ImageCrop

in namespace DotVVM.BusinessPack.Controls

Renders an ImageCrop control allowing to zoom, rotate and crop images.

Usage & Scenarios

A control which lets the user to make basic edits (like cropping, resizing or rotating) with a specified image.

Sample 1: Basic Usage

The ImageUrl property specifies the URL of the image that is being edited.

The Operations property must be bound to a property of type ImageOperations in the viewmodel. This object contains the following properties:

Resize represents the scale ratio of the image.
Rotate represents represents the rotation angle.
Crop represents a rectangular area (with Left, Top, Width and Height properties) the crop settings.
Round represents the radius of the rounded corners.

You can use the DefaultImageFactory class to load the image, apply the ImageOperations to it and save the result image.

page.dothtml
ViewModel.cs

<bp:ImageCrop ImageUrl="{value: ImagePath}"
              Operations="{value: ImageOperations}" />

<p>Left: {{value: ImageOperations.Crop.Left}}px</p>
<p>Top: {{value: ImageOperations.Crop.Top}}px</p>
<p>Width: {{value: ImageOperations.Crop.Width}}px</p>
<p>Height: {{value: ImageOperations.Crop.Height}}px</p>
<p>Rotate: {{value: ImageOperations.Rotate}}°</p>
<p>Resize: {{value: ImageOperations.Resize}}px</p>

<bp:Button Text="Save"
           Click="{command: Save()}" />
<br />
<br />

<p>Result: <a href="{value: Result}">{{value: Result}}</a></p>
<img src="{value: Result}" />

using DotVVM.BusinessPack.Controls;
using DotVVM.Framework.Utils;
using DotVVM.Framework.ViewModel;


namespace DotvvmWeb.Views.Docs.Controls.businesspack.ImageCrop.sample1
{
    public class ViewModel : DotvvmViewModelBase
    {
        public string ImagePath { get; set; } = "/Resources/Images/picture.jpg";
        public string Result { get; set; }
        public ImageOperations ImageOperations { get; set; } = new ImageOperations();

        public void Save()
        {
            Result = $"/App_Images/{SecureGuidGenerator.GenerateGuid()}.png";

            using (var factory = new DefaultImageFactory())
            {
                factory
                    .Load(GetPhysicalPath(ImagePath))
                    .Apply(ImageOperations)
                    .Save(GetPhysicalPath(Result));
            }
        }

        private string GetPhysicalPath(string url)
        {
            return Context.Configuration.ApplicationPhysicalPath + url.Substring(1).Replace("/", "\\");
        }
    }
}

Sample 2: Aspect Ratio

The ratio between the width and height of the cropped area can be set using the AspectRatio property. The value of the property is string and the control expects two numbers separated by a colon, e.g. 1:1, 4:3, 16:9 etc.

page.dothtml
ViewModel.cs

<bp:ImageCrop ImageUrl="{value: ImagePath}"
              Operations="{value: ImageOperations}"
              AspectRatio="1:1" />

using DotVVM.BusinessPack.Controls;
using DotVVM.Framework.ViewModel;

namespace DotvvmWeb.Views.Docs.Controls.businesspack.ImageCrop.sample2
{
    public class ViewModel : DotvvmViewModelBase
    {
        public string ImagePath { get; set; } = "/Resources/Images/picture.jpg";
        public ImageOperations ImageOperations { get; set; } = new ImageOperations();
    }
}

Sample 3: Forced Crop Radius

To make the border radius fixed, the ForcedCropRadius property can be used. It expects a value between 0 and 50.

0 means no border radius. 50 means maximum border radius. The value is in percent, so the border radius of 50% can be used to make a circle.

page.dothtml
ViewModel.cs

<bp:ImageCrop ImageUrl="{value: ImagePath}"
              Operations="{value: ImageOperations}"
              ForcedCropRadius="50" />

using DotVVM.BusinessPack.Controls;
using DotVVM.Framework.ViewModel;


namespace DotvvmWeb.Views.Docs.Controls.businesspack.ImageCrop.sample3
{
    public class ViewModel : DotvvmViewModelBase
    {
        public string ImagePath { get; set; } = "/Resources/Images/picture.jpg";
        public ImageOperations ImageOperations { get; set; } = new ImageOperations();
    }
}

Sample 4: Forced Crop Area

The crop area dimensions can be fixed using the ForcedCropWidth and ForcedCropHeight properties.

page.dothtml
ViewModel.cs

<bp:ImageCrop ImageUrl="{value: ImagePath}"
              Operations="{value: ImageOperations}"
              ForcedCropWidth="150"
              ForcedCropHeight="150" />

using DotVVM.BusinessPack.Controls;
using DotVVM.Framework.ViewModel;

namespace DotvvmWeb.Views.Docs.Controls.businesspack.ImageCrop.sample4
{
    public class ViewModel : DotvvmViewModelBase
    {
        public string ImagePath { get; set; } = "/Resources/Images/picture.jpg";
        public ImageOperations ImageOperations { get; set; } = new ImageOperations();
    }
}

Sample 5: Changed Event

When the user changes any parameter of the image, the Changed event can be used to call a command in the viewmodel.

page.dothtml
ViewModel.cs

<bp:ImageCrop ImageUrl="{value: ImagePath}"
              Operations="{value: ImageOperations}"
              Changed="{command: Changed()}" />

<p>Change count: {{value: ChangeCount}}</p>

using DotVVM.BusinessPack.Controls;
using DotVVM.Framework.ViewModel;

namespace DotvvmWeb.Views.Docs.Controls.businesspack.ImageCrop.sample5
{
    public class ViewModel : DotvvmViewModelBase
    {
        public int ChangeCount { get; set; }
        public string ImagePath { get; set; } = "/Resources/Images/picture.jpg";
        public ImageOperations ImageOperations { get; set; } = new ImageOperations();

        public void Changed()
        {
            ChangeCount++;
        }
    }
}

Sample 6: Predefined Operations

If you set the ImageOperations parameters from the viewmodel, you can specify default values for the control.

page.dothtml
ViewModel.cs

<bp:ImageCrop ImageUrl="{value: ImagePath}"
              Operations="{value: ImageOperations}" />

using DotVVM.BusinessPack.Controls;
using DotVVM.Framework.ViewModel;

namespace DotvvmWeb.Views.Docs.Controls.businesspack.ImageCrop.sample6
{
    public class ViewModel : DotvvmViewModelBase
    {
        public string ImagePath { get; set; } = "/Resources/Images/picture.jpg";

        public ImageOperations ImageOperations { get; set; } = new ImageOperations {
            Crop = new CropRectangle {
                Left = 150,
                Top = 150,
                Width = 100,
                Height = 100
            },
            Resize = 400,
            Rotate = 45,
            Round = 50
        };
    }
}

Sample 7: Custom Icons

To customize the look of toolbar icons in the control, you can use the following properties:

SwitchToMovingIconCssClass allows to customize the switch mode icon. The default value is fa fa-arrows (FontAwesome).
SwitchToCroppingIconCssClass allows to customize the switch mode icon. The default value is fa fa-crop (FontAwesome).
ResetIconCssClass allows to customize the reset icon. The default value is fa fa-refresh (FontAwesome).
RotateLeftIconCssClass allows to customize the rotate left icon. The default value is fa fa-rotate-left (FontAwesome).
RotateRightIconCssClass allows to customize the rotate right icon. The default value is fa fa-rotate-right (FontAwesome).
ZoomInIconCssClass allows to customize the zoom in icon. The default value is fa fa-search-plus (FontAwesome).
ZoomOutIconCssClass allows to customize the zoom out icon. The default value is fa fa-search-minus (FontAwesome).

page.dothtml
ViewModel.cs

<bp:ImageCrop ImageUrl="{value: ImagePath}"
              Operations="{value: ImageOperations}"
              ResetIconCssClass="refresh"
              RotateLeftIconCssClass="rotate-left"
              RotateRightIconCssClass="rotate-right"
              ZoomInIconCssClass="plus"
              ZoomOutIconCssClass="minus" />

using DotVVM.BusinessPack.Controls;
using DotVVM.Framework.ViewModel;

namespace DotvvmWeb.Views.Docs.Controls.businesspack.ImageCrop.sample7
{
    public class ViewModel : DotvvmViewModelBase
    {
        public string ImagePath { get; set; } = "/Resources/Images/picture.jpg";
        public ImageOperations ImageOperations { get; set; } = new ImageOperations();
    }
}

Properties

Name	Type	Description	Notes	Default Value
AspectRatio	String	Gets or sets the aspect ratio to force when cropping the image (eg. 1:1).	attribute inner element static value bindable default	null
Attributes	Dictionary<String,Object>		attribute inner element static value bindable default	null
ClientIDMode	ClientIDMode	Gets or sets the client ID generation algorithm.	attribute inner element static value bindable default	Static
DataContext	Object	Gets or sets a data context for the control and its children. All value and command bindings are evaluated in context of this value.	attribute inner element static value bindable default	null
ForcedCropHeight	Int32?	Gets or sets the forced height of the cropped image. If the ForcedCropWidth property is not set, it is computed automatically (see the AspectRatio).	attribute inner element static value bindable default	null
ForcedCropRadius	Int32?	Gets or sets the forced radius of the image corners. The value must be between 0 and 50 % (both inclusive). It is not set by default.	attribute inner element static value bindable default	null
ForcedCropWidth	Int32?	Gets or sets the forced width of the cropped image. If the ForcedCropHeight property is not set, it is computed automatically (see the AspectRatio).	attribute inner element static value bindable default	null
ID	String	Gets or sets the unique control ID.	attribute inner element static value bindable default	null
ImageUrl	String	Gets or sets the URL of an image to crop.	attribute inner element static value bindable default	null
InnerText	String	Gets or sets the inner text of the HTML element.	attribute inner element static value bindable default	null
Operations	ImageOperations	Gets or sets the operations applied to the image being cropped.	attribute inner element static value bindable default	null
ResetIconCssClass	String	Gets or sets the CSS class for the icon displayed on the reset button. The default value is FaRefresh.	attribute inner element static value bindable default	fa fa-refresh
RotateLeftIconCssClass	String	Gets or sets the CSS class for the icon displayed on the rotate-left button. The default value is FaRotateLeft.	attribute inner element static value bindable default	fa fa-rotate-left
RotateRightIconCssClass	String	Gets or sets the CSS class for the icon displayed on the rotate-right button. The default value is FaRotateRight.	attribute inner element static value bindable default	fa fa-rotate-right
SwitchToCroppingIconCssClass	String	Gets or sets the CSS class for the icon displayed on the button switching from Cropping mode to Moving mode. The default value is FaCrop.	attribute inner element static value bindable default	fa fa-crop
SwitchToMovingIconCssClass	String	Gets or sets the CSS class for the icon displayed on the button switching from Cropping mode to Moving mode. The default value is FaArrows.	attribute inner element static value bindable default	fa fa-arrows
Visible	Boolean	Gets or sets whether the control is visible.	attribute inner element static value bindable default	True
ZoomInIconCssClass	String	Gets or sets the CSS class for the icon displayed on the zoom-in button. The default value is FaSearchPlus.	attribute inner element static value bindable default	fa fa-search-plus
ZoomOutIconCssClass	String	Gets or sets the CSS class for the icon displayed on the zoom-out button. The default value is FaSearchMinus.	attribute inner element static value bindable default	fa fa-search-minus

Events

	Name	Type	Description
	Changed	Command	Gets or sets the command that will be triggered when the image attributes are changed.