/// <summary>
/// Mouse button pressed in the control.
/// </summary>
/// <param name="e">Event arguments.</param>
/// <param name="isHandled">Returns true if event is handled and no further processing required.</param>
internal void OnMouseDown(MouseEventArgs e, ref bool isHandled)
{
// Reset last clicked annotation object and stop text editing
if (lastClickedAnnotation != null)
{
TextAnnotation textAnnotation = lastClickedAnnotation as TextAnnotation;
if (textAnnotation != null)
{
// Stop annotation text editing
textAnnotation.StopTextEditing();
}
lastClickedAnnotation = null;
}
// Check if in annotation placement mode
if (this.placingAnnotation != null)
{
// Process mouse down
this.placingAnnotation.PlacementMouseDown(new PointF(e.X, e.Y), e.Button);
// Set handled flag
isHandled = true;
return;
}
// Process only left mouse buttons
if (e.Button == MouseButtons.Left)
{
bool updateRequired = false;
this._resizingMode = ResizingMode.None;
// Check if mouse buton was pressed in any selection handles areas
Annotation annotation =
HitTestSelectionHandles(new PointF(e.X, e.Y), ref this._resizingMode);
// Check if mouse button was pressed over one of the annotation objects
if (annotation == null && this.Count > 0)
{
HitTestResult result = this.Chart.HitTest(e.X, e.Y, ChartElementType.Annotation);
if (result != null && result.ChartElementType == ChartElementType.Annotation)
{
annotation = (Annotation)result.Object;
}
}
// Unselect all annotations if mouse clicked outside any annotations
if (annotation == null || !annotation.IsSelected)
{
if ((Control.ModifierKeys & Keys.Control) != Keys.Control &&
(Control.ModifierKeys & Keys.Shift) != Keys.Shift)
{
foreach (Annotation annot in this.Chart.Annotations)
{
if (annot != annotation && annot.IsSelected)
{
annot.IsSelected = false;
updateRequired = true;
// Call selection changed notification
if (this.Chart != null)
{
this.Chart.OnAnnotationSelectionChanged(annot);
}
}
}
}
}
// Process mouse action in the annotation object
if (annotation != null)
{
// Mouse down event handled
isHandled = true;
// Select/Unselect annotation
Annotation selectableAnnotation = annotation;
if (annotation.AnnotationGroup != null)
{
// Select annotation group when click on any child annotations
selectableAnnotation = annotation.AnnotationGroup;
}
if (!selectableAnnotation.IsSelected && selectableAnnotation.AllowSelecting)
{
selectableAnnotation.IsSelected = true;
updateRequired = true;
// Call selection changed notification
if (this.Chart != null)
{
this.Chart.OnAnnotationSelectionChanged(selectableAnnotation);
}
}
else if ((Control.ModifierKeys & Keys.Control) == Keys.Control ||
(Control.ModifierKeys & Keys.Shift) == Keys.Shift)
{
selectableAnnotation.IsSelected = false;
updateRequired = true;
// Call selection changed notification
if (this.Chart != null)
{
this.Chart.OnAnnotationSelectionChanged(selectableAnnotation);
}
}
// Remember last clicked and selected annotation
lastClickedAnnotation = annotation;
// Rember mouse position
this._movingResizingStartPoint = new PointF(e.X, e.Y);
// Start moving, repositioning or resizing of annotation
if (annotation.IsSelected)
{
// Check if one of selection handles was clicked on
this._resizingMode = annotation.GetSelectionHandle(this._movingResizingStartPoint);
if (!annotation.AllowResizing &&
this._resizingMode >= ResizingMode.TopLeftHandle &&
this._resizingMode <= ResizingMode.LeftHandle)
{
this._resizingMode = ResizingMode.None;
}
if (!annotation.AllowAnchorMoving &&
this._resizingMode == ResizingMode.AnchorHandle)
{
this._resizingMode = ResizingMode.None;
}
if (this._resizingMode == ResizingMode.None && annotation.AllowMoving)
{
// Annotation moving mode
this._resizingMode = ResizingMode.Moving;
}
}
else
{
if (this._resizingMode == ResizingMode.None && annotation.AllowMoving)
{
// Do not allow moving child annotations inside the group.
// Only the whole group can be selected, resized or repositioned.
if (annotation.AnnotationGroup != null)
{
// Move the group instead
lastClickedAnnotation = annotation.AnnotationGroup;
}
// Annotation moving mode
this._resizingMode = ResizingMode.Moving;
}
}
}
// Update chart
if (updateRequired)
{
// Invalidate and update the chart
this.Chart.Invalidate(true);
this.Chart.UpdateAnnotations();
}
}
}
