SynthController.m

#import "SynthController.h"
#import <PYMIDI/PYMIDI.h>
#import <objc/runtime.h>
#import "InstrumentsDataSource.h"
#import "ChannelsDataSource.h"


// Lightweight NSView subclass that accepts dropped .sf2/.dls files and forwards
// them to the app delegate's application:openFile:. We don't subclass at design
// time; instead awakeFromNib runtime-swaps the window's contentView class to
// this one and registers the drag types. No ivars added — safe to swap.
@interface SoundFontDropView : NSView
@end

static BOOL SoundFontDropView_isSoundFontURL(NSURL* u)
{
    NSString* ext = [[u pathExtension] lowercaseString];
    return [ext isEqualToString:@"sf2"] || [ext isEqualToString:@"dls"];
}

@implementation SoundFontDropView

- (NSDragOperation)draggingEntered:(id<NSDraggingInfo>)sender
{
    NSArray* urls = [[sender draggingPasteboard]
        readObjectsForClasses:[NSArray arrayWithObject:[NSURL class]] options:nil];
    for (NSURL* u in urls) {
        if (SoundFontDropView_isSoundFontURL(u)) return NSDragOperationCopy;
    }
    return NSDragOperationNone;
}

- (BOOL)prepareForDragOperation:(id<NSDraggingInfo>)sender { return YES; }

- (BOOL)performDragOperation:(id<NSDraggingInfo>)sender
{
    NSArray* urls = [[sender draggingPasteboard]
        readObjectsForClasses:[NSArray arrayWithObject:[NSURL class]] options:nil];
    id delegate = [NSApp delegate];
    BOOL anyOpened = NO;
    for (NSURL* u in urls) {
        if (!SoundFontDropView_isSoundFontURL(u)) continue;
        if ([delegate respondsToSelector:@selector(application:openFile:)]) {
            if ([delegate application:NSApp openFile:[u path]]) anyOpened = YES;
        }
    }
    return anyOpened;
}

@end


@implementation SynthController


- (void)awakeFromNib
{
    ChannelsDataSource* channelsDataSource;
    InstrumentsDataSource* instrumentsDataSource;
    NSPoint origin;
    
    audioSystem = [[AudioSystem alloc] init];
    
    virtualDestination = [[PYMIDIVirtualDestination alloc] initWithName:@"SimpleSynth virtual input"];
    
    [self buildMIDIInputPopUp];
    [[NSNotificationCenter defaultCenter]
        addObserver:self selector:@selector(midiSetupChanged:)
        name:@"PYMIDISetupChanged" object:nil
    ];

    // This alloc/init pair is split over 2 lines to stop silly compiler warnings.
    channelsDataSource = [ChannelsDataSource alloc];
    channelsDataSource = [channelsDataSource initWithAudioSystem:audioSystem];
    [channelsTable setDataSource:channelsDataSource];
    [[NSNotificationCenter defaultCenter]
        addObserver:self selector:@selector(audioSystemInstrumentChanged:)
        name:@"instrumentChanged" object:audioSystem
    ];
        
    // Catch when user picks a new MIDI channel to update Instruments selection to match
    [[NSNotificationCenter defaultCenter]
     addObserver:self selector:@selector(channelsTableSelectionChanged:)
     name:@"NSTableViewSelectionDidChangeNotification" object:channelsTable
    ];
    
    // The following hardcoded values should really be dynamically pulled from the
    // AudioSystem, but the values you get when doing that make the slider very
    // lop-sided.  I'd also have to set the slider labels dynamically.
    [cutoffSlider setMinValue:10.0];
    [cutoffSlider setMaxValue:12000.0];
    [audioSystem setFilterCutoff:12000.0];
    [cutoffSlider setFloatValue:[audioSystem getFilterCutoff]];
    
    instrumentsDataSource = [[InstrumentsDataSource alloc] initWithAudioSystem:audioSystem];
    [instrumentsTable setDataSource:instrumentsDataSource];
    [[NSNotificationCenter defaultCenter]
        addObserver:self selector:@selector(instrumentsTableSelectionChanged:)
        name:@"NSTableViewSelectionDidChangeNotification" object:instrumentsTable
    ];
    [self updateMIDIDetails];
    // We must delay opening the drawer until the window is visible
    [instrumentsDrawer performSelector:@selector(open) withObject:nil afterDelay:0];
   
    if (![mainWindow setFrameUsingName:@"MainWindowFrame"]) {
        // Center our window, taking the width of the drawer into account.
        [mainWindow center];
        origin = [mainWindow frame].origin;
        origin = NSMakePoint (origin.x - [instrumentsDrawer contentSize].width/2.0, origin.y);
        [mainWindow setFrameOrigin:origin];
    }
    [mainWindow setFrameAutosaveName:@"MainWindowFrame"];

    uiUpdateTimer = [NSTimer scheduledTimerWithTimeInterval:0.5 target:self selector:@selector(updateUI:) userInfo:nil repeats:YES];
    [uiUpdateTimer retain];

    // Enable drag-and-drop of .sf2/.dls files onto the main window. Swap the
    // contentView's class at runtime so it can respond as a drag destination,
    // then register the file-URL pasteboard type.
    NSView* cv = [mainWindow contentView];
    object_setClass(cv, [SoundFontDropView class]);
    [cv registerForDraggedTypes:[NSArray arrayWithObject:NSPasteboardTypeFileURL]];

    [self installVolumeControl];
}


// Insert a master-volume row above the CPU display. The nib doesn't have one
// (this app pre-dates the need: it was designed when the Apple DLS synth's
// fixed level matched system volume expectations). We make room by shrinking
// the channels table from the bottom, then add a Volume label + NSSlider
// anchored to the bottom of the content view.
- (void)installVolumeControl
{
    NSView* cv = [mainWindow contentView];
    const CGFloat kRowHeight = 28.0;

    // Find the channels NSScrollView and the cutoff slider so we can
    // calculate the inserted row's y position.
    NSScrollView* scroll = nil;
    for (NSView* v in [cv subviews]) {
        if ([v isKindOfClass:[NSScrollView class]]) { scroll = (NSScrollView*)v; break; }
    }
    if (!scroll) return;

    // Shrink the table from the bottom to free up vertical space for the
    // new row. The scroll view keeps its widthSizable/heightSizable mask, so
    // it grows correctly when the window is resized.
    NSRect tf = [scroll frame];
    tf.origin.y    += kRowHeight;
    tf.size.height -= kRowHeight;
    [scroll setFrame:tf];

    // Build the row at the freed space, just above the existing cutoff row.
    // Match the cutoff row's column geometry so they line up vertically.
    NSRect cutoffFrame = [cutoffSlider frame];
    CGFloat rowY = NSMaxY(cutoffFrame) + 6.0;

    NSTextField* label = [NSTextField labelWithString:@"Volume:"];
    [label setFrame:NSMakeRect(9, rowY + 3, 84, 17)];
    [label setAutoresizingMask:NSViewMaxXMargin | NSViewMaxYMargin];
    [cv addSubview:label];

    NSSlider* slider = [[[NSSlider alloc]
        initWithFrame:NSMakeRect(NSMinX(cutoffFrame), rowY,
                                 NSWidth(cutoffFrame), NSHeight(cutoffFrame))] autorelease];
    [slider setAutoresizingMask:NSViewWidthSizable | NSViewMaxYMargin];
    [slider setMinValue:0.0];
    [slider setMaxValue:2.0];
    [slider setFloatValue:[audioSystem getMasterVolume]];
    [slider setContinuous:YES];
    [slider setTarget:self];
    [slider setAction:@selector(volumeSliderChanged:)];
    [cv addSubview:slider];
    volumeSlider = slider;
}


- (void)updateUI:(NSTimer*)timer
{
    [self updateCPULoadGuage];
}


- (void)buildMIDIInputPopUp
{
    PYMIDIManager*	manager = [PYMIDIManager sharedInstance];
    NSArray*		sources;
    NSEnumerator*	enumerator;
    PYMIDIEndpoint*	input;

    [midiInputPopup removeAllItems];
    
    sources = [manager realSources];
    enumerator = [sources objectEnumerator];
    while (input = [enumerator nextObject]) {
        [midiInputPopup addItemWithTitle:[input displayName]];
        [[midiInputPopup lastItem] setRepresentedObject:input];
    }
    
    if ([sources count] > 0) {
        [[midiInputPopup menu] addItem:[NSMenuItem separatorItem]];
    }
    
    [midiInputPopup addItemWithTitle:[virtualDestination name]];
    [[midiInputPopup lastItem] setRepresentedObject:virtualDestination];
    
    if ([audioSystem midiInput] == nil) {
        if ([sources count] > 0)
            [audioSystem setMIDIInput:[sources objectAtIndex:0]];
        else
            [audioSystem setMIDIInput:virtualDestination];
    }
    
    [midiInputPopup selectItemAtIndex:[midiInputPopup indexOfItemWithRepresentedObject:[audioSystem midiInput]]];
}



// This is called when the user selects a new MIDI input from the popup
- (IBAction)midiInputChanged:(id)sender
{
    [audioSystem setMIDIInput:[[midiInputPopup selectedItem] representedObject]];
}


- (void)midiSetupChanged:(NSNotification*)notification
{
    [self buildMIDIInputPopUp];
}


// Displays the standard Open panel and routes any chosen file through
// application:openFile: (the same entry point used by Finder, the dock,
// drag-and-drop, and the Open Recent menu).
- (IBAction)openDocument:(id)sender
{
    NSOpenPanel* openPanel = [NSOpenPanel openPanel];
    [openPanel setAllowsMultipleSelection:YES];
    [openPanel setCanChooseDirectories:NO];
    [openPanel setCanChooseFiles:YES];
    [openPanel setAllowedFileTypes:[NSArray arrayWithObjects:@"sf2", @"dls", nil]];

    if ([openPanel runModal] != NSModalResponseOK) return;

    for (NSURL* url in [openPanel URLs]) {
        [self application:[NSApplication sharedApplication] openFile:[url path]];
    }
}


- (IBAction)restoreAppleSounds:(id)sender
{
    [audioSystem restoreAppleSounds];
    [soundSetTextField setStringValue:@"Apple DLS Sound Set"];
    [channelsTable reloadData];
    [instrumentsTable reloadData];
    [channelsTable selectRow:0 byExtendingSelection:NO];
    [self updateInstrumentSelection];
    [self updateMIDIDetails];
}


// Called to open a particular file, either by openDocument: above, by the Open
// Recent menu, by Finder/Dock, or by drag-and-drop. The actual bank load runs
// off the main thread (banks can be hundreds of MB), so we return YES
// immediately and report any failure via an alert once the async load returns.
- (BOOL)application:(NSApplication*)theApplication openFile:(NSString*)filename
{
    NSString* basename = [filename lastPathComponent];
    NSString* prevText = [[[soundSetTextField stringValue] copy] autorelease];

    [soundSetTextField setStringValue:
        [NSString stringWithFormat:@"Loading %@…", basename]];

    [audioSystem openFileAsync:filename completion:^(BOOL success, OSStatus err) {
        if (success) {
            [soundSetTextField setStringValue:basename];
            [channelsTable reloadData];
            [instrumentsTable reloadData];
            [self updateMIDIDetails];
            [channelsTable selectRow:0 byExtendingSelection:NO];
            [self updateInstrumentSelection];

            [[NSDocumentController sharedDocumentController]
                noteNewRecentDocumentURL:[NSURL fileURLWithPath:filename]];
        } else {
            [soundSetTextField setStringValue:prevText];
            [self displayOpenFailedAlert:filename withError:err];
        }
    }];

    return YES;
}


// Best-effort interpretation of the OSStatus returned by AudioUnitSetProperty
// when loading a SoundFont/DLS bank.
static NSString* SynthOpenErrorDescription(OSStatus error)
{
    switch (error) {
        case kAudio_MemFullError:
            return @"There isn't enough memory to load this bank. "
                   @"Multi-gigabyte SoundFonts can exceed what the built-in "
                   @"DLS synth supports.";
        case kAudio_FileNotFoundError:
            return @"The file could not be found.";
        case kAudio_FilePermissionError:
            return @"SimpleSynth doesn't have permission to read the file.";
        case kAudio_BadFilePathError:
            return @"The file path is not valid.";
        case kAudio_ParamError:
        case kAudioUnitErr_InvalidProperty:
        case kAudioUnitErr_FileNotSpecified:
        case kAudioUnitErr_UnknownFileType:
        case kAudioUnitErr_FormatNotSupported:
            return @"The file is not a SoundFont or DLS bank that SimpleSynth "
                   @"can read.";
        default:
            return [NSString stringWithFormat:
                @"The bank could not be loaded (AudioUnit error %d).",
                (int)error];
    }
}

- (void)displayOpenFailedAlert:(NSString*)fileName withError:(OSStatus)error
{
    NSAlert* alert = [[[NSAlert alloc] init] autorelease];
    [alert setAlertStyle:NSAlertStyleWarning];
    [alert setMessageText:[NSString stringWithFormat:
        @"Couldn’t open “%@”", [fileName lastPathComponent]]];
    [alert setInformativeText:SynthOpenErrorDescription(error)];
    [alert addButtonWithTitle:@"OK"];
    [alert runModal];
}


- (void)audioSystemInstrumentChanged:(NSNotification*)notification
{
    [channelsTable reloadData];
}


- (void)channelsTableSelectionChanged:(NSNotification*)notification
{
    [self updateInstrumentSelection];
}


- (void)updateInstrumentSelection
{
    UInt32 channel = [channelsTable selectedRow];
	MusicDeviceInstrumentID channelInstrumentID = [audioSystem currentInstrumentOnChannel:channel];
	UInt32 instrumentIndex = [audioSystem indexOfInstrumentID:channelInstrumentID];
	[instrumentsTable selectRow:instrumentIndex byExtendingSelection:NO];
}


- (void)instrumentsTableSelectionChanged:(NSNotification*)notification
{
    int channel = [channelsTable selectedRow];
    int instrumentIndex = [instrumentsTable selectedRow];
    MusicDeviceInstrumentID instrumentID = [audioSystem instrumentIDAtIndex:instrumentIndex];
    
    [self updateMIDIDetails];
    
    [audioSystem setInstrument:instrumentID forChannel:channel];
}


- (void)updateMIDIDetails
{
    int instrumentIndex = [instrumentsTable selectedRow];
    MusicDeviceInstrumentID instrumentID = [audioSystem instrumentIDAtIndex:instrumentIndex];
    MIDIInstrument instrument = [AudioSystem instrumentIDToInstrument:instrumentID];
    
    [programNumberField setIntValue:instrument.programChange + 1];
    [bankSelectMSBField setIntValue:instrument.bankSelectMSB];
    [bankSelectLSBField setIntValue:instrument.bankSelectLSB];
}


// This is called when the user moves the filter cutoff slider
- (IBAction)cutoffSliderChanged:(id)sender
{
    [audioSystem setFilterCutoff:[cutoffSlider floatValue]];
}


// Called when the user drags the master volume slider. AUMultiChannelMixer's
// volume parameter has kAudioUnitParameterFlag_CanRamp, so AppKit hands
// successive values to the AU without zipper noise.
- (IBAction)volumeSliderChanged:(id)sender
{
    [audioSystem setMasterVolume:[volumeSlider floatValue]];
}


- (void)updateCPULoadGuage
{
    float load = [audioSystem getCPULoad];
    
    [cpuLoadGuage setFloatValue:load];
}


- (IBAction)displayLicense:(id)sender
{
    [[NSWorkspace sharedWorkspace]
        openFile:[[NSBundle mainBundle] pathForResource:@"License" ofType:@"html"]
    ];
}


- (IBAction)visitWebSite:(id)sender
{
    [[NSWorkspace sharedWorkspace] openURL:[NSURL URLWithString:@"http://notahat.com/simplesynth/"]];
}


- (IBAction)sendFeedback:(id)sender
{
    NSString* name = [[NSBundle mainBundle] objectForInfoDictionaryKey:@"CFBundleName"];
    name = [[name componentsSeparatedByString:@" "] componentsJoinedByString:@"%20"];

    NSString* version = [[NSBundle mainBundle] objectForInfoDictionaryKey:@"CFBundleShortVersionString"];
	version = [[version componentsSeparatedByString:@" "] componentsJoinedByString:@"%20"];
   
    [[NSWorkspace sharedWorkspace] openURL:[NSURL
        URLWithString:[NSString
            stringWithFormat:@"mailto:simplesynth@notahat.com?subject=%@%%20%@", name, version
        ]
    ]];
}


@end