4-12: Touch Screen Buttons

Touch Attributes

When the display hardware selected in Powervision includes a Touch Screen, then the graphic widgets in the Page designer Toolbox will include a new set of attributes for Touch Functionality. These include the following:

• Touch Action - When the button is pressed and released this event will fire. If the finger is moved to a different location out of the touch zone then released it will not fire.
• Touch Action Start - This event fires once when the touch button is pressed.
• Touch Action Continue - This event will continuously fire at a rate of 15 - 20mSec  until the button is released. Note: This feature has been deprecated, use the Touch Start/Stop actions to start and stop the timer on a User Event. This will prove more useful since the timing can be better controlled.
• Touch Action Release - This event fires once when the touch button is released.

Touch Zone

The Touch Zone is defined by the widgets Bounding Box. In the text widget below, the bounding box that appears when you select the widget, represents the boundary of the Touch Zone. This of course can be resized as needed as well as background primitives can be added so the user can see the button.

Touch Zone Hierarchy

Touch buttons have their own hierarchy much like layers do. The touch button that is at the very top both on its order in a page and the layer the page is on overrides all buttons in that same area underneath it but only if it is activated. 

Activating or Disabling a Button

To activate a touch button simply select one of the three options, Fire an Event, Go to View, or Disable Key  on any of the buttons Touch Actions. To remove touch functionality select Clear Transitions for the selected Touch Actions, Not Mapped will be displayed.   To Completely disable the button and any other in the same area on a lower layer select Disable Key.                                                                         

Blocking Touch Buttons

A graphic element on a higher layer placed over the top of a touch button on a lower layer does not block that touch buttons functionality. For example if you have the Menu Layer showing that contains several touch buttons then you receive a fault message and display that on the Pop-Up layer with a solid background image, the menu buttons underneath will still be active. Even though the user cannot see the touch buttons under the background, they are still functional and if the user touches the screen in that area the buttons actions will fire.

To prevent lower layer touch buttons from firing, add a image, rectangle, or touch widget that covers the entire screen then select "Disable Key" from the Touch Action selector. This will block all touch functions underneath it but you will still be able to add new touch buttons on top of it.