Re: [Qemu-devel] [PATCH v2] ui/cocoa: Fix absolute input device grabbing issues on Mojave

[Chen Zhang]

> On Mar 27, 2019, at 12:15 AM, Peter Maydell <address@hidden> wrote:
> 
> On Tue, 19 Mar 2019 at 03:51, Chen Zhang <address@hidden 
> <mailto:address@hidden>> wrote:
>> 
>> On Mojave, absolute input device, i.e. tablet, had trouble re-grabbing
>> the cursor in re-entry into the virtual screen area. In some cases,
>> the `window` property of NSEvent object is nil, after exit of cursor,
>> meaning that the `-locationInWindow` method would return value in screen
>> coordinates. Current implementation used raw locations from NSEvent
>> without considering whether the value was for the window coordinates or
>> the macOS screen coordinates, nor was the zooming factor for Zoom-to-Fit
>> included for fullscreen mode.
>> 
>> In fullscreen mode, the fullscreen cocoa window might not be the key
>> window, therefore location of event in virtual coordinates should suffice
>> for the condition of grabbing.
>> 
>> This patch fixed boundary check methods for cursor in normal and fullscreen
>> with/without Zoom-to-Fit on macOS Mojave.
>> 
>> Signed-off-by: Chen Zhang <address@hidden>
>> ---
>> ui/cocoa.m | 39 +++++++++++++++++++++++++++++++++++++--
>> 1 file changed, 37 insertions(+), 2 deletions(-)
>> 
> 
> Hi; this doesn't compile for me, I'm afraid. I've appended the full
> compiler error log, but the problem seems to be that
> the convertPointFromScreen method of NSWindow doesn't exist.
> I'm not entirely sure why, since the API docs say that method
> was introduced in OSX 10.12 and I'm running 10.13.6, but
> at least at the moment our minimum OSX version is 10.10,
> so we need something to handle that anyway.
Hi,

Just double-checked on a MacMini mid 2011 with macOS 10.13.6, Xcode 10.1. This 
NSWindow API did exist, and the patch could be built without error.
Searching convertPointFromScreen in Xcode.app’s platform SDK showed that it was 
defined at line 440 in NSWindow.h of AppKit.framework.

May I ask what build environment did you use (as printed by `xcode-select -p`)?
> 
> (http://codeworkshop.net/objc-diff/sdkdiffs/macos/10.14/AppKit.html 
> <http://codeworkshop.net/objc-diff/sdkdiffs/macos/10.14/AppKit.html>
> suggests that maybe the docs are wrong and this method
> was only added in 10.14; that would certainly fit the symptoms.)
> 
> 
> /Users/pm215/src/qemu/ui/cocoa.m:414:35: warning: instance method
> '-convertPointFromScreen:' not found
>      (return type defaults to 'id') [-Wobjc-method-access]
>            return [[self window] convertPointFromScreen:[ev 
> locationInWindow]];
>                                  ^~~~~~~~~~~~~~~~~~~~~~
> /System/Library/Frameworks/AppKit.framework/Headers/NSWindow.h:191:12:
> note: receiver is instance of class declared here
> @interface NSWindow : NSResponder <NSAnimatablePropertyContainer,
> NSUserInterfaceValidations, NSUserInterfaceItemIdenti...
>           ^
> /Users/pm215/src/qemu/ui/cocoa.m:414:20: error: returning 'id' from a
> function with incompatible result type 'CGPoint'
>      (aka 'struct CGPoint')
>            return [[self window] convertPointFromScreen:[ev 
> locationInWindow]];
>                   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> /Users/pm215/src/qemu/ui/cocoa.m:416:61: warning: instance method
> '-convertPointFromScreen:' not found
>      (return type defaults to 'id') [-Wobjc-method-access]
>            CGPoint loc = [self convertPoint:[[self window]
> convertPointFromScreen:[ev locationInWindow]] fromView:nil];
> 
> ^~~~~~~~~~~~~~~~~~~~~~
> /System/Library/Frameworks/AppKit.framework/Headers/NSWindow.h:191:12:
> note: receiver is instance of class declared here
> @interface NSWindow : NSResponder <NSAnimatablePropertyContainer,
> NSUserInterfaceValidations, NSUserInterfaceItemIdenti...
>           ^
> /Users/pm215/src/qemu/ui/cocoa.m:416:46: error: sending 'id' to
> parameter of incompatible type 'NSPoint' (aka 'struct CGPoint')
>            CGPoint loc = [self convertPoint:[[self window]
> convertPointFromScreen:[ev locationInWindow]] fromView:nil];
> 
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> /System/Library/Frameworks/AppKit.framework/Headers/NSView.h:196:34:
> note: passing argument to parameter 'point' here
> - (NSPoint)convertPoint:(NSPoint)point fromView:(nullable NSView *)view;
>                                 ^
> /Users/pm215/src/qemu/ui/cocoa.m:435:67: warning: instance method
> '-convertPointToScreen:' not found
>      (return type defaults to 'id') [-Wobjc-method-access]
>        return [[self window] convertPointFromScreen:[eventWindow
> convertPointToScreen:[ev locationInWindow]]];
> 
> ^~~~~~~~~~~~~~~~~~~~
> /System/Library/Frameworks/AppKit.framework/Headers/NSWindow.h:191:12:
> note: receiver is instance of class declared here
> @interface NSWindow : NSResponder <NSAnimatablePropertyContainer,
> NSUserInterfaceValidations, NSUserInterfaceItemIdenti...
>           ^
> /Users/pm215/src/qemu/ui/cocoa.m:435:31: warning: instance method
> '-convertPointFromScreen:' not found
>      (return type defaults to 'id') [-Wobjc-method-access]
>        return [[self window] convertPointFromScreen:[eventWindow
> convertPointToScreen:[ev locationInWindow]]];
>                              ^~~~~~~~~~~~~~~~~~~~~~
> /System/Library/Frameworks/AppKit.framework/Headers/NSWindow.h:191:12:
> note: receiver is instance of class declared here
> @interface NSWindow : NSResponder <NSAnimatablePropertyContainer,
> NSUserInterfaceValidations, NSUserInterfaceItemIdenti...
>           ^
> /Users/pm215/src/qemu/ui/cocoa.m:435:16: error: returning 'id' from a
> function with incompatible result type 'CGPoint'
>      (aka 'struct CGPoint')
>        return [[self window] convertPointFromScreen:[eventWindow
> convertPointToScreen:[ev locationInWindow]]];
>               
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 4 warnings and 3 errors generated.
> 
> thanks
> -- PMM

Best regards,