Instead of, say,
var th *material.Theme
var btn *widget.Clickable
material.Button(th, "Click me").Layout(gtx, btn)
move the widget state objects to the constructor:
material.Button(th, btn, "Click me").Layout(gtx)
The advatage is that several widgets can now be used without
wrapping them in function literals. For example,
layout.Inset{}.Layout(gtx, func(gtx layout.Context) layout.Dimensions {
material.Button(th, "Click me").Layout(gtx, btn)
})
collapses to just
layout.Inset{}.Layout(gtx, material.Button(th, btn, "Click me").Layout)
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Change the definition of Widget from the implicit
type Widget func()
to the explicit functional
type Widget func(gtx layout.Context) layout.Dimensions
The advantages are numerous:
- Clearer connection between the incoming context and the output dimensions.
- Returning the Dimensions are impossible to omit.
- Contexts passed by value, so its fields can be exported
and freely mutated by the program.
The only disadvantage is the longer function literals and the many "returns".
What tipped the scales in favour of the explicit Widget variant is that type
aliases can dramatically shorten the literals:
type (
C = layout.Context
D = layout.Dimensions
)
widget := func(gtx C) D {
...
}
Note that the aliases are not part of the Gio API and it is up to each user
whether they want to use them.
Finally the Go proposal for lightweight function literals,
https://github.com/golang/go/issues/21498, may remove the disadvantage
completely in future.
Context becomes a plain struct with only public fields, and its Reset is
replaced by a NewContext convenience constructor.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Use Inset instead, matching the other buttons.
Redefine Size to apply to the icon size, without padding.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
layout.FRect, layout.FPt for converting from integer to floating point,
useful for drawing operations.
f32.Pt is a shorthand that mirrors image.Pt.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Instead of
type Contraints struct {
Width, Height Constraint
}
use
type Constraints struct {
Min, Max image.Point
}
which leads to simpler use. For example, the Min method is trivally replaced by
the field, and the RigidConstraints constructor is no longer a net win.
API Change. Rewrites:
gofmt -r 'gtx.Constraints.Min() -> gtx.Constraints.Min'
gofmt -r 'gtx.Constraints.Width.Min -> gtx.Constraints.Min.X'
gofmt -r 'gtx.Constraints.Height.Min -> gtx.Constraints.Min.Y'
gofmt -r 'gtx.Constraints.Height.Max -> gtx.Constraints.Max.Y'
gofmt -r 'gtx.Constraints.Width.Max -> gtx.Constraints.Max.X'
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Key had an unfortunate association with keyboard input.
This is an API change. The following rewrites were run to fixup
Gio code:
$ gofmt -r 'pointer.InputOp{Key:a} -> pointer.InputOp{Tag:a}' -w .
$ gofmt -r 'pointer.InputOp{Key:a, Grab:b} -> pointer.InputOp{Tag:a, Grab:b}' -w .
$ gofmt -r 'key.InputOp{Key:a} -> key.InputOp{Tag:a}' -w .
$ gofmt -r 'key.InputOp{Key:a, Focus:b} -> key.InputOp{Tag:a, Focus:b}' -w .
$ gofmt -r 'event.Key -> event.Tag' -w .
Signed-off-by: Elias Naur <mail@eliasnaur.com>
The app.ReadClipboard and app.WriteClipboard can be used to interact
with the system clipboard. The clipboard may be asynchronous, so
system.ClipboardEvent is introduced to deliver the result of a read.
Updates gio#31
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Before this change, we had a viewDo that serialized a function on a view
on a single goroutine. For better or worse, most callbacks in Cocoa
happen on the main thread, so we might as well use that.
The only exception is the frame callback from the CADisplayLink.
We could force that through the main thread as well, but for
efficiency settle with making the view-to-window map synchronized.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Asynchronous drawing happens only in onFrameCallback, where we have to
check for disappearing views. onDraw however, is synchronous and should
always have a valid view.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Before, the wakeup pipe both woke the event loop and implied a redraw.
We're going to use the notication for more, so deduce the need for redraw
from window state instead.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
The implementation was too optimistic: some platforms require a
window context for accessing the clipboard.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Elias Naur