Conveying urgency via a control

A desktop manager for a multi-processing graphic user interface operating system operable to control the display of a plurality of controls each occupying respective display areas on a desktop, the desktop manager being characterised by means adapted to receive a request for urgency from a process owning a control;

• and means adapted to diminish the display of one or more of any other controls to draw the attention of a user to the control owned by the process requesting urgency;
• wherein the desktop manager is responsive to an urgency request from a process owning a control to remove pixels from the other controls displayed on the desktop;
• wherein processes owning controls are adapted to store bitmap copies of said controls, said desktop manager is adapted to remove selected pixels from the bitmap copies of the controls owned by one or more of other controls and to update the desktop display using said bitmap copies;
• and
• wherein said desktop manager is adapted to store a z-order of said bitmap copies and is adapted to remove pixels from said bitmaps by iterating through locations in said bitmap copies of the other controls from a lowest bitmap in said z-order to a highest bitmap in said order and by setting the colour for each location to the colour of the control beneath it in the z-order.