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use {
super::{
scroll_bar::ScrollBar, Widget, WidgetAddress, WidgetBaseOf, WidgetExt, WidgetGeometry,
},
crate::{
event::{LayoutEvent, MouseScrollEvent},
impl_widget_base,
layout::{grid::grid_layout, SizeHints},
types::{Axis, PhysicalPixels, PpxSuffix, Rect},
},
anyhow::Result,
std::cmp::max,
widgem_macros::impl_with,
};
pub struct ScrollArea {
base: WidgetBaseOf<Self>,
}
const INDEX_SCROLL_BAR_X: u64 = 0;
const INDEX_SCROLL_BAR_Y: u64 = 1;
const INDEX_VIEWPORT: u64 = 2;
const KEY_CONTENT_IN_VIEWPORT: u64 = 0;
#[impl_with]
impl ScrollArea {
fn has_content(&self) -> bool {
self.base
.get_dyn_child(INDEX_VIEWPORT)
.unwrap()
.base()
.has_child(KEY_CONTENT_IN_VIEWPORT)
}
// TODO: naming?
pub fn set_content<T: Widget>(&mut self) -> &mut T {
assert!(!self.has_content());
self.base
.get_dyn_child_mut(INDEX_VIEWPORT)
.unwrap()
.base_mut()
.add_child_with_key::<T>(KEY_CONTENT_IN_VIEWPORT)
}
// pub fn set_content(&mut self, content: Box<dyn Widget>) {
// if self.has_content() {
// self.common.children[INDEX_VIEWPORT]
// .widget
// .common_mut()
// .remove_child(0)
// .unwrap();
// }
// self.common.children[INDEX_VIEWPORT]
// .widget
// .common_mut()
// .add_child(content, LayoutItemOptions::default());
// }
// TODO: take_content; default impl for empty scroll area
// pub fn on_value_changed(&mut self, callback: Callback<i32>) {
// self.value_changed = Some(callback);
// }
// fn size_hints(&mut self) -> SizeHints {
// let xscroll_x = self.common.children[0].widget.cached_size_hint_x();
// let yscroll_x = self.common.children[1].widget.cached_size_hint_x();
// let content_x = if let Some(child) = self.common.children.get(2) {
// widget.cached_size_hint_x()
// } else {
// SizeHint::new_fallback()
// };
// let xscroll_y = self.common.children[0]
// .widget
// .cached_size_hint_y(xscroll_x.preferred);
// let yscroll_y = self.common.children[1]
// .widget
// .cached_size_hint_y(yscroll_x.preferred);
// let content_y = self.common.children[2]
// .widget
// .cached_size_hint_y(content_x.preferred);
// SizeHints {
// xscroll_x,
// yscroll_x,
// content_x,
// xscroll_y: xscroll_y,
// yscroll_y,
// content_y,
// }
// }
fn relayout(&mut self, changed_size_hints: &[WidgetAddress]) -> Result<()> {
let geometry = self.base.geometry_or_err()?.clone();
grid_layout(self, changed_size_hints);
if self.has_content() {
let value_x = self
.base
.get_child::<ScrollBar>(INDEX_SCROLL_BAR_X)
.unwrap()
.value();
let value_y = self
.base
.get_child::<ScrollBar>(INDEX_SCROLL_BAR_Y)
.unwrap()
.value();
let Some(viewport_rect) = self
.base
.get_dyn_child_mut(INDEX_VIEWPORT)
.unwrap()
.base_mut()
.rect_in_parent()
else {
return Ok(());
};
let content_size_x = self
.base
.get_dyn_child_mut(INDEX_VIEWPORT)
.unwrap()
.base_mut()
.get_dyn_child_mut(KEY_CONTENT_IN_VIEWPORT)
.unwrap()
.size_hint_x()
.preferred;
let content_size_y = self
.base
.get_dyn_child_mut(INDEX_VIEWPORT)
.unwrap()
.base_mut()
.get_dyn_child_mut(KEY_CONTENT_IN_VIEWPORT)
.unwrap()
.size_hint_y(content_size_x)
.preferred;
let content_rect = Rect::from_xywh(
PhysicalPixels::from_i32(-value_x),
PhysicalPixels::from_i32(-value_y),
content_size_x,
content_size_y,
);
self.base
.get_dyn_child_mut(INDEX_VIEWPORT)
.unwrap()
.base_mut()
.get_dyn_child_mut(KEY_CONTENT_IN_VIEWPORT)
.unwrap()
.set_geometry(
Some(WidgetGeometry::new(&geometry, content_rect)),
changed_size_hints,
);
let max_value_x = max(0.ppx(), content_size_x - viewport_rect.size_x());
let max_value_y = max(0.ppx(), content_size_y - viewport_rect.size_y());
self.base
.get_child_mut::<ScrollBar>(INDEX_SCROLL_BAR_X)
.unwrap()
.set_value_range(0..=max_value_x.to_i32());
self.base
.get_child_mut::<ScrollBar>(INDEX_SCROLL_BAR_Y)
.unwrap()
.set_value_range(0..=max_value_y.to_i32());
}
Ok(())
}
}
impl Widget for ScrollArea {
impl_widget_base!();
fn new(mut base: WidgetBaseOf<Self>) -> Self {
let relayout = base.callback(|this, _| this.relayout(&[]));
// TODO: icons, localized name
base.add_child_with_key::<ScrollBar>(INDEX_SCROLL_BAR_X)
.set_column(0)
.set_row(1)
.on_value_changed(relayout.clone());
base.add_child_with_key::<ScrollBar>(INDEX_SCROLL_BAR_Y)
.set_column(1)
.set_row(0)
.set_axis(Axis::Y)
.on_value_changed(relayout);
base.add_child_with_key::<Viewport>(INDEX_VIEWPORT)
.set_column(0)
.set_row(0);
Self { base }
}
fn handle_layout(&mut self, event: LayoutEvent) -> Result<()> {
self.relayout(&event.changed_size_hints)
}
fn handle_mouse_scroll(&mut self, event: MouseScrollEvent) -> Result<bool> {
let delta = event.unified_delta(&self.base);
let scroll_x = self
.base
.get_child_mut::<ScrollBar>(INDEX_SCROLL_BAR_X)
.unwrap();
let new_value_x = scroll_x.value() - delta.x.round() as i32;
scroll_x.set_value(new_value_x.clamp(
*scroll_x.value_range().start(),
*scroll_x.value_range().end(),
));
let scroll_y = self
.base
.get_child_mut::<ScrollBar>(INDEX_SCROLL_BAR_Y)
.unwrap();
let new_value_y = scroll_y.value() - delta.y.round() as i32;
scroll_y.set_value(new_value_y.clamp(
*scroll_y.value_range().start(),
*scroll_y.value_range().end(),
));
Ok(true)
}
}
pub struct Viewport {
base: WidgetBaseOf<Self>,
}
impl Viewport {}
impl Widget for Viewport {
impl_widget_base!();
fn new(base: WidgetBaseOf<Self>) -> Self {
Self { base }
}
fn handle_size_hint_x_request(&mut self) -> Result<SizeHints> {
Ok(SizeHints {
min: 0.ppx(),
preferred: 0.ppx(),
is_fixed: false,
})
}
fn handle_size_hint_y_request(&mut self, _size_x: PhysicalPixels) -> Result<SizeHints> {
Ok(SizeHints {
min: 0.ppx(),
preferred: 0.ppx(),
is_fixed: false,
})
}
}