70 lines
2.6 KiB
Go
70 lines
2.6 KiB
Go
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// 6 july 2014
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package ui
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// Doer is a channel that takes Requests returned by the various functions and methods of package ui.
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// There are two main Doers: ui.Do, which is for outside event handlers, and the Doer passed into an event handler function.
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// You should not create or use your own Doers; these are meaningless.
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type Doer chan *Request
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// Do is the main way to issue requests to package ui.
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// Requests returned by the various functions and methods of package ui should be sent across Do to have them performed.
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// When an event is dispatched to an event handler, that event handler will receive a new Doer which is active for the life of the event handler, and any requests made to Do will block until the event handler returns.
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var Do = make(Doer)
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// Request represents a request issued to the package.
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// These are returned by the various functions and methods of package ui and are sent to either Do or to the currently active event handler channel.
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// There are also several convenience functions that perfrom common operations with requests.
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type Request struct {
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op func()
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resp chan interface{}
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}
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// Response returns a channel which is pulsed exactly once, then immeidately closed, with the response from the function that issued the request.
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// If the function does not return a value, this value will be the zero value of struct{}.
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// Otherwise, the type of this value depends on the function that created the Request.
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func (r *Request) Response() <-chan interface{} {
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return r.resp
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}
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// Wait is a convenience function that performs a Request and waits for that request to be processed.
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// If the request returns a value, it is discarded.
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// You should generally use Wait on functions that do not return a value.
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// See the documentation of Bool for an example.
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func Wait(c Doer, r *Request) {
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c <- r
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<-r.resp
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}
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// Bool is a convenience function that performs a Request that returns a bool, waits for that request to be processed, and returns the result.
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// For example:
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// if ui.Bool(ui.Do, checkbox.Checked()) { /* do stuff */ }
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func Bool(c Doer, r *Request) bool {
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c <- r
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return (<-r.resp).(bool)
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}
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// Int is like Bool, but for int.
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func Int(c Doer, r *Request) int {
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c <- r
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return (<-r.resp).(int)
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}
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// String is like Bool, but for string.
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func String(c Doer, r *Request) string {
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c <- r
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return (<-r.resp).(string)
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}
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// IntSlice is like Bool, but for []int.
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func IntSlice(c Doer, r *Request) []int {
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c <- r
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return (<-r.resp).([]int)
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}
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// StringSlice is like Bool, but for []string.
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func StringSlice(c Doer, r *Request) []string {
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c <- r
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return (<-r.resp).([]string)
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}
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