Tag: vertical line annotation

Hello,

I just purchased this library 2 days ago, and my first impression is WOW! Very happy with my purchase for my small team. That being said I have a unique design requirement and I’m struggling to figure out how to resolve.

Our app utilizes a cursor indicator in the form of a vertical line, this indicator is used as a visual reference and synced across multiple charts. The behavior needs to be similar to how a RollOver modifier works, however the vertical line needs to stay in place, when the user is not “Mouse – Left Down”. Because the RollOver indicator goes away when not hovering over the chart, I decided to make a custom mouse modifier.

Essentially I created a “vertical line annotation” then disabled the dragging (want it to be moved only by mouse cursor movement, and not requiring the user to drag). Made a custom mouse modifier, where OnMouseModiferDown I set a bool flag, then OnMouseMoodiferMove I get the mouse cursor position and update the X1 binding of the cursor, finally OnMouseModiferUp I set the bool flag to false.

The Issue: With my custom mouse modifier the Vertical Line annotation lags the mouse position, It almost looks like there is some sort of smoothing applied to the movement? Is there a way to turn this effect off or reduce it? Here is a link to the behavior to highlight what I’m seeing.
Video of Behavior

My Code is given below.

Xaml

<local:mouseMove ExecuteOn="MouseMove"/>

<s:VerticalSliceModifier IsEnabled="True">
    <s:VerticalSliceModifier.VerticalLines>
        <s:VerticalLineAnnotation IsEditable="False" LabelPlacement="Axis" ShowLabel="False" X1="{Binding cursorPoint Mode=TwoWay}" Style="{StaticResource sliceStyle}" />
    </s:VerticalSliceModifier.VerticalLines>
</s:VerticalSliceModifier>

C#, Mouse Modifier (MouseMove)

public class mouseMove : XAxisDragModifier
    {
        private bool moveCursor { get; set; }
        public override void OnModifierMouseDown(ModifierMouseArgs e)
        {
            if (e.MouseButtons == MouseButtons.Left)
            {
                moveCursor = true;
            }
        }
        public override void OnModifierMouseUp(ModifierMouseArgs e)
        {
            if (e.MouseButtons == MouseButtons.Left)
            {
                moveCursor = false;
            }
        }
        public override void OnModifierMouseMove(ModifierMouseArgs e)
        {
            if ((Keyboard.Modifiers == ModifierKeys.Control))
            {
                //This is my keybind for the RuberBandXY, ignore this mouse event if Ctrl + Left Mouse Down
            }
            else
            {
                if (moveCursor)
                {
                    // Get mouse point
                    var mousePoint = e.MousePoint;

                    mousePoint = ParentSurface.RootGrid.TranslatePoint(mousePoint, ParentSurface.ModifierSurface);
                    var xDataValue = ParentSurface.XAxis.GetDataValue(mousePoint.X);
                    ParentSurface.Annotations[0].X1 = xDataValue;
                }

            }
        }
    }