Initial Commit

Charts/Navigation/LongOperationsIndicator.cs

@@ -0,0 +1,144 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Input;
+using System.Windows.Threading;
+
+namespace Microsoft.Research.DynamicDataDisplay.Charts.Navigation
+{
+    public sealed class LongOperationsIndicator : IPlotterElement
+    {
+        public LongOperationsIndicator()
+        {
+            timer.Tick += new EventHandler(timer_Tick);
+        }
+
+        private void timer_Tick(object sender, EventArgs e)
+        {
+            UpdateWaitIndicator();
+            timer.Stop();
+        }
+
+        #region IPlotterElement Members
+
+        void IPlotterElement.OnPlotterAttached(Plotter plotter)
+        {
+            this.plotter = plotter;
+        }
+
+        void IPlotterElement.OnPlotterDetaching(Plotter plotter)
+        {
+            this.plotter = null;
+        }
+
+        private Plotter plotter;
+        Plotter IPlotterElement.Plotter
+        {
+            get { return plotter; }
+        }
+
+        #endregion
+
+        #region LongOperationRunning
+
+        public static void BeginLongOperation(DependencyObject obj)
+        {
+            obj.SetValue(LongOperationRunningProperty, true);
+        }
+
+        public static void EndLongOperation(DependencyObject obj)
+        {
+            obj.SetValue(LongOperationRunningProperty, false);
+        }
+
+        public static bool GetLongOperationRunning(DependencyObject obj)
+        {
+            return (bool)obj.GetValue(LongOperationRunningProperty);
+        }
+
+        public static void SetLongOperationRunning(DependencyObject obj, bool value)
+        {
+            obj.SetValue(LongOperationRunningProperty, value);
+        }
+
+        public static readonly DependencyProperty LongOperationRunningProperty = DependencyProperty.RegisterAttached(
+          "LongOperationRunning",
+          typeof(bool),
+          typeof(LongOperationsIndicator),
+          new FrameworkPropertyMetadata(false, OnLongOperationRunningChanged));
+
+        private static void OnLongOperationRunningChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
+        {
+            Plotter plotter = null;
+            IPlotterElement element = d as IPlotterElement;
+            if (element == null)
+            {
+                plotter = Plotter.GetPlotter(d);
+            }
+            else
+            {
+                plotter = element.Plotter;
+            }
+
+            if (plotter != null)
+            {
+                var indicator = plotter.Children.OfType<LongOperationsIndicator>().FirstOrDefault();
+                if (indicator != null)
+                {
+                    indicator.OnLongOperationRunningChanged(element, (bool)e.NewValue);
+                }
+            }
+        }
+
+        UIElement indicator = LoadIndicator();
+
+        private static UIElement LoadIndicator()
+        {
+            var resources = (ResourceDictionary)Application.LoadComponent(new Uri("/DynamicDataDisplay;component/Charts/Navigation/LongOperationsIndicatorResources.xaml", UriKind.Relative));
+            UIElement indicator = (UIElement)resources["Indicator"];
+            return indicator;
+        }
+
+        private readonly DispatcherTimer timer = new DispatcherTimer { Interval = TimeSpan.FromMilliseconds(100) };
+        private int operationsCounter = 0;
+        private void OnLongOperationRunningChanged(IPlotterElement element, bool longOperationRunning)
+        {
+            int change = longOperationRunning ? +1 : -1;
+            operationsCounter += change;
+
+            if (plotter == null) return;
+
+            if (operationsCounter == 1)
+            {
+                timer.Start();
+            }
+            else if (operationsCounter == 0)
+            {
+                timer.Stop();
+                UpdateWaitIndicator();
+            }
+        }
+
+        private void UpdateWaitIndicator()
+        {
+            if (operationsCounter == 1)
+            {
+                if (!plotter.MainCanvas.Children.Contains(indicator))
+                {
+                    plotter.MainCanvas.Children.Add(indicator);
+                }
+                plotter.Cursor = Cursors.Wait;
+            }
+            else if (operationsCounter == 0)
+            {
+                plotter.MainCanvas.Children.Remove(indicator);
+                plotter.ClearValue(Plotter.CursorProperty);
+            }
+        }
+
+        #endregion // end of LongOperationRunning
+    }
+}