make popup_flags use ImGuiPopupFlags_MouseButtonRight as a default value instead of 1

[Rune-Magic]

• ImGuiPopupFlags_MouseButtonRight is more self documenting than 1
• 1 is also bad for bindings since they usually use the enums directly instead of the typedefs

[ocornut]

Err... did you try to compile this?

[Rune-Magic]

oops

[ocornut]

It's rather terrible in the first place that those 4 api have a non-zero default parameters due to legacy reason, I think I would prefer to find a solution to this problem that allows us to switch the default to 0.

I didn't have a good solution for it back then when fed80b9 was pushed.
Since:

• this is now a 5+ years change.
• BeginPopupContextXXX() is imho rarely used with ImGuiPopupFlags_MouseButtonLeft, let alone with an explicit 0.

We could decide to make the breaking change of:

• Changing all ImGuiPopupFlags_MouseButtonXXX values to be non-zero.
• When none is set, use the default which is ImGuiPopupFlags_MouseButtonRight.
• Reserve bit 0-1 are "unauthorized use" to detect use of hardcoded 1 or 2.

This would still work:

• BeginPopupContextXXX(...., ImGuiPopupFlags_MouseButtonLeft)

This would break behavior by changing the button from left to right:

• BeginPopuContextXXX(...., 0);

I believe it's an acceptable breaking change especially since it can be regexp searched..

[Rune-Magic]

yeah that would nice

[ocornut]

Applied this change, see #9157