GetItemViewBounds Method

C#
Visual Basic
Objective-C
Java

public virtual LeadRectD GetItemViewBounds( 
   ImageViewerItem item,
   ImageViewerItemPart part,
   bool clipped
)

'Declaration

Public Overridable Function GetItemViewBounds( _
   ByVal item As ImageViewerItem, _
   ByVal part As ImageViewerItemPart, _
   ByVal clipped As Boolean _
) As LeadRectD

Parameters

item: The item. Must be a valid item inside this viewer.
part: The item part requested.
clipped: true to return the bounding rectangle intersected with the current viewer control area, otherwise; false.

Return Value

The bounding rectangle in pixels or LeadRectD.Empty if the item is not visible, does not have an image or outside the clipping area.

Use ConvertBoundsToView to convert a bound from logical to physical coordinates.

For more information refer to Image Viewer Appearance, Image Viewer Transformation, and Image Viewer Bounds and Transform.

This example will show how to use GetItemBounds to perform manual hit-testing on the item.

Start with the ImageViewer example, remove all the code inside the example function (search for the "// TODO: add example code here" comment) and insert the following code:

C#
Visual Basic
WinRT C#
WinRT JavaScript
Silverlight C#
Silverlight VB

Copy Code

Imports Leadtools
Imports Leadtools.Controls
Imports Leadtools.Codecs
Imports Leadtools.Drawing
Imports Leadtools.ImageProcessing
Imports Leadtools.ImageProcessing.Color

' Clear all the images already the viewer
_imageViewer.Items.Clear()
' Use vertical view layout
_imageViewer.ViewLayout = New ImageViewerVerticalViewLayout()
' Make sure the item size is larger than the image size (thumbnails mode)
_imageViewer.ItemSize = LeadSize.Create(200, 200)
_imageViewer.ItemPadding = New Padding(8, 8, 8, 20)
_imageViewer.ImageBorderThickness = 1
' Add 4 items to the viewer
Using codecs As New RasterCodecs()
   For page As Integer = 1 To 4
      Dim item As New ImageViewerItem()
      Dim fileName As String = Path.Combine(ImagesPath.Path, String.Format("ocr{0}.tif", page))

      ' Create a thumbnail from the image
      Using image As RasterImage = codecs.Load(fileName, page)
         item.Image = image.CreateThumbnail(180, 180, 24, RasterViewPerspective.TopLeft, RasterSizeFlags.Resample)
      End Using

      item.Text = String.Format("Item {0}", page - 1)
      _imageViewer.Items.Add(item)
   Next page
End Using

' Hook to the viewer mouse click event
AddHandler _imageViewer.MouseClick,
Sub(sender, e)
   ' Loop through each item, get the view bounds of the image (the physical location and size on the viewer surface of the item)
   ' and perform hit-testing
   For Each item As ImageViewerItem In _imageViewer.Items
      ' Pass part as image and clipped as true, we are only interested on what we are seeing
      Dim bounds As LeadRectD = _imageViewer.GetItemViewBounds(item, ImageViewerItemPart.Image, True)
      ' Hit-test. GetItemViewBounds returns the value in the control coordinates, same as the mouse click
      If bounds.Contains(e.X, e.Y) Then
         MessageBox.Show("Clicked the image of item at index " & _imageViewer.Items.IndexOf(item))
         Return
      End If
   Next item

using Leadtools;
using Leadtools.Controls;
using Leadtools.Codecs;
using Leadtools.Drawing;
using Leadtools.ImageProcessing;
using Leadtools.ImageProcessing.Color;

// Clear all the images already the viewer
_imageViewer.Items.Clear();
// Use vertical view layout
_imageViewer.ViewLayout = new ImageViewerVerticalViewLayout();
// Make sure the item size is larger than the image size (thumbnails mode)
_imageViewer.ItemSize = LeadSize.Create(200, 200);
_imageViewer.ItemPadding = new Padding(8, 8, 8, 20);
_imageViewer.ImageBorderThickness = 1;
// Add 4 items to the viewer
using (var codecs = new RasterCodecs())
{
   for (var page = 1; page <= 4; page++)
   {
      var item = new ImageViewerItem();
      var fileName = Path.Combine(ImagesPath.Path, string.Format("ocr{0}.tif", page));

      // Create a thumbnail from the image
      using (var image = codecs.Load(fileName, page))
      {
         item.Image = image.CreateThumbnail(180, 180, 24, RasterViewPerspective.TopLeft, RasterSizeFlags.Resample);
      }

      item.Text = string.Format("Item {0}", page - 1);
      _imageViewer.Items.Add(item);
   }
}

// Hook to the viewer mouse click event
_imageViewer.MouseClick += (sender, e) =>
{
   // Loop through each item, get the view bounds of the image (the physical location and size on the viewer surface of the item)
   // and perform hit-testing
   foreach (var item in _imageViewer.Items)
   {
      // Pass part as image and clipped as true, we are only interested on what we are seeing
      var bounds = _imageViewer.GetItemViewBounds(item, ImageViewerItemPart.Image, true);
      // Hit-test. GetItemViewBounds returns the value in the control coordinates, same as the mouse click
      if (bounds.Contains(e.X, e.Y))
      {
         MessageBox.Show("Clicked the image of item at index " + _imageViewer.Items.IndexOf(item));
         return;
      }
   }
};

Target Platforms

Reference

ImageViewer Class
ImageViewer Members