first commit

Library/PackageCache/com.unity.timeline@1.7.6/Editor/Manipulators/TimeAreaAutoPanner.cs

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+using UnityEngine;
+
+namespace UnityEditor.Timeline
+{
+    class TimeAreaAutoPanner
+    {
+        readonly WindowState m_State;
+        readonly TimelineWindow m_Window;
+        readonly Rect m_ViewRect;
+
+        const float k_PixelDistanceToMaxSpeed = 100.0f;
+        const float k_MaxPanSpeed = 30.0f;
+
+        public TimeAreaAutoPanner(WindowState state)
+        {
+            m_State = state;
+            m_Window = m_State.GetWindow();
+
+            var shownRange = m_State.timeAreaShownRange;
+            var trackViewBounds = m_Window.sequenceRect;
+            m_ViewRect = Rect.MinMaxRect(m_State.TimeToPixel(shownRange.x), trackViewBounds.yMin,
+                m_State.TimeToPixel(shownRange.y), trackViewBounds.yMax);
+        }
+
+        public void OnGUI(Event evt)
+        {
+            if (evt.type != EventType.Layout)
+                return;
+
+            var hFactor = 0.0f;
+            var vFactor = 0.0f;
+
+            bool horizontalPan = GetPanFactor(evt.mousePosition.x, m_ViewRect.xMin, m_ViewRect.xMax, out hFactor);
+            bool verticalPan = GetPanFactor(evt.mousePosition.y, m_ViewRect.yMin, m_ViewRect.yMax, out vFactor);
+
+            if (horizontalPan)
+            {
+                var translation = m_State.timeAreaTranslation;
+                translation.x += hFactor * k_MaxPanSpeed;
+
+                m_State.SetTimeAreaTransform(translation, m_State.timeAreaScale);
+            }
+
+            if (verticalPan)
+            {
+                var translation = m_Window.treeView.scrollPosition;
+                translation.y -= vFactor * k_MaxPanSpeed;
+
+                m_Window.treeView.scrollPosition = translation;
+            }
+        }
+
+        static bool GetPanFactor(float v, float min, float max, out float factor)
+        {
+            factor = 0.0f;
+
+            if (v < min)
+            {
+                factor = Mathf.Clamp01((min - v) / k_PixelDistanceToMaxSpeed);
+                return true;
+            }
+
+            if (v > max)
+            {
+                factor = -Mathf.Clamp01((v - max) / k_PixelDistanceToMaxSpeed);
+                return true;
+            }
+
+            return false;
+        }
+    }
+}