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|
# Built-in Elements
## Overview
go-tui provides HTML-like elements (`<div>`, `<span>`, `<p>`, `<ul>`, `<li>`, `<button>`, `<input>`, `<table>`, `<progress>`, `<hr>`, `<br>`) that compile to `tui.New()` calls with appropriate defaults. Here's what each one does and when to use it.
## Container Elements
`<div>` is the primary layout container. It renders as a flexbox container with `Row` direction by default. Use Tailwind classes or attributes to configure direction, alignment, gaps, and sizing:
```gsx
// Horizontal layout (default)
<div class="flex gap-2">
<span>Left</span>
<span>Right</span>
</div>
// Vertical layout
<div class="flex-col gap-1 p-1 border-rounded">
<span>Top</span>
<span>Bottom</span>
</div>
// Nested layout
<div class="flex gap-1">
<div class="flex-col border-single p-1" width={20}>
<span>Sidebar</span>
</div>
<div class="flex-col grow border-single p-1">
<span>Content</span>
</div>
</div>
```
Every visible element in go-tui is ultimately a `<div>` with different default options applied.
## Text Elements
### span
`<span>` displays inline text. Use it for styled text content within a layout:
```gsx
<span>Plain text</span>
<span class="text-cyan font-bold">Styled text</span>
<span class="text-[#ff6600]">Hex-colored text</span>
```
### p
`<p>` renders paragraph text that wraps automatically when it exceeds the available width:
```gsx
<p>{"This paragraph text wraps automatically when the content exceeds the available width. Use <p> for longer text blocks."}</p>
```
Use `<span>` for short inline labels and `<p>` for longer text that should word-wrap.
## Separator Elements
### hr
`<hr>` draws a horizontal rule across the container width. It's self-closing:
```gsx
<div class="flex-col gap-1">
<span>Above the line</span>
<hr />
<span>Below the line</span>
</div>
```
### br
`<br>` inserts a blank line break. Also self-closing:
```gsx
<div class="flex-col">
<span>Line one</span>
<br />
<span>Line three (with a blank line above)</span>
</div>
```
## List Elements
`<ul>` creates a list container and `<li>` renders list items with bullet markers. Nest them together for bulleted lists:
```gsx
<ul class="flex-col p-1">
<li><span>First item</span></li>
<li><span>Second item</span></li>
<li><span class="text-cyan">Third (styled)</span></li>
</ul>
```
Each `<li>` automatically prepends a bullet character. Put any content inside the `<li>`, typically a `<span>` with text, but it can contain other elements too.
## Table Element
`<table>` acts as a flex container for tabular data. Build tables by composing `<div>` rows with fixed-width columns and an `<hr>` separator between the header and body:
```gsx
<table class="flex-col p-1">
// Header row
<div class="flex gap-2">
<span class="w-10 font-bold">Name</span>
<span class="w-10 font-bold">Role</span>
<span class="w-5 font-bold">Lvl</span>
</div>
<hr />
// Data rows
<div class="flex gap-2">
<span class="w-10 text-cyan">Alice</span>
<span class="w-10">Engineer</span>
<span class="w-5 text-green">Sr</span>
</div>
<div class="flex gap-2">
<span class="w-10 text-cyan">Bob</span>
<span class="w-10">Designer</span>
<span class="w-5 text-yellow">Jr</span>
</div>
</table>
```
The fixed widths on each column (`w-10`, `w-5`) keep columns aligned across rows. Use `gap-2` on the row `<div>` for spacing between columns.
## Button Element
`<button>` renders a clickable button. Combine it with refs for mouse handling (see the [Refs and Clicks guide](refs-and-clicks)):
```gsx
<div class="flex gap-2">
<button>{"Save"}</button>
<button class="font-bold">{"Submit"}</button>
<button disabled={true}>{"Disabled"}</button>
</div>
```
The `disabled` attribute visually dims the button. Wire up click handling through the `MouseListener` interface with `HandleClicks` and a `Ref` bound to the button.
## Input Element
`<input>` is a single-line text input with cursor management and placeholder support. It is self-closing and focus-aware.
Bind `value` to a `*State[string]` for two-way binding. Typing updates the state, and changing the state updates the display:
```gsx
<input value={s.name} placeholder="Type your name..." width={30} border={tui.BorderRounded} />
```
You can also set `focusColor` to change the border color when focused, or use `focusGradient` and `borderGradient` for gradient borders:
```gsx
<input
value={s.name}
placeholder="Type here..."
width={30}
border={tui.BorderRounded}
focusColor={tui.Magenta}
/>
// Gradient border that shifts color when focused
<input
value={s.query}
placeholder="Search..."
border={tui.BorderRounded}
borderGradient={tui.NewGradient(tui.Blue, tui.Cyan)}
focusGradient={tui.NewGradient(tui.Cyan, tui.Magenta)}
/>
```
Wire up `onSubmit` for Enter key handling and `onChange` to react to each keystroke.
## TextArea Element
`<textarea>` is a multi-line text input with word wrapping and cursor navigation. Like `<input>`, it is self-closing and focus-aware.
Bind `value` to a `*State[string]` for two-way binding. Set `maxHeight` to cap the visible rows, and use `submitKey` to control how Enter behaves:
```gsx
<textarea
value={s.note}
placeholder="Write a note..."
width={40}
maxHeight={6}
border={tui.BorderRounded}
onSubmit={s.onSave}
focusColor={tui.BrightRed}
/>
```
By default, Enter triggers `onSubmit` and Ctrl+J inserts a newline. Set `submitKey` to a different key (like `tui.KeyCtrlS`) to make Enter insert newlines instead.
The same border styling options from Input apply here: `focusColor`, `borderGradient`, and `focusGradient`.
## Progress Bars
There's no built-in progress element yet, but a helper function does the job:
```go
func progressBar(value, width int) string {
filled := value * width / 100
bar := ""
for i := 0; i < width; i++ {
if i < filled {
bar += "█"
} else {
bar += "░"
}
}
return bar
}
```
Then use it in your template with styling:
```gsx
<div class="flex gap-2 items-center">
<span class="font-dim w-10">Download:</span>
<span class="text-cyan">{progressBar(e.progress.Get(), 25)}</span>
<span class="text-cyan font-bold">{fmt.Sprintf("%d%%", e.progress.Get())}</span>
</div>
```
Color the bar with `text-cyan`, `text-green`, `text-yellow`, etc. to convey meaning (progress, success, warning).
## Modal Dialogs
The `<modal>` element renders as a full-screen overlay. When open, it dims the background and closes on Escape and backdrop clicks by default. With `trapFocus` enabled (the default), it also traps Tab navigation and blocks unhandled keys from parents. Set `trapFocus={false}` to let keys pass through, or provide a `keyMap` for custom hotkeys.
Bind the `open` attribute to a `*State[bool]` to control visibility. Use `onActivate` on buttons to handle Enter key activation:
```gsx
<modal open={s.showDialog} class="justify-center items-center">
<div class="border-rounded p-2 flex-col gap-1 w-40">
<span class="font-bold text-yellow">Are you sure?</span>
<button class="px-2 border-rounded focusable text-green font-bold" onActivate={s.cancel}>Cancel</button>
<button class="px-2 border-rounded focusable text-red font-bold" onActivate={s.confirm}>Confirm</button>
</div>
</modal>
```
The modal container uses flexbox layout, so `justify-center items-center` centers the dialog, while `justify-end items-stretch` pins it as a bottom sheet. Tab and Shift+Tab cycle between focusable children. Enter triggers the focused element's `onActivate` callback. Mouse clicks on elements with `onActivate` also trigger it.
Key attributes:
| Attribute | Default | Description |
|-----------|---------|-------------|
| `open` | (required) | `*State[bool]` controlling visibility |
| `backdrop` | `"dim"` | `"dim"`, `"blank"`, or `"none"` |
| `closeOnEscape` | `true` | Escape key closes the modal |
| `closeOnBackdropClick` | `true` | Clicking outside the dialog closes it |
| `trapFocus` | `true` | Restrict Tab navigation and block unhandled keys from parents |
| `keyMap` | — | Custom `KeyMap` bindings for modal hotkeys |
Focusable elements with borders get an automatic cyan highlight when focused. The first focusable child receives focus when the modal opens.
## Complete Example
This elements gallery demonstrates every built-in element type in a scrollable layout, including Input and TextArea with two-way value binding:
```gsx
package main
import (
"fmt"
tui "github.com/grindlemire/go-tui"
)
type elementsApp struct {
progress *tui.State[int]
scrollY *tui.State[int]
content *tui.Ref
name *tui.State[string]
note *tui.State[string]
selectedBtn *tui.State[string]
btnRefs *tui.RefMap[string]
}
func Elements() *elementsApp {
return &elementsApp{
progress: tui.NewState(62),
scrollY: tui.NewState(0),
content: tui.NewRef(),
name: tui.NewState(""),
note: tui.NewState(""),
selectedBtn: tui.NewState(""),
btnRefs: tui.NewRefMap[string](),
}
}
func (e *elementsApp) onNoteSubmit(text string) {
e.note.Set(text)
}
func greeting(name string) string {
if name == "" {
return "Hello, World!"
}
return fmt.Sprintf("Hello, %s!", name)
}
func (e *elementsApp) scrollBy(delta int) {
el := e.content.El()
if el == nil {
return
}
_, maxY := el.MaxScroll()
newY := e.scrollY.Get() + delta
if newY < 0 {
newY = 0
} else if newY > maxY {
newY = maxY
}
e.scrollY.Set(newY)
}
func (e *elementsApp) KeyMap() tui.KeyMap {
return tui.KeyMap{
tui.On(tui.KeyEscape, func(ke tui.KeyEvent) { ke.App().Stop() }),
tui.On(tui.Rune('q'), func(ke tui.KeyEvent) { ke.App().Stop() }),
tui.On(tui.KeyTab, func(ke tui.KeyEvent) { ke.App().FocusNext() }),
tui.On(tui.KeyTab.Shift(), func(ke tui.KeyEvent) { ke.App().FocusPrev() }),
tui.On(tui.Rune('+'), func(ke tui.KeyEvent) {
v := e.progress.Get() + 5
if v > 100 {
v = 100
}
e.progress.Set(v)
}),
tui.On(tui.Rune('-'), func(ke tui.KeyEvent) {
v := e.progress.Get() - 5
if v < 0 {
v = 0
}
e.progress.Set(v)
}),
tui.On(tui.Rune('j'), func(ke tui.KeyEvent) { e.scrollBy(1) }),
tui.On(tui.Rune('k'), func(ke tui.KeyEvent) { e.scrollBy(-1) }),
tui.On(tui.KeyDown, func(ke tui.KeyEvent) { e.scrollBy(1) }),
tui.On(tui.KeyUp, func(ke tui.KeyEvent) { e.scrollBy(-1) }),
}
}
func (e *elementsApp) HandleMouse(me tui.MouseEvent) bool {
switch me.Button {
case tui.MouseWheelUp:
e.scrollBy(-1)
return true
case tui.MouseWheelDown:
e.scrollBy(1)
return true
}
if me.Button == tui.MouseLeft && me.Action == tui.MousePress {
for name, el := range e.btnRefs.All() {
if el != nil && el.ContainsPoint(me.X, me.Y) {
if name != "Disabled" {
e.selectedBtn.Set(name)
}
return true
}
}
}
return false
}
var buttonLabels = []string{"Save", "Cancel", "Submit", "Disabled"}
func progressBar(value, width int) string {
filled := value * width / 100
bar := ""
for i := 0; i < width; i++ {
if i < filled {
bar += "█"
} else {
bar += "░"
}
}
return bar
}
templ (e *elementsApp) Render() {
<div
ref={e.content}
class="flex-col gap-1 h-full"
scrollable={tui.ScrollVertical}
scrollOffset={0, e.scrollY.Get()}
>
<span class="text-gradient-cyan-magenta font-bold">Built-in Elements</span>
// Text Elements
<div class="flex-col border-rounded p-1 gap-1">
<span class="text-gradient-cyan-magenta font-bold">Text Elements</span>
<p>{"Paragraph text (<p>) wraps automatically when the content exceeds the available width. This demonstrates how longer text content is displayed."}</p>
<hr />
<span class="text-cyan">{"This is a <span> element for inline styled text"}</span>
<br />
<span class="font-dim">{"<hr> above draws a line, <br> inserts a blank line"}</span>
</div>
// Lists and Table side by side
<div class="flex gap-1">
<div class="flex-col border-rounded p-1 gap-1">
<span class="text-gradient-cyan-magenta font-bold">{"Lists (<ul> / <li>)"}</span>
<ul class="flex-col p-1">
<li><span>First item</span></li>
<li><span>Second item</span></li>
<li><span>Third item</span></li>
<li><span class="text-cyan">Fourth (styled)</span></li>
</ul>
</div>
<div class="flex-col border-rounded p-1 gap-1">
<span class="text-gradient-cyan-magenta font-bold">Table</span>
<table class="p-1">
<tr>
<th>Name</th>
<th>Role</th>
<th>Lvl</th>
</tr>
<hr />
<tr>
<td class="text-cyan">Alice</td>
<td>Engineer</td>
<td class="text-green">Sr</td>
</tr>
<tr>
<td class="text-cyan">Bob</td>
<td>Designer</td>
<td class="text-yellow">Jr</td>
</tr>
</table>
</div>
</div>
// Buttons
<div class="flex-col border-rounded p-1 gap-1">
<span class="text-gradient-cyan-magenta font-bold">Buttons</span>
<div class="flex gap-2">
for _, label := range buttonLabels {
if label == "Disabled" {
<button ref={e.btnRefs} key={label} class="font-dim" disabled={true}>{label}</button>
} else {
if label == e.selectedBtn.Get() {
<button ref={e.btnRefs} key={label} class="font-bold text-cyan">{label}</button>
} else {
<button ref={e.btnRefs} key={label}>{label}</button>
}
}
}
</div>
</div>
// Input & TextArea
<div class="flex-col border-rounded p-1 gap-1">
<span class="text-gradient-cyan-magenta font-bold">Input & TextArea</span>
<div class="flex gap-2">
<div class="flex-col gap-1 w-1/2">
<div class="flex gap-2 items-center">
<span class="font-dim">Name:</span>
<input
placeholder="Type your name..."
value={e.name}
width={30}
border={tui.BorderRounded}
focusGradient={tui.NewGradient(tui.Cyan, tui.Magenta)}
/>
</div>
<span class="text-cyan font-bold" width={30}>
{greeting(e.name.Get())}
</span>
</div>
<div class="flex-col gap-1 w-1/2">
<div class="flex gap-2 items-center">
<span class="font-dim">Note:</span>
<textarea
placeholder="Write a note..."
width={30}
maxHeight={4}
border={tui.BorderRounded}
onSubmit={e.onNoteSubmit}
focusColor={tui.BrightRed}
/>
</div>
if e.note.Get() != "" {
<span class="text-cyan font-bold">{fmt.Sprintf("Saved: %s", e.note.Get())}</span>
}
</div>
</div>
<span class="font-dim">Tab to cycle focus | Esc to blur | Enter submits note</span>
</div>
// Progress bars
<div class="flex-col border-rounded p-1 gap-1">
<span class="text-gradient-cyan-magenta font-bold">Progress Bars</span>
<div class="flex gap-2 items-center">
<span class="font-dim w-10">Download:</span>
<span class="text-cyan">{progressBar(e.progress.Get(), 25)}</span>
<span class="text-cyan font-bold">{fmt.Sprintf("%d%%", e.progress.Get())}</span>
</div>
<div class="flex gap-2 items-center">
<span class="font-dim w-10">Upload:</span>
<span class="text-green">{progressBar(100, 25)}</span>
<span class="text-green font-bold">{"100%"}</span>
</div>
<div class="flex gap-2 items-center">
<span class="font-dim w-10">Build:</span>
<span class="text-yellow">{progressBar(35, 25)}</span>
<span class="text-yellow font-bold">{"35%"}</span>
</div>
</div>
<span class="font-dim">tab focus input | +/- progress | j/k scroll | q quit</span>
</div>
}
```
With `main.go`:
```go
package main
import (
"fmt"
"os"
tui "github.com/grindlemire/go-tui"
)
func main() {
app, err := tui.NewApp(
tui.WithRootComponent(Elements()),
)
if err != nil {
fmt.Fprintf(os.Stderr, "Failed to create app: %v\n", err)
os.Exit(1)
}
defer app.Close()
if err := app.Run(); err != nil {
fmt.Fprintf(os.Stderr, "App error: %v\n", err)
os.Exit(1)
}
}
```
Generate and run:
```bash
tui generate ./...
go run .
```
Scroll through the gallery with j/k or arrow keys:
## Next Steps
- [Streaming Data](streaming) - Build a live data viewer with channels and auto-scroll
- [Refs and Click Handling](refs-and-clicks) - Mouse hit-testing with element references
|