OSX's scrolling direction

MacOSX and iOS
1

Hi Jules,

In Lion, there’s that new (so-called) ‘natural scrolling direction’ for trackpad.
The problem is that when controlling sliders thru trackpad, the fader’s action it’s reversed : scrolling up lowers the slider and vice versa.
A ‘scrolling direction’ option would be handy (and save some brain sanity) !

Salvator

2

Yes, I’ve been meaning to do something about that…

Not sure what’s the correct approach though. Perhaps the whole mouseWheelMove() callback needs to be overhauled to provide a more useful structure as its argument, which could provide extra info like whether the wheel is reversed, whether there are both a vertical and horizontal wheels present, etc. Then things like the slider could make smarter decisions. Would require a lot of people changing their code though…

3

Ah ! I thought default arguments would avoid too much change in user’s code…
Personally though, I don’t mind changing things in my code for this.

Salvator

4

It’s one of those things I wish I’d done differently years ago when I originally created the method. But yes, it’s probably worth causing some inconvenience to people to make it future-proof.

5

Cool,

It works ! Thanks,
for anybody interested : it’s easy to implement without changing much in user’s code, by keeping local float and assigning wheel.deltaX/Y to that local float :

float wheelIncrementY;    
float wheelIncrementX; 
 wheel.isReversed ? wheelIncrementX = - wheel.deltaX : wheelIncrementX = wheel.deltaX;
 wheel.isReversed ? wheelIncrementY = - wheel.deltaY : wheelIncrementY = wheel.deltaY;

Salvator

6

In juce_mac_NSViewComponentPeer.mm there’s a tiny issue :

const float scale = 0.5f / 256.0f;
is declared inside #if defined (MAC_OS_X_VERSION_10_7) && MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_7
But it’s also used after the #endif, and this cause a ‘scale not declared’ problem in my case.
Moving declaration prior the definition fix it.

Salvator

7

Thanks, I already fixed that scale thing.

wheel.isReversed ? wheelIncrementX = - wheel.deltaX : wheelIncrementX = wheel.deltaX;

…ouch… Assignments inside conditional statement expressions, really!?

8

what about :

wheelIncrementX = (wheel.isReversed ? - wheel.deltaX : wheel.deltaX); wheelIncrementY = (wheel.isReversed ? - wheel.deltaY : wheel.deltaY); Salvator

9

Much better!

10

Sorry again to bother with this, but the fix work only for 10.7 SDK here.
While compiling a project with the 10.6SDK , but running on 10.7, all my faders were reversed when using the mouse wheel.
Will try to stick with the 10.7SDK, but maybe someone else will have the surprise…

Salvator

11

True, but there’s really nothing I can do about that. People should really be using the latest SDK anyway, it doesn’t make much sense to use an older one.

12

You can do it like this in your mouseWheelEvent

bool negative = false; #if defined (MAC_OS_X_VERSION_10_6) && MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_7 if([NSEvent instancesRespondToSelector:@selector(isDirectionInvertedFromDevice:)]) negative = [theEvent isDirectionInvertedFromDevice]; #endif
This could help perhaps?

13

We’re still using 10.5/10.5 (Base/Deployment SDK) as plugins made with 10.6/10.5 crash on 10.5 systems. This might have changed in the meantime and we didn’t switch to 10.7 / XCode 4 for development yet but my previous impression of this Base/Deployment stuff is that it’s a great idea that unfortunately doesn’t work.

Chris

14

[quote=“Best4gotten”]You can do it like this in your mouseWheelEvent

bool negative = false; #if defined (MAC_OS_X_VERSION_10_6) && MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_7 if([NSEvent instancesRespondToSelector:@selector(isDirectionInvertedFromDevice:)]) negative = [theEvent isDirectionInvertedFromDevice]; #endif
This could help perhaps?[/quote]

Thanks, I do already do it that way, which is fine for anyone using a newer SDK, but some people are still using pre-10.6 SDKs.