<Swing Dev> [9] JDK-8049069 : JButton incorrect behaviour on button release

[Ajit Ghaisas]

Hi,
       
    In JDK-6u115, this bug is not reproducible.
    Fix for JDK-7088744 did  not break the JButton behavior.
    This bug is regression due to changes done to SwingUtilities as a fix of JDK-7146377.  

    After reading comments on JBS for JDK-7146377, I realized that the modification was done to support left mouse drag.
    Ideally, it should have been done using a new public method such as isLeftMouseButtonDown() and using it in test/client code. 
    In this case, we will need to add isMiddleMouseButtonDown() and isRightMouseButtonDown() methods as well. 
    Modifying existing APIs as well as introducing new public APIs raises a risk of forced test/client code modifications. (This is the reason why I have chosen option 2 as mentioned below)

    I have fixed the JDK-8049069 in BasicButtonListener.java as there is no need to use swingUtilities methods in mousePressed() and mouseReleased() methods.

Regards,
Ajit

-----Original Message-----
From: Sergey Bylokhov 
Sent: Friday, March 25, 2016 3:33 AM
To: Ajit Ghaisas; swing-dev at openjdk.java.net; Alexander Scherbatiy; Rajeev Chamyal
Subject: Re: <Swing Dev> [9] JDK-8049069 : JButton incorrect behaviour on button release

Hi, Ajit.
Is this bug a regression of JDK-7088744 or JDK-8049069, or it works this way in jdk6 as well?
I guess the code in jdk6 was something like this:
     public static boolean isLeftMouseButton(MouseEvent anEvent) {
          return ((anEvent.getModifiers() & InputEvent.BUTTON1_MASK) != 0);
     }

On 24.03.16 12:55, Ajit Ghaisas wrote:
> Hi,
>
> Bug : https://bugs.openjdk.java.net/browse/JDK-8049069
>
> Issue :  A JButton which is pressed using left mouse button gets released if right mouse button is pressed and released.
>
> Root cause :
> ---------------
> In file BasicButtonListener.java, mousePressed() and mouseReleased() methods check whether the event is from left mouse button.
> This check is done using ----  if (SwingUtilities.isLeftMouseButton(e) 
> ) This method returns true if left mouse button is down OR event is from left mouse button.
> SwingUtilities.isLeftMouseButton() returns true if it is called for right mouse event while holding left button down. This causes mouseReleased() method to release pressed JButton.
>
>
> Alternatives considered :
> -----------------------------
> 1. Modifying SwingUtilities.isLeftMouseButton() method to only test 
> for whether the event is from left mouse button only 2. Modifying mousePressed() and mouseReleased() methods to check for whether the event is from left mouse button using argument passed to them.
>
> Option 1 will break the code wherever SwingUtilities.isLeftMouseButton() is used to test for left mouse button down.
> File history revealed that the mouse button down condition is added to fix another bug.
>
> Hence, option 2 is chosen as it is safe and intuitive.
> I have also added a test. It passes on Windows, Linux and Mac.
> Test mentioned in comment on the bug also passed.
>
> Please review the webrev :
>
> http://cr.openjdk.java.net/~aghaisas/8049069/webrev.00/
>
> Regards,
> Ajit
>


--
Best regards, Sergey.