Text Selection Specification

Is there a good, full-detail description/definition/specification anywhere (preferably online, but I’d buy a print book if necessary) of how text selection works under RISC OS using the left mouse button for cursor positioning and selection and the right button for adjustment? Perhaps there is a document like a user interface implementation guide that would describe the exact mechanics?

I want to re-create the interface on Mac OS X, but I want to make sure that my implementation functions exactly the same as selection does on RISC OS. Unfortunately, though, I haven’t found much in the way of description at all, let alone a real specification.

If nothing exists, I will try to draft a specification and submit it to the community here for critique to make sure I’m not missing anything. Thanks very much. 𝔹

Text Selection is determined by the particular Editor in use. Acorn did a Style Guide. We sell it here
Though I expect it is also available somewhere for free download.
It might be included in that!

Text Selection is determined by the particular Editor in use. Acorn did a Style Guide.

It is in the RPi RISC OS distribution:
SDFS::RISCOSpi.$.Documents.Books.PRMs.STYLE/PDF

“Section 11, Handling selection” would seem to be the relevant part – page 81.

The following is from the Zap manual (1.35 updated for version 1.40 features), which describes an ADJUST mouse button that works slightly differently from that of Edit, SrcEdit and StrongEd — namely, in Zap, ADJUST will move the cursor as the selected region is adjusted, unless the user holds down CTRL when making the adjustment. In Edit, SrcEdit and StrongEd, only SELECT may move the cursor, and modifications to the selected region made using ADJUST leave the cursor position as-is (i.e., the default and the “CTRL”-modified actions are swapped between StrongEd and Zap). I prefer the Edit/SrcEdit/StrongEd method, which to me seems cleaner — SELECT sets/changes the cursor location while ADJUST sets/changes the selected region, and does not have what seems like an inconsistent side-effect on the cursor location (similar to how scrolling in EMACS should not affect the cursor location, although for some reason it does). I assume that the Edit/SrcEdit/StrongEd method is the “official” one that comports better with RISC OS applications in general? Does the community have a strong preference for one method versus the other? Thanks very much.

—

Click SELECT: Place cursor at the clicked position.
Click MENU : Bring up the window menu.
Click ADJUST: 1. If the window contains a selection then it is resized.
2. If the window contains a cursor then a selection is
formed between the cursor and the click position.
3. The cursor is moved to the last used position (the hollow
square if neither of the above apply).

Drag SELECT: Selects a new region.
Drag ADJUST: Resizes the current region.
(in either case holding down CTRL leaves the cursor unmoved).

…

If there is no region selected then DRAG SELECT will mark a new region, and
ADJUST CLICK/DRAG will select between the clicked point and the cursor. If
there is already a region selected then DRAG SELECT will start selecting a
new region, ADJUST CLICK/DRAG will alter the old region. In either case, hold
down the CTRL key to leave the cursor unaffected by the selection.