From 211d70b4f3d12fb82ad9fc1789f949c0e29bf5c7 Mon Sep 17 00:00:00 2001
From: Emil Ernerfeldt <emilernerfeldt@gmail.com>
Date: Fri, 23 Oct 2020 15:16:04 +0200
Subject: [PATCH] [window] Remove ability to throw windows

---
 CHANGELOG.md                  |  1 +
 egui/src/containers/area.rs   | 24 ++----------------------
 egui/src/containers/window.rs |  4 ----
 egui/src/context.rs           |  1 -
 egui/src/memory.rs            | 17 ++---------------
 5 files changed, 5 insertions(+), 42 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index fc0b7595..2286d854 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,7 @@
 * Windows are now constrained to the screen
 * Panels: you can now create panels using `SidePanel` and `TopPanel`.
 * Fix a bug where some regions would slowly grow for non-integral scales (`pixels_per_point`).
+* You can no longer throw windows
 
 ## 0.2.0 - 2020-10-10
 
diff --git a/egui/src/containers/area.rs b/egui/src/containers/area.rs
index d1b4fe78..94ec9dcd 100644
--- a/egui/src/containers/area.rs
+++ b/egui/src/containers/area.rs
@@ -19,11 +19,6 @@ pub(crate) struct State {
     /// If false, clicks goes straight through to what is behind us.
     /// Good for tooltips etc.
     pub interactable: bool,
-
-    /// You can throw a moveable Area. It's fun.
-    /// TODO: separate out moveable to container?
-    #[cfg_attr(feature = "serde", serde(skip))]
-    pub vel: Vec2,
 }
 
 impl State {
@@ -128,7 +123,6 @@ impl Area {
             pos: default_pos.unwrap_or_else(|| automatic_area_position(ctx)),
             size: Vec2::zero(),
             interactable,
-            vel: Vec2::zero(),
         });
         state.pos = fixed_pos.unwrap_or(state.pos);
         state.pos = ctx.round_pos_to_pixels(state.pos);
@@ -183,6 +177,7 @@ impl Prepared {
         } else {
             None
         };
+
         let move_response = ctx.interact(
             layer_id,
             Rect::everything(),
@@ -191,23 +186,8 @@ impl Prepared {
             Sense::click_and_drag(),
         );
 
-        let input = ctx.input();
         if move_response.active {
-            state.pos += input.mouse.delta;
-            state.vel = input.mouse.velocity;
-        } else {
-            let stop_speed = 20.0; // Pixels per second.
-            let friction_coeff = 1000.0; // Pixels per second squared.
-            let dt = input.unstable_dt;
-
-            let friction = friction_coeff * dt;
-            if friction > state.vel.length() || state.vel.length() < stop_speed {
-                state.vel = Vec2::zero();
-            } else {
-                state.vel -= friction * state.vel.normalized();
-                state.pos += state.vel * dt;
-                ctx.request_repaint();
-            }
+            state.pos += ctx.input().mouse.delta;
         }
 
         state.pos = ctx.constrain_window_rect(state.rect()).min;
diff --git a/egui/src/containers/window.rs b/egui/src/containers/window.rs
index ecb90448..67876709 100644
--- a/egui/src/containers/window.rs
+++ b/egui/src/containers/window.rs
@@ -370,10 +370,6 @@ impl WindowInteraction {
     pub fn is_resize(&self) -> bool {
         self.left || self.right || self.top || self.bottom
     }
-
-    pub fn is_pure_move(&self) -> bool {
-        !self.is_resize()
-    }
 }
 
 fn interact(
diff --git a/egui/src/context.rs b/egui/src/context.rs
index 51fd12f9..edd676bd 100644
--- a/egui/src/context.rs
+++ b/egui/src/context.rs
@@ -277,7 +277,6 @@ impl Context {
                 pos: rect.min,
                 size: rect.size(),
                 interactable: true,
-                vel: Default::default(),
             },
         );
         Ui::new(self.clone(), layer_id, layer_id.id, rect, rect)
diff --git a/egui/src/memory.rs b/egui/src/memory.rs
index 692bdb63..c952e7d5 100644
--- a/egui/src/memory.rs
+++ b/egui/src/memory.rs
@@ -135,21 +135,8 @@ impl Memory {
     pub(crate) fn begin_frame(&mut self, prev_input: &crate::input::InputState) {
         self.interaction.begin_frame(prev_input);
 
-        if !prev_input.mouse.down || prev_input.mouse.pos.is_none() {
-            // mouse was not down last frame
-
-            let window_interaction = self.window_interaction.take();
-            if let Some(window_interaction) = window_interaction {
-                if window_interaction.is_pure_move() {
-                    // Throw windows because it is fun:
-                    let area_layer_id = window_interaction.area_layer_id;
-                    let area_state = self.areas.get(area_layer_id.id).cloned();
-                    if let Some(mut area_state) = area_state {
-                        area_state.vel = prev_input.mouse.velocity;
-                        self.areas.set_state(area_layer_id, area_state);
-                    }
-                }
-            }
+        if !prev_input.mouse.down {
+            self.window_interaction = None;
         }
     }