Release 260111

system/ui/lib/scroll_panel.py

@@ -0,0 +1,75 @@
+import pyray as rl
+from enum import IntEnum
+
+MOUSE_WHEEL_SCROLL_SPEED = 30
+INERTIA_FRICTION = 0.95  # The rate at which the inertia slows down
+MIN_VELOCITY = 0.1  # Minimum velocity before stopping the inertia
+
+
+class ScrollState(IntEnum):
+  IDLE = 0
+  DRAGGING_CONTENT = 1
+  DRAGGING_SCROLLBAR = 2
+
+
+class GuiScrollPanel:
+  def __init__(self, show_vertical_scroll_bar: bool = False):
+    self._scroll_state: ScrollState = ScrollState.IDLE
+    self._last_mouse_y: float = 0.0
+    self._offset = rl.Vector2(0, 0)
+    self._view = rl.Rectangle(0, 0, 0, 0)
+    self._show_vertical_scroll_bar: bool = show_vertical_scroll_bar
+    self._velocity_y = 0.0  # Velocity for inertia
+
+  def handle_scroll(self, bounds: rl.Rectangle, content: rl.Rectangle) -> rl.Vector2:
+    mouse_pos = rl.get_mouse_position()
+
+    # Handle dragging logic
+    if rl.check_collision_point_rec(mouse_pos, bounds) and rl.is_mouse_button_pressed(rl.MouseButton.MOUSE_BUTTON_LEFT):
+      if self._scroll_state == ScrollState.IDLE:
+        self._scroll_state = ScrollState.DRAGGING_CONTENT
+        if self._show_vertical_scroll_bar:
+          scrollbar_width = rl.gui_get_style(rl.GuiControl.LISTVIEW, rl.GuiListViewProperty.SCROLLBAR_WIDTH)
+          scrollbar_x = bounds.x + bounds.width - scrollbar_width
+          if mouse_pos.x >= scrollbar_x:
+            self._scroll_state = ScrollState.DRAGGING_SCROLLBAR
+
+        self._last_mouse_y = mouse_pos.y
+        self._velocity_y = 0.0  # Reset velocity when drag starts
+
+    if self._scroll_state != ScrollState.IDLE:
+      if rl.is_mouse_button_down(rl.MouseButton.MOUSE_BUTTON_LEFT):
+        delta_y = mouse_pos.y - self._last_mouse_y
+
+        if self._scroll_state == ScrollState.DRAGGING_CONTENT:
+          self._offset.y += delta_y
+        else:
+          delta_y = -delta_y
+
+        self._last_mouse_y = mouse_pos.y
+        self._velocity_y = delta_y  # Update velocity during drag
+      else:
+        self._scroll_state = ScrollState.IDLE
+
+    # Handle mouse wheel scrolling
+    wheel_move = rl.get_mouse_wheel_move()
+    if self._show_vertical_scroll_bar:
+      self._offset.y += wheel_move * (MOUSE_WHEEL_SCROLL_SPEED - 20)
+      rl.gui_scroll_panel(bounds, rl.ffi.NULL, content, self._offset, self._view)
+    else:
+      self._offset.y += wheel_move * MOUSE_WHEEL_SCROLL_SPEED
+
+    # Apply inertia (continue scrolling after mouse release)
+    if self._scroll_state == ScrollState.IDLE:
+      self._offset.y += self._velocity_y
+      self._velocity_y *= INERTIA_FRICTION  # Slow down velocity over time
+
+      # Stop scrolling when velocity is low
+      if abs(self._velocity_y) < MIN_VELOCITY:
+        self._velocity_y = 0.0
+
+    # Ensure scrolling doesn't go beyond bounds
+    max_scroll_y = max(content.height - bounds.height, 0)
+    self._offset.y = max(min(self._offset.y, 0), -max_scroll_y)
+
+    return self._offset