Unify logic by introducing scrollable::Scrollbar

This commit is contained in:
Héctor Ramón Jiménez 2019-12-03 06:48:29 +01:00
parent 6b25b4df22
commit 31e3b6fbcb
3 changed files with 169 additions and 171 deletions

View File

@ -61,17 +61,13 @@ impl text::Renderer for Null {
}
impl scrollable::Renderer for Null {
fn scrollbar_bounds(_bounds: Rectangle) -> Rectangle {
Default::default()
}
fn scroller_bounds(
fn scrollbar(
&self,
_bounds: Rectangle,
_content_bounds: Rectangle,
_scrollbar_bounds: Rectangle,
_offset: u32,
) -> Rectangle {
Default::default()
) -> Option<scrollable::Scrollbar> {
None
}
fn draw(
@ -81,8 +77,7 @@ impl scrollable::Renderer for Null {
_content_bounds: Rectangle,
_is_mouse_over: bool,
_is_mouse_over_scrollbar: bool,
_scrollbar_bounds: Rectangle,
_scroller_bounds: Rectangle,
_scrollbar: Option<scrollable::Scrollbar>,
_offset: u32,
_content: Self::Output,
) {

View File

@ -102,17 +102,6 @@ impl<'a, Message, Renderer> Scrollable<'a, Message, Renderer> {
}
}
fn scroll_percentage(
bounds: Rectangle,
scroller_bounds: Rectangle,
scroller_grabbed_at: f32,
cursor_position: Point,
) -> f32 {
(cursor_position.y + bounds.y
- scroller_bounds.height * scroller_grabbed_at)
/ (bounds.height - scroller_bounds.height)
}
impl<'a, Message, Renderer> Widget<Message, Renderer>
for Scrollable<'a, Message, Renderer>
where
@ -161,22 +150,6 @@ where
let content = layout.children().next().unwrap();
let content_bounds = content.bounds();
let offset = self.state.offset(bounds, content_bounds);
let scrollbar_bounds = Renderer::scrollbar_bounds(bounds);
let scroller_bounds = Renderer::scroller_bounds(
bounds,
content_bounds,
scrollbar_bounds,
offset,
);
let scrollbar_grab = ScrollbarItem::from_cursor_position(
bounds,
content_bounds,
scrollbar_bounds,
scroller_bounds,
cursor_position,
);
// TODO: Event capture. Nested scrollables should capture scroll events.
if is_mouse_over {
match event {
@ -195,48 +168,27 @@ where
}
}
if self.state.is_scroller_grabbed() || scrollbar_grab.is_some() {
let offset = self.state.offset(bounds, content_bounds);
let scrollbar = renderer.scrollbar(bounds, content_bounds, offset);
let is_mouse_over_scrollbar = scrollbar
.as_ref()
.map(|scrollbar| scrollbar.is_mouse_over(cursor_position))
.unwrap_or(false);
if self.state.is_scroller_grabbed() {
match event {
Event::Mouse(mouse::Event::Input {
button: mouse::Button::Left,
state,
}) => match state {
ButtonState::Pressed => {
let scroller_grabbed_at = match scrollbar_grab.unwrap()
{
ScrollbarItem::Background => 0.5,
ScrollbarItem::Scroller => {
(cursor_position.y - scroller_bounds.y)
/ scroller_bounds.height
}
};
self.state.scroll_to(
scroll_percentage(
bounds,
scroller_bounds,
scroller_grabbed_at,
cursor_position,
),
bounds,
content_bounds,
);
self.state.scroller_grabbed_at =
Some(scroller_grabbed_at);
}
ButtonState::Released => {
self.state.scroller_grabbed_at = None;
}
},
state: ButtonState::Released,
}) => {
self.state.scroller_grabbed_at = None;
}
Event::Mouse(mouse::Event::CursorMoved { .. }) => {
if let Some(scroller_grabbed_at) =
self.state.scroller_grabbed_at
if let (Some(scrollbar), Some(scroller_grabbed_at)) =
(scrollbar, self.state.scroller_grabbed_at)
{
self.state.scroll_to(
scroll_percentage(
bounds,
scroller_bounds,
scrollbar.scroll_percentage(
scroller_grabbed_at,
cursor_position,
),
@ -247,11 +199,35 @@ where
}
_ => {}
}
} else if is_mouse_over_scrollbar {
match event {
Event::Mouse(mouse::Event::Input {
button: mouse::Button::Left,
state: ButtonState::Pressed,
}) => {
if let Some(scrollbar) = scrollbar {
if let Some(scroller_grabbed_at) =
scrollbar.grab_scroller(cursor_position)
{
self.state.scroll_to(
scrollbar.scroll_percentage(
scroller_grabbed_at,
cursor_position,
),
bounds,
content_bounds,
);
self.state.scroller_grabbed_at =
Some(scroller_grabbed_at);
}
}
}
_ => {}
}
}
let cursor_position = if is_mouse_over
&& !(scrollbar_grab.is_some() || self.state.is_scroller_grabbed())
{
let cursor_position = if is_mouse_over && !is_mouse_over_scrollbar {
Point::new(
cursor_position.x,
cursor_position.y
@ -284,23 +260,13 @@ where
let content_layout = layout.children().next().unwrap();
let content_bounds = content_layout.bounds();
let offset = self.state.offset(bounds, content_bounds);
let scrollbar = renderer.scrollbar(bounds, content_bounds, offset);
let is_mouse_over = bounds.contains(cursor_position);
let scrollbar_bounds = Renderer::scrollbar_bounds(bounds);
let scroller_bounds = Renderer::scroller_bounds(
bounds,
content_bounds,
scrollbar_bounds,
offset,
);
let is_mouse_over_scrollbar = ScrollbarItem::from_cursor_position(
bounds,
content_bounds,
scrollbar_bounds,
scroller_bounds,
cursor_position,
)
.is_some();
let is_mouse_over_scrollbar = scrollbar
.as_ref()
.map(|scrollbar| scrollbar.is_mouse_over(cursor_position))
.unwrap_or(false);
let content = {
let cursor_position = if is_mouse_over && !is_mouse_over_scrollbar {
@ -319,8 +285,7 @@ where
content_layout.bounds(),
is_mouse_over,
is_mouse_over_scrollbar,
scrollbar_bounds,
scroller_bounds,
scrollbar,
offset,
content,
)
@ -409,33 +374,60 @@ impl State {
}
}
#[derive(Debug, Clone, Copy)]
enum ScrollbarItem {
Background,
Scroller,
/// The scrollbar of a [`Scrollable`].
///
/// [`Scrollable`]: struct.Scrollable.html
#[derive(Debug)]
pub struct Scrollbar {
/// The bounds of the [`Scrollbar`].
///
/// [`Scrollbar`]: struct.Scrollbar.html
pub bounds: Rectangle,
/// The bounds of the [`Scroller`].
///
/// [`Scroller`]: struct.Scroller.html
pub scroller: Scroller,
}
impl ScrollbarItem {
/// `None` means the cursor is not over any item
fn from_cursor_position(
bounds: Rectangle,
content_bounds: Rectangle,
scrollbar_bounds: Rectangle,
scroller_bounds: Rectangle,
cursor_position: Point,
) -> Option<ScrollbarItem> {
if content_bounds.height > bounds.height
&& scrollbar_bounds.contains(cursor_position)
{
Some(if scroller_bounds.contains(cursor_position) {
ScrollbarItem::Scroller
impl Scrollbar {
fn is_mouse_over(&self, cursor_position: Point) -> bool {
self.bounds.contains(cursor_position)
}
fn grab_scroller(&self, cursor_position: Point) -> Option<f32> {
if self.bounds.contains(cursor_position) {
Some(if self.scroller.bounds.contains(cursor_position) {
(cursor_position.y - self.scroller.bounds.y)
/ self.scroller.bounds.height
} else {
ScrollbarItem::Background
0.5
})
} else {
None
}
}
fn scroll_percentage(
&self,
grabbed_at: f32,
cursor_position: Point,
) -> f32 {
(cursor_position.y + self.bounds.y
- self.scroller.bounds.height * grabbed_at)
/ (self.bounds.height - self.scroller.bounds.height)
}
}
/// The handle of a [`Scrollbar`].
///
/// [`Scrollbar`]: struct.Scrollbar.html
#[derive(Debug, Clone, Copy)]
pub struct Scroller {
/// The bounds of the [`Scroller`].
///
/// [`Scroller`]: struct.Scrollbar.html
pub bounds: Rectangle,
}
/// The renderer of a [`Scrollable`].
@ -446,17 +438,17 @@ impl ScrollbarItem {
/// [`Scrollable`]: struct.Scrollable.html
/// [renderer]: ../../renderer/index.html
pub trait Renderer: crate::Renderer + Sized {
/// Returns the bounds of the scrollbar
fn scrollbar_bounds(bounds: Rectangle) -> Rectangle;
/// Returns the bounds of the scroller
/// "The part that you can drag around with your mouse to scroll"
fn scroller_bounds(
/// Returns the [`Scrollbar`] given the bounds and content bounds of a
/// [`Scrollable`].
///
/// [`Scrollbar`]: struct.Scrollbar.html
/// [`Scrollable`]: struct.Scrollable.html
fn scrollbar(
&self,
bounds: Rectangle,
content_bounds: Rectangle,
scrollbar_bounds: Rectangle,
offset: u32,
) -> Rectangle;
) -> Option<Scrollbar>;
/// Draws the [`Scrollable`].
///
@ -477,8 +469,7 @@ pub trait Renderer: crate::Renderer + Sized {
content_bounds: Rectangle,
is_mouse_over: bool,
is_mouse_over_scrollbar: bool,
scrollbar_bounds: Rectangle,
scroller_bounds: Rectangle,
scrollbar: Option<Scrollbar>,
offset: u32,
content: Self::Output,
) -> Self::Output;

View File

@ -5,30 +5,40 @@ const SCROLLBAR_WIDTH: u16 = 10;
const SCROLLBAR_MARGIN: u16 = 2;
impl scrollable::Renderer for Renderer {
fn scrollbar_bounds(bounds: Rectangle) -> Rectangle {
Rectangle {
x: bounds.x + bounds.width
- f32::from(SCROLLBAR_WIDTH + 2 * SCROLLBAR_MARGIN),
y: bounds.y,
width: f32::from(SCROLLBAR_WIDTH + 2 * SCROLLBAR_MARGIN),
height: bounds.height,
}
}
fn scroller_bounds(
fn scrollbar(
&self,
bounds: Rectangle,
content_bounds: Rectangle,
scrollbar_bounds: Rectangle,
offset: u32,
) -> Rectangle {
let ratio = bounds.height / content_bounds.height;
let scrollbar_height = bounds.height * ratio;
let y_offset = offset as f32 * ratio;
Rectangle {
x: scrollbar_bounds.x + f32::from(SCROLLBAR_MARGIN),
y: scrollbar_bounds.y + y_offset,
width: scrollbar_bounds.width - f32::from(2 * SCROLLBAR_MARGIN),
height: scrollbar_height,
) -> Option<scrollable::Scrollbar> {
if content_bounds.height > bounds.height {
let scrollbar_bounds = Rectangle {
x: bounds.x + bounds.width
- f32::from(SCROLLBAR_WIDTH + 2 * SCROLLBAR_MARGIN),
y: bounds.y,
width: f32::from(SCROLLBAR_WIDTH + 2 * SCROLLBAR_MARGIN),
height: bounds.height,
};
let ratio = bounds.height / content_bounds.height;
let scrollbar_height = bounds.height * ratio;
let y_offset = offset as f32 * ratio;
let scroller_bounds = Rectangle {
x: scrollbar_bounds.x + f32::from(SCROLLBAR_MARGIN),
y: scrollbar_bounds.y + y_offset,
width: scrollbar_bounds.width - f32::from(2 * SCROLLBAR_MARGIN),
height: scrollbar_height,
};
Some(scrollable::Scrollbar {
bounds: scrollbar_bounds,
scroller: scrollable::Scroller {
bounds: scroller_bounds,
},
})
} else {
None
}
}
@ -36,16 +46,13 @@ impl scrollable::Renderer for Renderer {
&mut self,
state: &scrollable::State,
bounds: Rectangle,
content_bounds: Rectangle,
_content_bounds: Rectangle,
is_mouse_over: bool,
is_mouse_over_scrollbar: bool,
scrollbar_bounds: Rectangle,
scroller_bounds: Rectangle,
scrollbar: Option<scrollable::Scrollbar>,
offset: u32,
(content, mouse_cursor): Self::Output,
) -> Self::Output {
let is_content_overflowing = content_bounds.height > bounds.height;
let clip = Primitive::Clip {
bounds,
offset: Vector::new(0, offset),
@ -53,36 +60,41 @@ impl scrollable::Renderer for Renderer {
};
(
if is_content_overflowing
&& (is_mouse_over || state.is_scroller_grabbed())
{
let scrollbar = Primitive::Quad {
bounds: scroller_bounds,
background: Background::Color([0.0, 0.0, 0.0, 0.7].into()),
border_radius: 5,
};
if is_mouse_over_scrollbar || state.is_scroller_grabbed() {
let scrollbar_background = Primitive::Quad {
bounds: Rectangle {
x: scrollbar_bounds.x + f32::from(SCROLLBAR_MARGIN),
width: scrollbar_bounds.width
- f32::from(2 * SCROLLBAR_MARGIN),
..scrollbar_bounds
},
if let Some(scrollbar) = scrollbar {
if is_mouse_over || state.is_scroller_grabbed() {
let scroller = Primitive::Quad {
bounds: scrollbar.scroller.bounds,
background: Background::Color(
[0.0, 0.0, 0.0, 0.3].into(),
[0.0, 0.0, 0.0, 0.7].into(),
),
border_radius: 5,
};
Primitive::Group {
primitives: vec![clip, scrollbar_background, scrollbar],
if is_mouse_over_scrollbar || state.is_scroller_grabbed() {
let scrollbar = Primitive::Quad {
bounds: Rectangle {
x: scrollbar.bounds.x
+ f32::from(SCROLLBAR_MARGIN),
width: scrollbar.bounds.width
- f32::from(2 * SCROLLBAR_MARGIN),
..scrollbar.bounds
},
background: Background::Color(
[0.0, 0.0, 0.0, 0.3].into(),
),
border_radius: 5,
};
Primitive::Group {
primitives: vec![clip, scrollbar, scroller],
}
} else {
Primitive::Group {
primitives: vec![clip, scroller],
}
}
} else {
Primitive::Group {
primitives: vec![clip, scrollbar],
}
clip
}
} else {
clip