Helm: Special-Purpose Visual Controls


A thumbnail is used to display an image of a particular image file on an Imagestore.

To use a thumbnail, place one on a panel, and set the Imagestore property to the correct Imagestore device. If you set ThumbMode to ShowCurrent, then the thumbnail will automatically update to show the currently loaded image on the layer specified by the Layer property.

Alternatively, if ThumbMode is ShowSelected, then the thumbnail will display the image whose filename is set in the ImageName property. This can be updated via scripts, using the SelectImage action.

Thumbnails can be resized to any size on the panel, but note that some Imagestore devices take significant time to render thumbnails, while others are not capable of rendering thumbnails at high quality levels.

If the Imagestore itself will not return a thumbnail of the file, Helm will attempt to retrieve the file and create a thumbnail locally.  Helm thumbnails are typically cached in the directory C:/Documents and Settings/All Users/Application Data/Rascular/BMP_Cache.


Imagestore The Imagestore to retrieve thumbnails from
Name A unique name for the item.
Layer The Imagestore keyer layer to track – used when ThumbMode is ShowCurrent
Display Determines if the image thumbnail, image name or both are displayed.
ImageName The name of the Image to thumbnail.
ThumbMode When ThumbMode is ShowCurrent, the thumbnail will automatically show the current image on the specified layer. If ThumbMode is ShowSelected, the thumbnail will display the image specified in ImageName action.


OnClick Occurs when the thumbnail is clicked on


SelectImage Select the image to display.


ImagePickers are a specialised kind of dropdown, which automatically presents a list of media files present on an Imagestore. Usually, they are used in conjunction with an OnClick event which uses the Text scriptable property to load the selected image into a keying layer.

ImagePickers inherit all the properties and events of DropDowns, and introduce some additional ones.


Imagestore The Imagestore to retrieve thumbnails from
FileType Determines if video files, audio files or fonts are to be displayed.
Filter Allows filtering of the displayed files to only thos matching a specific pattern. For example P*.OXT would display only those files whose names began with P and had the .OXT extension.


RefreshFiles Refresh the list of files. This is a useful action to place into the OnDropDown event of the Imagepicker, as it ensures the ImagePicker’s list of files to be up to date.