55 lines
2.2 KiB
Go
55 lines
2.2 KiB
Go
// 11 february 2014
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package ui
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import (
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"runtime"
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)
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// Go sets up the UI environment and pulses Ready.
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// If initialization fails, Go returns an error and Ready is not pulsed.
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// Otherwise, Go does not return to its caller until Stop is pulsed, at which point Go() will return nil.
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// After Go() returns, you cannot call future ui functions/methods meaningfully.
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// Pulsing Stop will cause Go() to return immediately; the programmer is responsible for cleaning up (for instance, hiding open Windows) beforehand.
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//
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// It is not safe to call ui.Go() in a goroutine. It must be called directly from main(). This means if your code calls other code-modal servers (such as http.ListenAndServe()), they must be run from goroutines. (This is due to limitations in various OSs, such as Mac OS X.)
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//
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// Go() does not process the command line for flags (that is, it does not call flag.Parse()), nor does package ui add any of the underlying toolkit's supported command-line flags.
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// If you must, and if the toolkit also has environment variable equivalents to these flags (for instance, GTK+), use those instead.
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func Go() error {
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runtime.LockOSThread()
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if err := uiinit(); err != nil {
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return err
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}
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Ready <- struct{}{}
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close(Ready)
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ui()
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return nil
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}
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// Ready is pulsed when Go() is ready to begin accepting requests to the safe methods.
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// Go() will wait for something to receive on Ready, then Ready will be closed.
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var Ready = make(chan struct{})
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// Stop should be pulsed when you are ready for Go() to return.
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// Pulsing Stop will cause Go() to return immediately; the programmer is responsible for cleaning up (for instance, hiding open Windows) beforehand.
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// Do not pulse Stop more than once.
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var Stop = make(chan struct{})
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// This function is a simple helper functionn that basically pushes the effect of a function call for later. This allows the selected safe Window methods to be safe.
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// TODO make sure this acts sanely if called from uitask itself
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func touitask(f func()) {
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done := make(chan struct{})
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defer close(done)
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go func() { // to avoid locking uitask itself
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done2 := make(chan struct{}) // make the chain uitask <- f <- uitask to avoid deadlocks
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defer close(done2)
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uitask <- func() {
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f()
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done2 <- struct{}{}
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}
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done <- <-done2
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}()
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<-done
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}
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