gio/layout/layout.go -rw-r--r-- 4.8 KiB
layout: added documentation

Added comment on the use of Dimension.Baseline and Direction.Layout constraint minimum clearing.
Also, renamed the Direction receiver for consistency and removed unnecessary conversions.

Signed-off-by: Pierre.Curto <pierre.curto@gmail.com>
all: remove redundant op.TransformOp.Offset

Use op.Offset instead, or create and manipulate a f32.Affine2D.

API change. Update your code with a gofmt rule:

	gofmt -r 'op.TransformOp{}.Offset -> op.Offset'

Signed-off-by: Elias Naur <mail@eliasnaur.com>
op: change CallOp to be a return value from MacroOp.Stop


	macro := op.Record(ops)



	macro := op.Record(ops)
	call := macro.Stop()


Which is more general (call.Add can take a different ops than the op.Record
that started it), and enforced the order between Stop and the subsequent Add.

Signed-off-by: Elias Naur <mail@eliasnaur.com>
ae8a377c — Thomas Bruyelle 5 months ago
op: add op.Push and op.Record funcs

The funcs replace stack.Push and macro.Record, which become private.
This makes stack and macro faster to write, in particular for stacks
where you can just write the following line to save and restore the
state :

  defer op.Push(ops).Pop()

This usage requires Push to return a pointer (since Pop has a pointer
receiver), or else the code doesn't compile.

For consistancy, I tried to do the same for op.Record, but this implied
to turn all the MacroOp fields into pointers, and this caused some
panics. As a result, op.Record doesn't return a pointer.

An other side effect pointed by Larry Clapp: StackOp and MacroOp are not
re-usable any more, you have to allocate a new one for each usage, using
the described funcs above.

Signed-off-by: Thomas Bruyelle <thomas.bruyelle@gmail.com>
layout: change Widget to take explicit Context and return explicit Dimensions

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>
layout: expand Constraints documentation

Signed-off-by: Elias Naur <mail@eliasnaur.com>
all: use new rectangle and point convenience functions

Signed-off-by: Elias Naur <mail@eliasnaur.com>
layout,f32: add convenience functions for rectangles and points

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>
layout: add Exact for constructing rigid Constraints matching a size

Signed-off-by: Elias Naur <mail@eliasnaur.com>
layout,widget: transpose Constraints to use image.Points for limits

Instead of

    type Contraints struct {
	    Width, Height Constraint


    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>
widget/material: use cosntraints for setting pointer hit areas

Signed-off-by: Elias Naur <mail@eliasnaur.com>
layout: replace Align with a Layout method on Direction

It's one less type (Align) and shorter:





It is also safer: since `layout.Align(...)` was a casting operation,
the Go compiler would not complain about an incompatible constant.

For example, the widget/material package contained a wrong cast:


which should have been


After this change, attempting `layout.Start.Layout(...)` result
in a compile error.

Signed-off-by: Elias Naur <mail@eliasnaur.com>
op: remove operation list argument from MacroOp.Add

The ability to invoke other operation lists belongs in the new CallOp.

While we're here, make MacroOp.Add use a pointer receiver to match the
other methods.

Signed-off-by: Elias Naur <mail@eliasnaur.com>
layout: move Context to its own file

Signed-off-by: Elias Naur <mail@eliasnaur.com>
layout: fix typo

Signed-off-by: Elias Naur <mail@eliasnaur.com>
layout: unexport Context.Layout and make it a function

Layout wasn't used outside package layout, so let's not export it.

Signed-off-by: Elias Naur <mail@eliasnaur.com>
layout: invert baseline to measure positive distance from bottom

With an inverted baseline, the zero value results in the widget
baseline aligned to its bottom.

Signed-off-by: Elias Naur <mail@eliasnaur.com>
layout: correct Align baseline

Signed-off-by: Elias Naur <mail@eliasnaur.com>
layout: adjust only max constraints on Inset

Only adjust minimums, and insets, if necessary.

Signed-off-by: Elias Naur <mail@eliasnaur.com>
layout: enforce constraints in Context.Layout

Signed-off-by: Elias Naur <mail@eliasnaur.com>
app,io/system: extract system events to separate package

Package app is the only package that depends on native libraries and
Cgo. Minimize its API, thereby minimizing Gio clients' dependency on
it. In the future, a headless, testing or remote "Window" should be
very easy to replace app.Window.

Signed-off-by: Elias Naur <mail@eliasnaur.com>