Add Viewport up/down scroll and some misc improvements

src/canvas.rs

@@ -16,7 +16,7 @@
 
 use std::vec::Vec;
 
-use im::Vector;
+use im::{vector, Vector};
 
 use serde::de::{Deserializer, SeqAccess, Visitor};
 use serde::ser::Serializer;
@@ -128,20 +128,48 @@ impl CanvasElement {
             }
         }
     }
-
-    pub fn get_path_mut(&mut self) -> Option<&mut Path> {
-        match self {
-            CanvasElement::Freehand { path, .. } => Some(path),
-        }
-    }
 }
 
 #[derive(Clone, druid::Data)]
 pub struct Canvas {
-    pub elements: Vector<CanvasElement>,
+    elements: Vector<CanvasElement>,
+    content_size: druid::Size,
 }
 
 impl Canvas {
+    pub fn new() -> Self {
+        Canvas {
+            elements: vector![],
+            content_size: druid::Size::new(0.0, 0.0),
+        }
+    }
+
+    pub fn new_with_elements(elements: Vector<CanvasElement>) -> Self {
+        let mut cv = Canvas::new();
+        for e in elements {
+            cv.add_element(e);
+        }
+        cv
+    }
+
+    pub fn add_element(&mut self, element: CanvasElement) {
+        self.content_size = self
+            .content_size
+            .to_rect()
+            .union(element.bounding_box())
+            .size();
+        self.elements.push_back(element);
+    }
+
+    pub fn remove_element_at(&mut self, index: usize) {
+        // TODO(enrico): content size should be recomputed
+        self.elements.remove(index);
+    }
+
+    pub fn elements(&self) -> &Vector<CanvasElement> {
+        &self.elements
+    }
+
     /// Find all CanvasElement that intersect with rect
     pub fn find_intersections(&self, rect: druid::Rect) -> Vec<usize> {
         let mut found_elements = Vec::<usize>::new();
@@ -157,6 +185,10 @@ impl Canvas {
 
         found_elements
     }
+
+    pub fn content_size(&self) -> druid::Size {
+        self.content_size
+    }
 }
 
 impl Serialize for Path {

src/main.rs

@@ -14,6 +14,8 @@
 //  You should have received a copy of the GNU Affero General Public License
 //  along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
+use std::path::PathBuf;
+
 use log::{info, warn};
 
 use druid::commands;
@@ -22,23 +24,28 @@ use druid::widget::prelude::*;
 use druid::widget::{Align, Button, CrossAxisAlignment, Flex, List, SizedBox, WidgetExt};
 use druid::{
     AppDelegate, AppLauncher, Color, Command, Data, DelegateCtx, Env, FileDialogOptions, FileSpec,
-    Handled, Lens, LocalizedString, Target, WindowDesc,
+    Handled, Lens, LocalizedString, Target, WidgetId, WindowDesc,
 };
 
 use im::Vector;
 
-use stiletto::canvas::Canvas;
-use stiletto::history::VersionedCanvas;
 use stiletto::tool::{CanvasToolCtx, CanvasToolParams};
-use stiletto::widget::{build_simple_tool_widget, CanvasState, CanvasToolIconState, CanvasWidget};
+use stiletto::widget::{
+    build_simple_tool_widget, CanvasState, CanvasToolIconState, CanvasWidget, SCROLL,
+};
 use stiletto::DocumentSnapshot;
 
 pub fn main() {
     let window = WindowDesc::new(build_ui)
         .window_size((1024.0, 1400.0))
-        .title(
-            LocalizedString::new("custom-widget-demo-window-title").with_placeholder("Stiletto"),
-        );
+        .title(|data: &StilettoState, _env: &Env| {
+            let doc_name = if let Some(path) = &data.current_file_path {
+                String::from(path.to_string_lossy())
+            } else {
+                String::from("New Document")
+            };
+            format!("Stiletto - {}", doc_name)
+        });
 
     let default_pen_params = CanvasToolParams::Pen {
         thickness: 2.0,
@@ -49,12 +56,7 @@ pub fn main() {
         color: Color::rgb(255.0, 0.0, 0.0),
     };
     let canvas_data = StilettoState {
-        canvas: CanvasState {
-            versioned_canvas: VersionedCanvas::new(Canvas {
-                elements: vector![],
-            }),
-            tool_ctx: CanvasToolCtx::new(default_pen_params.clone()),
-        },
+        canvas: CanvasState::new(CanvasToolCtx::new(default_pen_params.clone())),
         tool_icons: vector![
             CanvasToolIconState {
                 tool_params: default_pen_params,
@@ -70,6 +72,7 @@ pub fn main() {
             },
         ],
         current_tool: 0,
+        current_file_path: None,
     };
     AppLauncher::with_window(window)
         .use_simple_logger()
@@ -83,9 +86,13 @@ struct StilettoState {
     canvas: CanvasState,
     tool_icons: Vector<CanvasToolIconState>,
     current_tool: usize,
+    #[data(same_fn = "PartialEq::eq")]
+    current_file_path: Option<PathBuf>,
 }
 
 fn build_ui() -> impl Widget<StilettoState> {
+    let canvas_id = WidgetId::next();
+
     let history_buttons = Flex::row()
         .cross_axis_alignment(CrossAxisAlignment::Center)
         .with_child(Button::new("Undo").on_click(
@@ -103,6 +110,16 @@ fn build_ui() -> impl Widget<StilettoState> {
 
     let save_buttons = Flex::row()
         .cross_axis_alignment(CrossAxisAlignment::Center)
+        .with_child(Button::new("Up").on_click(
+            move |ctx: &mut EventCtx, _data: &mut StilettoState, _env: &Env| {
+                ctx.submit_command(Command::new(SCROLL, -30.0, canvas_id));
+            },
+        ))
+        .with_child(Button::new("Down").on_click(
+            move |ctx: &mut EventCtx, _data: &mut StilettoState, _env: &Env| {
+                ctx.submit_command(Command::new(SCROLL, 30.0, canvas_id));
+            },
+        ))
         .with_child(Button::new("Open").on_click(move |ctx, _, _| {
             ctx.submit_command(Command::new(
                 druid::commands::SHOW_OPEN_PANEL,
@@ -148,7 +165,12 @@ fn build_ui() -> impl Widget<StilettoState> {
         .cross_axis_alignment(CrossAxisAlignment::Center)
         .must_fill_main_axis(true)
         .with_child(SizedBox::new(Align::left(toolbar)).height(50.0))
-        .with_flex_child((CanvasWidget {}).lens(StilettoState::canvas), 1.0)
+        .with_flex_child(
+            CanvasWidget::new()
+                .lens(StilettoState::canvas)
+                .with_id(canvas_id),
+            1.0,
+        )
 }
 
 struct Delegate;
@@ -164,6 +186,10 @@ impl AppDelegate<StilettoState> for Delegate {
     ) -> Handled {
         use std::fs::File;
 
+        if cmd.get(commands::SAVE_FILE).is_some() {
+            //let path = data.current_file_path.as_ref().unwrap();
+            // TODO
+        }
         if let Some(file_info) = cmd.get(commands::SAVE_FILE_AS) {
             let res_file = File::create(file_info.path());
             if let Ok(f) = res_file {
@@ -172,6 +198,7 @@ impl AppDelegate<StilettoState> for Delegate {
                 if write_res.is_err() {
                     warn!("Error while saving: {:?}", write_res.err());
                 } else {
+                    data.current_file_path = Some(file_info.path().to_path_buf());
                     info!("Written to file: {}", file_info.path().display());
                 }
             } else {
@@ -185,9 +212,14 @@ impl AppDelegate<StilettoState> for Delegate {
                     serde_json::from_reader(f);
                 if let Ok(document_snapshot) = res_snapshot {
                     data.canvas.set_from_snapshot(document_snapshot);
+                    data.current_file_path = Some(file_info.path().to_path_buf());
                     info!("Loaded file {}", file_info.path().display());
                 } else {
-                    warn!("Error while loading {}: {:?}", file_info.path().display(), res_snapshot.err());
+                    warn!(
+                        "Error while loading {}: {:?}",
+                        file_info.path().display(),
+                        res_snapshot.err()
+                    );
                 }
             }
             return Handled::Yes;

src/tool.rs

@@ -15,7 +15,7 @@
 //  along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 use druid::kurbo::BezPath;
-use druid::{Color, Data, Env, Event, EventCtx, PaintCtx};
+use druid::{Affine, Color, Data, Env, Event, EventCtx, PaintCtx};
 
 use crate::canvas;
 use crate::canvas::{Canvas, CanvasElement};
@@ -71,11 +71,16 @@ impl CanvasToolCtx {
         ctx: &EventCtx,
         event: &Event,
         mut vcanvas: &mut VersionedCanvas,
+        transform: Affine,
         env: &Env,
     ) {
         match self.initial_params.tool_type() {
-            CanvasToolType::Pen => self.handle_pen_event(&ctx, &event, &mut vcanvas, &env),
-            CanvasToolType::Eraser => self.handle_erase_event(&ctx, &event, &mut vcanvas, &env),
+            CanvasToolType::Pen => {
+                self.handle_pen_event(&ctx, &event, &mut vcanvas, transform, &env)
+            }
+            CanvasToolType::Eraser => {
+                self.handle_erase_event(&ctx, &event, &mut vcanvas, transform, &env)
+            }
         }
     }
 
@@ -84,6 +89,7 @@ impl CanvasToolCtx {
         _ctx: &EventCtx,
         event: &Event,
         vcanvas: &mut VersionedCanvas,
+        transform: Affine,
         _env: &Env,
     ) {
         match (&mut self.state, event) {
@@ -91,13 +97,14 @@ impl CanvasToolCtx {
                 self.state = CanvasToolState::Erasing;
             }
             (CanvasToolState::Erasing, Event::MouseMove(mouse_event)) => {
-                let eraser_rect = druid::Rect::from_center_size(mouse_event.pos, (5.0, 5.0));
+                let eraser_rect =
+                    druid::Rect::from_center_size(transform * mouse_event.pos, (5.0, 5.0));
                 let elements = vcanvas.get().find_intersections(eraser_rect);
 
                 if !elements.is_empty() {
                     vcanvas.update(|canvas: &mut Canvas| {
                         for i in elements {
-                            canvas.elements.remove(i);
+                            canvas.remove_element_at(i);
                         }
                     });
                 }
@@ -114,6 +121,7 @@ impl CanvasToolCtx {
         _ctx: &EventCtx,
         event: &Event,
         vcanvas: &mut VersionedCanvas,
+        transform: Affine,
         _env: &Env,
     ) {
         match (&mut self.state, event) {
@@ -138,17 +146,28 @@ impl CanvasToolCtx {
                 },
                 Event::MouseMove(mouse_event),
             ) => {
-                current_path
-                    .get_path_mut()
-                    .unwrap()
-                    .kurbo_path
-                    .line_to((mouse_event.pos.x, mouse_event.pos.y));
+                if let CanvasElement::Freehand { ref mut path, .. } = current_path {
+                    path.kurbo_path
+                        .line_to((mouse_event.pos.x, mouse_event.pos.y));
+                }
             }
             (CanvasToolState::DrawingFreehand { .. }, Event::MouseUp(_)) => {
                 vcanvas.update(move |canvas: &mut Canvas| {
                     let current_state = std::mem::replace(&mut self.state, CanvasToolState::Idle);
                     if let CanvasToolState::DrawingFreehand { current_path, .. } = current_state {
-                        canvas.elements.push_back(current_path);
+                        if let CanvasElement::Freehand {
+                            mut path,
+                            mut thickness,
+                            stroke_color,
+                        } = current_path
+                        {
+                            path.kurbo_path.apply_affine(transform);
+                            canvas.add_element(CanvasElement::Freehand {
+                                path,
+                                thickness,
+                                stroke_color,
+                            });
+                        }
                     }
                 });
             }

src/widget/canvas.rs

@@ -21,8 +21,13 @@ use crate::history::VersionedCanvas;
 use crate::tool::CanvasToolCtx;
 use crate::DocumentSnapshot;
 
+use druid::scroll_component::ScrollComponent;
 use druid::widget::prelude::*;
-use druid::{Color, Data, Env, Event};
+use druid::widget::Viewport;
+use druid::{Affine, Color, Data, Env, Event};
+use druid::{Command, Selector, Target};
+
+pub const SCROLL: Selector<f64> = Selector::new("scroll_canvas");
 
 #[derive(Clone, Data)]
 pub struct CanvasState {
@@ -31,6 +36,12 @@ pub struct CanvasState {
 }
 
 impl CanvasState {
+    pub fn new(tool_ctx: CanvasToolCtx) -> Self {
+        CanvasState {
+            versioned_canvas: VersionedCanvas::new(Canvas::new()),
+            tool_ctx,
+        }
+    }
     pub fn perform_undo(&mut self) {
         //if !self.is_drawing() {
         self.versioned_canvas.undo();
@@ -50,7 +61,7 @@ impl CanvasState {
             canvas_elements: self
                 .versioned_canvas
                 .get()
-                .elements
+                .elements()
                 .iter()
                 .cloned()
                 .collect(),
@@ -58,9 +69,9 @@ impl CanvasState {
     }
 
     pub fn set_from_snapshot(&mut self, snapshot: DocumentSnapshot) {
-        self.versioned_canvas = VersionedCanvas::new(Canvas {
-            elements: Vector::from(snapshot.canvas_elements),
-        });
+        self.versioned_canvas = VersionedCanvas::new(Canvas::new_with_elements(Vector::from(
+            snapshot.canvas_elements,
+        )));
     }
 
     pub fn set_tool_ctx(&mut self, ctx: CanvasToolCtx) {
@@ -68,21 +79,62 @@ impl CanvasState {
     }
 }
 
-pub struct CanvasWidget;
+pub struct CanvasWidget {
+    viewport: Viewport,
+    scroll_component: ScrollComponent,
+}
+
+impl CanvasWidget {
+    pub fn new() -> Self {
+        CanvasWidget {
+            viewport: Viewport {
+                content_size: Size::new(0.0, 0.0),
+                rect: druid::Rect::new(0.0, 0.0, 0.0, 0.0),
+            },
+            scroll_component: ScrollComponent::new(),
+        }
+    }
+}
 
 impl Widget<CanvasState> for CanvasWidget {
     fn event(&mut self, ctx: &mut EventCtx, event: &Event, data: &mut CanvasState, env: &Env) {
-        data.tool_ctx
-            .handle_event(ctx, event, &mut data.versioned_canvas, env);
+        ctx.request_focus();
+        let mut needs_update = false;
+        match event {
+            Event::Command(cmd) => {
+                if let Some(value) = cmd.get(SCROLL) {
+                    self.viewport.rect.y0 += value;
+                    needs_update = true;
+                }
+            }
+            Event::KeyDown(key_event) => {
+                if key_event.code == druid::Code::ArrowDown {
+                    self.viewport.rect.y0 += 30.0;
+                    needs_update = true;
+                } else if key_event.code == druid::Code::ArrowUp {
+                    self.viewport.rect.y0 = 0.0_f64.max(self.viewport.rect.y0 - 30.0);
+                    needs_update = true;
+                }
+            }
+            _ => {
+                let transform = Affine::translate((self.viewport.rect.x0, self.viewport.rect.y0));
+                data.tool_ctx
+                    .handle_event(ctx, event, &mut data.versioned_canvas, transform, env);
+            }
+        }
+        if needs_update {
+            ctx.request_paint();
+        }
     }
 
     fn lifecycle(
         &mut self,
-        _ctx: &mut LifeCycleCtx,
-        _event: &LifeCycle,
+        ctx: &mut LifeCycleCtx,
+        event: &LifeCycle,
         _data: &CanvasState,
-        _env: &Env,
+        env: &Env,
     ) {
+        self.scroll_component.lifecycle(ctx, event, env);
     }
 
     fn update(
@@ -101,6 +153,7 @@ impl Widget<CanvasState> for CanvasWidget {
         //        ctx.request_paint_rect(e.bounding_box());
         //    }
         //} else {
+
         ctx.request_paint();
         //}
     }
@@ -128,15 +181,27 @@ impl Widget<CanvasState> for CanvasWidget {
         // (ctx.size() returns the size of the layout rect we're painting in)
         let size = ctx.size();
         let rect = size.to_rect();
-        // Note: ctx also has a `clear` method, but that clears the whole context,
-        // and we only want to clear this widget's area.
-        ctx.fill(rect, &Color::WHITE);
 
-        for element in data.versioned_canvas.get().elements.iter() {
+        let page_content_size = data.versioned_canvas.get().content_size();
+        ctx.fill(rect, &Color::WHITE);
+        self.viewport.rect = self.viewport.rect.with_size(size);
+        self.viewport.content_size = druid::Size::new(
+            self.viewport.rect.x1.max(page_content_size.width),
+            self.viewport.rect.y1.max(page_content_size.height),
+        );
+
+        ctx.save().unwrap();
+        ctx.transform(Affine::translate((
+            -self.viewport.rect.x0,
+            -self.viewport.rect.y0,
+        )));
+        for element in data.versioned_canvas.get().elements().iter() {
             element.draw(ctx);
         }
+        ctx.restore().unwrap();
         if data.tool_ctx.needs_repaint() {
             data.tool_ctx.paint(ctx, env);
         }
+        self.scroll_component.draw_bars(ctx, &self.viewport, env);
     }
 }