Make a tool to select a rectangular region. No way to pass back the

results yet. #574

game/src/sandbox/dashboards/mod.rs

@@ -11,6 +11,7 @@ mod commuter;
 mod generic_trip_table;
 mod misc;
 mod parking_overhead;
+mod selector;
 mod summaries;
 mod traffic_signals;
 mod trip_table;

game/src/sandbox/dashboards/selector.rs

@@ -0,0 +1,83 @@
+use geom::{Polygon, Pt2D};
+use widgetry::{
+    Color, EventCtx, GfxCtx, HorizontalAlignment, Key, Line, Outcome, Panel, State, TextExt,
+    VerticalAlignment, Widget,
+};
+
+use crate::app::{App, Transition};
+
+// TODO Lift to widgetry
+pub struct RectangularSelector {
+    panel: Panel,
+    region: Option<Polygon>,
+    corners: Option<(Pt2D, Pt2D, bool)>,
+}
+
+impl RectangularSelector {
+    pub fn new(ctx: &mut EventCtx, region: Option<Polygon>) -> Box<dyn State<App>> {
+        Box::new(RectangularSelector {
+            panel: Panel::new(Widget::col(vec![
+                Widget::row(vec![
+                    Line("Select a rectangular region")
+                        .small_heading()
+                        .into_widget(ctx),
+                    ctx.style().btn_close_widget(ctx),
+                ]),
+                // TODO Key style
+                "Hold control, then click and drag to draw".text_widget(ctx),
+            ]))
+            .aligned(HorizontalAlignment::Right, VerticalAlignment::Top)
+            .build(ctx),
+            region,
+            corners: None,
+        })
+    }
+}
+
+impl State<App> for RectangularSelector {
+    fn event(&mut self, ctx: &mut EventCtx, _: &mut App) -> Transition {
+        if ctx.is_key_down(Key::LeftControl) {
+            if ctx.input.left_mouse_button_released() {
+                if let Some((_, _, ref mut dragging)) = self.corners {
+                    *dragging = false;
+                }
+            }
+            if let Some(pt) = ctx.canvas.get_cursor_in_map_space() {
+                if ctx.input.left_mouse_button_pressed() {
+                    self.corners = Some((pt, pt, true));
+                }
+                if let Some((_, ref mut pt2, dragging)) = self.corners {
+                    if dragging {
+                        *pt2 = pt;
+                    }
+                }
+            }
+        } else {
+            ctx.canvas_movement();
+        }
+
+        match self.panel.event(ctx) {
+            Outcome::Clicked(x) => match x.as_ref() {
+                "close" => {
+                    return Transition::Pop;
+                }
+                _ => unreachable!(),
+            },
+            _ => {}
+        }
+
+        Transition::Keep
+    }
+
+    fn draw(&self, g: &mut GfxCtx, _: &App) {
+        self.panel.draw(g);
+        if let Some(p) = self.region.clone() {
+            g.draw_polygon(Color::BLUE.alpha(0.5), p);
+        }
+        if let Some((pt1, pt2, _)) = self.corners {
+            if let Some(p) = Polygon::rectangle_two_corners(pt1, pt2) {
+                g.draw_polygon(Color::RED.alpha(0.5), p);
+            }
+        }
+    }
+}

game/src/sandbox/dashboards/trip_table.rs

@@ -9,9 +9,10 @@ use widgetry::{
 };
 
 use super::generic_trip_table::{open_trip_transition, preview_trip};
+use super::selector::RectangularSelector;
+use super::DashTab;
 use crate::app::{App, Transition};
 use crate::common::{checkbox_per_mode, cmp_duration_shorter, color_for_mode};
-use crate::sandbox::dashboards::DashTab;
 
 pub struct TripTable {
     tab: DashTab,
@@ -136,6 +137,10 @@ impl State<App> for TripTable {
                     return Transition::Pop;
                 } else if self.table_tabs.handle_action(ctx, &x, &mut self.panel) {
                     // if true, tabs handled the action
+                } else if x == "filter starts" {
+                    return Transition::Push(RectangularSelector::new(ctx, None));
+                } else if x == "filter ends" {
+                    return Transition::Push(RectangularSelector::new(ctx, None));
                 } else {
                     unreachable!("unhandled action: {}", x)
                 }
@@ -313,6 +318,8 @@ fn make_table_finished_trips(app: &App) -> Table<App, FinishedTrip, Filters> {
                 Widget::row(vec![
                     Toggle::switch(ctx, "starting off-map", None, state.off_map_starts),
                     Toggle::switch(ctx, "ending off-map", None, state.off_map_ends),
+                    ctx.style().btn_plain.text("filter starts").build_def(ctx),
+                    ctx.style().btn_plain.text("filter ends").build_def(ctx),
                     if app.primary.has_modified_trips {
                         Toggle::switch(
                             ctx,