While I am technically right-handed, I have used my mouse left-handed for the last couple of years (it eases the stress on my right hand).
Most of the GUI desktop environments I have used have a Preferences setting for using a mouse left-handed. Either it is labelled “Left-handed” or “Switch left and right buttons” — both make it obvious what the setting is for.
There is no such setting in the Haiku mouse settings. There should be — especially for left-handed people who actually want to use their dominant finger for the most used button.
I agree, there should be a checkbox to make it easy. Contrary to Haiku philosophy, the Mouse preferences has even more configurability.
You can assign any physical mouse button to any logical button. Right-click a mouse button in the mouse representation and choose its logical number. To switch to left-handed, go from 1 - 3 - 2 to 2 - 3 - 1.
Yeah, I understand your feelings on this. The Mac, much as I love it, doesn’t have a left facing pointer either. But it’s more obvious with the gloved hand. And so the right pointing finger and the mouse pointer tilted to the right remain. I’ve thought it’d be possible to recompile app_server (if I recall correctly, the cursors are in there from the last time I played with Haiku) to address this, maybe with something like a switched_app_server and app_server package that could have different cursors and be loaded into the package system via a Preferences pane (and a reboot).
However, in getting to the point, as for changing the position of the mouse buttons, open the Mouse preflet from Preferences. This works in both the BeOS and in Haiku. In there, you’ll see an illustration of a mouse. Click the numbered buttons to switch them. So, as @humdinger already had mentioned, you can switch 2 to 1 and close the window. It’s also possible to turn off the 3-button setting altogether and use a 1-button mouse like a classic Macintosh from the menu right above the mouse, but in doing so, you obviously lose middle and right-click.
(In summary, though, I’ll also add this: even if the feature to ‘flip buttons’ was in Haiku, like it is in Mac and Windows, I grew frustrated with switching the buttons around and just use the default primary mouse button; everyone else’s computer has ‘normal’ mice anyway).
Actually you can also left click or even middle click, so that these preferences are still usable even if you messed up your mouse button configuration.
I agree we should hint more at the buttons in the mouse preview being clickable, however.
And btw, I use a left-handed trackball, which means the buttons for me are already flipped in hardware
@apgreimann: Thank you for your detailed instructions. The screenshots immediately make it clear what one has to do. Next time I boot Haiku (from the DVD), I’ll test it out.
My next step of playing with Haiku is to make a bootable USB stick with enough room to treat like a real system (albeit, slower than my SSD). There appear to be good instructions on doing that.
Problem here is with touchpads. Suppose you want a left handed mouse, but still want to use a touchpad. Since touchpads are hand-agnostic, configuring a left handed mouse will make the touchpad behave as a right-click when tapping.
The preflet is completely bad designed in that regard, Haiku needs configuration options for each peripherials.
Personally, I don’t see this as a big problem, as all my modern machines have a Synaptics ClickPad or similar (no buttons, but a ‘diving board’ design). Granted, there are the legacy two-button touchpads on the PCs (Macs have had one button trackpads from the Portable to the MacBook and MacBook Pros before the unibody designs), but honestly, it’s trying to solve a problem from the past. So, I think it shouldn’t really be a big priority to fix the ‘button problem’ as it’s something that’ll fade out into history. Mice and physical touchpads with buttons can still do the 2-1 switch. But it probably should have a “switch buttons” control like the Keymap preferences has for the Windows switchers (Ctrl over Alt).
I learned mousing right handed, because that is the societal norm and I’m right handed. Over the years, I too found this to be cumbersome and not ergonomic. So one day I got the bright idea to switch my mouse to the left side of the the keyboard. I never thought to remap the mouse buttons for left handed use. I instead remapped my left hand muscle memory to use standard right handed mouse button layout. I find this handy because I can use any mouse, anywhere as a left handed mouse without changing any settings. I’ve now been ambi-mouse-trous for nearly twenty years.
That said, it would be handy to have an easy button for switching button mapping.
Totally agree with the sentiments about leaving the mouse be. As a left mouser, I also don’t re-map my mouse. I used to, but when I realized that every other mouse out there was set the ‘right way’ it quickly grated. I’d right-click when I meant to left-click, etc. So instead of getting them confused, I quickly re-mapped my brain instead of the preference to use a standard mouse. Now, no matter what computer I’m on, if there isn’t a trackpad or trackball available, my index finger does the right clicking.
It’s relaxing, and I found that I can pick up a mouse on either side. Personally, I think the ‘left-handed’ mouse option in Windows (which is the only place I’ve seen that checkbox) does more harm than good, as it adapts to one mouse, not all mice.
Left versus right is not a problem. When using a mouse on my computer, I use it left-handed with the buttons remapped. When I go to use someone else’s computer with a right-handed mouse, I use my right hand. The correct buttons are used instinctively — that is why I originally remapped the mouse buttons for left-handed use as attempting to use it left-handed without remapping meant I spent all my time thinking about which finger to use.
For what it is worth, even though I am naturally right-handed, I have spent time doing things left-handed (including writing) and have discovered how biased the world is against left-handed people. Since it is possible to remap the buttons (and this appears to be a side-effect of being able to handle multi-button mice) it seems to me to be appropriate to be able to remap easily. Once I learnt the trick of clicking on the buttons on the image of the mouse in the preferences, it became trivial. The only issue is a UX one — this method may not be intuitively obvious to the first time user (I certainly did not figure it out).
By the way a, hopefully trivial, fix would be to insert a small phrase/sentence above or below the image of the mouse that says something like, “Click a button on the image to remap it”. There’s nothing wrong with the implementation — it is actually rather “cool”
By the way, it is not just Windows that makes switching the mouse buttons easy, it is also trivially done under Linux (I use Linux Mint as my main OS/desktop environment).
I use a computer at work. I don’t use the same computer every day. I do move the mouse to the left side for the ergonomics. Since I learned left handed mousing using right-handed mapping, this presents no problems for me. This of course is a personal preference. I’m just stating it as a use case that has worked for me for decades. My left hand doesn’t know that the pointer finger is supposed to push the primary mouse button. That’s the left ring finger’s job for me. The reverse is true for right hand. My right pointer finger is mapped for primary mouse button usage. But then again, all this fancy one-click remapping was unknown to me when I became ambi-mouse-trous.
The Mac, much as I love it, doesn’t have a left facing pointer either. But it’s more obvious with the gloved hand. 
