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use bitflags::bitflags;
use std::borrow::Cow;
use crate::sys;
use crate::Ui;
// TODO: support size constraints
/// Combo box height mode.
#[derive(Copy, Clone, Debug, PartialEq, Eq)]
pub enum ComboBoxHeight {
/// Max ~4 items visible.
Small,
/// Max ~8 items visible.
Regular,
/// Max ~20 items visible.
Large,
/// As many fitting items as possible visible.
Largest,
}
/// Combo box preview mode.
#[derive(Copy, Clone, Debug, PartialEq, Eq)]
pub enum ComboBoxPreviewMode {
/// Show only a box with the preview value
Label,
/// Show only an arrow button
ArrowButton,
/// Show a box with the preview value and an arrow button
Full,
}
bitflags!(
/// Flags for combo boxes
#[repr(transparent)]
pub struct ComboBoxFlags: u32 {
/// Align the popup toward the left by default
const POPUP_ALIGN_LEFT = sys::ImGuiComboFlags_PopupAlignLeft;
/// Max ~4 items visible.
const HEIGHT_SMALL = sys::ImGuiComboFlags_HeightSmall;
/// Max ~8 items visible (default)
const HEIGHT_REGULAR = sys::ImGuiComboFlags_HeightRegular;
/// Max ~20 items visible
const HEIGHT_LARGE = sys::ImGuiComboFlags_HeightLarge;
/// As many fitting items as possible
const HEIGHT_LARGEST = sys::ImGuiComboFlags_HeightLargest;
/// Display on the preview box without the square arrow button
const NO_ARROW_BUTTON = sys::ImGuiComboFlags_NoArrowButton;
/// Display only a square arrow button
const NO_PREVIEW = sys::ImGuiComboFlags_NoPreview;
}
);
/// Builder for a combo box widget
#[derive(Copy, Clone, Debug)]
#[must_use]
pub struct ComboBox<Label, Preview = &'static str> {
label: Label,
preview_value: Option<Preview>,
flags: ComboBoxFlags,
}
impl<Label: AsRef<str>> ComboBox<Label> {
/// Constructs a new combo box builder.
#[doc(alias = "BeginCombo")]
pub fn new(label: Label) -> Self {
ComboBox {
label,
preview_value: None,
flags: ComboBoxFlags::empty(),
}
}
}
impl<T: AsRef<str>, Preview: AsRef<str>> ComboBox<T, Preview> {
pub fn preview_value<Preview2: AsRef<str>>(
self,
preview_value: Preview2,
) -> ComboBox<T, Preview2> {
ComboBox {
label: self.label,
preview_value: Some(preview_value),
flags: self.flags,
}
}
/// Replaces all current settings with the given flags.
pub fn flags(mut self, flags: ComboBoxFlags) -> Self {
self.flags = flags;
self
}
/// Enables/disables aligning the combo box popup toward the left.
///
/// Disabled by default.
pub fn popup_align_left(mut self, popup_align_left: bool) -> Self {
self.flags
.set(ComboBoxFlags::POPUP_ALIGN_LEFT, popup_align_left);
self
}
/// Sets the combo box height.
///
/// Default: `ComboBoxHeight::Regular`
#[inline]
pub fn height(mut self, height: ComboBoxHeight) -> Self {
self.flags
.set(ComboBoxFlags::HEIGHT_SMALL, height == ComboBoxHeight::Small);
self.flags.set(
ComboBoxFlags::HEIGHT_REGULAR,
height == ComboBoxHeight::Regular,
);
self.flags
.set(ComboBoxFlags::HEIGHT_LARGE, height == ComboBoxHeight::Large);
self.flags.set(
ComboBoxFlags::HEIGHT_LARGEST,
height == ComboBoxHeight::Largest,
);
self
}
/// Sets the combo box preview mode.
///
/// Default: `ComboBoxPreviewMode::Full`
#[inline]
pub fn preview_mode(mut self, preview_mode: ComboBoxPreviewMode) -> Self {
self.flags.set(
ComboBoxFlags::NO_ARROW_BUTTON,
preview_mode == ComboBoxPreviewMode::Label,
);
self.flags.set(
ComboBoxFlags::NO_PREVIEW,
preview_mode == ComboBoxPreviewMode::ArrowButton,
);
self
}
/// Creates a combo box and starts appending to it.
///
/// Returns `Some(ComboBoxToken)` if the combo box is open. After content has been
/// rendered, the token must be ended by calling `.end()`.
///
/// Returns `None` if the combo box is not open and no content should be rendered.
#[must_use]
pub fn begin<'ui>(self, ui: &Ui<'ui>) -> Option<ComboBoxToken<'ui>> {
let should_render = unsafe {
if let Some(preview_value) = self.preview_value {
let (ptr_one, ptr_two) = ui.scratch_txt_two(self.label, preview_value);
sys::igBeginCombo(ptr_one, ptr_two, self.flags.bits() as i32)
} else {
let ptr_one = ui.scratch_txt(self.label);
sys::igBeginCombo(ptr_one, std::ptr::null(), self.flags.bits() as i32)
}
};
if should_render {
Some(ComboBoxToken::new(ui))
} else {
None
}
}
/// Creates a combo box and runs a closure to construct the popup contents.
/// Returns the result of the closure, if it is called.
///
/// Note: the closure is not called if the combo box is not open.
pub fn build<R, F: FnOnce() -> R>(self, ui: &Ui<'_>, f: F) -> Option<R> {
self.begin(ui).map(|_combo| f())
}
}
create_token!(
/// Tracks a combo box that can be ended by calling `.end()`
/// or by dropping.
pub struct ComboBoxToken<'ui>;
/// Ends a combo box
drop { sys::igEndCombo() }
);
/// # Convenience functions
impl<'ui> Ui<'ui> {
/// Creates a combo box which can be appended to with `Selectable::new`.
///
/// If you do not want to provide a preview, use [`begin_combo_no_preview`]. If you want
/// to pass flags, use [`begin_combo_with_flags`].
///
/// Returns `None` if the combo box is not open and no content should be rendered.
///
/// [`begin_combo_no_preview`]: Ui::begin_combo_no_preview
/// [`begin_combo_with_flags`]: Ui::begin_combo_with_flags
#[must_use]
#[doc(alias = "BeginCombo")]
pub fn begin_combo(
&self,
label: impl AsRef<str>,
preview_value: impl AsRef<str>,
) -> Option<ComboBoxToken<'ui>> {
self.begin_combo_with_flags(label, preview_value, ComboBoxFlags::empty())
}
/// Creates a combo box which can be appended to with `Selectable::new`.
///
/// If you do not want to provide a preview, use [begin_combo_no_preview].
/// Returns `Some(ComboBoxToken)` if the combo box is open. After content has been
/// rendered, the token must be ended by calling `.end()`.
///
/// Returns `None` if the combo box is not open and no content should be rendered.
///
/// [begin_combo_no_preview]: Ui::begin_combo_no_preview
#[must_use]
#[doc(alias = "BeginCombo")]
pub fn begin_combo_with_flags(
&self,
label: impl AsRef<str>,
preview_value: impl AsRef<str>,
flags: ComboBoxFlags,
) -> Option<ComboBoxToken<'ui>> {
self._begin_combo(label, Some(preview_value), flags)
}
/// Creates a combo box which can be appended to with `Selectable::new`.
///
/// If you want to provide a preview, use [begin_combo]. If you want
/// to pass flags, use [begin_combo_no_preview_with_flags].
///
/// Returns `Some(ComboBoxToken)` if the combo box is open. After content has been
/// rendered, the token must be ended by calling `.end()`.
///
/// Returns `None` if the combo box is not open and no content should be rendered.
///
/// [begin_combo]: Ui::begin_combo
/// [begin_combo_no_preview_with_flags]: Ui::begin_combo_no_preview_with_flags
#[must_use]
#[doc(alias = "BeginCombo")]
pub fn begin_combo_no_preview(&self, label: impl AsRef<str>) -> Option<ComboBoxToken<'ui>> {
self.begin_combo_no_preview_with_flags(label, ComboBoxFlags::empty())
}
/// Creates a combo box which can be appended to with `Selectable::new`.
///
/// If you do not want to provide a preview, use [begin_combo_no_preview].
/// Returns `Some(ComboBoxToken)` if the combo box is open. After content has been
/// rendered, the token must be ended by calling `.end()`.
///
/// Returns `None` if the combo box is not open and no content should be rendered.
///
/// [begin_combo_no_preview]: Ui::begin_combo_no_preview
#[must_use]
#[doc(alias = "BeginCombo")]
pub fn begin_combo_no_preview_with_flags(
&self,
label: impl AsRef<str>,
flags: ComboBoxFlags,
) -> Option<ComboBoxToken<'ui>> {
self._begin_combo(label, Option::<&'static str>::None, flags)
}
/// This is the internal begin combo method that they all...eventually call.
fn _begin_combo(
&self,
label: impl AsRef<str>,
preview_value: Option<impl AsRef<str>>,
flags: ComboBoxFlags,
) -> Option<ComboBoxToken<'ui>> {
let should_render = unsafe {
let (ptr_one, ptr_two) = self.scratch_txt_with_opt(label, preview_value);
sys::igBeginCombo(ptr_one, ptr_two, flags.bits() as i32)
};
if should_render {
Some(ComboBoxToken::new(self))
} else {
None
}
}
/// Builds a simple combo box for choosing from a slice of values
#[doc(alias = "Combo")]
pub fn combo<V, L>(
&self,
label: impl AsRef<str>,
current_item: &mut usize,
items: &[V],
label_fn: L,
) -> bool
where
for<'b> L: Fn(&'b V) -> Cow<'b, str>,
{
use crate::widget::selectable::Selectable;
let label_fn = &label_fn;
let mut result = false;
let preview_value = items.get(*current_item).map(label_fn);
if let Some(_cb) = self._begin_combo(label, preview_value, ComboBoxFlags::empty()) {
for (idx, item) in items.iter().enumerate() {
let text = label_fn(item);
let selected = idx == *current_item;
if Selectable::new(&text).selected(selected).build(self) {
*current_item = idx;
result = true;
}
if selected {
self.set_item_default_focus();
}
}
}
result
}
/// Builds a simple combo box for choosing from a slice of values
#[doc(alias = "Combo")]
pub fn combo_simple_string(
&self,
label: impl AsRef<str>,
current_item: &mut usize,
items: &[impl AsRef<str>],
) -> bool {
self.combo(label, current_item, items, |s| Cow::Borrowed(s.as_ref()))
}
}