Grass Valley Xstudio Vertigo Suite v.4.10 - Manual (Page 137)

6-24 Xstudio User Manual
Working with scene objects
Creating a controllable crawl with Xstudio
The following example demonstrates how to create a controllable crawl in Xstudio. In this
particular example, when the Start Crawl button is clicked, the local variable L:ticking
is set to true, the reset command forces the ticker to start from the beginning and the tick
command causes the first line to be loaded into the control panel textbox and displayed on
the scene side. The ItemStartEvent StartTick is actioned causing another tick command
to be issued and the next line of data to be displayed.
Pressing the Stop Crawl button sets the local variable to false and further ticks are
disabled. The crawl will complete the current information already loaded but will then crawl
off screen. As the last item crawls past position 0, the StopTick user event is triggered and
the background will cut off. The Clear Crawl command does the same as Stop Crawl but
in addition hides the crawl and background by setting the visibility to false causing them to
dissappear immediately.
N OTE
The Set Visibility actions can obviously be replaced by animations to enhance the display.
To create a controllable crawl:
1.
Open a new Panel + Scene.
2. Add a crawl object to the scene side.
3. Add a graphic object to the scene side as a background for the crawl.
4. Add a textbox and a button to the control side. Label the button Start Crawl.
5. Set up a Data Schema to access the required data (see “Schemas” on page 9-4 for
more information).
6. Set up a Ticker with the parameters shown below.