egui/emigui/src/containers/resize.rs
Emil Ernerfeldt b73fbb33d8 Improve size negotiation code.
Better enfocred minimum sizes.
You can now have windows that expand to fit their content.
2020-05-01 02:08:01 +02:00

246 lines
8.1 KiB
Rust

#![allow(unused_variables)] // TODO
use crate::*;
#[derive(Clone, Copy, Debug)]
pub struct State {
pub size: Vec2,
}
// TODO: auto-shink/grow should be part of another container!
#[derive(Clone, Copy, Debug)]
pub struct Resize {
/// If false, we are no enabled
resizable: bool,
// Will still try to stay within parent region bounds
min_size: Vec2,
max_size: Vec2,
default_size: Vec2,
// If true, won't allow you to make window so big that it creates spacing
auto_shrink_width: bool,
auto_shrink_height: bool,
// If true, won't allow you to resize smaller than that everything fits.
expand_width_to_fit_content: bool,
expand_height_to_fit_content: bool,
handle_offset: Vec2,
}
impl Default for Resize {
fn default() -> Self {
Self {
resizable: true,
min_size: Vec2::splat(32.0),
max_size: Vec2::infinity(),
default_size: vec2(f32::INFINITY, 200.0), // TODO
auto_shrink_width: false,
auto_shrink_height: false,
expand_width_to_fit_content: true,
expand_height_to_fit_content: true,
handle_offset: Default::default(),
}
}
}
impl Resize {
pub fn default_height(mut self, height: f32) -> Self {
self.default_size.y = height;
self
}
pub fn default_size(mut self, default_size: Vec2) -> Self {
self.default_size = default_size;
self
}
pub fn min_size(mut self, min_size: Vec2) -> Self {
self.min_size = min_size;
self
}
pub fn max_size(mut self, max_size: Vec2) -> Self {
self.max_size = max_size;
self
}
/// Can you resize it with the mouse?
/// Note that a window can still auto-resize
pub fn resizable(mut self, resizable: bool) -> Self {
self.resizable = resizable;
self
}
pub fn fixed_size(mut self, size: Vec2) -> Self {
self.auto_shrink_width = false;
self.auto_shrink_height = false;
self.expand_width_to_fit_content = false;
self.expand_height_to_fit_content = false;
self.default_size = size;
self.min_size = size;
self.max_size = size;
self.resizable = false;
self
}
pub fn as_wide_as_possible(mut self) -> Self {
self.min_size.x = f32::INFINITY;
self
}
/// true: prevent from resizing to smaller than contents.
/// false: allow shrinking to smaller than contents.
pub fn auto_expand(mut self, auto_expand: bool) -> Self {
self.expand_width_to_fit_content = auto_expand;
self.expand_height_to_fit_content = auto_expand;
self
}
/// true: prevent from resizing to smaller than contents.
/// false: allow shrinking to smaller than contents.
pub fn auto_expand_width(mut self, auto_expand: bool) -> Self {
self.expand_width_to_fit_content = auto_expand;
self
}
/// true: prevent from resizing to smaller than contents.
/// false: allow shrinking to smaller than contents.
pub fn auto_expand_height(mut self, auto_expand: bool) -> Self {
self.expand_height_to_fit_content = auto_expand;
self
}
/// Offset the position of the resize handle by this much
pub fn handle_offset(mut self, handle_offset: Vec2) -> Self {
self.handle_offset = handle_offset;
self
}
pub fn auto_shrink_width(mut self, auto_shrink_width: bool) -> Self {
self.auto_shrink_width = auto_shrink_width;
self
}
pub fn auto_shrink_height(mut self, auto_shrink_height: bool) -> Self {
self.auto_shrink_height = auto_shrink_height;
self
}
}
// TODO: a common trait for Things that follow this pattern
impl Resize {
pub fn show(mut self, region: &mut Region, add_contents: impl FnOnce(&mut Region)) {
if !self.resizable {
return add_contents(region);
}
let id = region.make_child_id("scroll");
self.min_size = self.min_size.min(region.available_space());
self.max_size = self.max_size.min(region.available_space());
self.max_size = self.max_size.max(self.min_size);
let (is_new, mut state) = match region.memory().resize.get(&id) {
Some(state) => (false, state.clone()),
None => {
let default_size = self.default_size.clamp(self.min_size..=self.max_size);
(true, State { size: default_size })
}
};
state.size = state.size.clamp(self.min_size..=self.max_size);
let last_frame_size = state.size;
let position = region.cursor();
// Resize-corner:
let corner_size = Vec2::splat(16.0); // TODO: style
let corner_rect = Rect::from_min_size(
position + state.size + self.handle_offset - corner_size,
corner_size,
);
let corner_interact = region.interact_rect(&corner_rect, id.with("corner"));
if corner_interact.active {
if let Some(mouse_pos) = region.input().mouse_pos {
// This is the desired size. We may not be able to achieve it.
state.size = mouse_pos - position + 0.5 * corner_interact.rect.size();
// We don't clamp to max size, because we want to be able to push against outer bounds.
// For instance, if we are inside a bigger Resize region, we want to expand that.
// state.size = state.size.clamp(self.min_size..=self.max_size);
state.size = state.size.max(self.min_size);
}
}
// ------------------------------
let inner_rect = Rect::from_min_size(region.cursor(), state.size);
let desired_size = {
let mut contents_region = region.child_region(inner_rect);
// If we pull the resize handle to shrink, we want to TRY to shink it.
// After laying out the contents, we might be much bigger.
// In those cases we don't want the clip_rect too be smaller, because
// then we will clip the contents of the region even thought the result gets larger. This is simply ugly!
contents_region.clip_rect.max = contents_region
.clip_rect
.max
.max(contents_region.clip_rect.min + last_frame_size)
.min(region.clip_rect.max); // Respect parent region
add_contents(&mut contents_region);
contents_region.bounding_size()
};
let desired_size = desired_size.ceil(); // Avoid rounding errors in math
// ------------------------------
if self.auto_shrink_width {
state.size.x = state.size.x.min(desired_size.x);
}
if self.auto_shrink_height {
state.size.y = state.size.y.min(desired_size.y);
}
if self.expand_width_to_fit_content || is_new {
state.size.x = state.size.x.max(desired_size.x);
}
if self.expand_height_to_fit_content || is_new {
state.size.y = state.size.y.max(desired_size.y);
}
state.size = state.size.max(self.min_size);
// state.size = state.size.clamp(self.min_size..=self.max_size);
state.size = state.size.round(); // TODO: round to pixels
region.reserve_space(state.size, None);
// ------------------------------
paint_resize_corner(region, &corner_rect, &corner_interact);
if corner_interact.hovered || corner_interact.active {
region.ctx().output.lock().cursor_icon = CursorIcon::ResizeNwSe;
}
region.memory().resize.insert(id, state);
}
}
fn paint_resize_corner(region: &mut Region, rect: &Rect, interact: &InteractInfo) {
let color = region.style().interact_stroke_color(&interact);
let width = region.style().interact_stroke_width(&interact);
let corner = rect.right_bottom().round(); // TODO: round to pixels
let mut w = 2.0;
while w < 12.0 {
region.add_paint_cmd(PaintCmd::line_segment(
(pos2(corner.x - w, corner.y), pos2(corner.x, corner.y - w)),
color,
width,
));
w += 4.0;
}
}