Re: Add bindings for custom menu items' isHidden to (an attribute of) a custom object?
Re: Add bindings for custom menu items' isHidden to (an attribute of) a custom object?
- Subject: Re: Add bindings for custom menu items' isHidden to (an attribute of) a custom object?
- From: Daryle Walker <email@hidden>
- Date: Mon, 08 Sep 2014 04:21:47 -0400
On Sep 8, 2014, at 3:10 AM, Daryle Walker <email@hidden> wrote:
> On Sep 8, 2014, at 1:12 AM, Daryle Walker <email@hidden> wrote:
[SNIP]
>>> @interface MyOverflowMenuController : NSObject
>>>
>>> //! Starts as nil; when set, this instance stores copies of the menu’s
>>> //! items and tracks the menu for item insertions, removals, and renames.
>>> @property (nonatomic) NSMenu * sourceMenu;
>>> //! Starts as zero; if the menu has more menu items that this value,
>>> //! the copies of the menu's latter items are stored in the overflow
>>> //! array instead of the direct array.
>>> @property (nonatomic, assign) NSUInteger maxDirectCount;
>>>
>>> //! Starts as empty; updated to mirror the source menu's menu-items.
>>> //! Keeps at most 'maxDirectCount' items. KVO-compliant.
>>> @property (nonatomic, readonly) NSArray * directMenuItems;
>>> //! Starts as empty; updated to mirror the source menu's menu-items.
>>> //! Keeps the overflow from 'directMenuItems'. KVO-compliant.
>>> @property (nonatomic, readonly) NSArray * overflowMenuItems;
>>>
>>> //! Transforms a NSMenu to a NSNumber with a BOOL value that's YES
>>> //! when the given menu is self.sourceMenu.
>>> @property (nonatomic, readonly) NSValueTransformer * isSourceMenuTransformer;
>>>
>>> @end
>>
>>
>> That last property is of a custom NSValueTransformer subclass. (Is not using a new .h/.m file pair for the subclass OK?) The subclass holds a pointer to the source menu, and gets updated when the outer class changes that property in the setter. The custom object should out-live the per-day history menu items. So how would connect each menu item’s Hidden attribute to the custom object and the value transformer? Am I using the right kind of transformer? The source-menu attribute should be KVO-compliant since I use the automatic getter and a custom setter (that mutate the two arrays).
>
> I tried:
>
>> static inline
>> NSMenuItem * CreateMenuItemForDay(NSCalendarDate *day, NSDateFormatter *format) {
>> NSString * const dayTitle = [format stringFromDate:day];
>> NSMenu * const daySubmenu = [[NSMenu alloc] initWithTitle:dayTitle];
>> NSMenuItem * const dayItem = [[NSMenuItem alloc] initWithTitle:dayTitle action:NULL keyEquivalent:@""];
>>
>> dayItem.representedObject = day;
>> dayItem.submenu = daySubmenu;
>>
>> // Attach a binding to let the menu item auto-hide when used as the Today menu item.
>> MyAppDelegate * const appDelegate = [NSApp delegate];
>>
>> [dayItem bind:NSHiddenBinding toObject:appDelegate.myOverflowMenuController.sourceMenu withKeyPath:@"sourceMenu" options:@{NSValueTransformerBindingOption: appDelegate.myOverflowMenuController.isSourceMenuTransformer}];
>> return dayItem;
>> }
>
> (Good thing I already #imported my application delegate header to get access to the load-URL-from-menu-item action.) I crashed with:
>
>> 2014-09-08 02:43:31.216 MyApp[28296:303] Controller cannot be nil
>> 2014-09-08 02:43:31.279 MyApp[28296:303] (
>> 0 CoreFoundation 0x00007fff8557625c __exceptionPreprocess + 172
>> 1 libobjc.A.dylib 0x00007fff8d741e75 objc_exception_throw + 43
>> 2 CoreFoundation 0x00007fff8557610c +[NSException raise:format:] + 204
>> 3 AppKit 0x00007fff8cc37499 -[NSBinder addBinding:toController:withKeyPath:valueTransformer:options:] + 337
>> 4 AppKit 0x00007fff8cc41c38 -[NSEditableBinder addBinding:toController:withKeyPath:valueTransformer:options:] + 51
>> 5 AppKit 0x00007fff8cc32efb -[NSObject(NSKeyValueBindingCreation) bind:toObject:withKeyPath:options:] + 639
>> 6 Prairie 0x0000000100006246 CreateMenuItemForDay + 678
>> 7 Prairie 0x0000000100005a44 -[MyHistoryMenus notifyOnHistoryLoad:] + 708
>> 8 CoreFoundation 0x00007fff85544e0c __CFNOTIFICATIONCENTER_IS_CALLING_OUT_TO_AN_OBSERVER__ + 12
>
> (Trimming out the reset of the stack.) The “sourceMenu” starts off as NIL and gets set by -prepareTodayHistoryMenu, which gets called when the array of WebHistory per-day menu items (and sub-menus) gets updated.
>
> …
>
> In the definition, instead of ‘@“sourceMenu”’, I used a constant. Looking at that in this e-mail, I realized I specified that property twice. I changed the second argument to “appDelegate.myOverflowMenuController” and it doesn’t crash. Now, none of the per-day web-history menus show up, not just the one for Today. (The one page I visited today does show up directly in the History, proving that the just-today web-history menu item mirroring system still works. All of the per-day menu items return YES through the custom value-transformer, or I screwed up the binding.
>
>> @interface MyCustomTargettingTransformer : NSValueTransformer
>>
>> //! Starts as nil; the menu instance to be compared.
>> @property (nonatomic) NSMenu * targetMenu;
>>
>> @end
>>
>> @implementation MyCustomTargettingTransformer
>>
>> + (Class)transformedValueClass {
>> return [NSNumber class];
>> }
>>
>> + (BOOL)allowsReverseTransformation {
>> return NO;
>> }
>>
>> - (id)transformedValue:(id)value {
>> return [NSNumber numberWithBool:(self.targetMenu == value)];
>> }
>>
>> @end
>
>
> (This is within the *.m file for MyOverflowMenuController.) In the setter for the “sourceMenu” property of MyOverflowMenuController, I set the “targetMenu” property of the “isSourceMenuTransformer” property of MyOverflowMenuController. When a using a custom setter for a property, are KVO notifications sent?
I tried some log-debugging:
> - (id)transformedValue:(id)value {
> NSLog(@"Calling -transformedValue with (%@) and self.targetMenu = %@.", value, self.targetMenu);
> return [NSNumber numberWithBool:(self.targetMenu == value)];
> }
> static inline
> NSMenuItem * CreateMenuItemForDay(NSCalendarDate *day, NSDateFormatter *format) {
> NSString * const dayTitle = [format stringFromDate:day];
> NSMenu * const daySubmenu = [[NSMenu alloc] initWithTitle:dayTitle];
> NSMenuItem * const dayItem = [[NSMenuItem alloc] initWithTitle:dayTitle action:NULL keyEquivalent:@""];
>
> dayItem.representedObject = day;
> dayItem.submenu = daySubmenu;
> NSLog(@"Creating menu item (%@) for day (%@).", dayItem, day);
>
> // Attach a binding to let the menu item auto-hide when used as the Today menu item.
> MyAppDelegate * const appDelegate = [NSApp delegate];
>
> [dayItem bind:NSHiddenBinding toObject:appDelegate.myOverflowMenuController withKeyPath:MyKeyPathSourceMenu options:@{NSValueTransformerBindingOption: appDelegate.myOverflowMenuController.isSourceMenuTransformer}];
> return dayItem;
> }
and got:
> 2014-09-08 03:54:10.776 MyApp[28618:303] Creating menu item (<NSMenuItem: 0x6080000aa500 Monday, September 8, 2014, submenu: 0x608000263800 (Monday, September 8, 2014)>) for day (2014-09-08 00:00:00 -0400).
> 2014-09-08 03:54:10.777 MyApp[28618:303] Calling -transformedValue with ((null)) and self.targetMenu = (null).
> 2014-09-08 03:54:10.777 MyApp[28618:303] Creating menu item (<NSMenuItem: 0x6080000aa6e0 Sunday, September 7, 2014, submenu: 0x608000269480 (Sunday, September 7, 2014)>) for day (2014-09-07 00:00:00 -0400).
> 2014-09-08 03:54:10.778 MyApp[28618:303] Calling -transformedValue with ((null)) and self.targetMenu = (null).
> 2014-09-08 03:54:10.778 MyApp[28618:303] Creating menu item (<NSMenuItem: 0x6080000aa8c0 Saturday, September 6, 2014, submenu: 0x608000268ac0 (Saturday, September 6, 2014)>) for day (2014-09-06 00:00:00 -0400).
> 2014-09-08 03:54:10.779 MyApp[28618:303] Calling -transformedValue with ((null)) and self.targetMenu = (null).
> 2014-09-08 03:54:10.779 MyApp[28618:303] Creating menu item (<NSMenuItem: 0x6080000aab00 Thursday, September 4, 2014, submenu: 0x608000268dc0 (Thursday, September 4, 2014)>) for day (2014-09-04 00:00:00 -0400).
> 2014-09-08 03:54:10.779 MyApp[28618:303] Calling -transformedValue with ((null)) and self.targetMenu = (null).
> 2014-09-08 03:54:10.782 MyApp[28618:303] Calling -transformedValue with (<NSMenu: 0x608000263800> SKIP) and self.targetMenu = <NSMenu: 0x608000263800> SKIP.
> 2014-09-08 03:54:10.796 MyApp[28618:303] Calling -transformedValue with (<NSMenu: 0x608000263800> SKIP) and self.targetMenu = <NSMenu: 0x608000263800> SKIP.
> 2014-09-08 03:54:10.796 MyApp[28618:303] Calling -transformedValue with (<NSMenu: 0x608000263800> SKIP) and self.targetMenu = <NSMenu: 0x608000263800> SKIP.
> 2014-09-08 03:54:10.797 MyApp[28618:303] Calling -transformedValue with (<NSMenu: 0x608000263800> SKIP) and self.targetMenu = <NSMenu: 0x608000263800> SKIP.
The test value and the target menu were always the same. Four runs of double NULL then four more with Today’s sub-menu (Sep. 8). So the transformer always returns YES and every per-day history menu item (and sub-menu) is hidden. How do I get “dayItem.submenu” to be the operand for the transformer? Did I mess up the binding? Or the transformer’s very design? Where did those 4 NULL runs come from?
…
Oh, for that last question, it’s because the “sourceMenu” property starts as NIL and I don’t change it until I create the per-day menus. It would have to be that way since I set the property to the sub-menu of the newest day (unless it’s before Today).
—
Daryle Walker
Mac, Internet, and Video Game Junkie
darylew AT mac DOT com
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