source: trunk/PrefsPane/src/AlertHelper.m @ 1046

/* Copyright (C) 2008-2009 Peter Speck
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#import "AlertHelper.h"
#import "GBDebug.h"

@interface AlertHelper ()

- (void)releaseDelegate;
- (BOOL)checkHasPreparedAlert:(NSString*)doingWhat;


- (void)simpleAlertDidEnd:(NSAlert *)alert returnCode:(int)returnCode
              contextInfo:(void *)contextInfo;

@end

//=======================================================================================================

@implementation AlertHelper

- (id)initWindowView:(NSView*)windowView
        withGbBundle:(NSBundle*)gbBundle
{
    if ((self = [super init])) {
        _windowView = [windowView retain];
        NSString* iconPath = [gbBundle pathForResource:@"tangerine" ofType:@"icns"];
        NSAssert(iconPath, @"Missing tangerine.icns");
        _glimmerIcon = [[[NSImage alloc] initWithContentsOfFile:iconPath] retain];
    }
    return self;
}

- (void)dealloc
{
    [_glimmerIcon release];
    [_windowView release];
    [_accessoryView release];
    [super dealloc];
}

- (NSWindow*)window
{
    return [_windowView window];
}

- (BOOL)canDisplayAlert
{
    return !_alertIsOpen && [_windowView window];
}

#pragma mark ------------------------ private

- (void)releaseDelegate
{
    [_callbackDelegate release];
    _callbackDelegate = NULL;
    _callbackSelector = NULL;
}

- (void)dismissAlert
{
    DebugNSLog(@"dismissAlert, open = %d", _alertIsOpen);
    [self dismissAlertWithInvokeDelegate:NO withReturnCode:0];
}

- (void)dismissAlertWithInvokeDelegate:(BOOL)callDelegate withReturnCode:(NSInteger)returnCode
{
    if (!_alertIsOpen)
        return;
    DebugNSLog(@"dismissAlertWithInvokeDelegate, isOpen=%d, callDelegate=%d, returnCode=%ld", _alertIsOpen, callDelegate, (long)returnCode);
    _alertIsOpen = NO; // otherwise the method is called recursively by simpleAlertDidEnd
    _lastAlertReturnCode = returnCode;
    /*
     Make the alert sheet go away before the delegate is called, so the delegate is able to show another sheet.
     Must call [NSApp endSheet] to get the sheet really gone, otherwise we can't show another sheet.
     [orderOut] performs the animation.
    */
    if (_usingSheet) {
        [NSApp endSheet:[_alert window]];
        [[_alert window] orderOut:self];
        _usingSheet = NO;
    }
    if (callDelegate && _callbackDelegate) {
        // http://theocacao.com/document.page/264
        NSMethodSignature* sig = [[_callbackDelegate class] instanceMethodSignatureForSelector:_callbackSelector];
        NSInvocation* invo = [NSInvocation invocationWithMethodSignature:sig];
        [invo setTarget:_callbackDelegate];
        [invo setSelector:_callbackSelector];
        [invo setArgument:&returnCode atIndex:2];
        [invo invoke];
        [self releaseDelegate];
    }
    [_alert autorelease];
    _alert = NULL;
    [_accessoryView autorelease];
    _accessoryView = NULL;
}

- (NSInteger)lastAlertReturnCode
{
    return _lastAlertReturnCode;
}

- (void)simpleAlertDidEnd:(NSAlert *)alert returnCode:(int)returnCode
              contextInfo:(void *)contextInfo
{
    if (alert == _alert)
        [self dismissAlertWithInvokeDelegate:YES withReturnCode:returnCode];
}

- (BOOL)checkHasPreparedAlert:(NSString*)doingWhat
{
    if (!_alert) {
        NSLog(@"Can't %@ when no alert has been prepared.", doingWhat);
        [GBDebug debugDumpStackframe];
        return NO;
    }
    if (_alertIsOpen) {
        NSLog(@"Can't %@ when alert already is open.", doingWhat);
        [GBDebug debugDumpStackframe];
        return NO;
    }
    return YES;
}


#pragma mark ------------------------ building blocks

- (void)prepareWarningAlertWithTitle:(NSString*)title
              withInformativeText:(NSString*)infoText
{
    [self prepareAlertWithTitle:title withInformativeText:infoText withStyle:NSWarningAlertStyle];
}

- (void)prepareCriticalAlertWithTitle:(NSString*)title
               withInformativeText:(NSString*)infoText
{
    [self prepareAlertWithTitle:title withInformativeText:infoText withStyle:NSCriticalAlertStyle];
}

- (void)prepareInformativeAlertWithTitle:(NSString*)title
                  withInformativeText:(NSString*)infoText
{
    [self prepareAlertWithTitle:title withInformativeText:infoText withStyle:NSInformationalAlertStyle];
}

- (void)prepareAlertWithTitle:(NSString*)title
          withInformativeText:(NSString*)infoText
                    withStyle:(NSAlertStyle)alertStyle
{
    if (_alertIsOpen) {
        [GBDebug debugDumpStackframe];
        NSLog(@"Can't prepare another alert while an alert is open.");
        return;
    }
    if (!title) {
        [GBDebug debugDumpStackframe];
        NSLog(@"the title must not be NULL");
        title = @"?"; // better than crashing with NSAssert.
    }
    if (!_alert) {
        _alert = [[NSAlert alloc] init]; // release in delegate
        [_alert setIcon:_glimmerIcon];
    }
    [_alert setMessageText:title];
    if (infoText) // NSAlert can't handle NULL
        [_alert setInformativeText:infoText];
}

- (void)setDelegate:(NSObject*)callbackDelegate
       withSelector:(SEL)callbackSelector
{
    NSAssert((_callbackDelegate != NULL) == (_callbackSelector != NULL), @"_callbackDelegate / _callbackSelector");
    if (![self checkHasPreparedAlert:@"set delegate"])
        return;
    [self releaseDelegate];
    _callbackDelegate = [callbackDelegate retain];
    _callbackSelector = callbackSelector;
}

- (NSButton*)addButtonWithTitle:(NSString*)title
{
    if (!title) {
        [GBDebug debugDumpStackframe];
        NSLog(@"the button title must not be NULL");
        title = @"?"; // better than crashing with NSAssert.
    }
    if (![self checkHasPreparedAlert:@"add button"])
        return NULL;
    return [_alert addButtonWithTitle:title];
}

- (void)setAccessoryView:(NSView*)view
{
    if (!view) {
        [GBDebug debugDumpStackframe];
        NSLog(@"the view param must not be NULL");
        return;
    }
    if (![self checkHasPreparedAlert:@"set accessory view"])
        return;
    if (view == _accessoryView)
        return;
    NSView* oldView = _accessoryView;
    _accessoryView = [view retain];
    [_alert setAccessoryView:view];
    [oldView release];
}

- (void)layoutAlert
{
    if (![self checkHasPreparedAlert:@"layout alert"])
        return;
    [_alert layout];
}

- (void)showPreparedAlert
{
    if (![self checkHasPreparedAlert:@"show alert"])
        return;
    NSWindow* window = [self window];
    _alertIsOpen = YES;
    if (!window) {
        NSInteger returnCode = [_alert runModal];
        [self dismissAlertWithInvokeDelegate:YES withReturnCode:returnCode];
        return;
    }
    _usingSheet = YES;
    [_alert beginSheetModalForWindow:window
                      modalDelegate:self
                     didEndSelector:@selector(simpleAlertDidEnd:returnCode:contextInfo:)
                        contextInfo:NULL];
}

@end