<AWT Dev> [8] Review request for 7171045 [macosx] There are no enter or exit events reported against 8b39 for MouseEventsDuringDrag.

Sergey Bylokhov Sergey.Bylokhov at oracle.com
Mon Aug 27 05:43:24 PDT 2012

Hi, Alexander.
So NSTrackingCursorUpdate option is not necessary?

27.08.2012 15:29, Alexander Scherbatiy wrote:
> On 8/25/2012 12:49 AM, Sergey Bylokhov wrote:
>> Hi Alexander.
>> In the fix NSTrackingArea has NSTrackingCursorUpdate option but i did 
>> not see  cursorUpdate: method. Probably we can get some useful 
>> information from it?
>      Now all necessary information about the cursor updating is 
> tracked in the resetCursorRects method according to the 
> "Mouse-Tracking and Cursor-Update Events" doc:
> https://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/EventOverview/MouseTrackingEvents/MouseTrackingEvents.html
>    I tried to add the cursorUpdate method and in the case when a Frame 
> is pro-grammatically moved  out of the mouse cursor this method is not 
> invoked (probably as expected).
>    It means that the cursorUpdate method can't be used for the mouse 
> exit event generation in this case.
>    Such behavior is checked by the test: 
> test/java/awt/Mouse/EnterExitEvents/ResizingFrameTest.java
>    Thanks,
>    Alexandr.
>> 24.08.2012 17:53, Alexander Scherbatiy пишет:
>>> Could you review the updated fix:
>>>   http://cr.openjdk.java.net/~alexsch/7171045/webrev.04/
>>> The comments are below:
>>> On 8/23/2012 4:51 PM, Anthony Petrov wrote:
>>>> Hi Alexandr,
>>>> 1. In synthesizeMouseEnteredExitedEventsForAllWindows, can we 
>>>> iterate through app's windows only once and send both Exited and 
>>>> Entered events where needed?
>>>     Now, when we do not care about the order of the mouse enter/exit 
>>> events generation it is possible to do. I have updated the code.
>>>> 2. Also, it looks like nativeSynthesizeMouseEnteredExitedEvents no 
>>>> longer requires a window pointer as an argument.
>>>        Fixed.
>>>> 3. Here's a major concern: the LWWindowPeer (and other LW* classes) 
>>>> should never import C* classes. Instead you should've added a new 
>>>> method to the PlatformWindow interface, and used it from 
>>>> LWWindowPeer. The CPlatformWindow should've implemented this 
>>>> method, and called an appropriate native method from there. In this 
>>>> case, however, you actually need a static method, so it'd better be 
>>>> part of the LWToolkit interface, and implemented in the LWCToolkit 
>>>> class instead.
>>>      I see.  It seems that the getTopmostWindowUnderMouse method 
>>> implementation is different for the CPlatformWindow and for the 
>>> CPlatformEmbeddedFrame.
>>>      So I added the getTopmostPlatformWindowUnderMouse method to the 
>>> PlatformWindow  interface.
>>>     Thanks,
>>>     Alexandr.
>>>> -- 
>>>> best regards,
>>>> Anthony
>>>> On 08/23/12 15:40, Alexander Scherbatiy wrote:
>>>>> Could someone review the fix?
>>>>> Thanks,
>>>>> Alexandr.
>>>>> On 8/10/2012 6:00 PM, Alexander Scherbatiy wrote:
>>>>>> Could you review the updated fix:
>>>>>> http://cr.openjdk.java.net/~alexsch/7171045/webrev.02/
>>>>>> The comments are below:
>>>>>> On 8/7/2012 6:47 PM, Mike Swingler wrote:
>>>>>>> I noticed that, NSWindow's windowNumber is NSInteger, which is 32
>>>>>>> bits wide on 32-bit and 64 bits wide on 64-bit. Chopping that to a
>>>>>>> simple 32 bit int is probably not what you intended to do.
>>>>>> fixed.
>>>>>>> Also, have you considered simply calling -[NSWindow
>>>>>>> setAcceptsMouseMovedEvents:YES] in -[AWTView initWithRect:], and 
>>>>>>> then
>>>>>>> removing the calls that flip it on and off in -[AWTView
>>>>>>> mouseEntered:] and -[AWTView mouseExited"]? This would also 
>>>>>>> require a
>>>>>>> change in
>>>>>>> Java_sun_lwawt_macosx_CPlatformWindow_nativeSetNSWindowBounds(),
>>>>>>> which has a comment that states it only turns on mouse moved events
>>>>>>> if the window is currently under the mouse.
>>>>>> I tried it. The result that I got is that a dragging mouse from one
>>>>>> window to another does not generate mouse enter/exit events on the
>>>>>> second window in case when tracking rect is used and the
>>>>>> acceptsMouseMovedEvents flag is always set to YES.
>>>>>>> I would think that AppKit should be more than happy to send you
>>>>>>> mouse-over/enter/exited events as long as you say you want them. 
>>>>>>> Was
>>>>>>> this approach tried and didn't work for some reason?
>>>>>>>> Hi, Alexander.
>>>>>>>> Probably all this stuff can be simplified? Can you try to change
>>>>>>>> TrackingRect to TrackingArea with appropriate flags like
>>>>>>>> NSTrackingEnabledDuringMouseDrag etc.
>>>>>> I changed the TrackingRect to TrackingArea in the updated fix. It 
>>>>>> now
>>>>>> generates the mouse enter/exit events on the second window during 
>>>>>> drag.
>>>>>> So it is not necessary to generates such events from our side.
>>>>>> The getTopmostWindowUnderMouse is necessary to handle mouse 
>>>>>> enter/exit
>>>>>> events for component in case when a mouse is dragged from one window
>>>>>> to another.
>>>>>> Where the second window contains it's own components and the only 
>>>>>> way
>>>>>> to know about tracking over them are drag events which receives the
>>>>>> first window.
>>>>>> I think that the LWWindowPeer class code can be simplified if we
>>>>>> assume that window mouse enter/exit events are always come to the
>>>>>> current window.
>>>>>> So the component mouse enter/exit events can be tracked only in the
>>>>>> current or topmost window.
>>>>>> For this case I separated the global lastCommonMouseEventPeer 
>>>>>> which is
>>>>>> necessary for the cursor manager and the local lastMouseEventPeer.
>>>>>> According to the specification: The proper order of mouse-entered 
>>>>>> and
>>>>>> mouse-exited events received by tracking-area objects in an
>>>>>> application cannot be guaranteed.
>>>>>> https://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/EventOverview/TrackingAreaObjects/TrackingAreaObjects.html 
>>>>>> So it seems it is not possible to have one lastMouseEventPeer 
>>>>>> instead
>>>>>> of two: lastCommonMouseEventPeer and lastMouseEventPeer.
>>>>>> And there are possible situations that we can receive mouse drag 
>>>>>> event
>>>>>> between enter and exit.
>>>>>> To handle this the isMouseOver flag is added to the LWWindowPeer
>>>>>> class. So the component mouse enter/exit events are not generated if
>>>>>> the window mouse exited event is received and window mouse 
>>>>>> entered is
>>>>>> not.
>>>>>> There is the test:
>>>>>> test/java/awt/Mouse/EnterExitEvents/ResizingFrameTest.java
>>>>>> It shows that even using the TrackingArea some mouse enter/exit 
>>>>>> events
>>>>>> are not generateed in the following cases:
>>>>>> - window is created under the mouse
>>>>>> - window changes it's bounds so it becomes under the mouse
>>>>>> For this cases it still necessary to generate mouse enter/exit 
>>>>>> events
>>>>>> from our side.
>>>>>> I just moved the related code to one method
>>>>>> synthesizeMouseEnteredExitedEventsForAllWindows.
>>>>>> Thanks,
>>>>>> Alexandr.
>>>>>>>> 07.08.2012 15:17, Alexander Scherbatiy wrote:
>>>>>>>>> bug: http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7171045
>>>>>>>>> webrev: http://cr.openjdk.java.net/~alexsch/7171045/webrev.01/
>>>>>>>>> This is a regression after the fix 7154048 [macosx] At least drag
>>>>>>>>> twice, the toolbar can be dragged to the left side.
>>>>>>>>> In the case where a toolbar is created under a mouse and it is
>>>>>>>>> dragged over the initial window the mouse enter/exit events 
>>>>>>>>> should
>>>>>>>>> not be generated for the components which are under the toolbar.
>>>>>>>>> The current fix is supposed to solve this regression and also to
>>>>>>>>> fix generation of mouse enter/exit events for all cases where a
>>>>>>>>> mouse is dragged from one window to another or a new window is
>>>>>>>>> created under a mouse (like it is implemented for toolbar).
>>>>>>>>> Let's see the following cases
>>>>>>>>> 1) Mouse is dragged from a window and back to the same window.
>>>>>>>>> The Mac OS X system generates a mouse exit event only the first
>>>>>>>>> time when a mouse is dragged from a window and does not generate
>>>>>>>>> mouse enter/exit events next times during one drag trace.
>>>>>>>>> 2) Mouse is dragged from one window to another.
>>>>>>>>> The Mac OS X system does not generate mouse enter/exit events for
>>>>>>>>> the second window.
>>>>>>>>> 3) Mouse is dragged from one window to another and released.
>>>>>>>>> In this case the Mac OS X system generates mouse enter event for
>>>>>>>>> the second window only after releasing the mouse.
>>>>>>>>> 4) Clicking on window creates a new window after that the new
>>>>>>>>> window is dragged (toolbar dragging).
>>>>>>>>> However the Java system generates mouse enter/exit events each 
>>>>>>>>> time
>>>>>>>>> when a mouse is dragged over any window.
>>>>>>>>> To fix this the following methods are introduced:
>>>>>>>>> - Get topmost window under mouse
>>>>>>>>> - Synthesize mouse enter/exit events for all windows
>>>>>>>>> The dispatchMouseEvent method from the LWWindowPeer class is
>>>>>>>>> handled previous and next components and is able to generate 
>>>>>>>>> mouse
>>>>>>>>> enter/exit events for them.
>>>>>>>>> However the the AWTView native class contains isMouseOver flag
>>>>>>>>> which value becomes inconsistent if we do not updated it. Because
>>>>>>>>> of this the fix generates the mouse enter/exit window events 
>>>>>>>>> on the
>>>>>>>>> native side.
>>>>>>>>> Generating mouse enter/exit events always should be in order 
>>>>>>>>> where
>>>>>>>>> mouse exit events are generated before the mouse enter events.
>>>>>>>>> The synthesizeMouseEnteredExitedEventsForAllWindows method 
>>>>>>>>> tries to
>>>>>>>>> generate mouse enter/exit events for all windows during mouse 
>>>>>>>>> drag
>>>>>>>>> or window creation/window bounds changing.
>>>>>>>>> However only those windows which isMouseOver flag is differ from
>>>>>>>>> the isTopMostWindowUnderMouse state are affected.
>>>>>>>>> This method also tries to generate both mouse enter and exit 
>>>>>>>>> event
>>>>>>>>> for the same window but only one of them can be applicable 
>>>>>>>>> because
>>>>>>>>> the isTopMostWindowUnderMouse state is not changed for these 
>>>>>>>>> calls.
>>>>>>>>> So the window enter/exit events now are always generated from the
>>>>>>>>> native system and component enter/exit events are generated in 
>>>>>>>>> the
>>>>>>>>> LWWindowPeer class.
>>>>>>>>> LWWindowPeer class now uses three links to components: current,
>>>>>>>>> last and topmostUnderMouse. All of them are necessary because in
>>>>>>>>> case when a mouse is dragged from one window to another the 
>>>>>>>>> current
>>>>>>>>> component receives drag events and last and topmostUnderMouse 
>>>>>>>>> links
>>>>>>>>> handle components mouse exit/enter events on the second window.
>>>>>>>>> Thanks,
>>>>>>>>> Alexandr.
>>>>>>>> -- 
>>>>>>>> Best regards, Sergey.

Best regards, Sergey.

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