flow-website/content/docs/architecture/palette.smd
2025-10-31 21:41:48 +01:00

118 lines
No EOL
3.7 KiB
Text

---
.title = "Palettes",
.date = @date("2025-10-20T00:00:00"),
.author = "Igor Támara",
.layout = "tutorial.shtml",
.draft = false,
.custom = {
.githubedit = "docs/architecture/palette.smd",
.codepath ="src/tui/mode/overlay/clipboard_palette.zig",
},
---
Palettes are overlay menus that allow to select an item from the
presented list, applying a command with the selected element, optionally
deleting the selected item; it's possible to close the palette without
selecting anything(a.k.a. cancel), filter the elements, and having
special elements that trigger different actions.
Examples of palettes are command_palette, clipboard_palette, they all
are based on palette.zig that does all the heavy lifting and sets the
framework to create new palettes as simple as possible.
Palettes are an special case of minimode and for instance a mode, they
receive inputs from keyboards and execute the beforehand mentioned
actions in response.
To get the most of this section, it's recommended to have read about
[commands](/docs/architecture/command), and optionally
[minimodes](/docs/architecture/minimode).
[]($section.id("anatomy"))
## Defining the palette
Palettes are under `tui/overlay` and use the facilities offered by
`palette.zig` to perform all the operations.
1. Defining the list of elements
2. Filtering the elements
3. Perform an action with the selected element
Note: Palettes are meant to show options and allowing to select the
options to execute an action on the given selection. To maintain as
readable as possible the code and thus extensible, the data to be used
should be prepared previously.
[]($section.id("basic"))
### Fields
Basic fields that give hints to the user and need to be set are:
```zig
pub const label = "Clipboard history";
pub const name = " clipboard";
pub const description = "clipboard";
pub const icon = " ";
```
[]($section.id("entries"))
### Defining the list of elements in the palette
`load_entries` is in charge of populating the visible entries, each one
with an index.
```zig
pub fn load_entries(palette: *Type) !usize
```
The index will identify the action to be taken.
When populating with each entry, there must be a relation that links the
option chosen with the required action, and this happens in
`add_menu_entry` used when the user writes in the input to filter out
options.
```zig
pub fn add_menu_entry(palette: *Type, entry: *Entry, matches: ?[]const usize) !void {
```
The common line that will be used when registering the event to a
selected item is
```zig
try palette.menu.add_item_with_handler(value.written(), select);
```
[]($section.id("select"))
### Acting on selection
When the selection happens, it is time to invoke the command with the
selection and the palette needs to be closed. Those actions will be
handled inside `select`, whose signature is:
```zig
fn select(menu: **Type.MenuType, button: *Type.ButtonType, pos: Type.Pos) void {
```
Other common operations in the palettes can be inspected looking at the
source code of the palettes, all of them import `palette.zig`. Once the
are ready, it's time to make the palette available as a command.
[]($section.id("register"))
## Registering the palette
Commands that open the palette are defined in `tui.zig` in a similar way
it is done with [minimodes](/docs/architecture/minimode). We have got
you covered if in doubt about
[how to create a command](/docs/architecture/command).
To view a complete implementation of a palette, take a look at
[clipboard history palette commit](https://github.com/neurocyte/flow/commit/634a18cb5685a3c3fcfc08301306e628d33c3256)
[]($section.id("next"))
## Next steps
* [Minimodes](/docs/architecture/minimode)
* [Editor topics](/docs/architecture/editor)
* [On commands](/docs/architecture/command)
* [Architecture](/docs/architecture)