dispatcher: add window tag desc (#660)

* dispatcher: add window tag desc

* Window-Rules: add examples for tag

pages/Configuring/Dispatchers.md

@@ -50,6 +50,7 @@ layout pages (See the sidebar).
 | movewindowpixel | moves a selected window | `resizeparams,window` |
 | cyclenext | focuses the next window on a workspace | none (for next) or `prev` (for previous) additionally `tiled` for only tiled, `floating` for only floating. `prev tiled` is ok. |
 | swapnext | swaps the focused window with the next window on a workspace | none (for next) or `prev` (for previous) |
+| tagwindow | apply tag to current or the first window matching | `tag [window]`, e.g. `+code ^(foot)$`, `music` |
 | focuswindow | focuses the first window matching | window |
 | focusmonitor | focuses a monitor | monitor |
 | splitratio | changes the split ratio | floatvalue |

pages/Configuring/Window-Rules.md

@@ -72,6 +72,7 @@ class - class regex
 title - title regex
 initialclass - initialClass regex
 initialTitle - initialTitle regex
+tag - tag name
 xwayland - 0/1
 floating - 0/1
 fullscreen - 0/1
@@ -154,6 +155,7 @@ Dynamic rules are re-evaluated every time a property changes.
 | xray \[on\] | sets blur xray mode for the window (0 for off, 1 for on, unset for default) |
 | immediate | forces the window to allow to be torn. See [the Tearing page](../Tearing). |
 | nearestneighbor | forces the window to use the nearest neigbor filtering. |
+| tag \[name\] | apply tag to the window, use prefix `+`/`-` to set/unset flag, or no prefix to toggle the flag |
 
 {{< callout type=info >}}
 
@@ -181,6 +183,51 @@ qualifier makes them always effective.
 
 {{< /callout >}}
 
+### Tags
+
+Window may have several tags, either static or dynamic, dynamic tag will have a suffix of `*`.
+You may check window tags with `hyprctl clients`.
+
+Use `tagwindow` dispatcher to add a static tag to a window:
+
+```
+hyprctl dispatch tagwindow +code        # add tag to current window
+hyprctl dispatch tagwindow -- -code     # remove tag from current window (use `--` to protect the leading `-`)
+hyprctl dispatch tagwindow code         # toggle the tag of current window
+
+# or you can tag windows matched with a window regex
+hyprctl dispatch tagwindow +music deadbeef
+hyprctl dispatch tagwindow +media title:Celluloid
+```
+
+Use `tag` rule to add a dynamic tag to a window:
+
+```ini
+windowrulev2 = tag +term, class:(footclient)    # add dynamic tag `term*` to window footclient
+windowrulev2 = tag term, class:(footclient)     # toggle dynamic tag `term*` for window footclient
+windowrulev2 = tag +code, tag:cpp               # add dynamic tag `code*` to window with tag `cpp`
+
+windowrulev2 = opacity 0.8, tag:code            # set opacity for window with tag `code` or `code*`
+windowrulev2 = opacity 0.7, tag:cpp             # window with tag `cpp` will match both `code` and `cpp`, the last one will override prior match
+windowrulev2 = opacity 0.6, tag:term*           # set opacity for window with tag `term*` only, `term` will not be matched
+
+windowrulev2 = tag -code, tag:term              # remove dynamic tag `code*` for window with tag `term` or `term*`
+```
+
+Or with keybind for convenience:
+
+```ini
+bind = $mod Ctrl, 2, tagwindow, alpha_0.2
+bind = $mod Ctrl, 4, tagwindow, alpha_0.4
+
+windowrulev2 = opacity 0.2 override, tag:alpha_0.2
+windowrulev2 = opacity 0.4 override, tag:alpha_0.4
+```
+
+The `tag` rule can only manipulate dynamic tags, and the `tagwindow` dispatcher only work with static tags
+(as once the dispatcher is called, dynamic tags will be cleared).
+
+
 ### Example Rules
 
 ```ini