Better mouse scroll drag

Now saturates when to the top or left.

examples/list_view.rs

@@ -57,9 +57,9 @@ fn main() {
  )
  .with(|list| for i in 0..50 {
  list.add_child(
-  &format!("Item {}", i),
-  EditView::new(),
-  );
+ &format!("Item {}", i),
+ EditView::new(),
+ );
  }),
  ),
  );

src/views/list_view.rs

@@ -346,9 +346,8 @@ impl View for ListView {
  offset,
  } if self.scrollbase.is_dragging() =>
  {
- position
- .checked_sub(offset)
- .map(|position| self.scrollbase.drag(position));
+ let position = position.saturating_sub(offset);
+ self.scrollbase.drag(position);
  return EventResult::Consumed(None);
  }
  Event::Mouse {
@@ -397,12 +396,10 @@ impl View for ListView {
  direction::Direction::back(),
  )
  }
- Event::Key(Key::End) | Event::Ctrl(Key::End) => {
- self.move_focus(
- usize::max_value(),
- direction::Direction::front(),
- )
- }
+ Event::Key(Key::End) | Event::Ctrl(Key::End) => self.move_focus(
+ usize::max_value(),
+ direction::Direction::front(),
+ ),
  Event::Key(Key::Tab) => {
  self.move_focus(1, direction::Direction::front())
  }

src/views/menu_popup.rs

@@ -234,8 +234,8 @@ impl View for MenuPopup {
  }
  printer.print_hline((1, 0), printer.size.x - 2, " ");
  printer.print((2, 0), label);
- printer.print((printer.size.x.saturating_sub(4), 0),
-   ">>");
+ let x = printer.size.x.saturating_sub(4);
+ printer.print((x, 0), ">>");
  }
  MenuItem::Leaf(ref label, _) => {
  if printer.size.x < 2 {
@@ -333,9 +333,8 @@ impl View for MenuPopup {
  } => {
  // If the mouse is dragged, we always consume the event.
  fix_scroll = false;
- position
- .checked_sub(offset + (0, 1))
- .map(|position| self.scrollbase.drag(position));
+ let position = position.saturating_sub(offset);
+ self.scrollbase.drag(position);
  }
  Event::Mouse {
  event: MouseEvent::Press(_),

src/views/select_view.rs

@@ -375,9 +375,8 @@ impl<T: 'static> SelectView<T> {
  } => {
  // If the mouse is dragged, we always consume the event.
  fix_scroll = false;
- position
- .checked_sub(offset)
- .map(|position| self.scrollbase.drag(position));
+ let position = position.saturating_sub(offset);
+ self.scrollbase.drag(position);
  }
  Event::Mouse {
  event: MouseEvent::Press(_),

src/views/text_area.rs

@@ -502,9 +502,8 @@ impl View for TextArea {
  offset,
  } => {
  fix_scroll = false;
- position
- .checked_sub(offset)
- .map(|position| self.scrollbase.drag(position));
+ let position = position.saturating_sub(offset);
+ self.scrollbase.drag(position);
  }
  Event::Mouse {
  event: MouseEvent::Press(_),

src/views/text_view.rs

@@ -303,9 +303,8 @@ impl View for TextView {
  offset,
  } => {
  // If the mouse is dragged, we always consume the event.
- position
- .checked_sub(offset)
- .map(|position| self.scrollbase.drag(position));
+ let position = position.saturating_sub(offset);
+ self.scrollbase.drag(position);
  }
  Event::Mouse {
  event: MouseEvent::Release(MouseButton::Left),