Bug 378484

In Krita 3.1.x and older, Popup palette has a few usability issues that cause unwanted actions:

1) Right-click can pick color and select brush presets. 

As Krita 3.1.x's current design, when the cursor is above the popup palette, another right click selects something on the palette before closing it down. This is bad because: Right click is associated with BRINGING UP the popup palette -- we expect another right-click to be associated with CLOSING DOWN the palette. We normally don't pay attention to the cursor position when we close the palette, so it is very easy to select unwanted colors and brush presets accidentally, breaking the flow.

2) Holding Right-click and release automatically selects brush preset and close popup palette.

Holding right click over canvas can bring up popup palette. Keep holding it and move the cursor over a brush preset icon and release, the preset will be selected and the palette close down immediately. This aggravates the problem of (1). What's more, releasing the right button over the palette's color picker doesn't do anything, an inconsistency of UI interaction. 

Allowing holding-key command is usually a bad idea because mouse and stylus does not work the same:

A) A mouse runs on a solid surface, which means a CLICK can be done in a clean and reliable way.

B) A stylus is supported by soft flesh. When the force over a barrel button is lifted, the bouncing back flesh keeps the button activated for a longer period. We cannot predict when the clicking mechanism is bring released. In this case, many (EXPECTED) CLICKS are recognized as HOLDING by the system. That's why it's very difficult to use a 1-button in-line remote control of a headset to perform NEXT (2-clicks) and BACK (3-clicks).

Therefore, we should always consider that on a stylus, CLICKS and HOLDING cannot be executed in a reliable way and they always mix with each other. 

The issues above cause too many unwanted changes of color and brush and confusion in Krita. Therefore I suggest:

A) Do not allow right click to select popup palette items.

B) Do not auto-select-and-close when a holding-right-click is released, keep the popup palette up so we can have time to look, think, select.

C) Treat all holding right-clicks as 1 normal right-click. Do not assign different functions to right-click and holding-right-click.