Unexpected behaviour when trying to cancel a gesture

[maurges]

Describe the bug

When you start a send_keys gesture, it will go through with the action even if you reset the gesture progress to 0.

So for example, I have this in my config:

    <!-- New tab -->
    <gesture type="SWIPE" fingers="3" direction="UP">
      <action type="SEND_KEYS">
        <modifiers>Control_L</modifiers>
        <keys>T</keys>
      </action>
    </gesture>
    <!-- Close tab -->
    <gesture type="SWIPE" fingers="3" direction="DOWN">
      <action type="SEND_KEYS">
        <modifiers>Control_L</modifiers>
        <keys>W</keys>
        <repeat>false</repeat>
        <on>end</on>
      </action>
    </gesture>

The usual behaviour is: I swipe my three fingers down, take them off the touchpad, and a tab closes.
The unusual behaviour: I swipe my three fingers down, and while my fingers are still on the touchpad, start swiping them back up again; then when I take my fingers off the touchpad, a tab still closes.

Expected behaviour

When moving a gestire in the opposite direction, it should be cancelled

Actual behaviour

The gesture completes regardless of swipe direction

Your environment

• Version of Touchégg: v2.0.4
• Operating System: opensuse 15.1
• Desktop Environment: KDE 5.12.8

[maurges]

Upon inspection with xev, I can see the cause: the keys are pressed on gesture start, and released on gesture end, so there is no way to cancel the gesture at all.