Focus in/out actions and user action pass-through mechanism for panel subunit

A target device configured for coupling to a controller device via a digital bus, said target device comprising:

• logic for storing a panel graphical user interface (GUI) descriptor, said panel GUI descriptor defining an on-screen display to be displayed on said controller device, said panel GUI descriptor further defining a button of said on-screen display and a button identifier associated with said button;
• and
• logic for receiving said button identifier and a focus user action from said controller device;
• and
• logic for updating said panel GUI descriptor according to said button identifier and said focus user action.

In a system having a controller device coupled to a target device via a digital bus, a method for realizing a complex graphical user interface (GUI) on said controller device, said method comprising the steps of:

• said controller device receiving a panel GUI descriptor from said target device, said panel GUI descriptor defining an on-screen display to be displayed on said controller device, said panel GUI descriptor further defining a user action pass-through element of said on-screen display;
• and
• said controller device passing through a focus navigation command to said target device when said user action pass-through element is in focus,
• wherein said target device is adapted to update said panel GUI descriptor upon receiving said focus navigation command.

A target device configured for coupling to a controller device via a digital bus, said target device comprising:

• logic for storing a panel graphical user interface (GUI) descriptor, said panel GUI descriptor defining an on-screen display to be displayed on said controller device, said panel GUI descriptor further defining a user action pass-through button of said on-screen display;
• and
• logic for receiving a focus navigation command from said controller device when said user action pass-through button is in focus;
• and
• logic for updating said panel GUI descriptor according to said focus navigation command.