view: Implement set-position and set-geometry

[ThreeFx]

The command set-position x y sets the current view's coordinates to be (x, y) relative to the current output. The view will always remain within the bounds of the current output. Any parts of the view that end up outside of the current output are silently truncated.

The command set-geometry w h sets the geometry of a view to be w wide and h high. Any parts of the view that end up outside of the current output's bounding box are silently truncated.

View truncation is applied as shown below:

+-------------+              +-------------+
|   output    |              |   output    |
|      +------+--+  ------>  |      +------+
|      | view |  |           |      | view |
+------+------+  |           +------+------+
       +---------+

---

In addition to the above commands, this refactors the move and resize functions to use the setPosition and setGeometry commands. This way there is only one true way of setting position and geometry of windows.

[ThreeFx]

This closes #368 btw :)

[ThreeFx]

It's nice for positioning some windows as part of a larger setup (e.g. a terminal running find <zig files> | entr zig build). Other than that: The issue told me to do it :P

[ifreund]

It's nice for positioning some windows as part of a larger setup (e.g. a terminal running find <zig files> | entr zig build).

hmm, could you elaborate a bit more on this? From a code standpoint this PR seems solid, I'm just not yet convinced that this feature is widely useful due to the restriction to always targeting the focused view.

[ThreeFx]

hmm, could you elaborate a bit more on this?

During my Master's thesis, I used something like this to set up my initial workspace(s) every morning:

riverctl spawn "alacritty --with --some --extra --args"
sleep 0.2
riverctl move right 100

riverctl spawn "other stuff"
sleep 0.2
riverctl snap up

Having set-position and set-geometry makes this process a bit nicer.

[ifreund]

Hit a panic when attempting to move a view past the edge of the output in a nested session:

debug(cursor): enter move cursor mode
thread 26410 panic: attempt to cast negative value to unsigned integer
/home/ifreund/projects/river/river/View.zig:559:31: 0x29bd89 in View.setPositionAndGeometry (river)
    self.pending.box.height = @intCast(u32, y_end - y_start);
                              ^
/home/ifreund/projects/river/river/View.zig:504:32: 0x276985 in View.setPosition (river)
    self.setPositionAndGeometry(x, y, self.pending.box.width, self.pending.box.height);
                               ^
/home/ifreund/projects/river/river/View.zig:438:21: 0x24a871 in View.move (river)
    self.setPosition(self.pending.box.x + dx, self.pending.box.y + dy);
                    ^
/home/ifreund/projects/river/river/Cursor.zig:754:22: 0x233757 in Cursor.processMotion (river)
            view.move(@floatToInt(i32, delta_x), @floatToInt(i32, delta_y));
                     ^
/home/ifreund/projects/river/river/Cursor.zig:382:23: 0x232f81 in Cursor.handleMotionAbsolute (river)
    self.processMotion(event.device, event.time_msec, dx, dy, dx, dy);
                      ^
/home/ifreund/projects/river/zig-cache/zig-wayland/wayland_server_core.zig:492:25: 0x230a40 in .wayland.wayland_server_core.struct:490:17.wrapper (river)
                        @call(.{ .modifier = .always_inline }, notify, .{ listener, @intToPtr(T, @ptrToInt(data)) });
                        ^
../util/signal.c:29:3: 0x7f9e85123f9b in wlr_signal_emit_safe (../util/signal.c)
../types/wlr_cursor.c:430:2: 0x7f9e850f9396 in handle_pointer_motion_absolute (../types/wlr_cursor.c)
../util/signal.c:29:3: 0x7f9e85123f9b in wlr_signal_emit_safe (../util/signal.c)
../backend/wayland/seat.c:104:2: 0x7f9e850d9ac2 in pointer_handle_motion (../backend/wayland/seat.c)
???:?:?: 0x7f9e84ce9e6c in ??? (???)
Panicked during a panic. Aborting.

[ifreund]

I've come around on having this feature in river. It's not really that complex and lets us unify some code paths. We should also be able to get rid of the separate resize handling in Cursor.processMotion() eventually though that could be done in a follow up PR.

[Danacus]

To add to what @ThreeFx already said, this feature could be useful for floating terminals. For example I use a floating terminal with an mpc client that can toggled with a key binding.

scratch_tag=$((1 << 20 ))
mpc_tag=$((1 << 21 ))

riverctl map normal Mod4 W toggle-focused-tags ${scratch_tag}
riverctl map normal Mod4+Shift M toggle-focused-tags ${mpc_tag}

riverctl set-focused-tags ${scratch_tag}

riverctl spawn "alacritty"
sleep 0.1
riverctl toggle-float
riverctl resize horizontal 200
riverctl resize vertical 200

riverctl set-focused-tags ${mpc_tag}

riverctl spawn "alacritty -e mpc-rs"
sleep 0.1
riverctl toggle-float
riverctl resize horizontal -100
riverctl resize vertical -200
riverctl snap down

riverctl set-focused-tags 1

set-position and set-geometry would give more control compared to snap and resize.

[justinesmithies]

I've come around on having this feature in river. It's not really that complex and lets us unify some code paths. We should also be able to get rid of the separate resize handling in Cursor.processMotion() eventually though that could be done in a follow up PR.

Is this feature still planned for River as I'd find it extremely useful ?

[ifreund]

Is this feature still planned for River as I'd find it extremely useful ?

I'm not opposed to it, though I don't have plans to implement it myself. In any case this PR is unfortunately quite out of date now.

I'd recommend anyone interested on working on this to wait until I resolve the issues described in #828 to avoid conflicts and save time for both of us.