By returning all events, widgets that might return early from its
event loop might throw away subsequent events. Instead of requiring
those widgets to store the event list, convert input.Queue to step
through the available events one at a time.
Functional revert of 1735d5ced8.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
I too often forget to initialize widgets' config and queue. Moving
them from fields to parameters fix that. The change results in a
little more verbosity but cleaner code.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Before this change, there was no guarantee that a PopOp matched
the intended PushOp. With a single stack operation, the client is
forced to match pop with the right push.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Single stepping events only makes sense for widgets with complex
state, e.g. the text.Editor. For the input.Events source, returning
all events in a single Events call is sufficient and more natural
for clients.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Now that the pass through mode is moved into its own PassOp op,
it doesn't make sense to collect all area types into one exported
type.
Add RectAreaOp and EllipseAreaOp for clients; the internal
representation is still a single op. It can be changed later without
breaking clients.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
To keep the interface slim, remove the helper methods and shorten
the essential method, Pixels, to Px.
Add and use unexported Config implementation in the app package.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
The dp and sp units are approximate and mostly used for layout
dimensions that operate in whole pixels. This change alters the
Config methods to return pixels in ints instead of floats, which
results in smoother use for layout and emphasize the inexactness of
the device independent units.
Clients can still access to raw PxPrDp and PxPrSp factors from
Config.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Before this change, clients were expected to set up the current
material (color or image) before laying out Labels and Editors.
This was done to avoid garbage from a hypothetical material
interface covering both colors and images.
However, some widgets need more than one material: the Editor had
HintImage for the hint text material.
This change implements generalized materials through blocks:
anywhere a material is expected, a ui.BlockOp is is assumed to
contain the operation(s) needed for setting the desired material.
This way we avoid allocations (interfaces) and keep the
abstraction over material types.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Change input.Events interface to return one event at a time until
the queue is empty.
Change text.Editor and gestures to match.
Re-add Editor.Submit while we're here; we don't want to enable
submit mode always.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Before this change, the Editor cleared its content after each
Submission event. If it didn't multiple submits for a frame would
not result in the cleared text for clients that wants to clear the
Editor between submits.
However, for clients that do not want to clear the content or that
wants to validate the text before accepting it were not supported.
Instead, switch to a event stepping model, where the client can
call Next to receive each EditorEvent (that is, Submit event) in
turn.
We can then delete the Submit flag on Editor and always report Submit
events.
We can also make Layout flush the pending events now that Editor
always has access to its Config and input queue.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
To avoid passing a queue type for each kind of input (pointer, key),
introduce package input for mapping a handler key to all input events.
Future input sources can be added without changes to programs, and
as an added bonus, event ordering is preserved across input sources.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Split out OpArea from OpHandler to allow stacked areas in a followup.
Replace hit closures with static shapes (rectangles and ellipses) to
avoid allocations. If needed, generic hit functions can be introduced
again later.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Instead of allocating and constructing a clip path, store path data
directly in op lists. Use separate op lists for cached text layout
paths.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
We're about to allow OpBlock for invoking ops from multiple (cached)
Ops containers. To allow for drawing state changes to stick after
invoking such a cached block, we can't let OpBlock perform an implicit
save and restore of drawing state.
Instead, introduce OpPush and OpPop for explicit drawing state stack
management.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
In preparation for an OpColor (and future OpGradient and similar).
Label and Editor no longer take an explicit source image. They
draw with the current image.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
The layout package switched from interfaces to functions for
composing layouts. The switch made sure that no garbage is
generated for transient layouts such as Align, Inset, Stack, Flex.
Unfortunately, that left the stateful widgets and layouts: as soon
as their layout methods are embedded in a transient layout, a
closure is generated that escapes to the heap.
To avoid garbage for both transient as well as stateful widgets,
replace the functional approach with explicit begin/end methods.
A begin method generally starts an op block and returns the adjusted
constraints. An end method takes computed dimensions, ends its op
block and returns adjusted dimensions.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Pros:
- Much less per-frame garbage
- Allow future preprocessing of ops while building it
- Much fewer interface calls and pointer chasing
- Allow future serialization of ops for remote rendering
Cons:
- Slightly clumsier API
Signed-off-by: Elias Naur <mail@eliasnaur.com>
With an interface instead of anonymous functions, amending an
area's parameters can be done even after adding it to an OpHandler.
This will be useful when we switch to serialized op lists.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Elias Naur