter on nsevent type here because GDK massages FlagsChanged
		   messages into GDK_KEY_{PRESS,RELEASE} but Cocoa won't
		   handle a FlagsChanged message as a keyDown or keyUp
		*/

		if ([nsevent type] == NSKeyDown) {
			[[[au_view window] firstResponder] keyDown:nsevent];
		} else if ([nsevent type] == NSKeyUp) {
			[[[au_view window] firstResponder] keyUp:nsevent];
		} else if ([nsevent type] == NSFlagsChanged) {
			[[[au_view window] firstResponder] flagsChanged:nsevent];
		}
	}
}

void
AUPluginUI::on_realize ()
{
	VBox::on_realize ();

	/* our windows should not have that resize indicator */

	NSWindow* win = get_nswindow ();
	if (win) {
		[win setShowsResizeIndicator:0];
	}
}

void
AUPluginUI::lower_box_realized ()
{
	if (au_view) {
		parent_cocoa_window ();
	} else if (carbon_window) {
		parent_carbon_window ();
	}
}

bool
AUPluginUI::lower_box_visibility_notify (GdkEventVisibility* ev)
{
#ifdef WITH_CARBON
	if (carbon_window  && ev->state != GDK_VISIBILITY_UNOBSCURED) {
		ShowWindow (carbon_window);
		ActivateWindow (carbon_window, TRUE);
		return true;
	}
#endif
	return false;
}

void
AUPluginUI::lower_box_map ()
{
	[au_view setHidden:0];
	update_view_size ();
}

void
AUPluginUI::lower_box_unmap ()
{
	[au_view setHidden:1];
}

void
AUPluginUI::lower_box_size_request (GtkRequisition* requisition)
{
	requisition->width  = req_width;
	requisition->height = req_height;
}

void
AUPluginUI::lower_box_size_allocate (Gtk::Allocation& allocation)
{
	update_view_size ();
}

void
AUPluginUI::on_window_hide ()
{
#ifdef WITH_CARBON
	if (carbon_window) {
		HideWindow (carbon_window);
		ActivateWindow (carbon_window, FALSE);
	}
#endif
	hide_all ();

#if 0
	NSArray* wins = [NSApp windows];
	for (uint32_t i = 0; i < [wins count]; i++) {
		id win = [wins objectAtIndex:i];
	}
#endif
}

bool
AUPluginUI::on_window_show (const string& /*title*/)
{
	/* this is idempotent so just call it every time we show the window */

	gtk_widget_realize (GTK_WIDGET(low_box.gobj()));

	show_all ();

#ifdef WITH_CARBON
	if (carbon_window) {
		ShowWindow (carbon_window);
		ActivateWindow (carbon_window, TRUE);
	}
#endif

	return true;
}

bool
AUPluginUI::start_updating (GdkEventAny*)
{
	return false;
}

bool
AUPluginUI::stop_updating (GdkEventAny*)
{
	return false;
}

PlugUIBase*
create_au_gui (boost::shared_ptr<PluginInsert> plugin_insert, VBox** box)
{
	AUPluginUI* aup = new AUPluginUI (plugin_insert);
	(*box) = aup;
	return aup;
}

void
AUPluginUI::start_live_resize ()
{
	in_live_resize = true;
}

void
AUPluginUI::end_live_resize ()
{
	in_live_resize = false;
}