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textual/docs/styles/visibility.md
Rodrigo Girão Serrão 559f976f78 Add more consistent phrasing.
Related issues: #2107
2023-03-23 11:04:17 +00:00

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# Visibility
The `visibility` style determines whether a widget is visible or not.
## Syntax
--8<-- "docs/snippets/syntax_block_start.md"
visibility: hidden | visible;
--8<-- "docs/snippets/syntax_block_end.md"
`visibility` takes one of two values to set the visibility of a widget.
### Values
| Value | Description |
|---------------------|-----------------------------------------|
| `hidden` | The widget will be invisible. |
| `visible` (default) | The widget will be displayed as normal. |
### Visibility inheritance
!!! note
Children of an invisible container _can_ be visible.
By default, children inherit the visibility of their parents.
So, if a container is set to be invisible, its children widgets will also be invisible by default.
However, those widgets can be made visible if their visibility is explicitly set to `visibility: visible`.
This is shown in the second example below.
## Examples
### Basic usage
Note that the second widget is hidden while leaving a space where it would have been rendered.
=== "Output"
```{.textual path="docs/examples/styles/visibility.py"}
```
=== "visibility.py"
```python
--8<-- "docs/examples/styles/visibility.py"
```
=== "visibility.css"
```sass hl_lines="14"
--8<-- "docs/examples/styles/visibility.css"
```
### Overriding container visibility
The next example shows the interaction of the `visibility` style with invisible containers that have visible children.
The app below has three rows with a `Horizontal` container per row and three placeholders per row.
The containers all have a white background, and then:
- the top container is visible by default (we can see the white background around the placeholders);
- the middle container is invisible and the children placeholders inherited that setting;
- the bottom container is invisible _but_ the children placeholders are visible because they were set to be visible.
=== "Output"
```{.textual path="docs/examples/styles/visibility_containers.py"}
```
=== "visibility_containers.py"
```python
--8<-- "docs/examples/styles/visibility_containers.py"
```
=== "visibility_containers.css"
```sass hl_lines="2-3 6 8-10 12-14 16-18"
--8<-- "docs/examples/styles/visibility_containers.css"
```
1. The padding and the white background let us know when the `Horizontal` is visible.
2. The top `Horizontal` is visible by default, and so are its children.
3. The middle `Horizontal` is made invisible and its children will inherit that setting.
4. The bottom `Horizontal` is made invisible...
5. ... but its children override that setting and become visible.
## CSS
```sass
/* Widget is invisible */
visibility: hidden;
/* Widget is visible */
visibility: visible;
```
## Python
```python
# Widget is invisible
self.styles.visibility = "hidden"
# Widget is visible
self.styles.visibility = "visible"
```
There is also a shortcut to set a Widget's visibility. The `visible` property on `Widget` may be set to `True` or `False`.
```python
# Make a widget invisible
widget.visible = False
# Make the widget visible again
widget.visible = True
```
## See also
- [`display`](./display.md) to specify whether a widget is displayed or not.