Files
gio/app/doc.go
T
Elias Naur a937a76534 app: rename UpdateEvent to FrameEvent and add Frame field
While "DrawEvent" was too specific (op.Ops contains non-draw events),
"Update" is too vague: it's a common word, and could be misunderstood
to mean update parts of a window, not replace it.

"FrameEvent" is more specific, and is the usual way to refer to immediate
mode drawing.

While we're here, unexport Window.Update and add a Frame function to
FrameEvent, to emphasize that updating the window frame is only
appropriate during the handling of a FrameEvent.

Signed-off-by: Elias Naur <mail@eliasnaur.com>
2019-10-12 14:01:46 +02:00

68 lines
1.6 KiB
Go

// SPDX-License-Identifier: Unlicense OR MIT
/*
Package app provides a platform-independent interface to operating system
functionality for running graphical user interfaces.
See https://gioui.org for instructions to set up and run Gio programs.
Windows
Create a new Window by calling NewWindow. On mobile platforms or when Gio
is embedded in another project, NewWindow merely connects with a previously
created window.
A Window is run by receiving events from its Events channel. The most
important event is FrameEvent that prompts an update of the window
contents and state.
For example:
import "gioui.org/unit"
w := app.NewWindow()
for e := range w.Events() {
if e, ok := e.(app.FrameEvent); ok {
ops.Reset()
// Add operations to ops.
...
// Completely replace the window contents and state.
w.Update(ops)
}
}
A program must keep receiving events from the event channel until
DestroyEvent is received.
Main
The Main function must be called from a programs main function, to hand over
control of the main thread to operating systems that need it.
Because Main is also blocking, the event loop of a Window must run in a goroutine.
For example, to display a blank but otherwise functional window:
package main
import "gioui.org/app"
func main() {
go func() {
w := app.NewWindow()
for range w.Events() {
}
}()
app.Main()
}
Event queue
A Window's Queue method returns an event.Queue implementation that distributes
incoming events to the event handlers declared in the latest frame.
See the gioui.org/ui package for more information about event handlers.
*/
package app