アプリケーション モーダル ダイアログと同様に、アラートを同期的に実行するためのカテゴリNSAlert
を作成しました。
NSInteger result;
// Run the alert as a sheet on the main window
result = [alert runModalSheet];
// Run the alert as a sheet on some other window
result = [alert runModalSheetForWindow:window];
コードはGitHubから入手でき、完全を期すために現在のバージョンが以下に掲載されています。
ヘッダファイルNSAlert+SynchronousSheet.h
:
#import <Cocoa/Cocoa.h>
@interface NSAlert (SynchronousSheet)
-(NSInteger) runModalSheetForWindow:(NSWindow *)aWindow;
-(NSInteger) runModalSheet;
@end
実装ファイルNSAlert+SynchronousSheet.m
:
#import "NSAlert+SynchronousSheet.h"
// Private methods -- use prefixes to avoid collisions with Apple's methods
@interface NSAlert ()
-(IBAction) BE_stopSynchronousSheet:(id)sender; // hide sheet & stop modal
-(void) BE_beginSheetModalForWindow:(NSWindow *)aWindow;
@end
@implementation NSAlert (SynchronousSheet)
-(NSInteger) runModalSheetForWindow:(NSWindow *)aWindow {
// Set ourselves as the target for button clicks
for (NSButton *button in [self buttons]) {
[button setTarget:self];
[button setAction:@selector(BE_stopSynchronousSheet:)];
}
// Bring up the sheet and wait until stopSynchronousSheet is triggered by a button click
[self performSelectorOnMainThread:@selector(BE_beginSheetModalForWindow:) withObject:aWindow waitUntilDone:YES];
NSInteger modalCode = [NSApp runModalForWindow:[self window]];
// This is called only after stopSynchronousSheet is called (that is,
// one of the buttons is clicked)
[NSApp performSelectorOnMainThread:@selector(endSheet:) withObject:[self window] waitUntilDone:YES];
// Remove the sheet from the screen
[[self window] performSelectorOnMainThread:@selector(orderOut:) withObject:self waitUntilDone:YES];
return modalCode;
}
-(NSInteger) runModalSheet {
return [self runModalSheetForWindow:[NSApp mainWindow]];
}
#pragma mark Private methods
-(IBAction) BE_stopSynchronousSheet:(id)sender {
// See which of the buttons was clicked
NSUInteger clickedButtonIndex = [[self buttons] indexOfObject:sender];
// Be consistent with Apple's documentation (see NSAlert's addButtonWithTitle) so that
// the fourth button is numbered NSAlertThirdButtonReturn + 1, and so on
NSInteger modalCode = 0;
if (clickedButtonIndex == NSAlertFirstButtonReturn)
modalCode = NSAlertFirstButtonReturn;
else if (clickedButtonIndex == NSAlertSecondButtonReturn)
modalCode = NSAlertSecondButtonReturn;
else if (clickedButtonIndex == NSAlertThirdButtonReturn)
modalCode = NSAlertThirdButtonReturn;
else
modalCode = NSAlertThirdButtonReturn + (clickedButtonIndex - 2);
[NSApp stopModalWithCode:modalCode];
}
-(void) BE_beginSheetModalForWindow:(NSWindow *)aWindow {
[self beginSheetModalForWindow:aWindow modalDelegate:nil didEndSelector:nil contextInfo:nil];
}
@end