Telltales: Rendering Safety-Critical UI

Building Telltales Example

Before you can build the Telltales example, you must build Qt Safe Renderer. For instructions how to build Qt Safe Renderer and the Telltales example, see Building Qt Safe Renderer.

Telltales Example

The Telltales example demonstrates how the safety-critical UI is rendered in a separate process by Qt Safe Renderer. The example has platform specific sub-projects for a host platform, QNX, and INTEGRITY. For instructions on how to run the examples in the target device, see Running Examples on QNX.

Setting Run Settings for Telltales Example

When you run Telltales, Qt Safe Renderer renders .ui.srl files that are found under <Qt installation directory>/Examples/QtSafeRenderer-<version>/saferenderer/telltales/desktop/layoutData. Indicators generates these files when you build it.

Before you run the Telltales example targeted for the host platform, you must set the path to the generated .ui.srl files as follows:

  1. Launch Qt Creator
  2. Open the Telltales example.
  3. Select Projects > Build & Run > Run.
  4. In Command line arguments, type the name of the .ui.srl file. For example, MainForm.ui.srl.
  5. In Working directory, type the path to the .ui.srl file, that is, <Qt installation directory>/Examples/QtSafeRenderer-<version>/saferenderer/telltales/desktop/layoutData.

Rendering Safe Content of Indicators in Telltales UI

Telltales is designed so that when it is run parallel to Indicators, Qt Safe Renderer renders the safe UI elements that are defined in Indicators. Qt Safe Renderer renders them in the Telltales UI. The rendered layout data is included in the .ui.srl files that are found under <Qt installation directory>/Examples/QtSafeRenderer-<version>/saferenderer/telltales/desktop/layoutData (see Setting Run Settings for Telltales Example).

To demonstrate the functionality, build both examples and run first Telltales, then Indicators.

Running the Example

When you run Telltales, its application window is black at first. After running also Indicators, you should see the same safety-critical UI elements both in the Indicators window (1) and Telltales window (2). In the Telltales window, Qt Safe Renderer renders the safety-critical content included in the .ui.srl files.

You can build and run Telltales and Indicators with the following steps:

  1. Select Build > Run QMake.
  2. Select Build > Build Project <a project name>.

To run the project, select Build > Run.

Example Files


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