History

The TcHmiVnHistory history control controls the history functionality of an ImageWatch control via a toolbar and provides a graphical list (Image List) of the history images. The description of each configuration option can be found under the following categories on this page. For each category there are sub-chapters with further information. This control can only be used in connection with an ImageWatch control and only provides the display and operation of the history functionality. The data and the associated configuration can be found in ImageWatch Control.

	For all the following attributes, the control has a getter and a setter method. For example, both the `getBarColor(): SolidColor` and `setBarColor(value: SolidColor): void` methods exist for the `BarColor` attribute. The use of the attributes is explained in more detail in the linked subchapters. All further attributes, events and permissions provided by the Controls base class can be found in the TwinCAT HMI documentation.

Category: Colors

Attribute	Type	Description
`BarColor`	`SolidColor`	Color of the toolbar (see Categories Toolbar).

Category: Common

The following attribute is used to specify the link to the ImageWatch control.

Attribute	Type	Description
`ImageWatchControl`	TcHmiVnImage	Link to the ImageWatch Control instance that is to be controlled.

Category: Toolbar

The following attributes can be used to customize the Toolbar of the control.

Attribute	Type	Description
`ToolbarVisible`	`Boolean`	Toolbar display.
`QueueIndexVisible`	`Boolean`	Input value of the index for the choice or display of the specified history image when `ImageFreeze` is activated. 0 corresponds to the last image received.
`NavigationButtonsVisible`	`Boolean`	Buttons to go forward or back one image entry in the image history when `ImageFreeze` is activated.
`NavigationEndButtonsVisible`	`Boolean`	Buttons to jump to the first or last image received in the history when `ImageFreeze` is activated.
`FreezeButtonVisible`	`Boolean`	Button to pause the image update of the linked ImageWatch. The history functionality can only be used if `ImageFreeze` is activated.
`DownloadButtonVisible`	`Boolean`	Button to trigger a browser-specific download of the currently displayed image in original size, see Image download.
`ToolbarHeight`	`Number (px)`	Height of the toolbar.
`QueueIndexWidth`	`Number (px)`	Width of the `QueueIndex` input field and the total number of entries.

Category: List

The following attributes can be used to customize the image list of the control.

Attribute	Type	Description
`ImageListVisible`	`Boolean`	Display of the image list.
`ListFontFamily`	`FontFamily`	Font of the Image List.
`ListFontSize`	`MeasurementValue`	Font size of the Image List.
`ListFontStyle`	`FontStyle`	Font Style of the Image List.
`ListFontWeight`	`FontWeight`	Font Weight of the Image List.

Further Information