Choosing a Concurrency Style
An OpenROAD control frame application can have any number of frames open at the same time. The open frames can be in one of two states: active or inactive. You should choose a style to use and use it consistently throughout your application.
Active Frames
An active frame is a frame that has the input focus and that end users can work in. Users can click the mouse in the frame, select menu or button operations, or enter data. They can also reposition the frame on the screen.
Inactive Frames
An inactive frame is one in which the end user cannot execute an operation. A frame can become inactive in one of two ways:
• The frame executes a callframe statement
• The frame is temporarily blocked (even though it was opened with an openframe statement) because another frame is busy
If one frame is executing an event block that takes a long time, for example, all other frames are blocked.
In both cases an hourglass appears when the user moves the cursor over the inactive frame.