This change gets rid of the event.Queue interface by replacing it with
input.Source values. Source provides the interface to Router necessary
to implement interface widgets.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
The majority of scrolling happens by manipulating the index of the first
displayed item instead of by just manipulating the offset. This lets us
avoid having to render all items that were scrolled past.
Instead of numbers of items we could've accepted a ratio in [0, 1] to
scroll by or to, to match the data we get from scrollbars. However,
there are more use cases for scrolling by items, such as keyboard
shortcuts, go-to dialogs, etc. And converting from [0, 1] to items is
trivial for the user as long as they know the number of items, and will
usually be handled for them by a theme.
Signed-off-by: Dominik Honnef <dominik@honnef.co>
op.Offset is a convenience function most often used by layouts. Layouts
usually operate in integer coordinates, and the float32 version of op.Offset
needlessly force conversions from int to float32. This change makes op.Offset
take integer coordinates, to better match its intended use.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Updated the documentation for layout.List to include the details about how
drawing is performed for items in it. This gives the user an understanding about
how so many items can be drawn for performance.
Signed-off-by: Thomas Mathews <thomas.c.mathews@gmail.com>
Clipping all children once to the entire List area is enough. The
change was motivated by #389 where individual child clips would
make it harder for focus scroll heuristics to work.
References: https://todo.sr.ht/~eliasnaur/gio/389
Signed-off-by: Elias Naur <mail@eliasnaur.com>
A recent change added automatic scrolling to move focused widgets
into view. This change modifies List to layout an extra child at
each of its ends, to enable focus to move to them and trigger
automatic scrolling of the list.
For https://github.com/tailscale/tailscale/issues/4278.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Before, List would only report the remaining scrollable area of the visible
children when positioned close to either end. Now, List always report infinite
scroll bounds *unless* it is positioned at an extremum.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
When the Min constraints are set but the list
has no item to display, use those as the list
returned dimensions.
Signed-off-by: Pierre Curto <pierre.curto@gmail.com>
The op.Save and Load methods exist to support the need for
transformation, clip, pointer area state to behave as stacks. For
example, layout needs to apply an offset to its children but not
subsequent operations.
Before this change, op.Save and Load were used to save and restore the
state:
ops := new(op.Ops)
// Save state.
state := op.Save(ops)
// Apply offset.
op.Offset(...).Add(ops)
// Draw with offset applied.
draw(ops)
// Restore state.
state.Load()
A drawback with the op.Save mechanism is that there is no direct
connection between the state change and the saving and loading of state.
This causes confusion as to when a Save/Load is needed and who is
responsible for performing them, which leads to subtle bugs and over-use
of Save/Loads.
This change gets rid of the general state stack and replaces it with
per-state stacks. There is now a stack for transformation, clip, pointer
areas, and they can only be restored by the code pushing state to them.
The example above now becomes:
ops := new(op.Ops)
// Push offset to the transformation stack.
stack := op.Offset(...).Push(ops)
// Draw with offset applied.
draw(ops)
// Restore state.
stack.Pop()
For convenience, transformation also be Add'ed if the stack operation is
not required.
Simple state such as the current material no longer has a way to be
restored; it is assumed the client of a PaintOp adds their desired
material operation before it.
API change: replace op.Save/Load with explicit Push/Pop scopes for
op.TransformOps, pointer.AreaOps, clip.Ops.
To ease porting, this change retains a version of op.Save/Load that
saves and restores the transformation and clip stacks. It also retains
an Add method for clip.Op.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
This commit adds a Length field to the
layout.Position. This field contains an approximation
of the overall length of the list's contents.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
The semantics were relaxed in a previous commit; this change renames
to operations accordingly.
API change. Use gofmt to adjust your code accordingly:
gofmt -r 'op.Push(a).Pop() -> op.Save(a).Load()'
gofmt -r 'op.Push(a) -> op.Save(a)'
gofmt -r 'v.Pop() -> v.Load()'
gofmt -r 'op.StackOp -> op.StateOp'
Signed-off-by: Elias Naur <mail@eliasnaur.com>
I found the interplay of List's Layout/init/next/more/end methods
somewhat confusing and hard to reason about, so I refactored them.
Signed-off-by: Larry Clapp <larry@theclapp.org>
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>
An interface for scaling dp and sp is overkill, at least for all
current uses. Make it a concrete struct type, and rename it to the
shorter and more precise Metric.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Then, make layout.Context.Now a field, copied from FrameEvent.Now.
API change:
gofmt -r 'gtx.Now() -> gtx.Now'
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Converting
macro := op.Record(ops)
...
macro.Stop()
macro.Add()
to
macro := op.Record(ops)
...
call := macro.Stop()
call.Add(ops)
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>
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>
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>
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>
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>
While here, unexport the Queue and Config fields. The NewContext
cosntructor is shorter, and there is no reason to expose the fields
to accidental mutation.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Put List.{first|offset|beforeEnd} into a new exported Position slot, and
also export each individually.
Have to put BeforeEnd into the Position slot to support ScrollToEnd
lists.
Signed-off-by: Larry Clapp <larry@theclapp.org>
Remembering the order of the corners in the RoundRect is difficult,
which suggest that RoundRect should be a struct with named fields.
Do that, and make Rect the special case where corner radii are all
zero.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Package ui is now only about units except for the Config.Now method.
Remove Now and rename Config to Converter. Add layout.Config to
replace the old ui.Config.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Elias Naur