Interface IEditHandle
- All Known Implementing Classes:
PointEditHandle
,TranslateEditHandle
Map
that can react to events to perform an edit operation.
Edit handles are used in the context of a IEditHandles
. IEditHandles
implementations are responsible for providing and updating edit handles during editing. IEditHandles
implementations typically allow to replace/customize/remove handles.
Edit handles can have one of 3 states
. This state determines:
- the order in which the
Editor
passes events to handles - the order in which the
Editor
gets themouse cursor
from a handle - how a handle can paint itself. Highlighted or Active handles are typically painted differently than Inactive handles.
The edit handle is responsible for deciding when it needs to be repainted. For that purpose, it is given an IInvalidationCallback
, see setInvalidationCallback
. This invalidation callback must be called whenever the handle needs to be repainted.
Concrete implementations of this interface have specific behavior. For example:
PointEditHandle
: allows you to move a point to a new location, or apply an action to a point location, insert a new point in aPolyline
for example. This handle typically paints itself as anIIcon
.TranslateEditHandle
: allows you to translate aGeometry
to a new location. This handle typically doesn't paint itself, because theGeometry
to be moved is already painted.
-
Method Summary
Modifier and TypeMethodDescriptionvoid
addEditStateObserver
(IInvalidationCallback observer) Adds an observer that is called when theedit state
of this handle has changed.Returns the current state of this handle.Returns the current mouse cursor that should be displayed for this handle.onEvent
(IInputEvent inputEvent, FeatureEditContext context) Handles the given event, and returns if the event was consumed or not.void
paint
(FeatureCanvas canvas, FeatureEditContext context) Paints this handle on the given canvas.void
removeEditStateObserver
(IInvalidationCallback observer) Removes the given observer.void
setInvalidationCallback
(IInvalidationCallback invalidationCallback) Sets the callback for the handle to call when its visual representation or cursor has changed.
-
Method Details
-
onEvent
@NotNull EventResult onEvent(@NotNull IInputEvent inputEvent, @NotNull FeatureEditContext context) throws NullPointerException Handles the given event, and returns if the event was consumed or not.While handling events,
IEditHandles
can mark themselves as highlighted or as Active. Related to event handling, the main effect of this is that highlighted or active handles get a higher priority compared to other handles: they get the chance to consume events first. See EditHandleState- Parameters:
inputEvent
- the event to handle, cannot benull
context
- the context, cannot benull
- Returns:
- if the event was consumed or not
- Throws:
NullPointerException
- whennull
is passed.
-
paint
Paints this handle on the given canvas.This method is called when
- the handle's
IEditHandles
fires anEditHandlesEvent
containing this handle, when the handle is newly added or removed for example. - the handle triggers a new paint call itself by calling its
invalidation callback
.
This method only gets called on the UI thread, so there is no need for additional synchronization.
- Parameters:
canvas
- the canvas on which this handle gets painted.context
- the context, cannot benull
- the handle's
-
getEditState
Returns the current state of this handle.- Returns:
- the current state of this handle.
-
getMouseCursor
Returns the current mouse cursor that should be displayed for this handle.This method typically returns a value when this handle is highlighted or active. If not,
null
can be returned.- Returns:
- the current mouse cursor that should be displayed for this handle.
-
setInvalidationCallback
Sets the callback for the handle to call when its visual representation or cursor has changed.Calling this callback triggers a new call to this handle's
paint
method.- Parameters:
invalidationCallback
- the callback for the handle to call when its visual representation has changed
-
addEditStateObserver
Adds an observer that is called when theedit state
of this handle has changed.Adding the same observer twice is forbidden, and will cause an exception to be thrown.
- Parameters:
observer
- an observer- Throws:
IllegalArgumentException
- when the observer was already added.- Since:
- 2023.1
-
removeEditStateObserver
void removeEditStateObserver(@NotNull IInvalidationCallback observer) throws IllegalArgumentException Removes the given observer.If the given observer was never added, an exception is thrown.
- Parameters:
observer
- an observer- Throws:
IllegalArgumentException
- when the observer is not known.- Since:
- 2023.1
-