Adds support for invalidating a single rectangle.

druid-shell/examples/invalidate.rs

@@ -0,0 +1,102 @@
+// Copyright 2020 The xi-editor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use std::any::Any;
+
+use std::time::{Duration, Instant};
+
+use druid_shell::kurbo::{Point, Rect};
+use druid_shell::piet::{Color, Piet, RenderContext};
+
+use druid_shell::{Application, TimerToken, WinHandler, WindowBuilder, WindowHandle};
+
+struct InvalidateTest {
+    handle: WindowHandle,
+    size: (f64, f64),
+    start_time: Instant,
+    color: Color,
+    rect: Rect,
+}
+
+impl InvalidateTest {
+    fn update_color_and_rect(&mut self) {
+        let time_since_start = (Instant::now() - self.start_time).as_nanos();
+        let (r, g, b, _) = self.color.as_rgba_u8();
+        self.color = match (time_since_start % 2, time_since_start % 3) {
+            (0, _) => Color::rgb8(r.wrapping_add(10), g, b),
+            (_, 0) => Color::rgb8(r, g.wrapping_add(10), b),
+            (_, _) => Color::rgb8(r, g, b.wrapping_add(10)),
+        };
+
+        self.rect.x0 = (self.rect.x0 + 5.0) % self.size.0;
+        self.rect.x1 = (self.rect.x1 + 5.5) % self.size.0;
+        self.rect.y0 = (self.rect.y0 + 3.0) % self.size.1;
+        self.rect.y1 = (self.rect.y1 + 3.5) % self.size.1;
+    }
+}
+
+impl WinHandler for InvalidateTest {
+    fn connect(&mut self, handle: &WindowHandle) {
+        self.handle = handle.clone();
+        self.handle.request_timer(Duration::from_millis(60));
+    }
+
+    fn timer(&mut self, _id: TimerToken) {
+        self.update_color_and_rect();
+        self.handle.invalidate_rect(self.rect);
+        self.handle.request_timer(Duration::from_millis(60));
+    }
+
+    fn paint(&mut self, piet: &mut Piet, rect: Rect) -> bool {
+        piet.fill(rect, &self.color);
+        false
+    }
+
+    fn size(&mut self, width: u32, height: u32) {
+        let dpi = self.handle.get_dpi();
+        let dpi_scale = dpi as f64 / 96.0;
+        let width_f = (width as f64) / dpi_scale;
+        let height_f = (height as f64) / dpi_scale;
+        self.size = (width_f, height_f);
+    }
+
+    fn command(&mut self, id: u32) {
+        match id {
+            0x100 => self.handle.close(),
+            _ => println!("unexpected id {}", id),
+        }
+    }
+
+    fn as_any(&mut self) -> &mut dyn Any {
+        self
+    }
+}
+
+fn main() {
+    let mut app = Application::new(None);
+    let mut builder = WindowBuilder::new();
+    let inv_test = InvalidateTest {
+        size: Default::default(),
+        handle: Default::default(),
+        start_time: Instant::now(),
+        rect: Rect::from_origin_size(Point::ZERO, (10.0, 20.0)),
+        color: Color::WHITE,
+    };
+    builder.set_handler(Box::new(inv_test));
+    builder.set_title("Invalidate tester");
+
+    let window = builder.build().unwrap();
+    window.show();
+    app.run();
+}

druid-shell/examples/perftest.rs

@@ -36,7 +36,7 @@ impl WinHandler for PerfTest {
         self.handle = handle.clone();
     }
 
-    fn paint(&mut self, piet: &mut Piet) -> bool {
+    fn paint(&mut self, piet: &mut Piet, _: Rect) -> bool {
         let (width, height) = self.size;
         let rect = Rect::new(0.0, 0.0, width, height);
         piet.fill(rect, &BG_COLOR);

druid-shell/examples/shello.rs

@@ -36,7 +36,7 @@ impl WinHandler for HelloState {
         self.handle = handle.clone();
     }
 
-    fn paint(&mut self, piet: &mut piet_common::Piet) -> bool {
+    fn paint(&mut self, piet: &mut piet_common::Piet, _: Rect) -> bool {
         let (width, height) = self.size;
         let rect = Rect::new(0.0, 0.0, width, height);
         piet.fill(rect, &BG_COLOR);

druid-shell/src/platform/gtk/window.rs

@@ -30,7 +30,7 @@ use gio::ApplicationExt;
 use gtk::prelude::*;
 use gtk::{AccelGroup, ApplicationWindow};
 
-use crate::kurbo::{Point, Size, Vec2};
+use crate::kurbo::{Point, Rect, Size, Vec2};
 use crate::piet::{Piet, RenderContext};
 
 use super::application::with_application;
@@ -242,14 +242,11 @@ impl WindowBuilder {
         drawing_area.connect_draw(clone!(handle => move |widget, context| {
             if let Some(state) = handle.state.upgrade() {
 
-                let extents = context.clip_extents();
+                let extents = widget.get_allocation();
                 let dpi_scale = state.window.get_window()
                     .map(|w| w.get_display().get_default_screen().get_resolution())
                     .unwrap_or(96.0) / 96.0;
-                let size = (
-                    ((extents.2 - extents.0) * dpi_scale) as u32,
-                    ((extents.3 - extents.1) * dpi_scale) as u32,
-                );
+                let size = ((extents.width as f64 * dpi_scale) as u32, (extents.height as f64 * dpi_scale) as u32);
 
                 if last_size.get() != size {
                     last_size.set(size);
@@ -258,11 +255,13 @@ impl WindowBuilder {
 
                 // For some reason piet needs a mutable context, so give it one I guess.
                 let mut context = context.clone();
+                let (x0, y0, x1, y1) = context.clip_extents();
                 let mut piet_context = Piet::new(&mut context);
 
                 if let Ok(mut handler_borrow) = state.handler.try_borrow_mut() {
+                    let invalid_rect = Rect::new(x0 * dpi_scale, y0 * dpi_scale, x1 * dpi_scale, y1 * dpi_scale);
                     let anim = handler_borrow
-                        .paint(&mut piet_context);
+                        .paint(&mut piet_context, invalid_rect);
                     if let Err(e) = piet_context.finish() {
                         eprintln!("piet error on render: {:?}", e);
                     }
@@ -508,6 +507,26 @@ impl WindowHandle {
         }
     }
 
+    /// Request invalidation of one rectangle.
+    pub fn invalidate_rect(&self, rect: Rect) {
+        let dpi_scale = self.get_dpi() as f64 / 96.0;
+        let rect = Rect::from_origin_size(
+            (rect.x0 * dpi_scale, rect.y0 * dpi_scale),
+            rect.size() * dpi_scale,
+        );
+
+        // GTK+ takes rects with integer coordinates, and non-negative width/height.
+        let r = rect.abs().expand();
+        if let Some(state) = self.state.upgrade() {
+            state.window.queue_draw_area(
+                r.x0 as i32,
+                r.y0 as i32,
+                r.width() as i32,
+                r.height() as i32,
+            );
+        }
+    }
+
     pub fn text(&self) -> Text {
         Text::new()
     }

druid-shell/src/platform/mac/window.rs

@@ -38,7 +38,7 @@ use objc::{class, msg_send, sel, sel_impl};
 use cairo::{Context, QuartzSurface};
 use log::{error, info};
 
-use crate::kurbo::{Point, Size, Vec2};
+use crate::kurbo::{Point, Rect, Size, Vec2};
 use crate::piet::{Piet, RenderContext};
 
 use super::dialog;
@@ -503,6 +503,10 @@ extern "C" fn draw_rect(this: &mut Object, _: Sel, dirtyRect: NSRect) {
         let frame = NSView::frame(this as *mut _);
         let width = frame.size.width as u32;
         let height = frame.size.height as u32;
+        let rect = Rect::from_origin_size(
+            (dirtyRect.origin.x, dirtyRect.origin.y),
+            (dirtyRect.size.width, dirtyRect.size.height),
+        );
         let cairo_surface =
             QuartzSurface::create_for_cg_context(cgcontext, width, height).expect("cairo surface");
         let mut cairo_ctx = Context::new(&cairo_surface);
@@ -511,7 +515,7 @@ extern "C" fn draw_rect(this: &mut Object, _: Sel, dirtyRect: NSRect) {
         let mut piet_ctx = Piet::new(&mut cairo_ctx);
         let view_state: *mut c_void = *this.get_ivar("viewState");
         let view_state = &mut *(view_state as *mut ViewState);
-        let anim = (*view_state).handler.paint(&mut piet_ctx);
+        let anim = (*view_state).handler.paint(&mut piet_ctx, rect);
         if let Err(e) = piet_ctx.finish() {
             error!("{}", e)
         }
@@ -639,6 +643,18 @@ impl WindowHandle {
         }
     }
 
+    /// Request invalidation of one rectangle.
+    pub fn invalidate_rect(&self, rect: Rect) {
+        let rect = NSRect::new(
+            NSPoint::new(rect.x0, rect.y0),
+            NSSize::new(rect.width(), rect.height()),
+        );
+        unsafe {
+            // We could share impl with redraw, but we'd need to deal with nil.
+            let () = msg_send![*self.nsview.load(), setNeedsDisplayInRect: rect];
+        }
+    }
+
     pub fn set_cursor(&mut self, cursor: &Cursor) {
         unsafe {
             let nscursor = class!(NSCursor);

druid-shell/src/platform/web/window.rs

@@ -25,7 +25,7 @@ use instant::Instant;
 use wasm_bindgen::prelude::*;
 use wasm_bindgen::JsCast;
 
-use crate::kurbo::{Point, Size, Vec2};
+use crate::kurbo::{Point, Rect, Size, Vec2};
 
 use crate::piet::RenderContext;
 
@@ -89,14 +89,13 @@ struct WindowState {
     window: web_sys::Window,
     canvas: web_sys::HtmlCanvasElement,
     context: web_sys::CanvasRenderingContext2d,
+    invalid_rect: Cell<Rect>,
 }
 
 impl WindowState {
-    fn render(&self) -> bool {
-        self.context
-            .clear_rect(0.0, 0.0, self.get_width() as f64, self.get_height() as f64);
+    fn render(&self, invalid_rect: Rect) -> bool {
         let mut piet_ctx = piet_common::Piet::new(self.context.clone(), self.window.clone());
-        let want_anim_frame = self.handler.borrow_mut().paint(&mut piet_ctx);
+        let want_anim_frame = self.handler.borrow_mut().paint(&mut piet_ctx, invalid_rect);
         if let Err(e) = piet_ctx.finish() {
             log::error!("piet error on render: {:?}", e);
         }
@@ -370,6 +369,7 @@ impl WindowBuilder {
             window,
             canvas,
             context,
+            invalid_rect: Cell::new(Rect::ZERO),
         });
 
         setup_web_callbacks(&window);
@@ -411,7 +411,27 @@ impl WindowHandle {
         log::warn!("bring_to_frontand_focus unimplemented for web");
     }
 
+    pub fn invalidate_rect(&self, rect: Rect) {
+        if let Some(s) = self.0.upgrade() {
+            let cur_rect = s.invalid_rect.get();
+            if cur_rect.width() == 0.0 || cur_rect.height() == 0.0 {
+                s.invalid_rect.set(rect);
+            } else if rect.width() != 0.0 && rect.height() != 0.0 {
+                s.invalid_rect.set(cur_rect.union(rect));
+            }
+        }
+        self.render_soon();
+    }
+
     pub fn invalidate(&self) {
+        if let Some(s) = self.0.upgrade() {
+            let rect = Rect::from_origin_size(
+                Point::ORIGIN,
+                // FIXME: does this need scaling? Not sure exactly where dpr enters...
+                (s.get_width() as f64, s.get_height() as f64),
+            );
+            s.invalid_rect.set(rect);
+        }
         self.render_soon();
     }
 
@@ -478,9 +498,11 @@ impl WindowHandle {
     fn render_soon(&self) {
         if let Some(s) = self.0.upgrade() {
             let handle = self.clone();
+            let rect = s.invalid_rect.get();
+            s.invalid_rect.set(Rect::ZERO);
             let state = s.clone();
             s.request_animation_frame(move || {
-                let want_anim_frame = state.render();
+                let want_anim_frame = state.render(rect);
                 if want_anim_frame {
                     handle.render_soon();
                 }