8282703: Axis is not cached in the LinuxTouchTransform class

[AlexanderScherbatiy]

An axis is not cached in the LinuxTouchTransform class.

To reproduce the issue I added System.out.printf("initTransform: axis: %d, index: %d%n", axis, index); log to the LinuxTouchTransform.initTransform() method: https://github.com/openjdk/jfx/blob/5112be957be70dd6521e6fb6ee64e669c148729c/modules/javafx.graphics/src/main/java/com/sun/glass/ui/monocle/LinuxTouchTransform.java#L117 run the JFXButtonExample sample and tapped the touch screen on a Raspberry Pi with Touchscreen.

The result was

initTransform: axis: 47, index: 0
initTransform: axis: 57, index: 0
initTransform: axis: 53, index: 0
initTransform: axis: 54, index: 0
initTransform: axis: 0, index: 0
initTransform: axis: 1, index: 0
initTransform: axis: 53, index: 0
initTransform: axis: 54, index: 0
initTransform: axis: 0, index: 0
initTransform: axis: 1, index: 0
initTransform: axis: 53, index: 0
initTransform: axis: 54, index: 0
initTransform: axis: 0, index: 0
initTransform: axis: 1, index: 0

The initTransform() is called several times for axis 0,1,47,53,54 and index is always set to zero.

The straight forward fix is to store the given axis in the axes array: "axes[index] = axis". This is the first commit for the current fix. Using this fix the output with printf from initTransform() method looks like:

initTransform: axis: 47, index: 0
initTransform: axis: 57, index: 1
initTransform: axis: 53, index: 2
initTransform: axis: 54, index: 4
initTransform: axis: 1, index: 5

Now all axes are printed only once and the index value is different for each axes.

However, the minimum/maximum values are retrieved and cached for ABS_X/Y and ABS_MT_POSITION_X/Y axes after the fist tap on the screen. The second commit improves this moving the ABS_X/Y and ABS_MT_POSITION_X/Y axes initialization into the LinuxTouchTransform constructor.

Now the touch logs look like:

// LinuxTouchTransform constructor
// device: /dev/input/mouse0
initTransform: axis: 0, index: 0
initTransform: axis: 1, index: 1
initTransform: axis: 53, index: 2
initTransform: axis: 54, index: 3

// LinuxTouchTransform constructor
// device: /dev/input/event2
initTransform: axis: 0, index: 0
initTransform: axis: 1, index: 1
initTransform: axis: 53, index: 2
initTransform: axis: 54, index: 3

// the first tap
initTransform: axis: 57, index: 4
initTransform: axis: 47, index: 5

The ABS_X/Y and ABS_MT_POSITION_X/Y axes and corresponding minimum/maximum values are initialized in the constructor. The other axes which stores only default values in translates and scalars arrays are initialized during touch events.

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Issue

• JDK-8282703: Axis is not cached in the LinuxTouchTransform class

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[chilliger]

@AlexanderScherbatiy Did I miss something? Is touch now support with GTK? I thought the implementation is missing for GTK: https://github.com/openjdk/jfx/pull/457

[kevinrushforth]

Did I miss something? Is touch now support with GTK? I thought the implementation is missing for GTK

This PR is for Monocle, which is not used for desktop Linux (it's for embedded systems like Raspberry Pi).

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@AlexanderScherbatiy This pull request has been inactive for more than 4 weeks and will be automatically closed if another 4 weeks passes without any activity. To avoid this, simply add a new comment to the pull request. Feel free to ask for assistance if you need help with progressing this pull request towards integration!

[AlexanderScherbatiy]

@AlexanderScherbatiy This pull request has been inactive for more than 4 weeks and will be automatically closed if another 4 weeks passes without any activity. To avoid this, simply add a new comment to the pull request. Feel free to ask for assistance if you need help with progressing this pull request towards integration!

Could you review the fix?

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@AlexanderScherbatiy This pull request has been inactive for more than 4 weeks and will be automatically closed if another 4 weeks passes without any activity. To avoid this, simply add a new comment to the pull request. Feel free to ask for assistance if you need help with progressing this pull request towards integration!

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@AlexanderScherbatiy This pull request has been inactive for more than 8 weeks and will now be automatically closed. If you would like to continue working on this pull request in the future, feel free to reopen it! This can be done using the /open pull request command.