1 files changed, 68 insertions, 0 deletions
diff --git a/src/app/input/selection.rs b/src/app/input/selection.rs
new file mode 100644
index 00000000..953e9b26
--- /dev/null
+++ b/src/app/input/selection.rs
@@ -0,0 +1,68 @@
+use crossterm::event::{MouseEvent, MouseEventKind};
+
+use crate::app::state::AppState;
+
+impl AppState {
+    fn update_selection_cursor(
+        &mut self,
+        pane_id: crate::layout::PaneId,
+        screen_col: u16,
+        screen_row: u16,
+    ) {
+        let Some(info) = self.pane_info_by_id(pane_id).cloned() else {
+            return;
+        };
+        let metrics = self.pane_scroll_metrics(pane_id);
+        if let Some(selection) = self.selection.as_mut() {
+            selection.drag(screen_col, screen_row, info.inner_rect, metrics);
+        }
+    }
+
+    fn selection_edge_scroll_lines(distance: u16) -> usize {
+        usize::from(distance).saturating_mul(3).clamp(3, 15)
+    }
+
+    pub(super) fn update_selection_drag(&mut self, screen_col: u16, screen_row: u16) {
+        let Some(pane_id) = self.selection.as_ref().map(|selection| selection.pane_id) else {
+            return;
+        };
+        let Some(info) = self.pane_info_by_id(pane_id).cloned() else {
+            return;
+        };
+
+        let bottom = info.inner_rect.y + info.inner_rect.height.saturating_sub(1);
+        if screen_row < info.inner_rect.y {
+            self.scroll_pane_up(
+                pane_id,
+                Self::selection_edge_scroll_lines(info.inner_rect.y - screen_row),
+            );
+        } else if screen_row > bottom {
+            self.scroll_pane_down(
+                pane_id,
+                Self::selection_edge_scroll_lines(screen_row - bottom),
+            );
+        }
+
+        self.update_selection_cursor(pane_id, screen_col, screen_row);
+    }
+
+    pub(super) fn scroll_selection_with_wheel(&mut self, mouse: MouseEvent) -> bool {
+        const LINES_PER_NOTCH: usize = 3;
+
+        let Some(selection) = self.selection.as_ref() else {
+            return false;
+        };
+        if !selection.is_in_progress() {
+            return false;
+        }
+        let pane_id = selection.pane_id;
+        self.focus_pane(pane_id);
+        match mouse.kind {
+            MouseEventKind::ScrollUp => self.scroll_pane_up(pane_id, LINES_PER_NOTCH),
+            MouseEventKind::ScrollDown => self.scroll_pane_down(pane_id, LINES_PER_NOTCH),
+            _ => return false,
+        }
+        self.update_selection_cursor(pane_id, mouse.column, mouse.row);
+        true
+    }
+}